Estimation for probabilistic distribution of residual strength of sandwich structure with impact-induced damage

A new approach was developed to estimate the probabilistic distribution of the residual strength of honeycomb sandwich structures subjected to impact-induced damage. The model was derived from the assumption that the residual strength is a function of the static strength of the unimpacted sandwich structures and the impact damage of the impacted structures. The probabilistic distribution of the residual strength was calculated from the probabilistic properties (mean and variance) of the strength of the unimpacted laminates and the impact damage at a given impact energy. The model was experimentally verified by using an experimental program for a Nomex® honeycomb core sandwich structure. The experimental program included a series of impact and three-point flexural tests to generate the residual strength of a sandwich structure. Theoretical predictions on the probabilistic distribution were in conformance with the experimental results.