On The Absorber Based On The Inward Introverted Composite Tube

In order to develop a more reliable,energy efficient and versatile anti-impact energy absorber,an innovative shock absorber based the failure of composite tube is presented.The energy absorber is composed of a composite tube and a connecting cap at both ends,wherein the inner surface of one connecting cap is plane,and the inner surface of the other connecting cap is a curved surface.So the tube is folded and pushed into itself cavity under axially impact.There is no debris overflowing after the composites collapsing,and the debris filled in the inner of tube increases the energy absorption.The impact energy is mainly absorbed by the fracture of fiber,delamination and friction between composite tube and the cylinder wall of the sleeve.The corresponding static and dynamic impact experiments had been conducted to explore the effect of curvature of the inner surface of the cap on the energy absorption.The results show that this innovative energy absorber is applicable for lightweight crashworthy structures in terms of decreasing the initial peak load and increasing specific energy absorption(SEA).The cutter with the radiation knife edge can also be installed in the connecting cap of the energy absorber,improving the failure load effectively in the stable stage after the use of the cutter,which means that the energy absorption performance is significantly improved.The shear failure experiment of the cutter was carried out to study the proportion of the absorbed energy.At the same time,the influence of the pin connection on the energy absorption effect of the energy absorber was also explored.To investigate the application of absorber to shock-resistance of the seat in the helicopter,a nonlinear lumped parameter mathematical model for human was setup.According to the experiment date,a nonlinear model of the initial loading force is developed to fit the crush process of absorber.And based on the simulation result of the human response model,the absorber presents great performance in terms of shock-resistance.