板料V形弯曲回弹的动力显式有限元分析

Dynamic explicit finite element analysis of springback of sheet V-bend i ng

板料成形后的回弹对精度影响较大,在数值模拟时对回弹进行精确预测显得非常重要.基于连续介质力学及有限变形理论,建立了适合于三维板料成形分析的显式算法的有限元数学模型,采取集中质量矩阵,用动力显式积分的方法,使位移计算显式化,避免了由材料、几何、边界条件等高度非线性因素引起的计算收敛问题.根据该模型开发了动力显式算法的板料成形过程模拟的有限元分析程序DESSFORM3D,应用该软件模拟了包括回弹在内的整个板料V形弯曲的成形过程.通过3个不同凸模行程时计算与实验的板料几何形状对比以及计算结果与实验结果对比,验证了软件计算结果的准确性.

Springback o f plates after forming greatly affects its precision.So it appeas to be very im portant to have a precision forecast of the resilience in numerical simulation .Based on the continuum mechanics and finite deformation theory,a dynamic expl icit finite element model for simulating the three dimensional sheet forming pr ocess has been established.In integration,the dynamic explicit algorithm has b een used with the lumped mass matrix so that it facilitates the calculation of t he displacement and avoids the convergence caused by the nonlin-earity in mate rial,geometry and boundary conditions.A finite element analysis program DESSF ORM3D for the simulation of sheet forming process using dynamic explicit integr ation has been developed.The entire forming process of sheet V-bending includi ng springback has been simulated.By comparison between experimental and calcul ated sheet geometries and results for three different punch travels,the accura cy of the calculated results of the program is verified.