Inverse first-order reliability method for probabilistic fatigue life prediction. of composite laminates under multiaxial loading
|
|
- Caroline Black
- 6 years ago
- Views:
Transcription
1 Inverse irst-order reliabilit method or probabilistic atiue lie prediction o composite laminates under multiaial loadin Yibin Xian and Yonmin Liu* Department o Civil and Environmental Enineerin Clarson Universit Potsdam Y.3699 USA Abstract: Multiaial atiue reliabilit is a challenin problem despite etensive proress made durin the past ew decades. Anisotropic materials such as composite laminates are under eneral multiaial stress state even i the applied loadin is uniaial. A eneral methodolo or multiaial atiue reliabilit analsis o composite laminates is proposed in this paper. The proposed methodolo is based on a uniied multiaial atiue model or both isotropic and anisotropic materials and the inverse irst-order reliabilit method Inverse FORM or probabilistic lie prediction. The current atiue model is a critical plane-based model. The critical plane orientation is theoreticall determined b minimizin the damae introduced b the hdrostatic stress amplitude. One o the advantaes o the multiaial atiue model is that it has almost no applicabilit limitations with respect to dierent materials. A time dependent limit state unction o material ailure is developed based on the proposed mechanism model or probabilistic lie prediction. Inverse FORM method is proposed to calculate the atiue lie under a speciied ailure probabilit. Various uncertainties rom materials properties pl coniurations and volume ractions are included in the proposed methodolo. A wide rane eperimental atiue data o composite laminates is used to validate the proposed methodolo. It is observed that the proposed methodolo ives a satisactor * Correspondin author Tel.: ; Fa: ; liu@clarson.edu
2 prediction or both median lie and its conidence bounds. Kewords: multiaial atiue composite laminate reliabilit inverse FORM Introduction Composite materials are widel used or man dierent industries such as aerospace and automobile because o their hih strenth and stiness. The lon term durabilit o composite materials is critical or the saet and interit o structural and mechanical sstems. Composite materials are inhomoeneous and anisotropic which maes the atiue problems o composite materials more complicated than that o homoenous and isotropic materials e.. metallic materials. The atiue o composite laminates is multiaial and a special analsis approach is required or an accurate lie prediction. In eneral the multiaial problem can be divided into two cases: one is caused b the anisotrop o composite materials and the other is caused b the eternal multiaial loadin. Man enineerin materials ehibit some deree o anisotrop in mechanical properties such as unidirectional and multidirectional composite. Unlie the etensive proress in multiaial atiue analsis o isotropic materials much urther eort is needed to include the anisotrop o the material Miller and Brown985. Several investiations have been reported or anisotropic composite laminates. Deriec and Van Paepeem 00 classiied eistin atiue models into three cateories: atiue lie models S- curves phenomenoloical models or residual strenth or residual stiness and proressive damae models. Hasin and Rotem 973 proposed a ailure criterion which mimic the orm o static strenth criterion based on two major ailure modes iber ailure and matri ailure. Sims and Brodon 977 etended the static ailure
3 principle proposed b Tsai-Hill to atiue problem. Aboul Waa et al. 997 investiated the application o some polnomial ailure criteria or atiue analsis. Reisnider and Gao 99 proposed a micromechanics-based model which can tae into account the interacial bond. Wu 993 proposed dierent ailure criteria based on the Tsai-Hill criterion. Philippidis and Vassilopoulos Sep 999 proposed a ailure criterion based on the Tsai-Wu criterion. Petermanna and Plumtree 00 proposed a critical plane model or unidirectional laminates under o-ais tension-tension atiue loadin. Kawai 00 Kawai et al 00 proposed an eective stress model or the unidirectional laminates under o-ais loadin which is based on the Tsai-Hill static strenth theor. Liu and Mahadevan 005 proposed a multiaial damae accumulation model or multidirectional laminates under tension-tension atiue loadin. Sinle applied o-ais loadin causes proportional multiaial stress state within the laminates. Most o the atiue models or anisotropic composite laminates are or proportional multiaial stress state; however ver ew theoretical and eperimental studies are ound in the literature or the non-proportional multiaial atiue analsis. o universall accepted multiaial atiue damae model eists or dierent materials and dierent loadin conditions Liu and Mahadevan007. In addition hue uncertainties are associated with the atiue damae process o composite materials which is usuall larer than that o metallic materials Liu and Mahadevan007. The uncertainties associated with the atiue damae accumulation can be caused b material properties structural coniurations and the manuacturin processes. A probabilistic approach is more suitable or atiue analsis o composite materials. 3
4 The e objective o this stud is to develop a probabilistic lie prediction ramewor or composite laminates. Man atiue reliabilit analsis methodoloies used the simulation-based approach such as direct Monte Carlo simulation to calculate the probabilistic lie prediction Liu and Mahadevan 007; Liu and Mahadevan009. This approach is time consumin or sstem level applications. Other approaches solved the problem in a similar wa with that o the time-dependent reliabilit i.e. calculatin the reliabilit level at a taret lie Liu and Mahadevan007 Liu and Mahadevan009. This approach cannot ive direct probabilistic lie prediction. A novel inverse irst-order reliabilit method FORM is proposed in this stud to calculate the residual lie directl. The inverse FORM method is oriinall proposed or reliabilit-based optimal desin RBDO problem Der Kiurehian Zhan and Li994. Several studies or static ailure usin the inverse FORM method have been reported in the literature. Sanranasoontorn et al. 004 developed an inverse reliabilit procedure or wind turbine components. Chen et al. 006 applied the inverse FORM method to estimate the cable saet o lon-span bride. Ver ew studies have been ound on the investiation o the inverse FORM method to time dependent atiue problem probabl due to the diiculties with the implicit response unction Chen Zhan Cai and Xiao007. In this paper a eneral methodolo or multiaial atiue reliabilit analsis o composite laminates is proposed. The proposed methodolo is based on a uniied multiaial atiue model or both isotropic and anisotropic materials Liu and Mahadevan 007 and the inverse irst-order reliabilit method FORM or time dependent atiue reliabilit analsis. The current atiue model is a critical plane-based model. Most o the earlier models based on the critical plane approach assume that the critical plane onl 4
5 depends on the stress state. In the current model the critical plane not onl depends on the stress state but also on the material properties. The critical plane is theoreticall determined b minimizin the damae introduced b the hdrostatic stress amplitude which maes the proposed model have almost no applicabilit limitations with respect to dierent materials. Various uncertainties rom materials properties pl coniurations and volume ractions are included in the proposed methodolo. Probabilistic lie prediction usin the inverse FORM method is compared with direct Monte Carlo simulation or model veriication. A wide rane o eperimental atiue data o composite laminates are used to validate the proposed methodolo. Generall the predictions based on the proposed model aree with the eperimental observations ver well. Multiaial atiue model Multiaial atiue model or isotropic materials A multiaial atiue damae criterion Liu and Mahadevan005 was developed based on the nonlinear combination o the normal stress amplitude shear stress amplitude and hdrostatic stress amplitude actin on the critical plane as σ aα τ t aα σ H aα β where σ aα a α t and H σ aα are the normal stress amplitude shear stress amplitude and hdrostatic stress amplitude actin on the critical plane respectivel; α is the anle between the critical plane and the maimum normal stress plane; and t are atiue limits in pure uniaial and pure shear tests respectivel; and and β are material parameters which can be determined b uniaial and pure shear atiue limits. Detailed 5
