Abstract: Using ANSYS/LS-DYNA, a 3D model of bended pipes was built and propagation of L(0,2) mode guided waves in pipes was simulated. The group velocity curves of L(0,2) and T(0,1) mode in bended pipes were calculated and compared with straight pipes of having the same diameter and thickness. Also, the ability of L(0,2) mode to detect defects located inner or outer side at bends was studied. Results showed that there would be a mode conversion when guided waves passed a bend part. When frequency increased, the mode conversion was more obvious. It was found that the difference of dispersion curves between curved pipes and straight pipes was small at low frequency and big at high frequency. And, L(0,2) mode performed better when used to detect outer side defects at bends.