Modelling and inverse investigation of the fracture process for a magnesia spinel refractory using a heterogeneous continuum model

The microcrack network that develops during the cooling stage of magnesia spinel refractories production process contributes to its heterogeneity. To simulate the fracture process of a magnesia spinel refractory subjected to a wedge splitting test, a heterogeneous continuum model with random distribution of the properties was developed. The tortuous crack path and fracture process development were investigated numerically and compared to experimental digital image correlation observation. Bilinear strain softening curves were used to depict the fracture behaviour of the refractories. With an inverse identification approach, the fracture parameters including tensile strength, ultimate displacement, and total specific fracture energy were obtained. The method is the basis for a realistic simulation of crack propagation in refractories used for industrial applications.