Effect of Previous Stress-Strain History on the Dynamic Hysteresis Loop for Rubber in Compression

Abstract

SEVERAL investigators have shown that the behaviour of rubber is affected appreciably by its previous stress-strain history. Their observations, in the main however, are based on indirect measurements of modulus and damping characteristics. Few, if any, have recorded stress-strain relationships in these investigations. Although it might be possible to calculate, from these indirect measurements, the slope and area of the dynamic hysteresis loop, such measurements give no indication of the position of the hysteresis loop relative to the axes of stress and strain. The position of the loop is of fundamental importance in assessing the dynamic characteristics of rubber, and plays a big part, for example, in determining the resilience of the material. To the best of our knowledge, little, or nothing, is known of the effect of previous stress-strain history on the position of the dynamic hysteresis loop, and it is felt that the test record presented below may be of immediate interest to workers in this field. The record forms part of a major investigation which it is hoped to publish later.