Design of a Bend Testing Machine for Determination of Residual Stresses by the MTS-3000 Ring-Core System

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1 American Jurnal f Mechanical Engineering, 017, Vl. 5, N. 6, Available nline at Science and Educatin Publishing DOI: /ajme Design f a Bend Testing Machine fr Determinatin f Residual Stresses by the MTS-3000 Ring-Cre System Patrik Šarga *, Štefan Beck, František Trebuňa Technical University f Kšice, Faculty f Mechanical Engineering, Letná 9, 0 00 Kšice, Slvak Republic *Crrespnding authr: patrik.sarga@tuke.sk Abstract The design and manufacture f bend testing machine fr testing the prperties f materials is addressed by several reputable cmpanies. Hwever, their prtflis include cmmnly used devices with a similar design [1,]. Hwever, determinatin f the residual stresses by the MTS-3000 Ring-Cre system requires atypical measurement cnditins, s it is nt pssible t use a cmmnly prduced and available bend testing machine. Fr this reasn, there was a need t design a bend testing machine that wuld meet all the required measurement cnditins. Keywrds: residual stresses, Ring-Cre methd, bend testing machine Cite This Article: Patrik Šarga, Štefan Beck, and František Trebuňa, Design f a Bend Testing Machine fr Determinatin f Residual Stresses by the MTS-3000 Ring-Cre System. American Jurnal f Mechanical Engineering, vl. 5, n. 6 (017): di: /ajme Intrductin There are several experimental methds t evaluate residual stress. The mst well-knwn methd fr determinatin f the residual stresses is the hle-drilling methd. The Ring-Cre methd is derived frm the hle-drilling methd, but n the examined specimen is nt frmed a hle, but a ring. Althugh the Ring-Cre methd causes mre destructin f the specimen, it als eliminates sme limitatins f the hle-drilling methd. The Ring-Cre methd can evaluate bth hmgeneus and nn-hmgeneus residual stresses alng the depth f the material [3,]. Hwever, the Ring-Cre methd is nt currently at the same level as the hle-drilling methd. Verificatin experiments have t be carried ut, and fr this reasn we have been designing ur wn bend testing machine t simulate internal stresses in the structure. (Figure 1). The measuring system must be placed abve the measured specimen and a ring f the required depth is drilled int the laded specimen. The design f the bend testing machine must take int accunt the lcatin f the measuring system Ring-Cre abve the sample and the need t generate a unifrm stress n the measured sample. Fur-pint bending will be cnsidered where tw members will supprt the measured specimen and the tw actuatrs psitined symmetrically between the supprts will apply a predetermined frce n the specimen t prduce stress, which is required fr the measurement. Befre designing, it is necessary t define the requirements that the device will have t meet in rder t be able t measure. Prvide sufficient space fr the lcatin and handling f the MTS-3000 Ring-Cre. The ability f the bend testing machine t generate a stress up t 100 MPa at the measuring pint f the specimen, thereby simulating the cnditins under which the material is expsed in a real envirnment.. Specimen Analysis Figure 1. MTS Ring-Cre system The task was t design a bend testing machine suitable fr the measuring system SINT MTS Ring - Cre A rectangular beam will serve as a specimen (Figure ). The design cnsidered the maximum pssible dimensin f the specimen that the designed bend testing machine shuld be able t lad. Specimen assembling will be cnsidered theretically with a hinge n ne side and a sliding articulatin n the ther side [5]. Due t the cnstructin f the MTS-3000 Ring-Cre and the way hw the machine makes ring cre, it is nt pssible t lad the specimen directly in the middle, but lad frces must be placed next t the measuring device. Fr this purpse, the lad shwn in the Figure 3 was