6 derivation and validation o the used multiaial atiue model can be ound in the reerred article Liu and Mahadevan005. Onl the results o the model parameters are reported here in Table. In Table s t is the atiue strenth ratio under the pure shear loadin and the pure uniaial loadin. For an arbitrar multiaial loadin histor the maimum stress amplitude plane is identiied irst. This is achieved b enumeration b chanin the anle b deree increments. Then the anle α and material parameters are determined or dierent materials accordin to Table. The critical plane is the plane which has an anle α with the maimum normal stress amplitude plane. Finall the stress components on the critical plane are calculated and the atiue damae is evaluated usin Eq.. ote that the critical plane in the proposed model depends not onl on the stress state maimum normal stress amplitude plane but also on the material propert anle α. Multiaial Fatiue Model or anisotropic material Man enineerin materials ehibit mechanical anisotrop such as wood rolled metals iber reinorced composite laminates etc. The uniaial and torsional atiue strenths also depend on the orientations o the aes at the critical point within the material. In the proposed multiaial atiue criterion Eq. atiue limits and t become unctions o the orientation θ sa θ and t θ. In order to etend the atiue model Eq. to anisotropic materials we need to speci a reerence plane on which the atiue strenth under uniaial and pure shear loadin can be evaluated. In the current model the e point is to calculate the anle between the maimum normal stress 6
7 amplitude plane and the critical plane. The reerence plane is irst deined or the anisotropic material as the plane that eperiences the maimum normal stress amplitude. Thus Eq is rewritten as a uniied multiaial atiue criterion: H σ a α τ a α σ a α β θ t θ θ ma ma where θ ma indicates the direction o maimum stress amplitude. For isotropic materials Eq. reduces to Eq. since the unctions θ and t θ become constants. The atiue lie model or anisotropic materials can be epressed as: ma β σ ac θ ma H τ ac σ ac θ ma 3 t θ ma Eq. 3 can be rewritten as: p θ ma β σ ac τ ac σ s θ ma H ac 0 4 where s t θ ma θ ma is the strenth ratio o under pure shear loadin and the θ ma uniaial loadin alon the direction o θ ma. p θ ma θ ma is the ratio o 0 uniaial strenth alon the directions o θ and θ 0. The let side o Eq. 4 can θ ma be treated as an equivalent stress amplitude. It can be used to correlate with the atiue lie usin the uniaial S- curve alon the direction o zero deree. Detailed derivation and concept can be ound in Liu and Mahadevan007 The procedure or the atiue analsis o anisotropic materials is almost identical with that o isotropic material. For an arbitrar loadin histor the maimum stress 7
8 amplitude plane is identiied irst. The uniaial and pure shear atiue strenth alon this direction is also evaluated rom eperimental data. Then the anle α and the material parameters are determined or dierent materials accordin to Table. otice that the quantit s in Table is now redeined as t θ ma s s θ ma. Finall the θ ma equivalent stress amplitude and the atiue lie are calculated usin Eq. 4. For an arbitrar anisotropic material the variation o the uniaial and pure shear atiue strenths correspondin to the orientation o the aes is quite comple and requires etensive eperimental wor to quanti. However or some special anisotropic materials this can be simpliied usin one o the strenth theories available in the literature. In this paper an eample o orthotropic composite laminate is used or illustration. Consider a iber reinorced composite laminate. Several static strenth theories have been proposed or orthotropic laminates such as Tsai-Hill and Tsai-Wu theor Daniel and Ishai006. In this stud the Tsai-Wu theor is used. For the case o plane stress the Tsai-Wu theor is epressed as: F 66 6 σ F σ F σ F σ F σ F σ σ 5 where σ and σ are the stresses alon the iber direction and transverse to the iber direction respectivel and σ 6 is the in-plane shear stress. F F F 66 F F and F are strenth parameters and can be calibrated usin eperiments. F F 66 F F F s s s s s s s s L s LT L F L F L F 0.5 T T T T 6 8
9 where s ± L s ± T are the strenths alon the iber direction and transverse to the iber direction respectivel. The plus smbol indicates tension strenth and the minus smbol indicates compression strenth. s LT is the in-plane shear strenth. For the atiue problem the stress terms in Eq. 5 reer to the stress amplitudes alon dierent directions. I the strenths are deined usin stress amplitude values the plus and minus smbols in the above strenth notation disappear since the stress amplitude is alwas positivel deined. Thus Eq. 5 and Eq. 6 are rewritten or the atiue problem as: F 66 6 σ F σ F σ F σ σ 7 F F F F F66 F 8 sl st slt Usin the Tsai-Wu strenth theor the uniaial strenth and shear strenth alon an arbitrar direction θ can be easil obtained as θ / t θ / F F 4 cos θ F F 8F 4 sin θ F 66 F sin θ cos θ F 66 sin θ cos θ cos θ sin θ 9 For the atiue lie model the atiue strenth coeicients are also unctions o the atiue lie which can be evaluated rom the eperimental S- curves. Eq. 9 is rewritten as: t θ / θ / F F 4 cos θ F F 8F 4 sin θ F 66 F sin θ cos θ F 66 sin θ cos θ cos θ sin θ 0 Substitutin Eq. 0 into Eq. 4 we can solve or the atiue lie. Similar to isotropic materials Eq. 4 usuall has no closed orm solution. In practical calculation a trial and error method can be used to ind. For an orthotropic composite laminate the 9
10 eperimental S- curves alon the iber direction transverse to the iber direction and in-plane shear stress are required in the proposed model. Then the atiue lie under arbitrar multiaial loadin can be predicted. The atiue model or the isotropic material is consistent with the atiue model or the anisotropic material derived in this section. I F F F66 the atiue model or the 3 orthotropic material is identical with the atiue model or the isotropic material with s 3 in which the Tsai-Wu criterion reduces to the von Mises criterion. The above discussion can be easil applied to a laminate with multiple plies ollowin the steps described in Liu and Mahadevan005. First divide the total atiue lie into several blocs. In each bloc chec the ailure o each pl usin the above model. I no ailure occurs accumulate the atiue damae or each pl. I ailure occurs assume that the pl strenth and stiness decrease to zero. Then update the lobal stiness matri and proceed to the net step. The computation continues till the entire laminate ails. The number o the loadin ccles to ailure is the atiue lie o the composite laminate. Inverse FORM method The above discussion is or deterministic analsis and is not suicient to capture the stochastic behavior o atiue damae o composite materials. A eneral inverse reliabilit methodolo is proposed in this stud to include various uncertainties rom materials eometries and manuacturin or probabilistic atiue lie prediction o unidirectional and multidirectional composite laminates. Details are shown below. Inverse FORM method The irst-order reliabilit method is a widel used numerical technique to calculate the reliabilit or ailure probabilit o various enineerin problems. Man studies have been 0
11 reported on static ailure problems usin the FORM method Thorndahl and Willems008 Sas and Barr996 Cizelj Mavo and Riesch-Oppermann994. It has been applied to atiue problems to calculate the time dependent reliabilit. Unlie the FORM method Liu and Mahadevan009 Haldar and Mahadevan000 the inverse FORM method tries to solve the unnown parameters under a speciied reliabilit or ailure probabilit level which is more suitable or probabilistic lie prediction i.e. remainin lie estimation correspondin to a taret reliabilit level. In the inverse FORM method a limit state unction needs to be developed irst such as the eneric epression o Eq.-a. is the vector o random variables and is the vector o indein variables. For eample could be the random material properties loadins and environmental actors and could be the time and spatial coordinates. The limit state unction need be transormed to the standard normal space or the calculation which is similar to the classical FORM method Haldar and Mahadevan000. The numerical search or the unnown parameters needs to satis the reliabilit constraints which are described in Eqs.b-c. β is the reliabilit inde which is deined as the distance rom oriin to the most probable point MPP in the standard normal space. The ailure probabilit P can be calculated usin the cumulative distribution unction CDF Φ o the standard Gaussian distribution. umerical search is required to ind the optimum solution which satisies the limit state unction Eq. d. Details o the eneral inverse FORM method and concept can be ound in Der Kiurehian Zhan and Li994.
