基于导波多尺度能量熵的钢绞线张拉力识别

Steel Strands Tension Identification Using Multi-scale Energy Entropy of Ultrasonic Guided Waves

为了有效评估在役钢绞线中预应力的损失程度,提出一种识别钢绞线张拉力的导波无损检测方法。在不同张拉力钢绞线上进行了超声导波传播数值模拟及实验,构建以导波多尺度能量熵为特征向量的识别指标进行钢绞线张拉力识别,并考虑了导波传播距离及采集方式的影响。结果表明:不同拉力作用下,导波多尺度能量熵差异显著,识别指标与钢绞线张拉力存在明显的线性关系;识别指标敏感性随导波传播距离的增加而增强,但其提升幅度随传播距离的增加而减小。与有限元模拟结果相比,实测识别指标传播距离增加957.69%,敏感性系数提高了20.3%。采用中心钢丝激励、中心钢丝接收导波的采集方式进行张拉力识别,敏感性更优;识别指标与张拉力之间的线性变化规律受导波采集方式的影响较小。

In order to effectively evaluate the loss of pre-stress in the in-service steel strand,aguided wave nondestructive testing method for identifying the tensile force of the steel strand is proposed.Numerical simulations and experiments of ultrasonic guided wave(UGW)propagation are carried out on steel strands with different tensions.The multi-scale energy entropy of UGWs is used as the feature vector to construct tension identification index,and the influence of propagation distance and acquisition method is analyzed.The results show that the multi-scale energy entropy of guided waves differs significantly under different tensile forces.An obvious linear relationship which is less affected by propagation distance and acquisition method between the identification index and tension can be found.Compared with the finite element results,the measured propagation distance of the identification index increased by 957.69%,and the sensitivity coefficient increased by 20.3%.The sensitivity of identification index grows with the increase of propagation distance,but the growth rate is opposite.The acquisition method of center wire excitation and center wire receiving is more sensitive to the change of tension.