A comparison of two damage models for inverse identification of mode Ⅰ fracture parameters: Case study of a refractory ceramic
Soheil Samadi, Shengli Jin, Dietmar Gruber, Harald Harmuth
Abstract
Fracture behavior of refractories influences their durability in high-temperature applications to a great extent. The fictitious crack model has been used for simulation of the fracture process of refractories and concrete materials. The present study investigates the effect of the lower post-failure stress limit of the softening law in the fictitious crack model by comparing an in-house developed subroutine for damaged elasticity model with the concrete damaged plasticity model implemented in Abaqus. The numerical wedge splitting tests show that in the case of brittle materials, the lower post-failure stress limit defined in the concrete damaged plasticity model resulted in energy consumption for crack propagation exceeding the defined fracture energy (114% higher in the case of a brittleness number of 4.4). Therefore, the developed damaged elasticity model allows for a more accurate simulation of fracture since the lower post-failure stress limit was decreased to 0.0001% of the tensile strength. Moreover, an inverse evaluation of the fracture parameters of an alumina spinel refractory material supported the developed model.