Modeling Energy Absorption with a Damage Mechanics Based Composite Material Model

The Matzenmiller—Lubliner—Taylor (MLT) model, a continuum damage mechanics (CDM) based model, was used in modeling energy absorption of composite structures in crashworthiness applications. It was found that the assumption of linear elastic unloading and reloading in MLT model resulted in a lower calculated energy absorption in thin wall composite tube axial crush simulations. A modification to compressive unloading was proposed and tested in an MLT-based user material model. The modified model improved the stability of the tube crush simulation and the simulation results. This study demonstrates the importance of properly representing the unloading response of damaged composites in energy absorption prediction.