基于实体单元的板材渐进成形数值模拟分析

Numerical simulation of the sheet metal incremental forming process using solid elements

为研究渐进成形的成形机理及工艺参数对成形力的影响,应用三维实体单元对成形过程进行数值模拟分析和相应的实验研究.在解决数值模拟中运动轨迹加载等难点问题的基础上,合理简化有限元分析模型,提高数值模拟计算效率.采用坐标网格法实验,并通过检测板材厚度的变化,验证了模拟结果的准确性.通过对模拟和实验结果的研究分析,提出了一种不同于剪切变形的新的变形机理,即主要变形区的板材是平面内拉伸变形及局部反向弯曲变形的组合;对成形力的数值模拟正交实验表明层间距是成形力的主要影响因素,并且成形力随层间距的减小而减小.

The incremental forming process was numerically simulated by three-dimenslon solid elements to study the deformation pattern and the impact of process parameters on forming force. The appropriate simplified finite element method model was established by solving the key problems as trajectories dynamic loading etc. Through coordinate grid method experiment and the detection of the wall thickness variation, the simulation results are agreed with the experiments. A new deformation pattern of sheet metal incremental forming different of the shear-dominant model is proposed, which is the combination of plane-stretching and reversed bending. The orthogonal simulation tests of forming force show that the interlayer spacing is a dominant factor and with the interlayer spacing reducing the forming force reduces.