12 Φ 0 : : : 0 : d p c b a β β The overall objective o the inverse FORM method is to ind a non-neative unction satisin all constraint conditions speciied in Eq.. Then the numerical search alorithm can be used to ind the solutions o the unnown parameters. Followin the eneral concept o the irst-order reliabilit method the limit state unction is approimated usin the irst-order Talor s series epansion to acilitate the calculation. First the limit state unction Eq. a is epanded around random variable vector and the indein variable vector is ied i n i i O Eq. can be rewritten as [ ] u u u u u 3 where n u The increments o and can be epressed as [ ] 0 d d 4 A non-neative merit unction considerin the constraints o Eq. a and Eq. d can be written as
13 3 [ ] 5 In Eq.5 both and are constants. et the reliabilit constraint Eq. b needs to be included. Substitute Eq.-b into Eq.-d one can obtain ar et t β 6 Usin irst order Talor s series epression the limit state unction can be epanded around and as m i i m m i i n i i O 7 Substitute Eq.7 into Eq.8 the indein variables can be epressed as [ ] et t ar β α 8 The increments o and can be epressed as [ ] d d et t et t ar ar β β 9 A merit unction considerin the reliabilit constraints can be written as ar 3 et t β α 0 Combine the two merit unction Eq. 5 and Eq. 0 a eneral unction is obtained as
14 4 [ ] 3 β umerical search alorithm is developed to iterativel solve the Eq.. The search alorithm is epressed as Eq. ater iterations. d a d a X d X X where d and d are the search directions correspondin to dierent merit unctions and can be calculated usin Eq. 4 and Eq. 9 respectivel. a and a are the weiht actors and can be calculated as a a 3 The converence criterion or the numerical search alorithm is ε 4 where ε is a small value and indicates that the relative dierence between two numerical solutions is small enouh to ensure the converence. Usin the proposed methodolo the comple probabilistic atiue lie prediction problem can be solved eicientl compared to the direct Monte Carlo simulation method. It is noted that the above derivation assumes the random variables are standard Gaussian variables. In practical enineerin application non-gaussian variables are commonl used or some nonneative phsical quantiies such as strenth and Youn s modulus. The proposed
15 inverse FORM method can be etended to non-gaussain variables with proper random variable transormation. This paper uses the transormation method proposed b Racwitz and Fiessler June 976 to transorm the non-gaussian variables to their equivalent standard normal space. Ater that the proposed inverse method can be used. Once the solutions are obtained in the standard normal space the inverse transormation can be used to transorm the solution to its oriinal space. The random variable transormation can be epressed as * X Φ F X σ X * X φ σ X σ X * * * X Φ [ FX ] σ X * * φ { Φ [ FX ]} X σ X * X 5 where Φ and * F X are the cumulative distribution unctions CDF o the standard normal random variable and the non-normal random variable respectivel. φ and * X are the probabilit densit unction PDF o the standard normal random variable and the non-normal random variable respectivel. This transormation wors well or the atiue problem o composite laminates since the distributions o random variables are not hihl sewed. For hihl sewed distribution the transormation proposed b Racwitz and Fiessler 978 can be used instead. umerical eample and model veriication The above discussed inverse FORM method is applied to probabilistic atiue lie prediction o composite laminates interatin the mechanism model. The limit state unction is shown as X X... X
16 X -3 are the random variables. is the indein actor and represents the ailure time. represents the proposed model o atiue lie prediction or composite materials. It is noted that the is a eneric implicit unction and no analtical solution or the derivatives is available. The perturbation-based inite dierence method Sauer006 is used to calculate the irst-order derivatives in the proposed inverse FORM ramewor. Thirteen random variables are included in the calculation. The includes the elastic modulus E E Poisson s ratio υ shear modulus G volume raction o ibers V pl thicness t and pl orientations θ. These random variables represent the basic material properties eometric coniurations and manuacturin actors. Material random atiue properties are also included. The ittin parameters o the material S- curves are assumed to be random variables. The classical power unction is used to describe the atiue S- curves under lonitudinal transverse and pure shear loadins i.e. S B A 7 where S is the stress amplitude level and is the atiue lie. A and B are material properties and are assumed to be random variables. Since three independent atiue S- curves are required in the proposed mechanism model si random variables are included. A D55 balanced laminate is selected or numerical eample which consists o three pairs o pl with identical thicness and elastic properties but with ±0 deree orientations. The mean value o the above mentioned random variables can be ound in Mandell J.F.Feb For demonstration purpose the coeicient o variation or all random variables is assumed to be All random variables are assumed to be 6
17 lonormal variables ecept or the power coeicient B in Eq. 4 which can tae the neative value and is assumed to ollow normal distribution. Fi. Comparison o the direct MC method with the inverse FORM method Fi. shows the probabilistic lie prediction usin both inverse FORM method and the direct Monte Carlo method. The solid line is the result o Monte Carlo MC Simulation with one million samples at a certain stress level at MPa. The inverse FORM results are shown as the trianular points which aree well with the MC simulation. The proposed inverse FORM can ive an accurate result and siniicantl reduce the computational time. It taes 9044 seconds usin the MC simulation. The inverse FORM method taes 4 seconds. All computations are perormed usin Matlab 007 on a dualcore PC.66 GHz with 3 Gb memor. The operatin sstem is Windows XP Proessional. Validation o the proposed method A wide rane o eperimental data on unidirectional and multidirectional composite laminates is used to demonstrate and validate the proposed probabilistic lie prediction methodolo. Eperimental data and statistics o input random variables Seven sets o atiue eperimental data or unidirectional composite laminate under o-ais loadin are emploed in this section and are listed in Table. The eperimental S- curves alon the iber direction transverse to the iber direction and pure in-plane shear stress are required in the proposed atiue model. The curves alon and transverse to the iber direction are usuall reported. However most o the atiue eperimental data do not include the pure shear test results. It is possibl due to 7
18 the diicult o applin the pure shear loadin to the composite laminate. In the proposed stud the S- curve under pure in-plane shear stress is calibrated use one additional o-ais atiue test data b a trial and error method Liu and Mahadevan005. For eample the S- curves or a D55 balanced laminate alon the iber and transverse to the iber are reported in Mandell J.F.Feb The eperimental data is shown in Fi. a and b or 0 o and 90 o respectivel. Statistical analsis can be done and the distribution o Alon Blon Atran Btran can be obtained. However no eperimental data were reported under pure shear loadin to obtain Ashear or Bshear directl. The pure shear S- curve is calibrated usin the balanced laminate [±45 o ] 3 and Ashear and Bshear can be obtained. Once the S- curves are obtained the atiue lie o composite laminates can be predicted or arbitrar orientations. The mean values o the strenth coeicients are shown in Table 3. All the si strenth coeicients are the input random variables or both unidirectional materials. All the input random variables are assumed to ollow lo-normal distribution ecept Blon Btran and Bshear which ollow normal distribution. Fi. Eperimental data: a [±0] 3 b [±90] 3 For multidirectional material another seven input random variables the elastic modulus E E Poisson s ratio υ shear modulus G volume raction o ibers V pl thicness t and pl orientations θ are included in the current model or calculation. The eometr properties and volume raction o the balanced laminate D55 are reported in Mandell J.F.Feb The coeicient o variation o all the other ive random variables are assumed to be 0.05 Liu and Mahadevan005. Validation or unidirectional composite materials 8
19 In Fi. 3 the model prediction o the median lie and its 90% conidence bounds are plotted toether with the eperimental data. The -ais is the atiue lie and the -ais is the stress amplitude. A semi-lo scale plot is used i.e. onl the -ais is in lo scale. The solid lines are the median prediction results and dashed lines are the 90% conidence bounds. All points are the eperimental observations under o-ais loadin at dierent anles. The anles o the o-ais loadin are shown in the leends. As shown in Fi. 3 the median prediction results aree ver well with the eperimental results. In addition dierent uncertainties o eperimental data can be quantitativel predicted usin the proposed probabilistic methods. Almost all the eperimental data lies in the 90% conidence bounds. Fi.3 Comparison o lie prediction with eperimental data or unidirectional composite laminates Validation or multidirectional composite laminates Fatiue test data o lass-iber-based multidirectional composite laminates Mandell J.F.Feb 003. are used to validate the proposed atiue model. The material chosen D55 is a balanced laminate which consists o pairs o laers with identical thicnesses and elastic properties but with ±0 o ±30 o ±40 o ±50 o ±60 o ±70 o ±80 o. Aain the atiue S- curve or pure shear test is not available. In the current stud the balanced laminate [±45] 3 is used to calibrate the shear S- curve. The prediction results and the eperimental observations are plotted in Fi. 4. The - ais is the atiue lie and the -ais is the applied stress amplitude. The solid lines are the median prediction results and dashed lines are the 90% conidence bounds. From Fi. 4 enerall satisactor results can be observed with a ew eceptions. In all cases the 9
20 median predictions capture the major trends in the eperimental observations. The 90% conidence bounds covers majorit o the eperimental data. Fi. 4 Comparison o lie prediction with eperimental data or multidirectional composite laminates Conclusion A eneral probabilistic lie prediction methodolo is proposed in this paper combinin a critical plane-based multiaial model and the inverse irst-order reliabilit method. The multiaial atiue model can be applied to both isotropic and anisotropic materials. The proposed inverse FORM method can eicientl calculate the atiue lie prediction correspondin to dierent taret reliabilit level compared to the direct Monte Carlo simulation method. Several conclusions can be drawn based on the current investiations. - Overall satisactor results are observed between model predictions and eperimental results or both unidirectional and multidirectional composite laminates. - The proposed inverse FORM method has been veriied with direct Monte Carlo simulation results and validated with etensive eperimental data. - The scatter o eperimental data can be predicted usin the quantiied uncertainties o material properties eometric coniurations and manuacturin processes and the proposed probabilistic ramewor. - It is observed that the predictions results have a better areement or unidirectional composite laminates which suests that a more comprehensive mechanism model or multidirectional composite laminates is required to include 0
21 other actors such as delaminatin between plies. Current investiation ocuses on the constant proportional multiaial loadin. Further model development and validation are needed or eneral nonproportional random loadin. Geometric eects such as holes and notches need urther stud or structural level applications. Acnowledement The research reported in this paper was supported b unds rom SF Award o. CMMI-0900 Project Manaer: Dr. Mahendra Sinh and b unds rom ational Aeronautics and Space Administration ASA Contract o. X09AY54A Project Manaer: Dr. Kai Goebel. The support is rateull acnowleded.
