Rapid simulation of impacts on composite sandwich panels inducing barely visible damage

The finite element based design tool, CODAC, has been developed for efficiently simulating the impact behavior of sandwich structures consisting of two composite face sheets and a compliant core. To achieve a rapid and accurate stress analysis, three-layered finite shell elements are used. A number of macromechanical damage models are implemented to model damage onset and damage growth.The transient impact analysis is assessed via an experimental impact test program on honeycomb sandwich panels. Force–time histories and damage sizes are examined. The influence of distinct damage and degradation models on the impact response is analyzed. Results show that the presented time-efficient methodology is capable of accurately modeling core failure behavior and rapidly simulating low-velocity impacts which induce barely visible damage.