频散曲线是导波检测的重要依据，现有方法通过数值计算获得特定波导的频散曲线，然而目前有非常多的波导构件，由于结构的复杂性无法计算其频散曲线。研究了通过导波检测信号实现频散曲线获取的方法。基于检测信号的时频分析结果，利用信号的能量最大值实现频散曲线的手动和自动获取。利用上述方法对钢棒、钢管等规则构件的检测信号实现特定模态频散曲线的获取，结果与数值求解的理论频散曲线符合得很好，验证了该方法的正确性。利用该方法得到了预应力钢绞线这一非规则结构波导的特定模态频散曲线。

The dispersion curve is an important basis for the guided wave testing. The numerical method is popular to calculate the dispersion curves of the special waveguide. But some waveguides with the complex structure can not to be calculated by numerical method. This paper studies on the dispersion curve obtained method from the testing signals. The maximum energy of the signal is applied to manual and automatic access to the dispersion curve based on the time-frequency analysis result. The dispersion curves obtained from the testing signals of the bars and pipes(regular waveguides) are in accordance with the theoretical results. And the method is used to obtain the dispersion curve of the pre-stressed steel strand(irregular waveguide).