Numerical aspects of non-coaxial model implementations

作者：Yang Yunming^*; Yu Hai Sui

来源：Computers and Geotechnics, 2010, 37(1-2): 93-102.

DOI：10.1016/j.compgeo.2009.07.007

• Non-coaxial
• Constitutive models
• Numerical implementation
• Finite element method

This paper ascertains the reasons for the numerical problems when the yield vertex non-coaxial model is implemented in the finite element analysis to predict the behaviour of complicated geotechnical engineering problems. The numerical problem, reflected in the failure of convergence in the non-linear solutions in ABAQUS, is likely to happen when a smaller non-coaxial plastic modulus is used. It is found that a large non-coaxial influence at the start of elastoplastic loading, which causes the predominance of non-coaxial plastic strain rate over the coaxial plastic strain rate in stress-strain responses, is the reason for the numerical problem. The original yield vertex non-coaxial model is modified to overcome the numerical problem. instead of a constant non-coaxial plastic modulus in the original yield vertex non-coaxial model, the non-coaxial modulus is made a function of cumulative deviatoric plastic strain. It shows that the modified non-coaxial model retains the functions of the original non-coaxial model. Meanwhile, it overcomes the non-convergence problem when a smaller non-coaxial plastic modulus, representing a larger non-coaxial influence. is used.

• 出版日期2010-3