Avaliação das propriedades mecânicas de compósitos obtidos pelos processos de laminação contínua e pultrusão

Abstract

In the recent years composite materials are being increasingly used in diverse industrial sectors, especially in the aerospace, automotive and offshore industry because they have competitive advantages over traditional materials such as steel, aluminum and wood. In general, composites show lightness, durability in aggressive environments and ease of molding. However, there is still little knowledge about the mechanical properties of these materials and therefore often end up being wrongly employed in relation to the end use. In these sense, the objective of this study was investigate the mechanical behavior of composite materials in the form of plane plates obtained by two distinct processes: Continuous lamination and Pultrusion, and so characterize them in order to guide its use for industrial applications. Initially, the materials were subjected to TGA analysis for determination of matrix/ reinforcement mass. After mechanical tests were made to determine the tensile strength, flexural and izod impact and analyzed the mechanisms of fracture resulting from tensile test and impact. Finally the materials were tested in relation to the fatigue behavior, in which was obtained SN curve for stress ratio R = 0.1. From the latter test, it was possible to build the equations that delineate the behavior of the materials as a function of the applied load and the number of cycles to which they are subject. The fatigue test also permitted calculates the fatigue fragility coefficient through the normalized fatigue curve for each analyzed material. The data showed that pultruded material exhibits superior performance in all studied properties, except when evaluating the fatigue behavior taking into account the variation of fragility to material fatigue in relation to the proportion matrix / reinforcement. The results indicate that the higher percentage of reinforcement in composite material will lower your resistance to fatigue.