【作者】 赵志峰；

【导师】 李言；

【作者基本信息】 西安理工大学 ， 机械电子工程， 2010， 硕士

【摘要】 钢丝绳是工程中应用极为广泛的一种挠性构件,随着钢丝绳使用的越来越广泛,由钢丝绳断绳引发的安全事故也日益增多,因此,研究钢丝绳的无损检测技术有着非常重要的现实意义。本文以钢丝绳断丝缺陷检测为目标,在了解国内外学者有关钢丝绳断丝检测方面的研究和钢丝绳结构的基础上,分析了钢丝绳的断丝形式及其特征,依据钢丝绳具有强导磁能力的特性,采用电磁检测方法和虚拟仪器技术实现了钢丝绳的断丝检测,并开发出钢丝绳断丝检测虚拟仪器系统。论文分析了钢丝绳断丝局部缺陷(Localized Fault,简称LF)漏磁检测方法的原理,讨论了钢丝绳的磁化方式以及各种磁化方式的磁化特性及其优缺点,确定了基于永磁特性的钢丝绳励磁方案和钢丝绳励磁磁路的结构及相关的磁路参数,选择了磁性材料,分析了磁化强度,设计出钢丝绳励磁器,成功实现了钢丝绳的励磁。建立了基于霍尔元件的钢丝绳断丝检测方案,设计出检测系统硬件电路,构建了钢丝绳断丝检测系统,成功实现了断丝信号的获取,实验表明,所设计的系统可以满足钢丝绳断丝检测的要求。由于钢丝绳断丝损伤信号是一随机出现的局部异常信号,通常叠加于背景噪声信号之上,其频率成份比较复杂,论文采用小波变换方法对断丝损伤信号进行预处理,研究了信号的特征,分析提取了断丝信号的特征参数,建立了钢丝绳断丝定量识别的RBF神经网络模型。采用虚拟仪器技术,开发出基于LABVIEW环境的钢丝绳断丝检测虚拟仪器系统,该系统把数据采集、数据处理和断丝状态识别等功能集成于一体,具有操作方便、灵活性高、可视化效果好的优点。大量实验结果表明,所开发的基于虚拟仪器的钢丝绳断丝检测系统可以较好地用于断丝状态的检测,断丝检出率大于90%。更多还原

【Abstract】 The steel wire rope is a flexible component which is widely used in engineering. With the rope used more widely, the security accidents caused by broken wire rope have been increasing and therefore the study of steel wire rope’s non-destructive testing technology is essential.The paper takes the detection of broken wire rope defects as the main object. On the basis of the domestic and foreign scholar’s research in broken wire rope’s testing and the construction of wire rope, the form of broken wire rope and its characteristics are analyzed. According to the wire rope’s strong magnetic capability characteristics, the detection of broken wire rope is achieved using electromagnetic detection method by virtual instrument technology, and the virtual instrument system for steel wire rope detection is developed.In this paper, the principle of magnetic flux leakage testing method for local defects (Localized Fault, referred to as LF) of wire rope breaking is analyzed; the magnetized ways of steel wire rope and their respective magnetic characteristics, advantages and disadvantages are discussed; the program of rope excitation based on permanent magnetic properties, the structure of magnetic circuit excitation for steel wire rope and relevant magnetic circuit parameters are determined; the magnetic materials are selected; the magnetic intensity is analyzed; the wire rope excitation device is designed, and the magnetization of steel wire rope is achieved successfully.The detection program for broken wire rope based on hall element is established; the hardware circuit of detection system is designed; the detection system for steel wire rope is built, and the acquisition of broken wire signal is achieved successfully. Experimental results show that the system can meet the needs of broken wires detection.As the broken wire rope damage signal is a local anomaly signal that is random arise, and is usually superimposed on the background noise signal, and has a complex frequency components, the method of wavelet transform is used to pretreat the broken wire damage signal in the paper. The characteristics of the signal are researched; the characteristic parameters of broken wire signal are analyzed and extracted, and the RBF neural network for broken wire’s identification is established.A virtual instrument system for broken wire rope testing based on LABVIEW environment is developed by virtual instrument technology. It integrates data acquisition, data processing and pattern recognition of broken wire, etc. together, and has the advantage of easy to operate, high flexibility and good visualization. Lots of experimental results show that the system for wire rope break detection based on virtual instrument developed in this paper can be well used in the detection of broken wires state. The rate of broken wire detection is greater than 90%.更多还原