Predictive modeling of an energy-absorbing sandwich structural concept using the building block approach

An energy-absorbing composite sandwich structural concept, comprised of a deep honeycomb core with carbon/epoxy facesheets, is subject to through-thickness crushing and penetration using a cylindrical pole. With the aid of the building block approach, the response of the structure is predicted by analysis supported by test evidence. Experiments are conducted at various levels of complexity, from the coupon level used to generate material properties to be used as input in the finite element models, through the element level used to calibrate the analysis models, and up to the component level to validate them. LS-DYNA is used to perform the analyses, including material models MAT 54 for the facesheets, MAT 126 for the honeycomb, and tie-break contact for the adhesive. Material models and contact formulations require extensive calibration of modeling parameters at the lower and intermediate levels of the building block pyramid, but eventually enable the prediction of the full-scale structure.