在abaqus的用户手册里只说了:Abaqus/Explicit offers distortion control to prevent solid elements from inverting or distorting excessively for these cases. The constraint method used in Abaqus/Explicit prevents each node on an element from punching inward toward the center of the element past a point where the element would become non-convex. Constraints are enforced by using a penalty approach, and you can control the associated distortion length ratio.并没给出具体的公式和方案，请问关于这里的罚函数法避免单元畸变有相关的参考文献吗