Verification of Quarter-step Exponential Map Method for Integration of Von-Mises Plasticity

Document Type : Original Article

Authors

• Nader Haji Aghajanpour1
• Mehrzad Sharifian
• Mehrdad Sharifian

Quchan University of Technology

10.22067/fum-mech.v30i1.64973

Abstract

Updating stress in a nonlinear finite element analysis is the most important part as the precision of the stress-updating algorithm greatly affects the accuracy of the final solutions.The most important part of the analysis is the stress-updating. There are two key factors that have impact on the efficiency evaluation; those are the accuracy and time. Based on this point, investigating the accuracy of the integration methods becomes important. In this study, the von-Mises plasticity model along with the linear isotropic and kinematic hardening mechanisms is considered in the small strain realm. In solving the plasticity differential equations system through a semi-implicit method, the prevalent approach is picking up the variables from the middle of the plasticity step. In order to assess the accuracy, here, the relations are derived so that one can pick up the variables from the first quarter of the plasticity step. Finally, to determine the accuracy and comparing two aforementioned methods, the numerical tests are performed.

Keywords

• Stress updating
• semi-implicit method
• von-Mises plasticity
• isotropic hardening
• kinematic hardening

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