斜拉索锚固区损伤的高阶纵向导波检测研究

摘要

To realize the effective detection of damage in the stay cable anchorage zone ,the ul‐trasonic non‐destructive detection technique of high‐order longitudinal guided waves was re‐searched ,using the combined method of theoretic analysis ,numerical simulation and tests .Based on the characteristic equation for the longitudinal guided wave propagation in a free steel wire ,the relevant program was firstly complied ,the dispersion curves of phase and group velocity of the longitudinal guided waves were calculated and the high‐order longitudinal guided wave mode L (0 , 6) was selected and was used for detection of the damage in the stay cable anchorage zone .Then the ABAQUS finite element axial symmetric model was used to simulate the propagation of the high‐order longitudinal guided waves in the free steel wire with or without defects and the influ‐ences of the scales of the different defects on the echo reflection coefficients of the guided waves were analyzed .Finally the free steel wires and sample stay cable were tested and verified .The re‐sults demonstrate that the tests are agreeable with the finite element simulation ,showing that the high‐order longitudinal guided waves can be used for detection of the simulated damage in the stay cable anchorage zone .%为了实现斜拉索锚固区损伤的有效检测，采用理论分析、数值模拟和试验研究相结合的方法，对高阶纵向超声导波无损检测技术进行研究。基于自由钢丝纵向导波传播的特征方程，编程计算其相速度和群速度的频散曲线，选取了其 L（0，6）高阶纵向导波模态用于斜拉索损伤的检测；并利用ABAQUS有限元轴对称模型模拟了高阶纵向导波在有、无缺陷自由钢丝中的传播，分析了不同缺陷大小对其回波反射系数的影响；最后，对自由钢丝和样品斜拉索进行了试验检测验证。结果表明，试验结果与有限元模拟结果相吻合，说明高阶纵向导波可以检测斜拉索锚固区的人工缺陷。