Boolean fragment operation was used to develop a simple three-dimensional block-cutting technique. The hexahedral grid that covers the whole solution domain was generated

and then each hexahedron was divided into 48 tetrahedrons to produce the mathematical cover. Each tetrahedron unit was intersected with the solution domain using the Boolean intersection operation to generate the manifold block. Based on the oriented theory of topology and the three-dimensional simplex integration theory

four kinds of oriented geometry data structure including oriented edge

oriented wire

oriented face and oriented shell

were generated in each manifold block to construct enclosed and oriented three-dimensional manifold elements. The concepts of connected inner face pair and connected oriented manifold element were proposed

and then the physical covers were generated by searching the connected inner face pair of the oriented manifold elements. Furthermore

the key points for calculation of the modified symmetric and anti-symmetric decomposition-based three-dimensional numerical manifold method were summarized. A simulation on the tension process of finite plastic deformation on three-dimensional joints was performed without the consideration of three- dimensional contact

crack propagation and singular field at crack tips. Reasonable numerical simulation results were obtained

which justified the validation of the pre-processing module and calculation algorithm.