On the robustness of the stabilized finite element method for delamination analysis of composites using cohesive elements

Abstract

We demonstrate the ability of a stabilized finite element method, inspired by the weighted Nitsche approach, to alleviate spurious traction oscillations at interlaminar interfaces during composite delamination. The method allows for the use of any value for the cohesive stiffness and obviates the need for ad hoc approaches to estimate the minimum penalty stiffness for accurate analysis. Simulation studies involving constant strain patch tests and benchmark delamination tests under mode-I, mode-II, and mixed-mode loadings show evidence of traction oscillations with the standard method. In contrast, the stabilized method is able to alleviate traction oscillations, which illustrates its efficacy and robustness.

Keywords:

• Nitsche method
• mixed-mode delamination
• traction oscillations
• numerical stability
• cohesive zone model

Acknowledgements

We thank Prof. Caglar Oskay at Vanderbilt University for his helpful comments on composite delamination analysis.

Additional information

Funding

GG and RD gratefully acknowledge the financial support of the Office of Naval Research – award#N0014-17-12040 (Program Officer: Mr. William Nickerson). CA would like to gratefully acknowledge the funding received through the New Faculty Initiation Grant (NFIG) # CE1920699NFIG 008957 at Indian Institute of Technology Madras.