Modeling Flexural Failure in Carbon-Fiber-Reinforced Polymer Composites

Thiago De Sousa Burgani,Seyedhamidreza Alaie,Mehran Tehrani

doi:10.3390/jcs6020033

Abstract

Flexural testing provides a rapid and straightforward assessment of fiber-reinforced composites’ performance. In many high-strength composites, flexural strength is higher than compressive strength. A finite-element model was developed to better understand this improvement in load-bearing capability and to predict the flexural strength of three different carbon-fiber-reinforced polymer composite systems. The model is validated against publicly available experimental data and verified using theory. Different failure criteria are evaluated with respect to their ability to predict the strength of composites under flexural loading. The Tsai–Wu criterion best explains the experimental data. An expansion in compressive stress limit for all three systems was observed and is explained by the compression from the loading roller and Poisson’s effects.

Highlights

Modeling the elastic behavior of orthotropic materials with transverse isotropy usually requires the characterization of five independent elastic constants, namely, E1, E2, G12, ν12 and G23, which represent Young’s modulus in the fiber direction, Young’s modulus perpendicular to the fiber direction, the in-plane shear modulus, the inplane Poisson’s ratio, the out-of-plane shear modulus, and the out-of-plane Poisson’s ratio, respectively [1]
Through finite-element analysis (FEA), this study investigates stress interactions occurring in unidirectional, 20 ply CFRP samples loaded through a three-point flexural
Through finite-element analysis (FEA), this study investigates stress interactions occurring in unidirectional, 20 ply CFRP samples loaded through a three-point flexural test, and predicts the flexural strength of each system with reasonable accuracy

Summary

Introduction

Extensive composite material characterization ensures safety compliance and provides critical design data in the listed industries. Modeling the elastic behavior of orthotropic materials with transverse isotropy usually requires the characterization of five independent elastic constants, namely, E1 , E2 , G12 , ν12 and G23 (or v23 ), which represent Young’s modulus in the fiber direction, Young’s modulus perpendicular to the fiber direction, the in-plane shear modulus, the inplane Poisson’s ratio, the out-of-plane shear modulus, and the out-of-plane Poisson’s ratio, respectively [1]. There are few significant mathematical relations for material strength resulting in numerous resource-intensive destructive tests, often providing single failure mode results. It is advantageous to study composite behavior under combined loading, and their dominating failure modes

Results

Discussion

Conclusion