A Repair Criterion for Impacted Composite Structures Based on the Prediction of the Residual Compressive Strength

The residual strength in particular the compression strength after damages due to low velocity impact is one of the most critical issue for composite laminates. If the impact event induces relevant damages on composite components, a repair of the degraded parts is necessary. The aim of this work is to develop a repair criterion to be applied on the composite structures of the European launch vehicle VEGA. The criterion is based on a numerical procedure which was validated in a previous research work and which allows to predict the impact damage and the post impact residual strength as function of the impact energy, making possible to determine the energy threshold beyond which it is necessary to repair the component.