22 Reerences: Aboul Waa M.. Hamd A. and El-Midan A.A. Combined bendin torsional atiue o woven rowin GRP. J En Mater Technol Trans ASME Chen J. Zhan J. Cai C.S. and Xiao R.-C. A new approach or solvin inverse reliabilit problems with implicit response unctions. Enineerin Structures Cizelj L. Mavo B. and Riesch-Oppermann H. Application o irst and second order reliabilit methods in the saet assessment o craced steam enerator tubin. uclear Enineerin and Desin Daniel I.M. and Ishai O. Enineerin mechanics o composite materials. Oord Universit Press ew Yor 006. Deriec J. and Paepeem W.V. Fatiue damae modelin o ibre-reinorced composite materials: Review. Applied Mechanics Reviews Der Kiurehian A. Zhan Y. and Li C.-C. Inverse reliabilit problem. J. Enr. Mech.ASCE El Kadi H. and Ellin F. Eect o stress ratio on the atiue o unidirectional lass ibre/epo composite laminae. Composites Haldar A. and Mahadevan S. Probabilit reliabilit and statistical methods in enineerin desin. John Wile ew Yor ; Chichester [Enland] 000. Hasin Z. and Rotem A. A atiue criterion or iber reinorced composite material. Journal o Composite Material Jin Chen R.-C.X. Application o inverse reliabilit method to estimation o cable saet actors o lon span suspension brides. Structural Enineerin and Mechanics 006 3o Kawai M. Hachinohe A. Taumida K. and Kawase Y. O-ais atiue behaviour and its damae mechanics modellin or unidirectional ibre-metal hbrid composite: GLARE. Composites Part A: Applied Science and Manuacturin Kawai M. Suda H. Eects o on-eative Mean Stress on the O-Ais Fatiue Behavior o Unidirectional Carbon/Epo Composites at Room Temperature. Journal o Composite Materials Ma Liu Y. and Mahadevan S. Multiaial hih-ccle atiue criterion and lie prediction or metals. International Journal o Fatiue Liu Y. and Mahadevan S. Probabilistic atiue lie prediction o multidirectional composite laminates. Composite Structures Liu Y. and Mahadevan S. A uniied multiaial atiue damae model or isotropic and anisotropic materials. International Journal o Fatiue Liu Y. and Mahadevan S. Stochastic atiue damae modelin under variable amplitude loadin. International Journal o Fatiue Liu Y. and Mahadevan S. Eicient methods or time-dependent atiue reliabilit analsis. AIAA Journal Mandell J.F. a.s.d.d. DOE/MSU Composite Materials Fatiue Database: Test Methods Materials and Analsis. Sandia ational Laboratories Albuquerque M Feb 003.
23 Miller K.J. Brown M.W. ASTM Committee E-9 on Fatiue. and ASTM Committee E-4 on Fracture Testin. Multiaial atiue : a smposium. American Societ or Testin and Materials Philadelphia Pa Petermann J. and Plumtree A. A uniied atiue ailure criterion or unidirectional laminates. Composites Part A: Applied Science and Manuacturin Philippidis T.P. Vassilopoulos A. P. Fatiue Strenth Prediction under Multiaial Stress. Journal o Composite Materials Sep Racwitz R.a.F. B. Structural Reliablit Under Combined Random Load Sequences. Computers & Structures Racwitz R.a.F. B. ote on Discrete Saet Checin When Usin on-ormal Stochastic Models or Basic Variables. Load Project Worin SessionMITCambrideMA June 976. Reisnider K.L. and Gao Z. A micromechanics model or composites under atiue loadin. International Journal o Fatiue Saranasoontorn K. and Manuel L. Eicient models or wind turbine etreme loads usin inverse reliabilit. Journal o Wind Enineerin and Industrial Aerodnamics Sauer T. umerical Analsis Sims D. and Brodon V. Fatiue behavior o composites under dierent loadin modes. Fatiue o ilamentar materials.astm STP Sas T.H. and Barr D.A. Assessin uncertaint in subsurace solute transport: eicient irst-order reliabilit methods. Environmental Sotware Thorndahl S. and Willems P. Probabilistic modellin o overlow surchare and loodin in urban drainae usin the irst-order reliabilit method and parameterization o local rain series. Water Research Wu L. Thermal and mechanical atiue analsis o CFRP laminates. Composite Structures
24 List o Fiures Fi. Comparison o the direct MC method with the inverse FORM method Fi. Eperimental data: a [±0] 3 ; b [±90] 3 Fi. 3 Comparison o lie prediction with eperimental data or unidirectional composite laminates a AS4/PEEK; b E-lass ibre/eop- with R 0; c E-lass ibre/eop- with R 0.5; d E-lass ibre/eop- with R -; e T800H/500 carbon/epo with R 0.; T800H/500 carbon/epo with R -0.3; T800H/500 carbon/epo with R 0.5; h E-lass/polester; i T800H/epo; j T800H/polmide; GLARE l GLARE Fi. 4 Comparison o lie prediction with eperimental data or multidirectional composite laminates a ±0 o ; b ±30 o ; c ±40 o ;d ±50 o ; e ±60 o ; ±70 o ; ±80 o List o Tables Table.Material parameters or atiue damae evaluation Table.Eperimental data or unidirectional materials Table 3. Eperimental data or uniaial materials and multidirectional material 4
25 Table.Material parameters or atiue damae evaluation Material Propert s t s t > α 4 4 / s 3 5 / s 4s cos α α 0 5 / s 4s 0 9 s β β [cos α s sin α ] β s Table.Eperimental data or unidirectional materials Material Reerences E-lass/polester Philippidis and Vassilopoulos Sep 999 E-lass ibre/epo- Kadi and Ellin 994 T800H/epo Kawai et al 00 T800H/polimide Kawai et al 00 AS4/PEEK Kawai et al 00 GLARE ibre metal laminates Kawai et al 00 T800H/500 carbon/epo Kawai and Suda Ma 004 5
26 Table 3. Eperimental data or uniaial materials and multidirectional material Alon Atran Ashear Materials \ Random variable MPa Blon MPa Btran MPa Bshear AS4/PEEK E-lass ibre/epo- R E-lass ibre/epo- R E-lass ibre/epo- R T800H/500 carbon/epo R T800H/500 carbon/epo R T800H/500 carbon/epo R E-lass/polester T800H/epo T800H/polimide GLARE ibre metal laminates D
Nonlinear Integro-differential Equations by Differential Transform Method with Adomian Polynomials
Math Sci Lett No - Mathematical Science Letters An International Journal http://ddoior//msl/ Nonlinear Intero-dierential Equations b Dierential Transorm Method with Adomian Polnomials S H Behir General
More informationBayesian Technique for Reducing Uncertainty in Fatigue Failure Model
9IDM- Bayesian Technique or Reducing Uncertainty in Fatigue Failure Model Sriram Pattabhiraman and Nam H. Kim University o Florida, Gainesville, FL, 36 Copyright 8 SAE International ABSTRACT In this paper,
More informationS. Srinivasan, Technip Offshore, Inc., Houston, TX
9 th ASCE Specialty Conerence on Probabilistic Mechanics and Structural Reliability PROBABILISTIC FAILURE PREDICTION OF FILAMENT-WOUND GLASS-FIBER Abstract REINFORCED COMPOSITE TUBES UNDER BIAXIAL LOADING
More informationBuckling of Double-walled Carbon Nanotubes
Buckling o Double-walled Carbon anotubes Y. H. Teo Engineering Science Programme ational University o Singapore Kent idge Singapore 960 Abstract This paper is concerned with the buckling o double-walled
More information6.1 The Linear Elastic Model
Linear lasticit The simplest constitutive law or solid materials is the linear elastic law, which assumes a linear relationship between stress and engineering strain. This assumption turns out to be an
More information9 Strength Theories of Lamina
9 trength Theories of Lamina 9- TRENGTH O ORTHOTROPIC LAMINA or isotropic materials the simplest method to predict failure is to compare the applied stresses to the strengths or some other allowable stresses.
