Approximation of Non-Linear Stress-Strain Curve for GFRP Tensile Specimens by Inverse Method

Studying the characteristics of materials through a finite element analysis (FEA) has various benefits; hence, many studies have been conducted to improve the reliability of the analysis results. In general, the mechanical properties used in FEA for metals and metal composites are stress-strain data obtained through tensile tests, which are used for modeling from a macroscopic perspective. While many studies have been conducted on metal materials, there are limited studies on the analysis of polymer composite materials produced through injection and special processing. In this study, existing inverse methods were applied, and an FEA was conducted to reproduce the axial displacement of the tensile specimens comprising glass fiber-reinforced polymer (GFRP); further, errors were examined by comparing the test and analysis results. To reduce such errors, the experiment and the FEA results were analyzed through parameter optimization based on various empirical formulas. The accuracy of various inverse methods were examined and an inverse method suitable for GFRP was proposed.