To optimize the process parameters, it is necessary to exactly predict failure modes during deep drawing of coated metal sheets, where two main failure forms are fracture and wrinkling. In this paper, finite element simulations based on continuous damage mechanics were used to study the failure behavior during a cylindrical deep drawing of metal sheets with nickel coating. It is shown that taking the effect of blank holder force into account, these two failure modes can be predicted. The simulation results are well consistent with that obtained from experiments.
In this paper,mechanical properties of Nickel film under residual stress have been systematically examined by finite element method in nanoindentation.It was found that load-displacement curves shifted under elastic residual stress and residual stress exceeded the yield stress for fixed indentation depth.Indentation profiles changed monotonously with compressive and tensile stresses at peak force which determinates contact area observed directly by finite element modeling （FEM）.The elastic residual stress has an effect slightly on the hardness but residual stress exceeded the yield stress shows a remarkable effect in nickel film.The hardness increased when residual stress exceeded the yield stress increased under tensile and compressive stress applied to specimen.The relationship between residual stress and hardness was linear.It was found that residual stresses didn＇t affect elastic modulus whether elastic residual stress or plastic stress was applied to specimen.
Lizeng Ling,Shiguo Long,Zengsheng Ma and Xu Liang Key Laboratory of Low Dimensional Materials and Application Technology of Ministry of Education,and Faculty of Materials,Optoelectronics and Physics,Xiangtan University,Xiangtan 411105,China