2 70 American Jurnal f Mechanical Engineering chsen, where the bending and reactin frces are als defined, thus defining the psitin f the wrking bending member as well as the psitin f the supprts n which the specimen is t be placed. Figure. Specimen: frnt view, side view Figure 3. Lcatin f lad frces In this case, it is a simple bend n the prismatic beam. With regard t the simplicity f the equilibrium cnditins and the way hw the mment is applied t the beam, the mathematical derivatin was mitted and the beam was described directly by the picture (Figure ), frm which it is bvius that the reactins will be directly prprtinal t the frce acting n the beam. In the BC sectin there are nly bending mments. Bending mment: M = Fx. () FF [NN] frce, xx [mmmm] - psitin vectr frm the reference pint. Secnd mment f area: W Jy z max = (3) h 30mm zmax = = = 15mm () JJ yy [mmmm ] quadratic mment t the neutral axis, zz mmmmmm maximal distance frm the neutral axis. Quadratic mment t the neutral axis: 3 b. h 50 mm.30mm J y = = = 11500mm (5) 1 1 Frm the equatin fr the bending stress, we express the magnitude f the frce. M σ = W F. x F.50mm 7500 mm.100mpa σ = = F = 3 b. h 7500mm 50mm 1 h 1 F = N. The calculatin shws that the magnitude f the required frce is F = N. 3. Design f the Frame f the Bend Testing Machine Figure. Graphical interpretatin f the laded beam The frame is the basic carrier in the cnstructin and engineering units. This is the part f the structure that frms the basic supprting part (skeletn) [6]. The frame has the task f transferring frces, mments and creating a suitable platfrm fr fastening and clamping ther parts f the cnstructin..1. Calculatin f the Necessary Frces and Reactins in the Supprts The fllwing sectin describes the calculatin f the required frces which have t be applied t the specimen t prduce the desired stress n the measured surface [5]. M σ = (1) W σσ [MMMMMM] required bending stress [100 MPa], MM [NNNNNN] bending mment, WW [mmmm ] secnd mment f area. Figure 5. Frame dimensins f the bending device

3 American Jurnal f Mechanical Engineering 71 The frame (Figure 5) is designed frm several standardized prfiles. Used prfiles and their STN standards: square prfile, seamless, ht-frmed steel tube: TR HR 0 x STN 5 70 I prfile ht-rlled steel bar: I 8 / B STN STN Flat ht-rlled steel bar: 0 x 0 STN STN Subsequently, frame lad analysis was perfrmed by using finite element methd in the sftware SlidWrks (Figure 6) [7,8]. Figure 7. Simulatin f the displacement n the frame. Bearing f the Specimen With regard t the bearing f the specimen and that the frce generated by the pistn n the specimen is equal t the frce acting n the specimen, a bearing, which can withstand twice the static lad value has been selected. A TASE35-N rller bearing was selected, which can transmit a radial dynamic lad f = N and a radial static lad f N (Figure 8) [9]. Figure 8. TASE35-N 5. Design f the Bending Tl As a wrking tl was selected prismatic rller made f tl steel class 19 and was psitined n the bending frame. The bending frame is slidly cnnected t the guide bars. The layut f each element is shwn in the Figure 9. Figure 6. a) Mesh mdel f the frame b) Simulatin f the stresses f the frame The displacements generated by the frces n the frame are shwn in the Figure 7. Figure 9. Simulatin f the displacement n the frame

4 7 American Jurnal f Mechanical Engineering 6. Selectin f the Direct Hydraulic Mtr As a drive unit was selected a hydrmtr. The Hydrmtr has been selected frm the available ffer frm cmpany HYDRAULICS s.r.., which deals with the prductin, develpment and servicing f hydraulic equipment and their cmpnents. On the basis f the minimum displacement frce requirement F = 15kN, was selected hydraulic mtr ISO 60 mdel MF (Figure 10) frm the catalg f HYDRAULICS s.r.. cmpany [10]. Figure 10. Direct hydraulic mtr ISO 60 MF Figure 11 shws the final design f the bend testing machine. Figure 11. Final design f the bend testing machine 7. Design f Hydraulic Circuit Elements Basic part f each hydraulic circuit is the pressure surce a hydraulic pwer pack cnsisting f a drive unit, a tank, a distributin f hydraulic fluid, valves and filters. The prpulsin unit is cmpsed f a hydraulic pump and an electric mtr [11,1]. Calculatin f the wrking pressure in the cylinders f the hydraulic pump: Ftl p jt = π. d (6) 37680N p jt = = 19.MPa π.50mm pp jjjj [MMMMMM] pressure in the cylinder f the hydraulic pump, FF tttt [NN] frce, dd [mmmm] pistn diameter. Calculatin f the flw rate delivered t the hydraulic pump: π. d Q =. v π.0.05mm 1 Q=.0.1 ms. (7) 3 1 = m. s = m. min QQ [mm 3. ss 1 ] pump flw rate, vv [mm. ss 1 ] pump speed Calculatin f the gemetric vlume f the hydraulic pump: The rtatin speed f the hydraulic pump is the same as that f the electric mtr nn = 950 mmmmmm 1. Q Vg = (8) n m. min Vg = min 3 = 1.39cm VV gg [mmmm 3 ] gemetric vlume f the hydraulic pump, nn [mmmmmm 1 ] rtatin speed f the electric mtr. Input pwer: Qj. pjt P = (9) t m. s MPa P = 0.8 = 787W PP [WW] input pwer, QQ jj [mm 3. ss 1 ] pump flw rate, η tt [ ] ttal efficiency. Accrding t the Arg Hyts cmpany catalg, we chse the SA-5U class J15, which cmplied all the calculated parameters [13,1]. Schematic view f the chsen hydraulic pwer pack SA-5U is shwn in the Figure 1 [13].

