International Journal of Engineering Research & Technology (IJERT) ISSN: 22711 Vol. 2 Issue, August 213 Analysis Of Riveted Butt Joint K. S. Bodadkar *1 * Pg. student of Department of Mechanical Engineering R.C.E.R.T. Chandrapur, India Prof. S. D. Khamankar ** 2 **Associate Professor Department of Mechanical Engineering R.C.E.R.T. Chandrapur, India Abstract Riveted joints are used in many structural works like ship buildings, in bridge structure and in manufacturing of boiler shells etc. The failures of ed joint takes place by tearing of the plate, shearing of and crushing of and plate under the action of overloading. Hence the stress pattern in ed butt joint by varying parameters like thickness of plate, linear pitch, transverse pitch and method of ing is studied. In this research,, numerical and experimental stress analyses are carried out. For analysis purpose virtual model of ed butt joint is prepared in ProE. And this CAD model is imported in ANSYS software where stress analysis is done by FEM. This analysis shows that, to have safe joint it is better to increase the thickness of main plate and linear pitch instead of increase in transverse pitch. Also the analysis shows that vonmises stresses obtained in chain ing are lesser as compared to diamond and zigzag ing. From this, it can be concluded that chain ing is the most safe method of ing. From the analysis, it is revealed that the results obtained are in good agreement to F.E.A results. Keywords: FEM, Riveted Joints, Shearing stress, Tearing stresses 1. Introduction For nearly a century, s are used for permanent joints between plates of boiler shell, structural members of bridges and part of railway wagons and coaches. For making a ed joint, a hole has to be drilled in the plate to be connected. Rive is used in many applications, such as cold ing of thin sheets, ing sheets of aeroplane structures, etc. Rive is much faster and also the cheapest process of producing a permanent joint. There are two types of ed joints, butt joint and lap joint. A butt joint is that in which the main plates are kept in alignment but (i.e. touching) each other and a cover plate (i.e. strap) is placed either on one side or on both sides of the main plates. The cover plate is then ed together with the main plates. The failures of ed joint takes place by tearing of the plate, shearing of and crushing of and plate under the action of overloading. Hence the stress pattern in ed butt joint by varying parameters like thickness of plate, linear pitch, transverse pitch and method of ing is studied. 2. Introduction to Problem, Scope and Methodology In this research ed joints using different elements under static load conditions are analyzed. For this purpose single double strap joint is considered under static loading conditions. Due to ing process complex residual stress state is introduced for the ed joint (both for the and the plates). During the installation process the plates are pressed together by the deformed. This causes surface contact stresses between the joined plates. The stresses are obtained ly. Then a 3D model is prepared in ProE software and its stress analysis is done by F.E.M. using ANSYS by varying parameter such as thickness of main plate (t), linear pitch (p) and transverse pitch (pt). Also the analysis is done for chain, diamond and zigzag ing using same number of s in each main plate. The experimental test model is prepared using aluminium alloy plate and. The test is carried out in universal tes machine to determine shearing strength of by applying tensile load on main plate. The plate and are made up of aluminium alloy and its mechanical properties are tabulated in Table.1. IJERTV2IS24 www.ijert.org 719
International Journal of Engineering Research & Technology (IJERT) ISSN: 22711 Vol. 2 Issue, August 213 Table 1 Properties of Material Table 2 Finite element analysis results Modulus of Elasticity E 71 Poisson s ratio ν.33 Density of material (Kg/mm 3 ) ρ 2.77e 3. Analytical Analysis of Riveted Butt Joint The stress calculations for ed butt joint are performed using following relations [1]. Tearing stress in a plate per pitch length f σt = n p d t concentration factor (k t = 2.3) is consider for the tearing of plate Shearing stress on f τ = n 2 П 4 d2 Crushing stress on and plate σc = f n d t Maximum shear stress τ max = 1 2 [ σt 2 + 4τ 2 Maximum principal stress σ 1 = σt 2 + 1 2 [ σt 2 + 4τ 2 ] Equivalent stress (Vonmises stress) σ eq = σ 2 + 3τ 2 4. Finite Element Analysis of Riveted Butt Joint Sr. no. 1 2 3 4 in single ed double strap butt joint Tearing stress (σ t ) in plate Shear (τ) in Max. shear (τ max ) in Max.Principal (σ 1 ) in Vonmises stress (σ eq ) in stresses Analytical stresses 2739 322.2 117 7. 