剪裁CAD冲压件的一步逆等几何分析方法

One-step inverse isogeometric analysis method for trimmed CAD stamping parts

提出一种可以直接分析剪裁CAD冲压件的一步逆等几何分析方法,在求解剪裁交点的基础上,对剪裁单元分类和重构,采用一步逆初始解算法对NURBS模型的控制网格进行展开,得到剪裁后NURBS模型的初始解。根据初始解得到的初始构型和原本的最终构型构建非线性平衡方程,采用Newton-Raphson迭代算法得到最终构型的厚度、等效应力、应变等物理量的分布。典型算例验证基于剪裁NURBS曲面的一步逆等几何分析方法的正确性和准确性。

A one-step inverse isogeometric analysis method is proposed, which can directly analyze the trimmed CAD stamping parts. On the basis of solving the trimmed intersection, the trimmed units are classified and reconstructed, and the one-step inverse initial solution algorithm is used to expand the control mesh of NURBS model to obtain the initial solution of trimmed NURBS model. The nonlinear equilibrium equation is constructed according to the initial configuration obtained from the initial solution and the original final configuration. The distribution of physical quantities, such as thickness, equivalent stress and strain of the final configuration, are obtained by Newton-Raphson iterative algorithm. The correctness and accuracy of the one-step inverse isogeometric analysis based on trimmed NURBS surface is verified by typical examples.