Prediction of residual burst strength for composite pressure vessels after low velocity impact

Composite pressure vessels have been widely used for high-pressure hydrogen storage. This paper aims to study the residual burst strength of composite pressure vessels after low velocity impact. An explicit-implicit combined model using strain-based three-dimensional failure theory is employed for numerical analysis, which is implemented by ABAQUS user-defined subroutines VUAMT, UMAT and ABAQUS-Python scripting language. Impacted-induced damage including the intralaminar fiber and matrix damage, and interface delamination is directly imported to the residual strength analysis to explore the whole-process damage mechanisms by using current model. For composite pressure vessels, the mechanical responses and damage behaviors of intralaminar damage and interface delamination at six impact energy are explored. After impact, the damage evolution under internal pressure for vessels is discussed. By comparison, the numerical results are basically consistent with experimental results. Besides, the effects of impact direction of strip impactor and liner type on the low velocity impact responses and residual burst strength are explored. By studying the influence of impact energy, liner type and impact direction systematically, it shows that fiber damage on the hoop layers caused by impact load can reduce the residual burst strength for current composite pressure vessels.