Backlash: a feature of the cyclic deformation of ceramic pastes

This paper offers a mathematical model to explain the rather peculiar results obtained in the cyclic tension–compression tests on various stiff ceramic pastes. The experimental results indicate a material with low strength in the middle of the cycle, rapidly strengthening at the extremes. Additionally there is a pronounced Bauschinger effect on strain reversal. The mathematical model is based on a previously published model for dry granular materials. This was specifically designed to simulate cyclic deformation, but a modification to include capillary tension allows excellent agreement between 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.