Crack Growth and Plastic Relaxation in a Drying Paste Layer

Uniform drying causes a quasi-two-dimensional cellular crack pattern in a thin layer of paste. In our previous research, we found that such cracks are created in a capillary state, and that the growth speed is determined by the rate of increase in tension in the layer, rather than by the magnitude of the tension itself. In this paper, we present a theoretical investigation of the effects of increasing negative pore pressure and plastic deformation on crack growth using a modified spring network model. The analytical and numerical results indicate that the stress-rate dependence of crack speed could be caused by the competition between plastic relaxation and crack growth.