Damage Constitutive Model of Wellbore Rock Based on M-integral

This paper investigates the local mechanical failure behavior of rock linings under uniaxial compression and applies the theory of configurational mechanics to describe the local mechanical failure behavior of rocks containing initial defects during the elastic deformation stage. The concept of a local mechanical failure driving factor, based on the conformal force conservation integral, is introduced. A relationship between the conformal force conservation integral and the local mechanical failure driving factor is established. Furthermore, the local mechanical failure driving factor, represented by the M-integral, is proposed as a new damage parameter. The damage constitutive model for borehole rock, which accounts for initial defects, is then modified to characterize the damage degree prior to local mechanical failure. Finally, a damage constitutive model for borehole rock, based on the M-integral, is constructed.