• Under lower axial pressure, the impact tendency of post-peak sandstone decreases, requiring more impacts to failure; under higher axial pressure, the impact tendency becomes strong, indicating a higher rock burst risk.
• Higher axial pressure reduces the dynamic strength of post-peak sandstone, accelerating its failure process.
• The dissipation-energy release rate exhibits a nonlinear quadratic polynomial relationship with axial pressure.
• With increasing axial pressure, shear failure dominates, and the microscopic failure mode transitions from composite intergranular/transgranular failure to single intergranular failure.