Numerical Simulation Of Structural Damage Of Fiber Reinforced Composites

Carbon fiber reinforced plastic (CFRP) composite structure is widely used in the field of weapon. The most typical structure is the gun barrel. When the gun is fired, the tube is easy to damage due to its own defects under the high pressure. It may cause immeasurable loss. The article with the typical structure of composite material barrel, which is the composite thick cylinder with metal liner and composite outer wrapped, as the object of the research, is based on the latest achievements of the research of the composite materials structure, by dint of the efficient calculation methods, conducts a basic research about the damage problem of CFRP thick cylinder, and provides strong theoretical support for composite materials in the application of gun tube.Two calculation methods which is the finite element method and the extended finite element method are used to study the influence factors of CFRP thick cylinder damage and cracking. The contents and conclusions of the article are embodied in the following aspects:(1) The user subroutine of the finite element software is shown to study CFRP thick cylinder structure damage. The impact of stacking sequence and boundary conditions on the initial damage load, damage modes, and damage propagation are considered. Numerical simulation results show that the composite layer of CFRP thick cylinder structure has the matrix damage, the fiber damage, and the shear damage. The different lay ways with fiber distribution angle influence the initial loading and the final damage form of CFRP thick cylinder structure.(2) Based on the extended finite element method, the crack propagation of CFRP thick cylinder structure is considered. The effective of the presented method is shown by the SIFs of the flat and the metal material thick cylinder. The crack propagation trend of CFRP thick cylinder with the different factors is discussed. Numerical results:the increase of the crack length, the load, and the decrease of wall thickness lead to the structure failure. Comparisons of SIFs among the metal material cylinder, the composite cylinder and CFRP thick cylinder show that CFRP thick cylinder is less likely to crack. The crack propagation trend of CFRP thick cylinder is influenced by the initial crack angle under the pressure load.