Study on the crack–inclusion interaction with coupled mechanical and thermal strains

•A formula for SIF change with coupled mechanical and thermal strains is proposed.•Finite element analysis is conducted to validate the formula with good agreement.•Influence of the shape and position of the inclusion is analyzed in the validation.•The effect for the crack growth is only depended on mismatched thermal strains.•Temperature-dependent elastic properties slightly affect SIF variation.

The interaction between a Mode I crack and an inclusion in an infinite medium is examined with consideration of coupled mechanical and thermal loads under plane strain condition. A closed-form formula for the change of the stress intensity factor is obtained based on the transformation toughening theory and the Eshelby inclusion method. The mismatched thermal expansion strains between the inclusion and the matrix are conducted as eigen strains. Then finite element method is implemented to validate the accuracy for the stress intensity factor variation from the developed formula. Finally, the effects of temperature-dependent elastic properties on the inclusion–crack interaction are estimated. It is also found that the shielding or amplifying effect on the crack growth is the dependence on the mismatched expansion coefficient if only the temperature increase or decrease is considered.