Anisotropic and heterogeneous acoustoplasticity of α-Ti during ultrasonic vibration assisted compression: modeling and experiments

•Twinning and dislocation slip mediated anisotropic ultrasonic softening was incorporated in the acoustic crystal plasticity model for HCP metals.•The proposed model can well capture the anisotropic and heterogeneous acoustoplasticity of α-Ti.•Sequentially increased ultrasonic softening in RD, TD, and ND is attributed to the higher ultrasonic activity of Ba slip and Ct twinning.•Ultrasonic vibration induced high dislocation density assists the nucleation and propagation of twins.