312 9.2 71 1.7 91 1.49 Fig. 1 Tearing stress contour on main plate with 3 mm thickness Fig.2. Shear stress contour on s with 3mm thickness of main plate In this chapter, threedimensional stress field solutions are obtained in the single ed double strap joint geometric configuration under both the residual stress field and external tensile loading. Threedimensional finite element models of ed butt joints have been developed using a commercial finite element program ANSYS (Workbench). Nonlinearity arising from the interaction (frictional contact condition) between the and Plates was incorporated in the model. The local stress state in a ed butt joint is very complex due to the residual stress (clamping stress applied by heads and radial pressure applied by expansion) resul from installation process, surface shear within the contac zone due to load transfer through friction, pin loading at hole due to load transfer through shear, secondary bending effects of the joint, and biaxial tension in plates due to the applied tensile load. Thus the results obtained from finite element analysis are shown in table 2 and fig. 1 to. Fig.3. Maximum Shear stress contour on s with 3mm thickness of main plate Fig.4. Maximum principal stress contour on s with 3mm thickness of plate IJERTV2IS24 www.ijert.org 1 72
MAX. SHEAR STRESS TEARING STRESS (MPA) SHEAR STRESS (N/MM2) International Journal of Engineering Research & Technology (IJERT) ISSN: 22711 Vol. 2 Issue, August 213 Table 3 Observation between FEA and s by varying thickness of main plate Fig.. Vonmises stress contour on s with 3mm thickness of plate. Experimental Analysis of Riveted Butt Joint A single ed butt joint as shown in fig. is considered for determination of shearing strength. A prototype of joint is prepared and it is tested on universal tes machine (UTM). The photograph of experimentation is shown in fig. 7. And the shearing stress thus determined is 7. MPa. es in ed butt joint ( MPa) Tearing stress (σ t ) Shear (τ) Max. (τ max ) shear Max.Princip al (σ 1 ) FEA stresses Analytical stresses Thickness of Thickness of main main plate (t)( plate (t) in mm mm) 2 19 171 32 24 193 393 29 24 2 2 1 71 1 7 1 Von mises stress(σ eq ) 112 19 11 71 91 92 17 9 13 11 71 3 9 14 94 14 7. 7. 7. 97 79 1 1 1 13 1 12 143 Fig. Dimension for test specimens 72 7 Fig. Variation of shear stress w.r.t. thickness of main plate Fig. 7 Failure of test specimen 4 2 F.E.Analys is Analytical analysis Fig. 9 Variation of tearing stress (normal stress) in plate w.r.t. thickness of plate. 1. Results and Discussions The comparison between finite element analysis and analysis result are as shown in table 3 and fig. to 12. 1 analyt ical Fig. 1 Variation of maximum shear stress in w.r.t. thickness of main plate. IJERTV2IS24 www.ijert.org 2 721
VONMISES STRESS MAX. PRINCIPAL STRESS MAX.SHEAR STRESS TEARING STRESS VOMMISES STRESS MAX. PRINCIPAL STRESS SHEAR STRESS International Journal of Engineering Research & Technology (IJERT) ISSN: 22711 Vol. 2 Issue, August 213 2 1 Fig.11 Variation of maximum principal stress in w.r.t. thickness of main plate. 3 2 1 Fig.12 Variation of vonmises stress in w.r.t. thickness of main plate From table 3 and fig. to 12 it is observed that good agreement is obtained between and F.E.A results. The following observations are obtained. From fig., it is observed that there is no effect of thickness of the main plate on shear stress in. From fig.9, it is observed that there is decrease in normal stress (tearing stress) in plate with increase in thickness of main plate. Fig.1 shows that there is decrease in maximum shear stress in with increase in thickness of main plate. Similarly fig.11 and fig.12 depicts that decrease in maximum principal stress and vonmises stress in with increase in thickness of main plate. Table 4 Observation between FE and analysis s by varying linear pitch of es in ed butt joint(mpa) Tearing stress(σ t ) in plate Shear (τ) in Max. shear τ max ) in Max.Princi pal (σ 1 ) in Von mises stress (σ eq ) in FEA Values Analytical Values Linear Pitch of Rivet (p) in mm Linear Pitch of Rivet (p) in mm 14 2 41 499 44 7 7 31 17 7 14 23 1 2 13 12 97 29 1 24 9 1 12 42 194 114 227 al al... 13 12 117 24 232 214 23 242 22 7 7 al Fig. 13 Variation of shear stress w.r.t. linear pitch of 1 Fig.14 Variation of tearing stress w.r.t. linear pitch of 1 14 13 12 11 1 Fig.1 Variation of maximum shear stress w.r.t. linear pitch of 3 2 1 Fig. 1 Variation of maximum principal stress w.r.t. linear pitch of 3 2 2 Fig. 17 Variation of vonmises stress w.r.t. linear pitch of IJERTV2IS24 www.ijert.org 3 722
