Composite Material Elastic Effective Coefficients Optimization by Means of a Micromechanical Mechanical Model

Abstract

The presented research work demonstrates an efficient methodology based on a micromechanical framework for the prediction of the effective elastic properties of strongly bonded long-fiber-reinforced materials (CFRP) used for the construction of tubular structures. Although numerous analytical and numerical micromechanical models have been developed to predict the mechanical response of CFRPs, either they cannot accurately predict complex mechanical responses due to limits on the input parameters or they are resource intensive. The generalized method of cells (GMC) is capable of assessing more detailed strain fields in the vicinity of fiber–matrix interfaces since it allows for a plethora of material and structural parameters to be defined while being computationally effective. The GMC homogenization approach is successfully combined with the covariance matrix adaptation evolution strategy (CMA–ES) to identify the effective elasticity tensor Cij of CFRP materials. The accuracy and efficiency of the proposed methodology are validated by comparing predicted effective properties with previously measured experimental data on CFRP cylindrical samples made of 3501-6 epoxy matrix reinforced with AS4 carbon fibers. The proposed and validated method can be successively used in both analyzing the mechanical responses of structures and designing new optimized composite materials.

Keywords

• micromechanics
• generalized method of cells
• optimization
• carbon fiber reinforced plastics cylinders
• covariance matrix adaptation evolution strategy