A review on analytical failure criteria for composite materials

Fiber-reinforced composite materials have found increasing industrial applications in the last decades, especially in the aerospace and ground transport fields, due to their high specific strength. However, even though this property allows having a lightweight and strong structure, some critical aspects still limit their use. Most of these depend on several types of undetectable defects and damages, which could affect the residual strength of the composite structures. The paper deals with failure mechanisms involving composite materials under several critic loading conditions, with the aim to assess the limits of currently used failure criteria for composite materials and to show the actual request of developing new failure criteria in order to increase the effectiveness of current design practices. Nowadays, such design practice is based on a damage tolerance philosophy, which allows a structure to tolerate the presence of damages during its in service life, only if the residual strength is kept higher than specific threshold values depending on the damage severity. Hence, the main goal of such paper is to assess the failure criteria's capability to predict the life of composite components under several quasi-static and dynamic loading conditions. Intra-laminar and inter-laminar failure criteria have been investigated and considerations have been provided about the possibility to model the post-failure phase and to implement them within numerical predictive tools, based on finite element method.