Micromechanical crack analysis of glass-epoxy laminated composites subjected to tension load

Abstract

The main objective of this study is to determine tensile properties of the glass-epoxy polymer composite material. The material is glass fiber 280 g/m², 'twill woven' with 100 cm width, type - Interglas 92125, and epoxy resin type MGS L-135, where samples are molded using hand manual method with 35% fiber weight per volume. Orientations were 0/90° i ±45°. In accordance with appropriate standards, tensile strength and modulus of elasticity were determined. Beside the analysis of the results obtained during the experiment, micro-mechanical analysis of the tensile failure appearance and development was conducted based on the observed cracked surface, which led to a confirmation of all characteristic mechanisms and cracks expected for this type of material and study. Micromechanical analysis performed on the cracked surfaces of the investigated samples, has led to a definition of a structure which is more suitable for exploitation of this material in a presence of this type of external load.

Predmet i cilj ovog rada je određivanje statičkih zateznih svojstava staklo-epoksi polimernog kompozitnog materijala. Ispitivani materijal je kompozitni materijal stakleno platno 280 g/m², 'twill tkanje' širine 100 cm, tip - Interglas 92125 i epoksi smola tip MGS L-135, a uzorci su oblikovani ručnom metodom sa 35% zapreminskog udela vlakana. Ispitivane su orijentacije 0/90° i ±45°. Određeni su zatezna čvrstoća i modul elastičnosti prema odgovarajućim standardnim ispitivanjima. Pored izvedene analize dobijenih rezultata, a na osnovu izgleda prelomnih površina uzoraka izvedena je i mikromehanička analiza nastanka i razvoja oštećenja pri zatezanju čime su potvrđeni svi mehanizmi i oštećenja karakteristični za ovakvu vrstu materijala i ispitivanja. Mikromehaničkom analizom na prelomnim površinama ispitivanih uzoraka se došlo do strukture koja je povoljnija u eksploataciji pri ovakvog tipu spoljašnog opterećenja.