Progressive damage analysis of a rate-dependent hybrid composite beam

A hybrid beam combined of a molded woven fabric beam and over injected or compressive molded short fiber composite material, are manufactured and three point bending tests with different loading rates and two different boundary conditions are performed. Since the experimental results demonstrate a rate dependent behavior of the beam, then to predict its mechanical behavior under different loading velocities two strain rate sensitive progressive damage models have been developed based on Continuum Damage Mechanics approach. For internal reinforcing constituent of the beam which dominated by matrix, the matrix failure index of Hashin-Rotem's failure criterion was chosen and for outer part which governed by fibers the maximum stress theory is considered as damage initiation indicator. For both models Lapczyk-Hurtado's approach is followed to capture damage propagation. To account for rate-dependent material properties, where is needed, equations derived from a logarithmic formula, are utilized. The models are applied on the commercial finite element software of ABAQUS using user-written subroutine based on explicit numerical method. The numerical results are verified by the bending tests and it is shown that the numerical results of the proposed models have shown better agreement with experimental results of compressive molding technology than back injected one.