Evaluation of crack propagation at CFRP/Al interface in composite pressure vessels subjected to temperature change

Abstract

The conditions of crack propagation and propagation behavior of composite pressure vessels with artificial defects at the CFRP/Al interface were evaluated when subjected to temperature changes. The prototype vessels with artificial cracks introduced by wrapping Teflon tapes on Al liners were made, and experiments were conducted to cool the inside wall of vessels. During the experiments, strain gauges and thermocouples were attached to the vessels to measure changes in strain and temperature. In addition, a crack propagation analysis for models of vessels with interface cracks was performed using the finite element method under the same conditions as in the experiments. In the experiments, some sudden changes in strains occurred while cooling. In analysis, some sudden changes in strains like that observed in the experiments occurred when cracks grew. The changes differed depending on the positions between crack tips and measurement points. Therefore, these changes can be used to evaluate the amount of interfacial crack propagation in the vessels.-