Dynamic powder compaction for parts with high-aspect ratio

A computer program has been developed to analyse one-dimensional elasto-pla stic wave propagation in a powder-filled container. A numerical integration along characteristic curves is introduced in this program. Characteristic curves are derived from an equation of motion, a constitutive equation and a compatibility equation. In the constitutive equation, the effect of strai n rate is taken into consideration. Using this computer program, loading co nditions to obtain uniform strain distribution are examined, varying parame ters such as the duration and peak of impulses. The following results were obtained: (1) the increase in strain near the fi xed end of the container caused by the reflection of the plastic wave contr ibutes to the uniform strain distribution; (2) this wave reflection has the same effect as the usage of a floating die; and (3) for the part with a sp ecific aspect ratio, there is an optimum condition of the duration and peak of the impulse. (C) 2000 Elsevier Science Ltd. All rights reserved.