Mechanical strength and low-velocity impact behavior of glass fiber reinforced filament wound pipes with different number of layers after hydrothermal aging

Abstract

Composite pipe is preferred over metal and other materials for water supply, liquid chemical transport, and fuel and gas transport. This is because composite pipes are more corrosion resistant, have a high strength/density ratio, high stiffness/density ratio, and more durable than metal pipes. The properties of the composite pipes employed may differ based on the operating environment. Therefore, determining the properties of the composite pipe according to the working environment is extremely important for its lifespan. The thickness of the samples is increased in line with different needs (such as increased strength). Increasing the thickness of samples, especially those exposed to different environmental conditions, and investigating the changes that will occur in the physical and mechanical properties of the samples are another important situation. In this investigation, glass fiber (GFRP) reinforced epoxy composite pipes have been examined, which were manufactured using the filament winding method with different layers [±55°]. To determine their properties in different working environments, the GFRP composite pipes were subjected to hydrothermal aging in pure water at 80°C for several days (7, 14, 21, and 28). The changes in their mechanical properties under working conditions were determined through hoop tensile strength tests and low velocity impact tests applied at different energy levels. The experimental results show that the tangential stress values increased by 10.59% as the number of layers increased. As the aging time increased, the durability of the 6-layer composite pipe decreased by 17.69%. Furthermore, the ability of the aged pipes to withstand damage was evaluated, revealing that the aging process exacerbated the damage within the pipes.