Estudo da infiltração de ar no processo de infusão de compósitos estruturais de pás eólicas

Abstract

In order to explore the technology through the construction of Wind blades, which generates electricity around the world, this project studied the mechanical behavior of composite materials, fundamental on its manufacture, with a matrix of epoxy resin and unidirectional fiber glass layer. Through infusion, manufacturing process that transfers the resin for a vacuum flow, the manufacture of polymeric materials may generate many kind of defects that compromises the mechanical characteristics of the material. The purpose of this paper was to analyse these defects from an infusion process with injection of different controlled air volumes. It was manufactured proof bodies for three different situations: Airless and defect free laminate, laminate with 1,5 liters of air and laminate with 3 liters of air. The proof bodies were manufactured with fiber glass L1800/07C07, epoxy resin EPIKOTE™ resin MGS™ RIMR035C and the hardener APIKURE™ Curing Agent MGS™ RIMH0 038, based on the ASTM D3039 norm. The ISO 527-5 standard was used as reference for the longitudinal traction tests. From a traction test machine, all the samples were tested in a static process until the total fracture, in order to reach the different modulus of elasticity matrix, the fracture deformation and Poisson coefficient of each sample. The tests with non-infiltrating test specimens, which did not receive any amount of air, had an average of 413.67 MPa rupture stress. The samples with 1.5 L of air had a mean of 397.51 MPa and the samples of 3 L of air had a mean of 396.56 MPa. The study demonstrated that, through the longitudinal tensile tests, the defects generated by induced manner had a negative impact on the mechanical strength of the composites.