More informationON AN ESTIMATION OF THE DAMPING PROPERTIES OF WOVEN FABRIC COMPOSITES
ON AN ESTIMATION OF THE DAMPING PROPERTIES OF WOVEN FABRIC COMPOSITES Masaru Zao 1, Tetsusei Kurashii 1, Yasumasa Naanishi 2 and Kin ya Matsumoto 2 1 Department o Management o Industry and Technology,
More informationC. Non-linear Difference and Differential Equations: Linearization and Phase Diagram Technique
C. Non-linear Difference and Differential Equations: Linearization and Phase Diaram Technique So far we have discussed methods of solvin linear difference and differential equations. Let us now discuss
More information18-660: Numerical Methods for Engineering Design and Optimization
8-66: Numerical Methods or Engineering Design and Optimization Xin Li Department o ECE Carnegie Mellon University Pittsburgh, PA 53 Slide Overview Linear Regression Ordinary least-squares regression Minima
More informationStability Analysis of a Geometrically Imperfect Structure using a Random Field Model
Stabilit Analsis of a Geometricall Imperfect Structure using a Random Field Model JAN VALEŠ, ZDENĚK KALA Department of Structural Mechanics Brno Universit of Technolog, Facult of Civil Engineering Veveří
More informationTetragonal or hexagonal symmetry in modeling of failure criteria for transversely isotropic materials
Tetragonal or heagonal smmetr in modeling of failure criteria for transversel isotropic materials MSc Michal Adamsi Supervisor: Prof. Artur Ganarsi Abstract Present wor deals with modeling of failure criteria
More informationProbabilistic fatigue life prediction of multidirectional composite laminates
Composite Structures 69 () 9 www.elsevier.com/locate/compstruct Probabilistic fatigue life prediction of multidirectional composite laminates Yongming Liu, Sankaran Mahadevan * Department of Civil and
More informationOPTIMIZATION AND EXPERIMENT OF COMPOSITE SQUARE BEAM
THE 19 TH INTERNATIONAL CONFERENCE ON COMPOSITE MATERIALS OPTIMIZATION AND EXPERIMENT OF COMPOSITE SQUARE BEAM T.Lili 1*, Y. Mingsen 1 1 College o Aerospace and Civil Engineering, Harbin Engineering Universit,
More informationME 7502 Lecture 2 Effective Properties of Particulate and Unidirectional Composites
ME 75 Lecture Effective Properties of Particulate and Unidirectional Composites Concepts from Elasticit Theor Statistical Homogeneit, Representative Volume Element, Composite Material Effective Stress-
More informationMICROMECHANICAL FAILURE ANALYSIS OF UNIDIRECTIONAL FIBER-REINFORCED COMPOSITES UNDER IN-PLANE AND TRANSVERSE SHEAR
THE 19 TH INTERNATIONAL CONFERENCE ON COMPOSITE MATERIALS MICROMECHANICAL FAILURE ANALYSIS OF UNIDIRECTIONAL FIBER-REINFORCED COMPOSITES UNDER IN-PLANE AND TRANSVERSE SHEAR Lei Yang*, Ying Yan, Zhiguo
More informationChapter 6 Reliability-based design and code developments
Chapter 6 Reliability-based design and code developments 6. General Reliability technology has become a powerul tool or the design engineer and is widely employed in practice. Structural reliability analysis
More informationLife Prediction Under Multiaxial Fatigue
Lie Prediction Under Multiaxial Fatigue D. Ramesh and M.M. Mayuram Department o Mechanical Engineering Indian Institute o Technology, Madras Chennai-600 036 (India) e-mail: mayuram@iitm.ac.in ABSTRACT
More informationOn-Line Trajectory Optimization Including Moving Threats and Targets
AIAA Guidance, Naviation, and Control Conerence and Ehibit 6-9 Auust 00, Providence, Rhode Island AIAA 00-59 On-Line rajector Optimization Includin Movin hreats and arets hannon wi *, Anthon Calise and
More informationSTRENGTH ESTIMATION OF END FAILURES IN CORRUGATED STEEL SHEAR DIAPHRAGMS
SDSS Rio STABILITY AND DUCTILITY OF STEEL STRUCTURES Nobutaka Shimizu et al. (Eds.) Rio de Janeiro, Brazil, September 8 -, STRENGTH ESTIMATION OF END FAILURES IN CORRUGATED STEEL SHEAR DIAPHRAGMS Nobutaka
More informationTime Series Analysis for Quality Improvement: a Soft Computing Approach
ESANN'4 proceedings - European Smposium on Artiicial Neural Networks Bruges (Belgium), 8-3 April 4, d-side publi., ISBN -9337-4-8, pp. 19-114 ime Series Analsis or Qualit Improvement: a Sot Computing Approach
More information9.1 The Square Root Function
Section 9.1 The Square Root Function 869 9.1 The Square Root Function In this section we turn our attention to the square root unction, the unction deined b the equation () =. (1) We begin the section
More informationEVALUATION OF FAILURE CRITERIA IN WOOD MEMBERS
EVALUATION OF FAILURE CRITERIA IN WOOD MEMBERS José M. Cabrero 1, Kifle G. Gebremedhin ABSTRACT: Multi-aial stress conditions eist in almost all engineering applications, but design procedures, in most
More informationSIMULATION OF HEAT TRANSFER THROUGH WOVEN FABRICS BASED ON THE FABRIC GEOMETRY MODEL
SIMULATION OF HEAT TRANSFER THROUGH WOVEN FABRICS BASED ON THE FABRIC GEOMETRY MODEL Zhenron Zhen a,b*, Nannan Zhan a and Xiaomin Zhao a,* a Collee o Tetiles, Tianjin Polytechnic University, Tianjin, 300387,
More information15 INTERLAMINAR STRESSES
15 INTERLAMINAR STRESSES 15-1 OUT-OF-PLANE STRESSES Classical laminate plate theor predicts the stresses in the plane of the lamina,, and τ but does not account for out-of-plane stresses, τ and τ. It assumes
More informationBond strength model for interfaces between nearsurface mounted (NSM) CFRP strips and concrete
University o Wollongong Research Online Faculty o Engineering and Inormation Sciences - Papers: Part A Faculty o Engineering and Inormation Sciences 2014 Bond strength model or interaces between nearsurace
More informationA Wavelet Collocation Method for Optimal Control. Problems
A Wavelet ollocation ethod or Optimal ontrol Problems Ran Dai * and John E. ochran Jr. Abstract A Haar wavelet technique is discussed as a method or discretizing the nonlinear sstem equations or optimal
More informationIncreasing and Decreasing Functions and the First Derivative Test. Increasing and Decreasing Functions. Video
SECTION and Decreasing Functions and the First Derivative Test 79 Section and Decreasing Functions and the First Derivative Test Determine intervals on which a unction is increasing or decreasing Appl
More informationStiffness and Strength Tailoring in Uniform Space-Filling Truss Structures
NASA Technical Paper 3210 April 1992 Stiffness and Strength Tailoring in Uniform Space-Filling Truss Structures Mark S. Lake Summar This paper presents a deterministic procedure for tailoring the continuum
More informationU- FUNCTION IN APPLICATIONS
Ushaov I. U-FUNKTION IN ALIATIONS RT&A # 0 6 Vol.7 0 September U- FUNTION IN ALIATIONS Igor Ushaov Sun Diego aliornia e-mail: igusha@gmail.com The ethod o Universal Generating Functions U-unctions was
More informationRELIABILITY OF BURIED PIPELINES WITH CORROSION DEFECTS UNDER VARYING BOUNDARY CONDITIONS
REIABIITY OF BURIE PIPEIES WITH CORROSIO EFECTS UER VARYIG BOUARY COITIOS Ouk-Sub ee 1 and ong-hyeok Kim 1. School o Mechanical Engineering, InHa University #53, Yonghyun-ong, am-ku, Incheon, 40-751, Korea
More informationCHAPTER-III CONVECTION IN A POROUS MEDIUM WITH EFFECT OF MAGNETIC FIELD, VARIABLE FLUID PROPERTIES AND VARYING WALL TEMPERATURE
CHAPER-III CONVECION IN A POROUS MEDIUM WIH EFFEC OF MAGNEIC FIELD, VARIABLE FLUID PROPERIES AND VARYING WALL EMPERAURE 3.1. INRODUCION Heat transer studies in porous media ind applications in several
More informationANALYTIC CENTER CUTTING PLANE METHODS FOR VARIATIONAL INEQUALITIES OVER CONVEX BODIES
ANALYI ENER UING PLANE MEHODS OR VARIAIONAL INEQUALIIES OVER ONVE BODIES Renin Zen School of Mathematical Sciences honqin Normal Universit honqin hina ABSRA An analtic center cuttin plane method is an
More informationLecture Triaxial Stress and Yield Criteria. When does yielding occurs in multi-axial stress states?
