抄録
The present paper is concerned with the duration of contact at plastic impact of a finite-length bar on a rigid body. The duration of impact is predicted on the basis of the strain-rate dependent theory of plastic wave propagation. Thus the variations of elastic-plastic stress at the impact end of lead bars are examined by using the constitutive equation obtained from the split Hopkinson bar. Next, a new method for measuring the duration of impact is proposed which is termed the sensing cylinder. This method is effective for measuring not only the duration of impact but also the impulsive force at the impact end. The experimental verifications of the duration of impact are made for lead bars of four different lengths. The time variations of stress at the impact end of the bars colliding with the sensing cylinder under various impact velocities are measured. The theoretical predictions are in good agreement with experimental observations.
