Effects of environment on fracture toughness of glass fiber/polyester composite

Abstract

The resistance of a material to crack propagation is greatly influenced by the fracture toughness of that material. Many parameters are responsible for the fracture and damage process of a material. In this work, an experimental investigation has been carried out on the fracture toughness of chopped strand mat glass fiber reinforced composite after exposing to various adverse environments, like, water, saline water, acidic water, organic fuel, ice temperature and hot air, for different durations using single edge notched (SEN) specimens. The sharp notch of different length sizes, namely, 2 mm, 4 mm, 6 mm (approximate), were cut in different specimens. It has been drawn a number of important inferences from this work. Fracture toughness is independent of crack size. There is a sizeable effect of environments on fracture toughness. A relationship between fracture toughness and duration of exposure under these adverse environments has been established. The fracture toughness has been found to decrease gradually with increased duration of environmental exposure, whereas the fracture toughness has been found to be independent of pre-crack/notch length.

Keywords: Fracture Toughness, Composite, Tensile loading

DOI: 10.3329/jme.v38i0.899

Journal of Mechanical Engineering Vol.38 Dec. 2007 pp.38-44