A Multiscale Analysis Method for Predicting the Transverse Mechanical Properties of Unidirectional Fibre-reinforced Composites

Abstract

Mechanical property prediction methods for composites are very important as theoretical tools for engineering structural design. To more accurately capture the transverse mechanical properties of composites, a multiscale analysis method is developed in this paper. The multiscale analysis method includes three scales: (1) At the microscale, a microscopic cohesive model based on atomic potential energy is established for the interface; (2) At the mesoscale, a unit cell model is established for the fibre, matrix and interface; and (3) At the macroscale, the homogenization method, failure criteria and damage degradation models are used for predicting the transverse mechanical properties. Subsequently, the transverse mechanical properties and the damage evolution process are simulated with the multiscale analysis method. A comparison between the simulations and experiments shows that the maximum error of the predicted transverse modulus and transverse strength is −4.45 % and −12.05 %, respectively. Finally, the effects of the interfacial strength on the macroscopic transverse mechanical properties and the damage onset are analysed. The following conclusions are drawn from the simulation results: (1) The interfacial strength has a more significant effect on the transverse strength and ultimate strain than on the transverse modulus; (2) Decreasing the interfacial strength has a greater effect on the transverse modulus, strength and ultimate strain than increasing the interfacial strength; and (3) The interfacial strength can change the damage onset.