Lecture 5.11 Triaial Stress and Yield Criteria When does ielding occurs in multi-aial stress states? Representing stress as a tensor operational stress sstem Compressive stress sstems Triaial stresses:
More informationIJSER 1. INTRODUCTION. M.Elhadary
1591 A new failure criterion for GRP composite materials subjected to in-phase and out-of-phase biaxial fatigue loading under different stress ratios M.Elhadary Abstract this studying the fatigue behavior
More informationStudy of In line Tube Bundle Heat Transfer to Downward Foam Flow
Proceedins o the 5th IASME/WSEAS Int. Conerence on Heat Transer, Thermal Enineerin and Environment, Athens, Greece, Auust 25-27, 7 167 Study o In line Tube Bundle Heat Transer to Downward Foam Flow J.
More informationSOME RESEARCH ON FINITE ELEMENT ANALYSIS OF COMPOSITE MATERIALS
The 3 rd International Conerence on DIAGNOSIS AND PREDICTION IN MECHANICAL ENGINEERING SYSTEMS DIPRE 12 SOME RESEARCH ON FINITE ELEMENT ANALYSIS OF Valeriu DULGHERU, Viorel BOSTAN, Marin GUŢU Technical
More informationDepartment of Physics and Astronomy 2 nd Year Laboratory. L2 Light Scattering
nd ear laborator script L Light Scattering Department o Phsics and Astronom nd Year Laborator L Light Scattering Scientiic aims and objectives To determine the densit o nano-spheres o polstrene suspended
More information3. Several Random Variables
. Several Random Variables. Two Random Variables. Conditional Probabilit--Revisited. Statistical Independence.4 Correlation between Random Variables. Densit unction o the Sum o Two Random Variables. Probabilit
More informationCharacterization of Internal State Variable for fiber fracture in UD Composite
Characterization o Internal State ariable or iber racture in UD Composite Modris Megnis,, Povl Brondsted 3, Sai A. Rehman 4, Tanveer Ahmad 5 Summary The continuum damage mechanics is used to describe the
More informationAXIALLY LOADED FRP CONFINED REINFORCED CONCRETE CROSS-SECTIONS
AXIALLY LOADED FRP CONFINED REINFORCED CONCRETE CROSS-SECTIONS Bernát Csuka Budapest University o Technology and Economics Department o Mechanics Materials and Structures Supervisor: László P. Kollár 1.
More informationMODULE - 2 LECTURE NOTES 3 LAGRANGE MULTIPLIERS AND KUHN-TUCKER CONDITIONS
Water Resources Systems Plannin and Manaement: Introduction to Optimization: arane Multipliers MODUE - ECTURE NOTES 3 AGRANGE MUTIPIERS AND KUHN-TUCKER CONDITIONS INTRODUCTION In the previous lecture the
More informationDesign criteria for Fiber Reinforced Rubber Bearings
Design criteria or Fiber Reinorced Rubber Bearings J. M. Kelly Earthquake Engineering Research Center University o Caliornia, Berkeley A. Calabrese & G. Serino Department o Structural Engineering University
More informationMODULE 6 LECTURE NOTES 1 REVIEW OF PROBABILITY THEORY. Most water resources decision problems face the risk of uncertainty mainly because of the
MODULE 6 LECTURE NOTES REVIEW OF PROBABILITY THEORY INTRODUCTION Most water resources decision problems ace the risk o uncertainty mainly because o the randomness o the variables that inluence the perormance
More information8 Properties of Lamina
8 Properties of Lamina 8- ORTHOTROPIC LAMINA An orthotropic lamina is a sheet with unique and predictable properties and consists of an assemblage of fibers ling in the plane of the sheet and held in place
More informationImplicit Second Derivative Hybrid Linear Multistep Method with Nested Predictors for Ordinary Differential Equations
American Scientiic Research Journal or Engineering, Technolog, and Sciences (ASRJETS) ISSN (Print) -44, ISSN (Online) -44 Global Societ o Scientiic Research and Researchers http://asretsournal.org/ Implicit
More informationAnd similarly in the other directions, so the overall result is expressed compactly as,
SQEP Tutorial Session 5: T7S0 Relates to Knowledge & Skills.5,.8 Last Update: //3 Force on an element of area; Definition of principal stresses and strains; Definition of Tresca and Mises equivalent stresses;
More information( x) f = where P and Q are polynomials.
9.8 Graphing Rational Functions Lets begin with a deinition. Deinition: Rational Function A rational unction is a unction o the orm ( ) ( ) ( ) P where P and Q are polynomials. Q An eample o a simple rational
More informationBIOT COEFFICIENTS OF UNIDIRECTIONAL FIBRE PACKED ASSEMBLIES: EXPERIMENTAL AND THEORETICAL
BIOT COEFFICIENTS OF UNIDIRECTIONAL FIBRE PACKED ASSEMBLIES: EXPERIMENTAL AND THEORETICAL Thang Tran, Sébastien Comas-Cardona,*, Nor-Edine Abria 2, Christophe Binétruy Polymers and Composites Technology
More informationMathematical Preliminaries. Developed for the Members of Azera Global By: Joseph D. Fournier B.Sc.E.E., M.Sc.E.E.