5 American Jurnal f Mechanical Engineering 73 Acknwledgements This wrk was supprted by grant prjects APVV and VEGA N. 1/0751/16. References 1 tank, drive/bell husing, 3 pump, electric mtr, 5 base blck (safety blck f the accumulatr), 6 hrizntal stacking assembly, 7 vertical stackling assembly, 8 pressure gauge, 9 return filter with by-pass, integrated air breather/filler and clgging indicatr, 10 cntinuus level gauge, 11 magnetic drain plug, 1 grunding pint 8. Cnclusins Figure 1. Hydraulic pwer pack SA-5U In the present article a design f a bend testing machine is described. The frame f the bend testing machine was designed with regard t the requirement fr sufficient space t wrk with the measuring system MTS-3000 Ring-Cre. Using the FEM methd in the SlidWrks prgram, simulatin f the stresses and displacements created n the frame in the laded state was perfrmed. Frm the btained values it was cncluded that the frame meets the requirements impsed n it. Prismatic cylindrical supprts have been designed t accmmdate the sample s that n undesirable stresses are prduced n the sample. Accrdingly, bending tls were als selected. As an actuatr f the bend testing machine, tw hydrmtrs were selected, which were t be able t draw sufficient pressure n the sample. Hydraulic pwer pack was als designed. [1] GEDNEY R.: Tensile testing basics, tips and trends [nline]. agazine.pdf. [] Flr standing test system, 318 family universal test machine [nline]. [3] Šarga P., Menda F.: Analysis f measuring chain fr evaluating residual stresses by ring-cre methd [nline]. Dstupné na internete: [] SINT TECHNOLOGY: MTS3000 RINGCORE [nline]. Dstupné na internete: RingCre.pdf. [5] TREBUŇA F., ŠIMČÁK F., JURICA V.: Pružnsť a pevnsť I., II. Vydanie, Vienala Kšice, 30 s., 001, ISBN [6] JOSEPH E. SHIGLEY, CHARLES R. MISCHKE, RICHARD G. BUDYNAS.: Knstruvaní strjních sučastí, Akademické nakladatelství VUTIUM, 010, 1159 s., ISBN [7] VLÁČILOVÁ, H. VILÍMKOVÁ, M. A HENCL, L. Základy práce v CAD systému SlidWrks. Cmputer Press, a.s., vydání [8] Slid Wrks tutrial meshing [nline]. Dstupné na internete: kgrund_n_meshing.htm?id=736dcee69ba5fa351936b6 a01. [9] Plummer blck husing units PASE [nline]. Dstupné na internete: [10] Prímčaré hydrmtry dle ISO 60 [nline]. Dstupné na internete: r55-57.pdf? [11] WATTTON, J.: Fluid Pwer Systems. 1. vyd., NY, Prentice Hall, [1] Static and fatigue testing f materials and prducts, 901LX-100 servhydraulic test system [nline]. Dstupné na internete: Serv-Hydraulic-Tst-System.pdf. [13] [1] Jihstrj, Gear pumps [nline],