Micromechanics analysis of fiber reinforced composites

Abstract

To meet the high strength-to-weight and stiffness-to-weight ratio requirements in aerospace structures, fibre reinforced composites have been often used. In the design of structures, we need the stress-strain relationship of the material. Plastic strain generally starts at some local region and spreads over large part of the cross-section and eventually comes to reach the maximum load or some crack initiation. The spread of this plastic strain is an indication of the level of material damage. To calculate this spread, we need to calculate the microscopic stress and strain fields. From the microscopic stress and strain, we can calculate the macroscopic stress-strain relationship. This paper shows a method to analyze the microscopic strain field of a multi-dimensional fiber reinforced composite in the elastic-plastic range under uniaxial, combined, radial and nonradial loadings. A numerical example is shown.