Analysis of Mechanical Properties of Carbon Fiber Reinforced Composite Laminate and Its Experimental Validation

Abstract

Fiber-reinforced composites have excellent mechanical properties, like high specific strength and specific modulus, etc. Laminates made from a combination of single-layer materials have a wide range of applications in aerospace transmission components because of the ability to meet the design requirement of lightweight. Conventional strength theories tend to predict laminates strength by establishing strength criterion from tensile, compression and shear strengths obtained from unidirectional slab tests. However, due to the significant anisotropy of the composites, in-situ effects indicate that sublayers of the same thickness and layup angle exhibit different matrix strengths in unidirectional slabs and in laminates, which resulting in errors of laminates strength between calculated and tested values. Moreover, it is costly and complex to test the laminates for each lay-up option to obtain its strength parameters. In response to the above issues, T800/WC502 material laminate with lay-up method of [0/45/90/-45/0]7 which is for the use of aero-engine case, was taken as an example to analyze the mechanical properties. The impact of in-situ effect was taken into account when establishing strength criterion. The mechanical properties and strength of this laminate were analyzed using macro-mechanical methods and finite element methods. Then the laminate was subjected to tensile tests in accordance with the test standards. Results of finite element analysis (FEA) were compared with the test data to analyze the accuracy of calculation. The results show that the FEA results have less error with the test data after taking into account the in-situ strength. This method provides a reference for subsequent research on the mechanical properties of aero-engine case.