Abstract：Fast and efficient contact detection algorithm is one of the most important key techniques to control computational efficiency in 3D discontinuous analysis such as the distinct element method. Based on direct contact detection method，field-decomposition，circumscribed-sphere detection，visibility and post-round are induced to develop a new contact detection algorithm for 3D convex polyhedron：Herein，the fundamental principle of the contact detection algorithm is described；and the methods to identify the neighboring block and to define the contact types and contact direction are analyzed. The algorithm is then applied to analyze the colliding process of a pair of columns subjected to impact loading. The result demonstrates that the contact detection algorithm is less cost，robust and apt to be realized.
