The paper presents the progressive failure analyses of composite laminate single bolt joints for three different laminate ply stacking sequences and four edge distances.Failure of composite bolted joint is a multiscale, multimode failure event. Designs and/or load cases that lead to competing failure in multiple modes can be more difficult to predict and can be used as test cases to study predictability of failure and the ability to capture the failure mode interactions. The goal of the analyses was to identify boltedjoint designs where the bearing failure mode and shear failure mode compete andcollaborate with each other. Progressive failure analyses performed uses the Hashin’s failure criteria to define onset of damage and an energy-based continuum damage model with a smeared crack representation for material stiffness degradation as function ofdamage. For short edge distances since shear stresses dominate a nonlinear materialmodel was used for the in-plane shear behavior. The progressive damage model was implemented as a user subroutine for explicit analysis (VUMAT) in ABAQUSTM finiteelement software. The model is validated from experimental pin bearing tests performedfor two different materials. The results indicate by varying edge distance to diameterratio and the proportion of 0, 45 and 90-degree plies in a laminates lead to design thatexhibit multi-mode failure with interaction in the failure modes and resulting load paths.These designs with multimode failure and interactive failure can be more useful tochoose for validation tests to assess accuracy of prediction models.
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