A model based on nonlinear oscillations to explain jumps on creep curves: II. Approximate solutions

Abstract

Using the method of relaxation oscillations, the authors derive approximate expressions for the amplitude, period and the waveform of the limit cycle solutions. Using these, an expression for the step size per cycle on the creep curve is derived. It is shown that these approximate solutions agree well with the numerical solutions. The theory predicts bounds on temperature and stress over which the steps are seen. The dependence of the step size and the period of the oscillation on stress and temperature permits mapping of the theoretical parameters on to the experimental ones. It is shown that this dependence is in agreement with the experimental results of Zagorukuyko et al. (1977).