| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 2001: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2000: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Research Abstract |
To understand energy dissipation for collision of inelastic solid from a viewpoint of nonlinear dynamics, we carried out both experimental and theoretical studies on this problem as follows :
(1) We built an experimental setup for pseudo-one-dimensional collision using steel rods, and measured energy dissipation, contact time during which two bodies collide each other, dynamical stress at the contact point through the strain on the rod. When the incident velocity is small compared to sound velocity, contact time and point stress could be well represented with the quasi-static theory by Hertz. On the other hand, for large incident velocity, it turned out that the classical theory could not be applied any more. We showed quantitatively the crossover between these two regime of the collision from experimental data.
(2) We investigated the collision of one-dimensional spring-bead model with nonlinear coupling between atoms. In the process during which energy of translational mode is converted into lattice vibration, dissipation takes place without any internal friction. We derived the dissipation rate, i.e., coefficient of restitution, from the consideration of transient exchange of energy. Furthermore, we showed that the fragments caused by collision obeyed a power low distribution. The exponent of the distribution agreed well with our theoretical prediction.
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