The material structure of laminated vibration damping steel sheet(LVDSS) was introduced in detail. An interface cohesive model between the skin sheets was developed by using a contact/interface approach, and the model was applied to simulate “T”-peel and lap-shear processes of LVDSS. The interface contact stress distribution during the “T”-peel and lap-shear processes is obtained, and the finite element analysis(FEA) results agree satisfactorily with the corresponding experimental results. As a result, the model is suitable to simulate the cohesive of
During stamping process, the material properties, process design parameters and production environments inevitably have variation and noisy factors, which possibly affect the sheet metal formability and the deformation of the die structure.After gaining a success in applying sheet metal forming numerical simulation analysis to get the forming loads during stamping process, a methodology of die structure analysis based on sheet metal forming simulation was proposed and validated by experiments.Based on these results, the effect related with initial blank thickness, blank holder force, blank positioning error and die alignment error variations to a DP600 hyperbolic bottomed cup drawing die's forming loads(especially unbalanced loads), and deformation and stress was studied numerically.The influence level of these variations to the die's forming loads, deformation and stress was disclosed.The findings can guide die design, die tryout and process control for high-strength steel(HSS) stamping with increased forming load and decreased sheet metal formability.
研究了基于形变理论的板料成形一步模拟法(又称为反算法).采用由CST(ConstantStrain T riangu lar)薄膜单元和DKT 6(D iscrete K irchhoff T riangu lar)板单元组合而成的DKT 12壳单元,既可以考虑面内薄膜力的作用,也可以叠加弯曲效应对单元的影响.引入Barlat提出的6个应变率分量表示的塑性势函数,可以更好地描述板料面内各向异性.用弧长展开法获得初始解,并利用反向变形法对其进行改进,增强了求解的稳定性,提高了计算精度.盒形件的拉深实例证明,该改进的方法可以更为有效地模拟实际变形情况,分析结果具有较高的可信度.
