LS-DYNA MAT54 modeling of the axial crushing of a composite tape sinusoidal specimen

The suitability of a progressive failure material model to simulate the quasi-static crushing of a composite specimen is evaluated. The commercially available material model MAT54 “Enhanced Composite Damage” in LS-DYNA is often utilized to simulate damage progression in dynamic failure simulations because it requires a reduced number of experimental input parameters compared to damage mechanics-based material models. The composite specimen used for the experiments is a semi-circular sinusoid, and is comprised of carbon fiber/epoxy unidirectional prepreg tape. Results show that MAT54 can successfully reproduce experimental results, however the simulation is highly sensitive to changes in model parameters, which are either non-physical (i.e. are purely mathematical expedients), or cannot be measured experimentally. These include element size, contact definition, load–penetration curve, and crush front softening parameter, among others. Therefore, achieving successful simulation results requires extensive calibration of these parameters by trial and error, and a deep understanding of the strengths and challenges of the selected modeling strategy.