VONMISES STRESS TEARING STRESS MAX.PRINCIPAL STRESS(MPa) MAX. SHEAR STRESS SHEAR STRESS International Journal of Engineering Research & Technology (IJERT) ISSN: 22711 Vol. 2 Issue, August 213 From the table 4 and fig 13 to fig.17, it is seen that There is no effect of linear pitch of the on the shear stress in the. There is decrease in tearing stress (normal stress) in the main plate with increase in linear pitch of. There is decrease in maximum principal stress, maximum shear stress and vonmises stress in with increase in linear pitch of. Table Observation between FE and analysis s by varying transverse pitch of es in ed butt joint (MPa) Tearing stress (σ t ) in plate Shear (τ) in Max.shear (τ max ) in Max.Principal (σ 1 ) in Von mises stress (σ eq ) in 4 2 FEA Values Analytical Values transverse Pitch transverse Pitch of of Rivet (p) in Rivet(p)in mm mm 1 2 22 1 2 22 14 7 17 7 14 23 1 2 4 1 72 94 23 149 27 44 9 4 7 11 231 132 24 1 2 22... 13 13 13 24 24 24 23 23 23 val ue Fig. 1 Variation of tearing stress w.r.t. transverse pitch of 7 7 1 2 22 al Fig. 19 Variation of shear stress w.r.t. transverse pitch of 14 13 13 134 132 1 2 22 Fig. 2 Variation of maximum shear stress w.r.t. transverse pitch of 23 23 234 232 23 22 22 1 2 22 TRANSVERSE PITCH(MM) Fig. 21 Variation of maximum principal stress w.r.t. transverse pitch of 2 2 24 22 2 1 2 22 Fig. 22 Variation of vonmises stress w.r.t. transverse pitch of From the table 4 and fig.1 to fig.22 it is observed that there is no effect of variation in transverse pitch on the stresses developed in main plate and. valu e IJERTV2IS24 www.ijert.org 4 723
International Journal of Engineering Research & Technology (IJERT) ISSN: 22711 Vol. 2 Issue, August 213 Table Observation between FE and analysis s by varying ing method. e s in ed butt joint (MPa) Tearing stress (σ t ) in plate Shear (τ) in Max. shear (τ max ) in Max.Pr incipal (σ 1 ) in Vonmises stress (σ eq ) in STRESS FEA Values Method reve Dia Zig mon zag d ing 7 4 3 2 1 22 14 141 1 29 149 297 7 7 97 14 4 2 13 29 of Cha in 497 34 17 7 14 23 1 2 Analytical Values Method reve Dia Zig mon zag d ing 4. 9. 13. 23. 22. 34.. of Cha in. 11 13 2 24 294 23 chain ing daimond in zigzag ing Fig.23 Variation of stresses w.r.t. method of ing From table and fig.23 it is found that minimum stresses are induced in chain ing as compared to other method of ing. Hence the chain ing produces 1 % to 11 % more safe joint as compared to diamond and zigzag ing. 7. Conclusion The experimental determination of breaking strength of ed butt joint revealed the shearing strength of 33 N (i.e. 7. MPa).The F.E analysis of ed butt joint for same geometry revealed the shear stress of 7 MPa. This investigation confirmed that shearing stress in the determined by experimentation and F.E. analyses are in close agreement. Analytical and F.E. static stress analysis of ed butt joint is performed by varying parameters like thickness of main plate, linear pitch of, transverse pitch of and method of ing, from which it is revealed that the result obtained are in good agreement to each other. Looking at variation of vonmises stress with respect to thickness of main plate (t) and linear pitch (p) it is found that the stresses decreases with increase in of these parameters. There is no effect of transverse pitch on the stress. Hence to have safe joint, it is better to increase the thickness of main plate and linear pitch instead of increase in transverse pitch. Also the analysis shows that vonmises stresses obtained in chain ing are lesser as compared to diamond and zigzag ing. From this, it can be concluded that chain ing is the most safe method of ing.. References [1]Marin Sandu, Adriana Sandu, Dan Mihai Constantinescu.; Strength Of Adhesively Bonded SingleStrapped Joints Loaded In Tension, The Romanian Academy, Series A, Volume 11,No.4, Pg. 371379 (21) [2]Essam A. AlBahkali.; Finite Element Modeling For Thermal es Developed In Riveted And RivetBonded Joints, International Journal Of Engineering & Technology IJETIJENS, Vol: 11, No. (211) [3]M D Banea1and L F M Da Silva.; Adhesively Bonded Joints in Composite Materials, Journal of Materials Design and Applications (29) [4]David Y. Hutton.:"Fundamentals of Finite Element Analysis". Tara McGraw Hill, New Delhi (24) []O. C. Zienkiewicz.:"The Finite Element Method", 3m Edition, Tata McGraw Hill, New Delhi. (1999) []U. C. Jindal.: Machine Design, Pearson Education in south asia (21). IJERTV2IS24 www.ijert.org 724