Interphase characterization of glass/epoxy composite using peridynamic method and micro tensile test

Abstract

ABSTRACT In this paper, a novel procedure is developed to characterize the interphase region using the nonlocal peridynamic method and micro tensile tests of glass/epoxy specimens with a single fiber of glass. For this purpose, micro tensile tests are performed by an accurate tensile test device and high-quality camera imaging for data sampling. The obtained displacements are analysed by the image processing method and used as target values in the peridynamic analyses. Multiscale mass points from macro to micro scale are generated to model the interphase region in single fiber specimens using the state-based peridynamic method. With the coupling of peridynamic and multivariate optimization codes, the program is automatically executed by the prediction of thickness and elastic modulus of interphase to achieve the desired displacements similar to micro tensile test results. In this innovative method, unlike nanoindentation tests, where the results are limited to a specific section or point, the interphase characterization gives an overall elastic modulus value along the examined length of the sample. The obtained results from the presented procedure show that the interphase elastic modulus is between 20.8 and 28.86 GPa and the interphase thickness is between 1.149 and 1.986 microns. The obtained results are in the range of nanoindentation tests results presented in the literature, and the difference could be due to the manufacturing conditions, epoxy properties, and quality of the fiber silane coatings.