Mechanical Behavior of Metals in Dynamic Compression

Abstract

A technique for the measurement of force and displacement data in metal processing at high rates of deformation is described briefly. Forces are determined by fast Fourier transformation of the signal from a quartz load cell and correction in the frequency domain for dynamic response of the load cell. Displacement is measured by a high frequency response fiber-optic transducer. The force and displacement signals are processed by an on-line computer which enables stress, strain, strain-rate, and other parameters to be determined and plotted rapidly. Results from continuous dynamic compression tests are presented in the form of computer generated stress-strain and stress-strain rate curves for two steels. In the strain rate range 10−3 s−1 to 102 s−1 an hydraulic testing machine is used. In the range 102 s−1 to 104 s−1 a drop forge is used. A discussion of the effects of specimen geometry in compression testing is included.