Energy absorbing device, e.g. automobile bumper - has sinusoidal grooves and is of terpolymer of ethylene!-propylene!-1,4-hexadiene

摘要

Energy-absorbing device, esp. an automobile bumper, is made of elastomer compsn. with shear modulus of elasticity at 20 degrees between 20.7 and 414 MPa. It has >=1 sinusoidal groove of width is not 1.5x (total length of the sinusoidal wave), measured along the axis halfway between the crests of the opposite sides of the groove. The length of the groove is 5-10x the width. The groove buckles under the action of the component along its length of the force of impact. The bumper is pref. of ethylene/propylene/1,4-hexadiene terpolymer. It may be of glass fibre reinforced elastomer or elastomeric foam.