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在大多数动态金属成形工序中,大量非线性变形过程引起坯料中产生大量的弹性应变能。坯料和模具动态接触过程中积累的弹性能在成形载荷消失以后释放,此能量释放就是弹性回弹的驱动力,驱使坯料向着原有几何形状回弹或变形。因此,在板料的成形过程中最后形状不仅仅取决于模具的轮廓形状,也取决于坯料部分在苏醒变形时存储的在其中的弹性能总量。而对于模具设计者则要求其必须准确地估计成型过程中将产生的回弹量,才能正确地估算出最终的形状。但在变形过程中积累的弹性能总量是众多过程参数(如载荷,材料参数)的函数,故如用传统的方法很难预测回弹变形,从而使得板料成形模具设计带来许多问题和挑战。利用ANSYS/LS-DYNA的非线性动力有限元程序的显式隐式连续求解功能,能有效地解决上述问题,模拟板料成形过程与卸载后板料回弹变形的全过程,得到成形过程中任一时刻各处的应力和应变值及卸载后板料的回弹结果。
In most dynamic metal forming processes, a large number of nonlinear deformation processes cause a large amount of elastic strain energy in the blank. The elastic energy accumulated during the dynamic contact between the billet and the mold is released after the forming load disappears. This energy release is the driving force for the elastic rebound, which causes the billet to rebound or deform to the original geometry. The final shape during the forming of the sheet therefore depends not only on the contour shape of the mold but also on the total amount of elastic energy stored in the blank portion upon waking deformation. For mold designers, they have to accurately estimate the amount of springback that will be generated during the forming process in order to correctly estimate the final shape. However, the total amount of elastic energy accumulated in the deformation process is a function of a large number of process parameters (such as load and material parameters). Therefore, it is difficult to predict springback deformation by the conventional method, which brings about many problems in sheet metal mold design challenge. The explicit implicit continuous solution function of ANSYS / LS-DYNA nonlinear dynamic finite element program can effectively solve the above problems, simulate the whole process of sheet metal forming process and unloading rebound deformation, get the forming process The stress and strain values everywhere at any one time, and the rebound results of the unloaded sheets.