Creep characterization and modelling of ordinary refractory ceramics under combined compression and shear loading conditions

Creep behaviour of ordinary refractory ceramics is evidently asymmetric under uniaxial tension and compression. In service, they are often exposed to multiaxial stress states. In the present paper, the modified shear test specimens were applied for a creep study in the shear-compression zone of the p-q diagram, and the pure shear creep parameters following the Norton-Bailey strain hardening equation were inversely identified in combination with a weighting function between pure shear and uniaxial compressive conditions. The weighting function was implemented in an in-house asymmetric creep constitutive model. The experimental curves can be well predicted with identified parameters of the asymmetric creep constitutive model. It shows that the shear creep of ordinary refractory ceramics is evidently different to uniaxial compressive/tensile creep. Consideration of shear creep in the thermomechanical modelling of industrial vessels increases the accuracy of simulation results and supports the lining concept optimization investigation.