整体壁板压展模具型面曲率半径的计算

Obtaining of Tool Surface Curvature Radius for Bending and Flattening Integral Panel

目的研究带有初始曲率的整体壁板在压展过程中的变形回弹规律,以确定压展模具的型面曲率半径。方法针对壁板压展回弹过程,用初始、加载和卸载3个典型状态来描述材料在截面圆周方向上的变形情况,推导应变和应力分布规律以及卸载后的力学平衡条件,从而得到壁板初始曲率半径、加载曲率半径以及卸载回弹后曲率半径之间的关系。再利用有限元仿真和试验,对理论推导的结果进行验证。结果通过数值计算,对比了理论计算中采用不同材料模型所得到的结果,表明材料模型的准确性对计算结果有较大的影响。得到了给定回弹后曲率半径情况下初始曲率半径与加载曲率半径之间的数值关系,以及给定初始曲率半径情况下加载曲率半径与回弹后曲率半径之间的数值关系,有限元仿真和试验结果验证了后者的准确性。结论通过对整体壁板压展过程进行理论推导,得到的结果能够较准确地描述曲率半径的变化规律,可作为压展模具型面设计的依据。

The work aims to study the deformation and springback rule of integral panel with initial curvature during bend-ing and flattening process to determine the curvature radius of tool surface.The deformation of material in the circumferential direction of section was described in three states of initial,loading and unloading.The distributions of strain and stress and the equilibrium conditions after unloading were deduced to obtain the relationship among the initial curvature radius,loading cur-vature radius and the springback curvature radius after unloading.Then,finite element simulation and experiment were con-ducted to verify the deduced result.In addition,the comparison of analytical results with different material models by numerical calculation showed that the accuracy of the material model had a certain impact on the calculation results.The numerical rela-tionship between the initial curvature radius and the loading curvature radius for a given springback curvature radius,and the numerical relationship between the loading curvature radius and the springback curvature radius for a given initial curvature ra-dius were obtained.The accuracy of the latter was verified by finite element simulation and results.The results obtained through theoretical derivation of bending and flattening process of integral panel are accurate enough to describe the variation law of the curvature radius,which can be used as the basis when design the tool surface.