Experimental and numerical investigation of flexural behavior of hat sectioned aluminum/carbon fiber reinforced mixed material composite beam

Abstract

Hybrid Composite laminates have been widely regarded as a family of highly damage tolerant materials with a high weight-saving potential. The main hindrance to full utilization of Hybrid Composite System in the automotive industry is their structural response as compared to monolithic materials like Steel or Aluminum (AL). The main goal of this research is to investigate the stiffness, weight savings, load-carrying capacity, failure Modes of Al/carbon fiber reinforced polymer (CRFP) hybrid composite system and validate the experimental results with computational Model. The multi-material hybrid composite system comprises of single hat section aluminum material adhesively bonded to woven carbon fiber plies by curing them under temperature and pressure. The effect of interface bonding between AL and CFRP layers on flexural behavior of the multi-material hybrid system was studied by developing three different types of specimens. The first category of specimens was manufactured by using epoxy from the prepreg only to provide adhesion between constituents, second ones were developed by using externally applied an extra layer of epoxy between AL-CFRP layers and finally the third type of samples utilizes 3 M adhesive tape to bond the CFRP and Aluminum sheet. The failure modes of these distinct specimens are studied under flexural loading. The effect of metal volume fraction (MVF) on the failure modes of the hybrid composite beam was also studied. It was found that the failure mode changes from rupture in the load-carrying area to gradual deformation as we increase the metal volume fraction in these hybrid composite specimens. Calculations were performed for the weight savings for these hybrid systems with respect to reference aluminum material having the same thickness as that of the multi-material hybrid system. Weight saving of 15–25% is documented for the multi-material hybrid system as compared to the weight of reference Aluminum material system. Stiffness and progressive damage failure result obtained from experimental three-point bending test are validated with the use of LSDYNA Finite Element Analysis (FEA) for specimens using the only epoxy from the prepreg to provide adhesion between constituents and for samples using externally applied an extra layer of epoxy between AL-CFRP layers for adhesion. Explicit finite element results were found in good agreement with the experimental results.