Initial stress equation for high-order numerical manifold method
Received:September 19, 2008  
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DOI:10.7511/jslx20102015
KeyWord:numerical manifold method (NMM)  high order polynomial cover functions  large deformation  initial stress  simplex integration
        
AuthorInstitution
苏海东 长江科学院 材料与结构研究所 武汉;长江科学院 非连续变形分析实验室,武汉
崔建华 长江科学院 材料与结构研究所 武汉;武汉大学 水利水电学院,武汉
谢小玲 长江科学院 材料与结构研究所 武汉
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Abstract:
      With high-order Numerical Manifold Method (NMM) or high-order Discontinuous Deformation Analysis (DDA) method, computational accuracy of structure deformation can be improved greatly. However, poor accuracy was obtained and even computation was not convergent while treating geometric nonlinear problems, due to inaccurate or incorrect high-order initial stress equation. Based on 2-D triangular mathematical meshes and polynomial cover functions, two methods are presented in this paper to solve the initial stress problems in high-order NMM. Exact equation for high-order initial stress is derived for the first time, reflecting configuration change of structures under large deformations when accumulating initial stresses at each step. The equation is expressed in polynomial form so as to be used in simplex integrations. Comparing with analytical solutions, good results for large deformation of a cantilever prove the validity of the equation. The methods can also take effect with 3-D tetrahedral mathematical meshes, and can be applied in high-order DDA or regular FEM after some modifications in the future.