Influência da orientação da fibra de vidro na resistência mecânica de laminados em compósitos de matriz epóxi

Abstract

Currently, composite materials have been increasingly used, being fundamental in the construction of aircraft, boats, racing cars and wind generators. In view of this situation, studies and analyzes focused on the area of activity of composites in general are increasingly necessary. In a wind blade design, various orientations of glass fibers are used, however, in different regions of the blade as well as in its components. Thus, the present study aims to analyze the mechanical behavior of composites widely used in wind blades composed of fiberglass in unidirectional (0°), bidirectional (+/-45°) and tridirectional (0°, +/- 45°) with epoxy resin matrix. Specimens were made for the 3 different angles mentioned above, all with fiberglass obtaining the same weight, they are: UD 1200g/m², BIAX 1200g/m², TRIAX 1200g/m²) with EPOXI RESIN MGS RIMR 035C – USA and ENDUR hardener. FOR EPOXY RESIN MGS RIMH 037. The samples were made by the vacuum-assisted infusion molding process, where the dimensions of the parts for testing were prepared based on the ASTM D 3039/D 3039M standard and subsequently subjected to Tg and tensile tests. It was observed that the sample with orientation of 0° has a high tensile strength, but has a very low ductility, breaking more easily after reaching the plastic zone. The sample with two orientations (+/-45°), has the lowest tensile strength of the three samples, but a higher ductility than the UD sample (0°), leaving the part in the plastic regime for a longer time before breaking. The sample with three orientations (0° and +/-45°), has the highest tensile strength, as well as greater ductility compared to the UD sample, and slightly lower compared to the biax sample.