DESIGN OF VISCOELASTIC IMPACT ABSORBERS - OPTIMAL MATERIAL PROPERTIES

Analytical investigations of impact absorption of linear and isothermal viscoelastic materials are described. Three methods based on different considerations and approximations are studied, and similarities are shown in their results. For a viscoelastic buffer of a given thickness, the optimal loss tangent is determined to be approximately one. Greater reductions in impact force can be achieved if the high loss is accompanied by stiffness reduced by a factor of three to four compared with that of an elastic buffer. If the impactor is spherical rather than flat, a higher loss tangent, of the order of 10, is needed to minimize the impact force. A more sophisticated interpretation scheme for the ball rebound test for screening the loss tangent of viscoelastic materials is derived. © 1990.