Static progressive damage finite element analysis of a certain type of composite pressure vessel

In addressing the issue of continuous damage evolution and failure prediction in composite pressure vessels, this paper combines the three-dimensional Hashin criterion with the equivalent displacement method to develop a static damage identification and progressive evolution model capable of accurately simulating material stiffness degradation under complex loading conditions. To validate the proposed model, carbon fiber/epoxy composite pressure vessels were used as the research subject. The UMAT subroutine, coupled with the Wound Composite Model (WCM) plugin, was employed to transform the principal material properties into off-axis properties and to establish the static damage identification and progressive evolution model for composite pressure vessels. Simulation results indicate that the vessel enters an initial damage state at an internal pressure of 62 MPa, with damage continuously evolving as the internal pressure increases, ultimately resulting in complete failure at 73.4 MPa. This model effectively simulates the entire process of damage initiation, propagation, and ultimate failure under internal pressure loading.