Experimental and numerical models to study the creep behavior of the unidirectional Alfa fiber composite strength by the photoelasticity method

In this paper, we propose an experimental and numerical model to study the creep behavior of the unidirectional Alfa fiber composite strength by the photoelasticity method. To have better mechanical properties, chemical treatment is made for Alfa fibers. Tensile tests are made to predict the Young modulus and tensile strength. These tests confirm that the chemical treatment during 48 Hours of Alfa fibers collected from the south region gives the best results. After that, specimens are made in Medapoxy STR resin and treated Alfa fibers of the south region. All fibers of specimens are arranged approximately in multiple hexagonal clusters embedded in the matrix. For the micromechanical fiber stress redistribution or load sharing theory to be applied, clusters must minimally contain one broken fiber. Consequently, we have a stress perturbation due to a fiber fracture, which propagates to the nearest-neighbor fibers. This perturbation enables us the photoelastic visualization of the fracture events during the creep tests. The contour diagram and fringe values give us the accurate distribution of stress near broken fibers showing local shear stress concentrations during the time. To simulate the creep response and failure mechanism, the Tsai-Wu failure criterion was applied on ANSYS explicit dynamic software. Because it merges between experimental tests and numerical simulation, the present study offers a real scientific contribution in the creep behavior of biobased composite strength by the photoelasticity method.