Backlash: a feature of the cyclic deformation of ceramic pastes

This paper offers a mathematical model to explain the rather peculiar resul ts obtained in the cyclic tension-compression tests on various stiff cerami c pastes. The experimental results indicate a material with low strength in the middle of the cycle, rapidly strengthening at the extremes. Additional ly there is a pronounced Bauschinger effect on strain reversal. The mathema tical model is based on a previously published model for dry granular mater ials. This was specifically designed to simulate cyclic deformation, but a modification to include capillary tension allows excellent agreement betwee n the simulation and experimental results on pastes. This demonstrates that the mechanics of granular materials is the appropriate basis for modelling these and similar materials rather than modified polymer rheology. (C) 200 0 Elsevier Science Ltd. All rights reserved.