中文摘要：

通过求解薄板的兰姆波频散方程，绘制了NiTi形状记忆合金薄板的频散曲线，并根据频散曲线选择了对合金相变敏感的兰姆波模式。利用PZT超声探头在合金薄板中激励并接收S1及S3模式的兰姆波，测量了温度变化时兰姆波的群速度。研究结果表明，随着NiTi合金相变过程中微观组织结构的变化，兰姆波群速度明显改变，可以根据兰姆波群速度变化测量合金薄板的相变温度。

英文摘要：

By solving the lamb wave dispersion equation for NiTi sheet, the dispersion curves were drawn. Lamb modes more sensitive in detecting phase transformation of NiTi alloy were selected on the basis of the dispersion curves. PZT transducers were used to excite and receive S1 and Sa Lamb waves on NiTi sheet. The wave group speed was measured when te.mperature of NiTi sheet changed. The results showed that some marked changes were observed in the dependence of the group speed versus temperature during phase transformation and phase transformation temperature of NiTi sheet might be examined by the change of the group speed.