Effect of different types of water soaking and re-drying on mechanical properties of glass fiber-epoxy composites
Achutha U Kini, Manjunath Shettar, Shilpa Suresh, M C Gowri Shankar
Abstract
Fiber-reinforced polymer (FRP) composites undergo different environmental conditions in the designed life span. An investigation on aging of FRPs in water helps to enhance the material’s durability. This article aims to explore the effect of different types of water soaking (viz., tap, sea, and rain water) and re-drying conditions on the tensile and flexural strengths of glass fiber-epoxy composites (GFEC). The prepared specimens are placed in the sea, tap, and rain water for 10 weeks. Some specimens are re-dried at 50°C for 5 weeks. The water uptake (%) of seawater aged specimens decreases compared to tap and rain water-aged specimens at the end of 10 weeks. Water soaking of composites has reduced the tensile and flexural strengths of GFEC by 14 to 17%. The strength of water-soaked composite specimens is partly retrieved in specimens that have been re-dried. More than 90% of the original value is retrieved for the strength of GFECs (as-made specimens). SEM analysis of the tensile specimen fracture surface reveals the causes of the specimen failure as well as the impact of water soaking, followed with re-drying.