Abstract: The dynamic response of the TiNi alloy clipped beam under large mass low-speed impact loading and the phase transformation evolutional character were investigated by employing numerical method. The purpose of this study is to explore the effect of phase transformation on the dynamic behavior of the structure. It is shown that the response consists of five periods, i.e. elastic flexural wave propagation; localization phase transformation which leads to structural instability; stationary phase transformation hinge forming; expanding of the phase transformation hinge and traveling of the phase transformation hinge; hinged bar structure. The phase transformation hinge is a general hinge which is formed under the bending moment and axial force. The phase transformation hinge has different characters compared with plastic hinge.