| 
													     		                            						                            																	    Abstract  The generations of three-dimensional manifold element and contact detection algorithm are the bottleneck problems that restrict the development of three-dimensional numerical manifold method. The generation of three- dimensional manifold element is studied. Based on previous works,the authors build mathematical cover system by three-dimensional finite element mesh generation technology,and develop three-dimensional block-cut technology into manifold cut technology for the formation of three-dimensional manifold element. Through the improvement of block data structure and block recognition algorithm,the authors extend coding algorithm of physical cover system by Dr. SHI Genhua from two-dimensional to three-dimensional;and then the generation of three- dimensional manifold element is achieved. And on this basis,the authors develop a three-dimensional manifold cutting program 3D_MC.f90;it can generate an arbitrary three-dimensional manifold element under tetrahedral and hexahedral mesh covers. As can be seen through several examples,manifold block shape and coding algorithm of node and element by three-dimensional manifolds procedure can meet the definition requirements of three-dimensional manifold element. It is proven that this algorithm is correct from the view of manifold cut.
																										     | 
														 
														
														
															| 
															    																	Received: 23 October 2009
																	    
															    															    															    															 | 
														 
														 																											    																														 
															 | 
															
																
															 | 
													    	
															 |