粘弾性体落下衝撃における材料係数の同定

抄録

This paper deals with the material modulus estimation for the impact of dropped viscoelastic material bodies. A bar model was investigated firstly as it is easy to understand the impact phenomena. Besides the fundamental material modulus of impact, Young's modulus and density, two dimensionless viscoelastic material parameters, the ratio of the long-term elastic modulus to the short-term one and the relaxation modulus to the wave propagation time along a bar, were found to be the other key parameters. The dropped viscoelastic spheres were investigated secondly and shown to have similar impact characteristics to bars regarding these two key parameters. We can estimate the material modulus very quickly in the computation analysis by tuning these parameters. And this approach is very useful to design the impact source of dropped sphere from the point of view of the viscoelastic materials.