Original paper(Vol.45 No.8 pp.939)
Development of dynamic loading device with stress sensing block and its experimental examination
Mimura Koji; Hirata Shin; Chuman Yoshitaka; Tanimura Shinji
Abstract:In recent years, an increasing interest has been paid for the exact measurement of stress-strain relation at high rate of strain to check the result of precise formulation of rate-sensitive constitutive equations. In the strain rate range above 102/s, the split Hopkinson bar method is commonly used for this purpose. In this method, however, the both input and output bars should be long enough to prevent the disturbance caused by the wave reflection at the ends of those two bars.
In this paper, the outline of a newly developed compact dynamic loading device using a stress sensing block which consists of a small cylindrical knob for stress measuring followed by a relatively large mass block, is drawn, and its application to the measurement of stress-strain relation at the strain rate of 103/s is discussed. With this device, the dimension of input and output bar system can be reduced to one half approx.1/3 of that of on ordinary split Hopkinson bar device, while the accuracy of the obtained stress-strain curve retains the same level of that obtained by the split Hopkinson bar device.
Key Words:compact dynamic loading device, stress sensing block, magnetic linear encoder, stress-strain measurement