Modelling and Analysis of Corrugated Sheet Metal Bending Process

Transcription

1 International Journal o Innovative esearc in Science, Modelling and Analysis o Corrugated Seet Metal Bending Process P.Devendran 1,.Sambasivam Assistant Proessor, Department o Mecatronics Engineering, SNS College o Tecnology, Tamilnadu, India 1 Assistant Proessor, Department o Mecatronics Engineering, SNS College o Tecnology, Tamilnadu, India ABSTACT: Seet metal orming is one o te most common metal orming processes. In Seet Metal industries accuracy plays a vital role. One o te major causes or te abrication o inconsistent seet metal part is springback wic is also deined as te recovery o elastic strain ater te tooling is expelled. Spring back o seet metal parts ater orming causes deviation rom te designed target sape and also produces downstream quality problems and assembly diiculties. So te crucial ting in te manuacturing is te problem o controlling springback eec. Te aim o tis project is to analysis and reduces te eect o springback in seet metal orming process o corrugated seets. First te inite element analysis (FEA) o corrugated seets is created using HYPEFOM by considering actor suc as material property, seet tickness, tooling geometry and process parameters. Here te numerical data wic is obtained rom inite element analysis are eed as te teacing data read or training te neural network by means o back propagation algoritm. Tus wit Artiicial Neural Network (ANN), te results o spring back eect or various combinations o seet tickness, material & punc orce are obtained and discussed. KEYWODS: Springback Eect, HyperForm, Corrugated Bending, Artiicial Neural Network. I. INTODUCTION Seet metal orming is te process to cange geometrical caracteristics o te seet metal witout removing te any material wen te orces applied on it. Te applied orce on te metal beyond its maximum yield point wic causes te material to deorm plastically but it couldn t be racture. During te bending operation inside o te neutral plane is compressed, wile te metal on te outside o te neutral plane is stretced. In bending process increase te strengt o te material. Te simple bending terminology igure 1 sown below. Seet metal orming processes include te processes like Bending, oll orming, Spinning, Deep Drawing and Stretc orming. Normally, Single bending operations are used in te industrial applications or analyzing springback eect in seet metal component. Te current trial-and-error metod o testing and controlling or springback eect is costly, time consuming, and remains as an obstacle in acieving sorter design production cycles wen compared wit corrugated bending operation. Te orming o seet metal into a drawing, corrugated alternate ridges and grooves wit a specially saped punc and die as sown in igure. A corrugated metal revetment is also made rom some type o roll ormed mill. Typically eavy-gauge steels like 16-gauge or 18-gauge can b used in te orming process. Figure 1 Bending Terminology Figure Corrugated Bending Copyrigt to IJISET DOI:1.1568/IJISET

2 International Journal o Innovative esearc in Science, Tereore, our present work ocuses on springback eect in corrugated bending operation. We use te same actors suc as seet tickness, punc radius, bend allowance, tooling geometry and process parameters. Tese actors are taken as input parameter or modeling in Hyper-orm and also analyzed te springback eect simulation in te same FEA tool. A. SPINGBACK EFFECT II. MATHEMATICAL MODELING OF SHEET METAL BENDING Springback is te dimensional cange o te ormed part ater te pressure o te orming tool as been released. Te elastic recovery is obtained as te results wen te strain is removed. Wen te load is released, te total strain is reduced owing to te elastic recovery. Te elastic recovery, and tereore te springback, will be greater te iger te yield stress, te lower te elastic modulus, and te greater te plastic strain. Hig strengt steels are te increased levels o springback due to te ig yield strengt o te steel and te variation in springback due to te material anisotropy. Hig strengt steels by deinition ave larger material yield stresses, require iger orces to orm parts and tend to be anisotropic in nature. Tese actors signiicantly aect te springback beavior o parts stamped rom tese steels. Springback control is one o te key concerns o te seet metal orming industry. Te current trial-and-error metod o testing and controlling or springback is costly, time consuming, and remains as an obstacle in acieving sorter design and production cycles. Furtermore, unavoidable variations in material and process parameters, wic lead to springback uncertainty, require active process control in order to produce consistent parts. During orming process, elastic stress gradients across te seet metal bending area builds up wic leads to accumulation o residual stresses. Due to te accumulation o residual stresses cause te material to return back some angle ater te load is removed. Ater te resultant deviations, te rework is needed or assembling te component into te proile, it require manual adjustment. Meanwile te components wic do not it in te inal assembly need to undergo te additional simming and assembly time. In tis paper, it clearly sows te set up procedure or perorming a springback analysis or adioss. Te part sape and stress and strain states at te end o a simple draw orming operation are te inputs to setup. Appropriate material and section properties are assigned to te blank component. Fixture constraints are applied to te part to eliminate rigid body modes. Springback is encountered in all orming process but it is most easily recognized and studied in bending. Te radius o curvature beore release o load is smaller tan te radius ater release o te load. But te bending allowance is same beore and ater bending. So B Tus te springback ratio (K s ), is given by, K s K s b Te springback ratio is deined in tis way is independent o seet tickness and depends only on te ratio o bend radius to seet tickness. Te springback in bending can be expressed by E E Copyrigt to IJISET DOI:1.1568/IJISET

