一种钢丝绳断丝无损定量检测方法

Non-destructive and quantitative detection method for broken wire rope

钢丝绳已广泛应用于电梯、起重机械、客运索道等相关行业,由其断丝、磨损等缺陷所引起的安全问题备受人们关注。采用低频透射式电涡流检测方法,设计一个探头沿径向对称布置的可调整式环形涡流探伤装置,克服了提离效应、边缘效应以及集肤效应对检测系统的影响。选取感应信号相对于激励信号的峰-峰值差和相位差作为特征量,采用数字式峰-峰值算法和占空比原理计算信号特征量。针对钢丝绳电涡流无损定量检测系统,采用断丝数量和断丝位置表征断丝缺陷,建立断丝缺陷与特征量、传感器参数、钢丝绳特性以及后两者间相对关系的广义函数模型,通过最小二乘拟合法确定系统函数模型,结合空间等间隔采样技术定量分析断丝缺陷,并探讨了此检测系统相关参数的确定。设计了一套以计算机为核心的无损检测系统,针对自制钢丝绳进行实验研究。实验结果表明特征量确定合理、提取方法合适、广义函数模型有效、系统总体方案可行,为钢丝绳电涡流无损定量检测系统的实现和推广奠定了基础。

Wire rope has been widely used in elevator,lifting machinery,passenger aerial ropeway and other related fields.Its safety problems caused by defects of wire-breaking and rope-wearing attract great attention.Using low frequency transmission eddy current test method,an adjustable annular symmetrical layout inspection device was designed;the influence of eddy current effect,uplifting effect and skin effect on detection system is overcome.The peak-peak difference and phase difference between response signal and excitation signal are selected as the signal features,and are calculated using digital peak-peak algorithm and duty cycle principle.The number and position of wire-breaking are used to represent the broken defects for the detection system,and then a generalized function model is established to describe the relation among characteristics,defects and sensor.The function model of the system is obtained using least-square fitting;and wire-breaking is analyzed through combining the function model with space interval sampling technology.The determination of related parameters of the detection system is also discussed.A nondestructive test system with computer as the core was designed for experimental study on rope samples made by ourselves.Experiment results show that the feature determination is reasonable,the feature extraction method is suitable,the generalized function model is effective,and the overall system scheme is feasible.This study lays the foundation for the realization and promotion of eddy current non-destructive and quantitative detection for wire rope.