Mathematical Preliminaries Developed or the Members o Azera Global B: Joseph D. Fournier B.Sc.E.E., M.Sc.E.E. Outline Chapter One, Sets: Slides: 3-27 Chapter Two, Introduction to unctions: Slides: 28-36
More informationExperimental and numerical analyses of FRC slabs on grade
Eperimental and numerical analses o FRC slabs on grade B. Belletti & R. Cerioni Department o Civil and Environmental Engineering and Architecture, Universit o Parma, Ital A. Meda Department o Civil Engineering,
More informationNumerical Methods - Lecture 2. Numerical Methods. Lecture 2. Analysis of errors in numerical methods
Numerical Methods - Lecture 1 Numerical Methods Lecture. Analysis o errors in numerical methods Numerical Methods - Lecture Why represent numbers in loating point ormat? Eample 1. How a number 56.78 can
More informationStrain Transformation and Rosette Gage Theory
Strain Transformation and Rosette Gage Theor It is often desired to measure the full state of strain on the surface of a part, that is to measure not onl the two etensional strains, and, but also the shear
More informationHYDROELASTIC TAILORING AND OPTIMIZATION OF A COMPOSITE MARINE PROPELLER
HYDROELASTIC TAILORING AND OPTIMIZATION OF A COMPOSITE MARINE PROPELLER José P. Blasques, Christian Berggreen and Poul Andersen Department o Mechanical Engineering, Technical University o Denmark Nils
More informationMAE 323: Chapter 4. Plane Stress and Plane Strain. The Stress Equilibrium Equation
The Stress Equilibrium Equation As we mentioned in Chapter 2, using the Galerkin formulation and a choice of shape functions, we can derive a discretized form of most differential equations. In Structural
More informationA STUDY OF 0 -FIBRE MICROBUCKLING IN MULTIDIRECTIONAL COMPOSITE LAMINATES
A STUDY OF -FIBRE MICROBUCKLING IN MULTIDIRECTIONAL COMPOSITE LAMINATES P. Berbinau and C. Soutis Department o Aeronautics, Imperial College o Science, Technology & Medicine Prince Consort Rd, London SW7
More informationMotion in Two Dimensions Sections Covered in the Text: Chapters 6 & 7, except 7.5 & 7.6
Motion in Two Dimensions Sections Covered in the Tet: Chapters 6 & 7, ecept 7.5 & 7.6 It is time to etend the definitions we developed in Note 03 to describe motion in 2D space. In doin so we shall find
More information3D NON-LINEAR FINITE ELEMENT MODELLING OF TRADITIONAL TIMBER CONNECTIONS
3D NON-LINEAR FINITE ELEMENT MODELLING OF TRADITIONAL TIMBER CONNECTIONS Bo-Han Xu 1, Abdelhamid Bouchaïr 1, Mustapha Taaount 1 ABSTRACT: In this paper, 3D non-linear inite element models are developed
More information1.1 The Equations of Motion
1.1 The Equations of Motion In Book I, balance of forces and moments acting on an component was enforced in order to ensure that the component was in equilibrium. Here, allowance is made for stresses which
More informationANALYSIS OF BI-STABILITY AND RESIDUAL STRESS RELAXATION IN HYBRID UNSYMMETRIC LAMINATES
ANALYSIS OF BI-STABILITY AND RESIDUAL STRESS RELAXATION IN HYBRID UNSYMMETRIC LAMINATES Fuhong Dai*, Hao Li, Shani Du Center for Composite Material and Structure, Harbin Institute of Technolog, China,5
More informationIdentification of muscle forces in human lower limbs during sagittal plane movements Part I: Human body modelling
Acta of ioenineerin and iomechanics Vol. No. 00 Identification of muscle forces in human lower limbs durin saittal plane movements Part I: uman bod modellin WOJCIEC LAJER KRZYSZOF DZIEWIECKI ZENON MAZUR
More informationCitation Key Engineering Materials, ,
NASITE: Nagasaki Universit's Ac Title Author(s) Interference Analsis between Crack Plate b Bod Force Method Ino, Takuichiro; Ueno, Shohei; Saim Citation Ke Engineering Materials, 577-578, Issue Date 2014
More informationMECHANICS OF MATERIALS
00 The McGraw-Hill Companies, Inc. All rights reserved. T Edition CHAPTER MECHANICS OF MATERIALS Ferdinand P. Beer E. Russell Johnston, Jr. John T. DeWolf Lecture Notes: J. Walt Oler Teas Tech Universit
More informationDETC A GENERALIZED MAX-MIN SAMPLE FOR RELIABILITY ASSESSMENT WITH DEPENDENT VARIABLES
Proceedings o the ASME International Design Engineering Technical Conerences & Computers and Inormation in Engineering Conerence IDETC/CIE August 7-,, Bualo, USA DETC- A GENERALIZED MAX-MIN SAMPLE FOR
More informationSlowly Changing Function Oriented Growth Analysis of Differential Monomials and Differential Polynomials
Slowly Chanin Function Oriented Growth Analysis o Dierential Monomials Dierential Polynomials SANJIB KUMAR DATTA Department o Mathematics University o kalyani Kalyani Dist-NadiaPIN- 7235 West Benal India
More informationA NOVEL METHOD OF INTERPOLATION AND EXTRAPOLATION OF FUNCTIONS BY A LINEAR INITIAL VALUE PROBLEM
A OVEL METHOD OF ITERPOLATIO AD EXTRAPOLATIO OF FUCTIOS BY A LIEAR IITIAL VALUE PROBLEM Michael Shatalov Sensor Science and Technolog o CSIR Manuacturing and Materials, P.O.Bo 395, Pretoria, CSIR and Department
More informationFATIGUE DURABILITY OF CONCRETE EXTERNALLY STRENGTHENED WITH FRP SHEETS
FATIGUE DURABILITY OF CONCRETE EXTERNALLY STRENGTHENED WITH FRP SHEETS H. Diab () and Zhishen Wu () () Department o Urban and Civil Engineering, Ibaraki University, Japan Abstract A primary concern o the
More informationObjectives. By the time the student is finished with this section of the workbook, he/she should be able
FUNCTIONS Quadratic Functions......8 Absolute Value Functions.....48 Translations o Functions..57 Radical Functions...61 Eponential Functions...7 Logarithmic Functions......8 Cubic Functions......91 Piece-Wise
More informationJournal of Advanced Mechanical Design, Systems, and Manufacturing
Numerical Analysis on Paper Separation Usin the Overlap Separation echanism * Hui CHENG **, Hiroshi IKEDA ** and Kazushi YOSHIDA ** ** echanical Enineerin Research Laboratory, Hitachi Ltd. 8- Horiuchi-machi,
More information9. v > 7.3 mi/h x < 2.5 or x > x between 1350 and 5650 hot dogs
.5 Etra Practice. no solution. (, 0) and ( 9, ). (, ) and (, ). (, 0) and (, 0) 5. no solution. ( + 5 5 + 5, ) and ( 5 5 5, ) 7. (0, ) and (, 0). (, ) and (, 0) 9. (, 0) 0. no solution. (, 5). a. Sample
More informationEstimation of the Vehicle Sideslip Angle by Means of the State Dependent Riccati Equation Technique
Proceedings o the World Congress on Engineering 7 Vol II WCE 7, Jul 5-7, 7, London, U.K. Estimation o the Vehicle Sideslip Angle b Means o the State Dependent Riccati Equation Technique S. Strano, M. Terzo
More informationReliability of Axially Loaded Fiber-Reinforced-Polymer Confined Reinforced Concrete Circular Columns
American J. o Engineering and Applied Sciences (1): 31-38, 009 ISSN 1941-700 009 Science Publications Reliability o Axially Loaded Fiber-Reinorced-Polymer Conined Reinorced Concrete Circular Columns Venkatarman
More informationAN OSCILLATOR MODEL FOR HIGH-PRECISION SYNCHRONIZATION PROTOCOL DISCRETE EVENT SIMULATION
39 th Annual Precise Time and Time Interval (PTTI Meetin AN OSCILLATOR MODEL FOR HIGH-PRECISION SYNCHRONIZATION PROTOCOL DISCRETE EVENT SIMULATION Geor Gaderer Austrian Academ o Sciences Viktor Kaplan
More informationA General Class of Estimators of Population Median Using Two Auxiliary Variables in Double Sampling
ohammad Khoshnevisan School o Accountin and inance riith University Australia Housila P. Sinh School o Studies in Statistics ikram University Ujjain - 56. P. India Sarjinder Sinh Departament o athematics
More informationModel to predict the mechanical behaviour of oriented rigid PVC
Louhborouh University Institutional Repository Model to predict the mechanical behaviour o oriented riid PVC This item was submitted to Louhborouh University's Institutional Repository by the/an author.
More informationFatigue verification of high loaded bolts of a rocket combustion chamber.