3 International Journal o Innovative esearc in Science, B. PECENTAGE OF THINNING: Percentage o tinning is anoter one main parameter in te seet metal bending process. Ater te bending te tickness o te blank is canged. Te cange in tickness causes te racture and not comortable to use. Tinning (%) is as ollows C. DIE COMPENSATION: Were, t- Initial tickness t- Final tickness Die compensation is used to reduce te deviation o te stamped part rom its design target geometry as a result o springback. Te original die geometry is morped by applying a displacement ield in a direction opposite to te springback o te seet metal. Special care is taken to avoid creating undercuts to negative drats as a result o te compensation. Te compensation o die sown in igure 3 Figure 3 Die Compensation III. DESIGN & MODELLING Te Pro E model o punc and die is import in Hyperorm-adioss sotware. From te imported part, te reerence point is set. Based on te reerence point a new sell part is created. And te total part is mesed by using Hypermes as sown in te igure 4 as ollows A. HYPEFOM HyperForm is a unique inite element based seet metal orming simulation sotware solution. HyperForm combines an extremely ast one-step solver and incremental orming solution wit te customized geometry manipulation and mes generation capabilities o HyperMes. HyperForm provides engineers, at any stage o product design, wit quick, valuable, and reliable inormation, reducing te overall product cycle. HyperForm's die module takes a giant leap in bringing te product designer closer to manuacturing by enabling engineers to create and analyze conceptual die designs in order to generate an optimized die. Die concepts can ten be read into any CAD system as a starting block or te actual die build. Integrated wit HyperView, HyperForm can export data in H3D ormat allowing results to be visualized using HyperView Player wit any web browser. Copyrigt to IJISET DOI:1.1568/IJISET

4 International Journal o Innovative esearc in Science, HyperForm One-Step and incremental analyses are tigtly integrated wit Hyper Morp and Hyper Study, wic allows te optimization o orming tools and process parameters using a igly automated approac. B. ALTAI HYPEMESH Figure 4 Example Model or HyperForm & HyperMes Altair HyperMes is a ig-perormance inite-element pre-processor or popular inite-element solvers. It allows engineers to analyze product design perormance in a igly interactive and visual environment. HyperMes s user interace is easy to learn and supports a number o CAD geometry and inite-element model ile ormats, tereby increasing interoperability and eiciency. Advanced unctionality witin HyperMes allows users to eiciently manipulate geometry and mes igly complex models. Tese unctionalities include extensive mesing and model control, morping tecnology to update existing meses to new design proposals and automatic mid-surace generation or complex designs wit varying wall ticknesses. Solid geometry enances tetra-mesing and exa-mesing by reducing interactive modeling times, wile batc mesing enables large scale mesing o parts wit no manual clean-up and minimal user input. C. ADIOSS adioss is a state-o-te-art inite element solver uniting implicit and explicit integration scemes or te solution o a wide variety o engineering problems, rom linear statics and linear dynamics to complex nonlinear transient dynamics and mecanical systems. Tis robust, multidisciplinary solver enables designers to maximize perormance related to durability, NVH, cras, saety, manuacturability, and luid-structure interaction, in order to bring innovative products to market aster. Copyrigt to IJISET DOI:1.1568/IJISET

5 International Journal o Innovative esearc in Science, A. INPUT PAAMETES IV. SIMULATION Te blank is made o mild steel. Te material is modeled as an elastic-plastic material wit isotropic elasticity, using te Hill anisotropic yield criterion or te plasticity. Te parameter o Linear Material Properties and Non- Linear Material properties are as ollows TABLE 4.1 LINEA MATEIAL POPETIES BLANK (HSS) DIE, PUNCH & BINDE Young s Modulus 1 GPa Young s Modulus 1 GPa Poisson atio.3 Poisson atio.3 Density 78 kg/m3 Density 78 kg/m3 SHEET (ALUMINIUM) DIE & PUNCH Young s Modulus 7 GPa Young s Modulus 7 GPa Poisson atio.33 Poisson atio.33 Density 87 kg/m3 Density 87 kg/m3 TABLE 4. NON LINEA MATEIAL POPETIES BLANK (HSS) DIE, PUNCH & BINDE Strengt Co-eicient (k) 58 MPa Die & Binder igid Body constrained in all direction Strain ardening Component (n).3 Punc igid body Free to move in Y Direction SHEET (ALUMINIUM) DIE & PUNCH Strengt Co-eicient (k) 131 MPa Die igid Body constrained in all direction Strain ardening Component (n).65 Punc igid body Free to move in Y Direction B. SIMULATION USING PAAMETES HyperForm is a unique inite element based seet metal orming simulation sotware solution. HyperForm combines an extremely ast one-step solver and incremental orming solution wit te customized geometry manipulation and mes generation capabilities o HyperMes. HyperForm provides engineers, at any stage o product design, wit quick, valuable, and reliable inormation, reducing te overall product cycle. Hyper Form s die module takes a giant leap in bringing te product designer closer to manuacturing by enabling engineers to create and analyze conceptual die designs in order to generate an optimized die. Die concepts can ten be read into any CAD system as a starting block or te actual die build. Integrated wit HyperView, HyperForm can export data in H3D ormat allowing results to be visualized using HyperView Player wit any web browser. HyperForm One-Step and incremental analyses are tigtly integrated wit HyperMorp and HyperStudy, wic allows te optimization o orming tools and process parameters using a igly automated approac. From igure 4 and 5, percentage o tinning o te blank occurs at te lengt o te blank. Tis is obtained by applying te punc velocity o m/s. Copyrigt to IJISET DOI:1.1568/IJISET

