Plastic Analysis of Ice Contact Problems

The plane problem of a rigid stamp on a truncated wedge of rigid/perfectly plastic material is solved by the method of characteristics for a generalized von Mises yield function. Quadratic dependence of shear strength on mean normal stress is included in the yield function. For the corresponding three-dimensional contact problem upper bounds on contact force are obtained by limit analysis. Both crushing and splitting failure modes are treated. Numerical results are presented in dimensionless form for application to the prediction of contact stress of ice on arctic structures with sloping sides.