Energy-Based Stiffness Degradation for Alleviation of Mesh Sensitivity for Progressive Failure Analysis of Center-Notched Composite Panels

Minguet, P.J., Karayev, K.Z., Balabanov, V., Lee, S., Muraliraj, N., Walker, T.H., Nelson, E.E., Robbins, D.

AIAA 2012-1620, 53rd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, Honolulu, Hawaii, 23 – 26 Apr 2012.

The residual strength of unstiffened notched composite panels was evaluated using the ABAQUS/Standard finite element code enhanced with the Helius:MCT™ multiscale progressive failure analysis add-on software. One of traditional drawbacks of performing progressive failure analysis (PFA) with the finite element method is that the predicted results can be sensitive to the size of the elements used in the simulation. Typically, PFA requires two key components: a set of failure criteria that determines when each particular failure mode initiates, and a damage evolution algorithm that directly controls the rate of stiffness degradation and indirectly controls the local load redistribution process. In this paper, the performance of Helius:MCT’s new energy-based material degradation model is investigated and shown to be successful in alleviating mesh dependency of the predicted progressive failure response of a number of different tensile loaded laminates containing various notches and holes. The availability of such a material model circumvents the need for the analyst to calibrate all model parameters to a specific fixed mesh.