6 International Journal o Innovative esearc in Science, Figure 5 Percentage o tinning at rame 9 Figure 6 Percentage o tinning at rame 1 From igure 7, te red mark represents te maximum stress distribution. Figure 7 Stress in 1t rame Te percentage o tinning o te material is low(minimum) and sows te maximum springback angle or te same punc velocity m/s as presented in igure 8 and 9. Figure 8 Springback Angle Figure 9 Magniied image o springback angle Copyrigt to IJISET DOI:1.1568/IJISET

7 International Journal o Innovative esearc in Science, Te springback can be reduced by increasing te punc velocity ranging rom m/s to 5 m/s. Te usage o binder acts as a support o te seet or blank. Tese binders can be used to decrease te stress distribution and also to reduce te springback. V. CONCLUSION Previous researcers ave concentrated only on springback eect using simple bending and te results are validated wit experimental and matematical calculations. Most o te industrial applications using corrugated seet metal bending. Te present work analyses te springback eect o corrugated bending using HYPEFOM- ADIOSS. It concludes tat, Spring back eect in corrugated bending canged wit varying tickness o te material. Te binders can be used to reduce springback eect and also elps to distribute te stress evenly EFEENCES [1] Garcia-omeu.M.L, Ciurana.J, Ferrer.I (7), Springback determination o seet metals in an air bending process based on an experimental work, Journal o Materials Processing Tecnology, Vol.191, pp [] Iab agai, Duraid Lazim, James A. Nemes (5), Anisotropy and springback in draw-bending o stainless steel 41 experimental and numerical study, Journal o Materials Processing Tecnology, Vol.166, pp [3] I-Nan Cou, Cingua Hung (1993), Finite element analysis and optimization on springback reduction, International Journal o Macine Tools & Manuacture, Vol.39, pp [4] Joacim.L, Grenestedt, Jack eany (7), Wrinkling o corrugated skin sandwic panels, Composites: Part A, Vol.38, pp [5] Jywen Wang, Suas Vermab, icard Alexander.B, Jenn-Terng Gauc (8), Springback control o seet metal air bending process, Journal o Manuacturing Processes, Vol.1, pp.1-7. [6] Kazeminezad.M, Hosseini.E (1), Optimum groove pressing die design to acieve desirable severely plastic deormed seets, Materials and Design, Vol.31, pp [7] Moon.Y.H, Kang.S.S, Co. J., Kim. T.G (3), Eect o tool temperature on te reduction o te springback o aluminum seets, Journal o Materials Processing Tecnology, Vol.13, pp [8] Ozgur tekaslan Ulvi Seker, Amet Ozdemir (6), Determining springback amount o steel seet metal as.5 mm tickness in bending dies, Materials and Design, Vol.7, pp [9] Panti.S.K, N. amakrisnan, Meraj Amed, Sambavi S. Sing, M.D. Goel (1), Finite Element Analysis o seet metal bending process to predict te springback, Materials and Design, Vol.31, pp [1] Sergei Alexandrov, Yeong-Maw Hwang (9), Te bending moment and springback in pure bending o anisotropic seets, International Journal o Solids and Structures, Vol.46, pp [11] Sirdel.A, Kaje.A, Mosksar.M.M (1), Experimental and inite element investigation o semi-constrained groove pressing process, Materials and Design, Vol.31, pp [1] Wei Gan, Wagoner..H (4), Die design metod or seet springback, International Journal o Mecanical Sciences, Vol.46, pp [13] Yang.Q, Gos.A.K (6), Production o ultraine-grain microstructure in Mg alloy by alternate biaxial reverse corrugation, Acta Materialia, Vol.54, pp [14] Zaer Tekiner (4), An experimental study on te examination o springback o seet metals wit several ticknesses and properties in bending dies, Journal o Materials Processing Tecnology, Vol.145, pp [15] ajinikant.v, Gaurav Arora, Narasaia.N, Venkateswarlu.K (8), Eect o repetitive corrugation and straigtening on al and al.5sc alloy, Materials Letters, Vol.6, pp Copyrigt to IJISET DOI:1.1568/IJISET