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Woven polymer-based composites exhibit highly non-linear behavior, which often results in very high strains to failure. A micromechanical model is developed to represent the large deformation kinematics of woven composites, and develop predictions for failure strain components in specific cases of multiaxial loading. Failure functions are proposed for macromechanical analyses of arbitrary cases of large deformation loading. The approach is validated against basic tension experiments performed using both digital image correlation and with specially designed instrumentation for large strain measurement. Predicted failure strains correspond well with experimental observations. The proposed failure functions are well suited for finite element applications involving user-defined material models.

Abstract: A progressive failure approach, applicable to woven polymer-based composites is developed and validated with experiments. Constitutive equations are formulated to characterize the mechanical response for fully non-linear, rate dependent, anisotropic behavior under dynamic loading. A mechanistic fiber failure theory is implemented, while a degradation model describes the stiffness reductions after failure. The approach is implemented in the Abaqus finite element code using a user material subroutine (UMAT) that defines the constitutive theory and implements the progressive failure methodology. The progressive failure approach is validated using basic tension and open hole tension experiments. The tests are performed using digital image correlation, which provides the complete non-uniform strain and displacement fields. The validation testing has included cases involving large deformations, where strains to failure are as high as 20%. The simulation results are in good agreement with experimental data. [Copyright &y& Elsevier]