M.Sc. Tezi Görüntüleme | |||||||||||||||||||||
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| Summary: In this thesis, the effects forming process data on the quasi-static and dynamic impact responses of beam like structures under axial loading were investigated by finite element method. In particular, the effects of plastic strains, thickness reductions and residual stresses due to deep drawing process on the energy absorption and deformation response of a frame having a simple hat profile and spot welded flat lid were examined. In these analyses, two different meshes were used. One was the deformed mesh coming from the forming and springback analysis , the other was created by transferring the final state data after the forming process on to a frame with the nominal cross sectional dimensions.During deep drawing process, different residual forming effects were created by changing the blank holder force The forming process causes significant changes in material strength, thickness and the final geometry of the structure. The plastic strains produced in the material during the forming process causes a stiffer response of the structure by giving rise to deformation hardening. However, the reduction in the thickness due to the same process weakens the structure. Consideration of all the data obtained from the forming process leads to the forming of a structure which exhibits more resistance against deformation.The analyses carried out by the mesh based upon the nominal geometric data showed that the magnitude of the blank holder force may have a considerable influence on the crash performance Key Words: Finite Element Method, LS-DYNA, Dynamic Crash, Static Crash, Residual Forming Effects, Deep Drawing Process, Springback, Mesh Coarsening, Energy Absorber, Implicit Method, Explicit Method | |||||||||||||||||||||