Structural changes of GFRP composite material after immersion in liquid nitrogen and normal water

Abstract

Composite materials are specially created today, with the best micro and macrostructural compositions. This type of material provides certain characteristics of composition, manufacture and design and provides some important advantages over traditional materials such as rigidity, mechanical strength, low weight, resistance to fatigue, impact and wear and a low manufacturing cost. In recent years, such materials have been produced and used in various fields such as the automotive industry, naval, railway, medical, sports, etc. The paper presents the results of the variations in the tensile curves of the GFRP composite material reinforced with fiberglass, used wind turbine blades construction. Tensile tests were carried out for determination of mechanical properties on four samples with aim of increasing the service life and to investigate the flaws during operation. One sample was immersed for 4 days in liquid nitrogen at an initial temperature of -70°C, the second sample was immersed in regular water for 7 days and the two other samples were dry. All sample having reinforcement at [0 ° / 90 °]. To establish the elastic properties of the material on the specimen immersed in liquid nitrogen and on the dry specimen a T-type rosette was mounted.