Fatigue veriication o high loaded bolts o a rocket combustion chamber. Marcus Lehmann 1 & Dieter Hummel 1 1 Airbus Deence and Space, Munich Zusammenassung Rocket engines withstand intense thermal and structural
More informationThermal Elastic Buckling of plates made of carbon nanotube reinforced polymer composite materials
THE 9 TH INTERNATIONAL CONFERENCE ON COMPOSITE MATERIALS Thermal Elastic Buckling o plates made o carbon nanotube reinorced polymer composite materials J. Naar Dastgerdi,, S. Marzban 3, G. Marquis, Applied
More information(One Dimension) Problem: for a function f(x), find x 0 such that f(x 0 ) = 0. f(x)
Solving Nonlinear Equations & Optimization One Dimension Problem: or a unction, ind 0 such that 0 = 0. 0 One Root: The Bisection Method This one s guaranteed to converge at least to a singularity, i not
More informationThis is an author-deposited version published in : Eprints ID : 11904
Open Archive TOULOUSE Archive Ouverte (OATAO) OATAO is an open access repository that collects the work o Toulouse researchers and makes it reely available over the web where possible. This is an author-deposited
More informationFinite element modeling incorporating nonlinearity of material behavior based on the fib Model Code 2010
Peer-reviewed & Open access journal www.academicpublishingplatorms.com Finite element modeling incorporating non-linearity o material behavior ATI - Applied Technologies & Innovations Volume 5 Issue November
More informationBEAM-COLUMNS SUMMARY: OBJECTIVES: REFERENCES: CONTENTS:
BEA-COLUS SUARY: Structural members subjected to axial compression and bending are nown as beam columns. The interaction o normal orce and bending ma be treated elasticall or plasticall using equilibrium
More informationFailure Diagrams of FRP Strengthened RC Beams
Failure Diagrams o FRP Strengthened RC Beams Abstract Bo GAO a, Christopher K. Y. LEUNG b and Jang-Kyo KIM a* a Department o Mechanical Engineering and b Department o Civil Engineering Hong Kong University
More informationApproximate probabilistic optimization using exact-capacity-approximate-response-distribution (ECARD)
Struct Multidisc Optim (009 38:613 66 DOI 10.1007/s00158-008-0310-z RESEARCH PAPER Approximate probabilistic optimization using exact-capacity-approximate-response-distribution (ECARD Sunil Kumar Richard
More informationDevelopment of Crane Tele-operation System using Laser Pointer Interface
23 IEEE/RSJ International Conerence on Intellient Robots and Systems (IROS) November 3-7, 23. Tokyo, Japan Development o Crane Tele-operation System usin Laser Pointer Interace Masaki Neishi, Hisasi Osumi
More informationResearch Article Equivalent Elastic Modulus of Asymmetrical Honeycomb
International Scholarl Research Network ISRN Mechanical Engineering Volume, Article ID 57, pages doi:.5//57 Research Article Equivalent Elastic Modulus of Asmmetrical Honecomb Dai-Heng Chen and Kenichi
More informationConsider a slender rod, fixed at one end and stretched, as illustrated in Fig ; the original position of the rod is shown dotted.
4.1 Strain If an object is placed on a table and then the table is moved, each material particle moves in space. The particles undergo a displacement. The particles have moved in space as a rigid bod.
More informationFunctions. Introduction
Functions,00 P,000 00 0 y 970 97 980 98 990 99 000 00 00 Fiure Standard and Poor s Inde with dividends reinvested (credit "bull": modiication o work by Prayitno Hadinata; credit "raph": modiication o work
More informationReliability assessment on maximum crack width of GFRPreinforced
Fourth International Conerence on FRP Composites in Civil Engineering (CICE2008) 22-24July 2008, Zurich, Switzerland Reliability assessment on maximum crack width o GFRPreinorced concrete beams Z. He and
More informationHYDROMAGNETIC DIVERGENT CHANNEL FLOW OF A VISCO- ELASTIC ELECTRICALLY CONDUCTING FLUID
Rita Choudhury et al. / International Journal o Engineering Science and Technology (IJEST) HYDROAGNETIC DIVERGENT CHANNEL FLOW OF A VISCO- ELASTIC ELECTRICALLY CONDUCTING FLUID RITA CHOUDHURY Department
More informationAcoustic forcing of flexural waves and acoustic fields for a thin plate in a fluid
Acoustic orcing o leural waves and acoustic ields or a thin plate in a luid Darryl MCMAHON Maritime Division, Deence Science and Technology Organisation, HMAS Stirling, WA Australia ABSTACT Consistency
More informationCharacterization of the Skew-Normal Distribution Via Order Statistics and Record Values
International Journal of Statistics and Probabilit; Vol. 4, No. 1; 2015 ISSN 1927-7032 E-ISSN 1927-7040 Published b Canadian Center of Science and Education Characterization of the Sew-Normal Distribution
More information1.4 Optimization of an orthogonally stiffened plate considering fatigue constraints
1.4 Optimization of an orthogonall stiffened plate considering fatigue constraints Luis M.C. Simões 1, József Farkas and Karol Jarmai 1 Universit of Coimbra, Portugal,lcsimoes@dec.uc.pt Universit of Miskolc,
More informationEVALUATION OF STRESS IN BMI-CARBON FIBER LAMINATE TO DETERMINE THE ONSET OF MICROCRACKING
EVALUATION OF STRESS IN BMI-CARBON FIBER LAMINATE TO DETERMINE THE ONSET OF MICROCRACKING A Thesis b BRENT DURRELL PICKLE Submitted to the Office of Graduate Studies of Teas A&M Universit in partial fulfillment
More informationScattering of Solitons of Modified KdV Equation with Self-consistent Sources
Commun. Theor. Phys. Beijing, China 49 8 pp. 89 84 c Chinese Physical Society Vol. 49, No. 4, April 5, 8 Scattering o Solitons o Modiied KdV Equation with Sel-consistent Sources ZHANG Da-Jun and WU Hua
More information8.4 Inverse Functions
Section 8. Inverse Functions 803 8. Inverse Functions As we saw in the last section, in order to solve application problems involving eponential unctions, we will need to be able to solve eponential equations
More informationFiber / Toughened Epoxy Composites under
Fatigue Behavior o Impact-Damaged Carbon Fiber / Toughened Epoxy Composites under Compressive loading Toshio Ogasawara, Hisaya Katoh, unao ugimoto, and Takashi Ishikawa Advanced d Composite Technology
More informationFATIGUE ANALYSIS: THE SUPER-NEUBER TECHNIQUE FOR CORRECTION OF LINEAR ELASTIC FE RESULTS
6 TH INTERNATIONAL CONGRESS OF THE AERONAUTICAL SCIENCES FATIGUE ANALYSIS: THE SUPER-NEUBER TECHNIQUE FOR CORRECTION OF LINEAR ELASTIC FE RESULTS L. Samuelsson * * Volvo Aero Corporation, Sweden Kewords:
More informationLecture 8 Optimization
4/9/015 Lecture 8 Optimization EE 4386/5301 Computational Methods in EE Spring 015 Optimization 1 Outline Introduction 1D Optimization Parabolic interpolation Golden section search Newton s method Multidimensional
More informationDevelopment of a Spiral Structure for an Active Catheter Overview of the Spiral Structure and Its Kinematic Configuration
Development o a Spiral Structure or an Active Catheter Overview o the Spiral Structure and Its Kinematic Coniguration Yoshihiko KOSEKI and Noriho KOYACHI Tatsuo ARAI Mechanical Engineering Laborator Department
More informationUNCERTAINTY EVALUATION OF SINUSOIDAL FORCE MEASUREMENT
XXI IMEKO World Congress Measurement in Research and Industry August 30 eptember 4, 05, Prague, Czech Republic UNCERTAINTY EVALUATION OF INUOIDAL FORCE MEAUREMENT Christian chlegel, Gabriela Kiekenap,Rol
More informationEVALUATION OF THERMAL TRANSPORT PROPERTIES USING A MICRO-CRACKING MODEL FOR WOVEN COMPOSITE LAMINATES
EVALUATION OF THERMAL TRANSPORT PROPERTIES USING A MICRO-CRACKING MODEL FOR WOVEN COMPOSITE LAMINATES C. Luo and P. E. DesJardin* Department of Mechanical and Aerospace Engineering Universit at Buffalo,
More information