Tensile strength and damage of open-cell ceramic foams under cylindrical splitting test

To widen the understanding of tensile failure of reticulated ceramic foams and expand the available mechanical method, a cylindrical splitting test is developed in the present study based on the alumina open-cell foams of three different pore densities. The biaxial method is validated by the characterization of mechanical parameters and the in-situ fracture process by digital image correlation, followed by a formula correction for effective tensile strength with the consideration of discrete crack paths. For the experimental setup curved loading platens, compliant pad and intermediate quasi-static loading rate are proposed for guaranteeing the tensile failure under radial compressive load. Tensile strength, fracture energy as well as brittleness increase with the foam pore density and the fracture behavior is the balanced result of material and foam structural support strength. An analytical model of splitting tensile strength with structural parameters is derived, which implies its dependence on the cell size and critical stress intensity factor of strut material.