Characteristics of thermoplastic composite tube under axial loading

Research into the design of lightweight automobile is driven by the need to reduce fuel consumption, to preserve dwindling hydrocarbon resources without compromising other attributes such as safety, performance, recyclability and costs. The automobile industry is seeing an increased need for the application of plastics and their derivatives in various forms, such as fiber reinforced plastics. These materials are used in the design and manufacture of various structural components, to reduce weight, cost and to improve fuel efficiency. A lot of effort is being directed at the development of structural plastics, to meet specific automotive requirements such as stiffness, safety, strength, durability and environmental standards like the recyclability. Crashworthiness of the automotive parts plays a key role in the safety of the vehicles. The use of thermoplastic composite materials in the automotive components can provide the advantages of weight, cost reduction and recyclability, in addition to eco-efficiency and renewability, compared to conventional materials. This paper presents an experimental study on quasi-static and dynamic axial crushing of composite circular tubes with various geometric characteristics; such structures were fabricated with a thermoplastic material both for the fibers and for the matrix. The data were recorded and analyzed in terms of load-displacement curves, specific energy absorption (SEA), crush force efficiency (CFE), stroke efficiency (SE) and crushing stress. The results obtained with the thermoplastic specimens were compared with those obtained with traditional thermoset. The failure mechanisms, obtained varying the geometric parameters and the boundary conditions, will be also presented and discussed.