适用于GJK-EPA的复杂单元间接触类型判别方法OA

To overcome the limitations of the coupled Gilbert-Johnson-Keerthi(GJK)and expanding polytope algorithm(EPA)in classifying contact types for complex-shaped elements,this study proposes an improved contact classification method.By introducing the concept of a contact reference plane,the contact classification problem between complex-shaped elements is simplified to determining the relationship between each element and the reference plane.Built on this approach,a natural packing simulation algorithm for complex-shaped elements is established under the discrete element framework,and the corresponding implementation code is developed.The theoretical foundation of the proposed method is analyzed through two representative contact cases,followed by packing simulation experiments involving polyhedral and cylindrical elements.The research results show that the proposed algorithm can accurately simulate the packing process of complex-shaped elements.Compared with the improved common-plane method and the GJK-EPA method,the improved GJK-EPA method produces smoother packing contours and more compact element arrangements,demonstrating superior simulation performance.In comparison to the traditional GJK-EPA method,the improved algorithm enhances the computational accuracy of packing simulations for cylindrical and polyhedral elements by 8.4%and 24.8%,respectively,validating the applicability and advanced nature of the proposed algorithm.