Comportamento mecânico de compósito de metal/fibra de juta com matriz epoxídica

Abstract

Several studies have been developed due to the advantages of the applications of composite materials in projects, mainly due to the high strength/weight and stiffness/weight ratios. Industries have sought to insert natural fibers in order to develop projects with more sustainable, lightweight and economical composites, and jute is among the most used natural fibers in reinforcing polymeric composite matrices. The present work aims at the development, characterization and numerical modeling of two laminated composites. The first laminate is made up of jute fiber and epoxy resin and the second is a hybrid laminate of the "sandwich"type with a matrix composed of the first laminate and two aluminum laminates on the upper and lower sides. Data acquisition was carried out through a broad experimental program to characterize the constituent materials of the laminates, as well as themselves. The jute fiber was characterized through mechanical, thermal and microscopic tests, and the influence of the treatment on the fiber properties was analyzed. The treated fibers were submitted to an alkaline treatment with a concentration of 5% NaOH. The viscoelastic behavior of the epoxy resin was described through rheological and thermal tests. Finally, the characterization of the composite properties was carried out through mechanical tests of traction, flexion, fracture energy and shear strength. After obtaining the properties, the numerical modeling was performed in the commercial software Abaqus, which provides in plane stress state elements the implementation of the Hashin criterion and damage evolution based on continuous damage mechanics. The simulations of the fiber reinforced composites (CRF) to tensile and 3-point bending stresses obtained satisfactory results. In relation to the simulations of the Fiber/Metal Laminates (FML), the results for both traction and bending, presented a slope higher than the experimental curves, this fact was attributed mainly to the union of the aluminum sheets with the surface of the CRF that presented delamination in some regions.