Modelling paper as a two-dimensional elastic–plastic stochastic network

Stochastic two-dimensional elastic–plastic network models are used to represent the inelastic deformation behavior of wellbonded paper. Linear kinematic hardening is employed with an initial non-zero back stress to represent anisotropic fiber yield. Network models are used to simulate simple monotonic tension and simple cyclic tension of paper materials. The performance of the models is compared to experimental results and found to perform reasonably well. The results suggest that interfiber bonding must be explicitly accounted for to adequately describe the material. Some discrepancy between the model and experimental cyclic tension results is believed to be due to time-dependent strain recovery in the material which is not represented in the network models. Experimental results are also presented which show that simple tension failure in these materials occurs along a line of localized deformation in a majority of the samples. This line is generally observed to form immediately prior to failure and is oriented at a well-defined angle with respect to the loading direction.