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 整绳破断力已成为钢丝绳检验的主要参数,根据GB/T8358－2006《钢丝绳破断拉神试验方法》对影响试验结果的因素进行了探讨,发现选择合适的夹持方法以及试验仪器能有效地提高试验成功率。     

Influence of steel wrapping on magneto-inductive testing of the main cables of suspension bridges

The number of structurally deficient or functionally obsolete bridges is likely to increase in coming years due to continued bridge aging and deterioration and a decrease in funding needed to maintain and repair these structures. In the case of suspension bridges, problems arise due to corrosion and wire breaks within the main cables of the bridge. The magnetic flux leakage (MFL) method has been known for many years and is used for inspection work in different fields, such as the non-destructive evaluation (NDE) of pipelines, arial tramways or stay cable bridges. A special characteristic of the main cables of suspension bridges is the presence of steel wrapping, which is used to compact the cable and hold it in shape. If a NDE by means of magnetic methods is performed on such a cable, disturbances due to the wrapping can be expected in the measured signal. Furthermore, the very large diameters of these cables (up to 500 mm) poses an unsolved challenge in the application of magnetic non-destructive testing methods.The finite element method (FEM) and other simulation techniques are widely used in any field of engineering. The possibility to simulate different scenarios and the ability to quantify physical properties at any position where real measurements cannot be performed are among the main advantages of such methods. In this work, a FE model is presented to investigate the influence of the steel wrapping on MFL data. After the characterization of the disturbance, a postprocessing algorithm to eliminate the disturbances is discussed. Further, boundary conditions for a successful application of the proposed method in a real application are formulated.     

钢丝绳无损检测技术在宝钢的应用

简述LMA型钢丝绳无损检测系统的结构和特点。在宝山钢铁集团公司利用该系统对在线钢丝绳进行无损检测,并结合倾向管理,可以保证在役钢丝绳运行的安全可靠,避免钢丝绳更换的盲目性,做到按照钢丝绳的运行状态来进行预知维修。     

Acoustic emission from wire ropes during proof load and fatigue testing

The paper describes an experimental investigation into the enhancement of proof and fatigue testing procedures for wire ropes by incorporating data from acoustic transducer signals. During proof load tests on a selection of damaged wire ropes, it is shown that acoustic emission increases significantly after the damage is inflicted, even though ropes continue to pass the proof test. The relationship between acoustic emission signal characteristics and wire breaks is investigated and it is found that the most effective acoustic signal discriminators are energy and amplitude. Finally, the pattern of acoustic emission signals during a fatigue test is studied and a suggestion is made for a filtering technique to improve the recognition of imminent failure.     

桥梁缆索金属损伤无损检测方法

缆索广泛应用于斜拉桥、悬索桥和拱形桥等桥梁结构中,其有效金属承载面积直接关系到桥梁安全。在分析桥梁缆索自身结构和使用工况的基础上,论述了桥梁缆索无损检测中遇到的难点,分析了可能应用于桥梁缆索金属损伤的无损检测方法的特点和局限性,其中声发射法可用于缆索的长期监测,但仅能给出相对检测结果;射线法和磁性检测法可用于缆索的逐点扫描检测,但检测移动辅助装置复杂;磁致伸缩导波检测方法可实现远距离的包括锚固区在内的金属损伤检测,但信号解释复杂。最后,提出了桥梁缆索磁致伸缩导波快速扫查和磁性精细扫查相结合的无盲区检测方法,该研究将促进桥梁缆索无损检测技术的深入发展。     

某河口闸门钢丝绳检测的案例和思考

某河口闸门应用钢丝绳进行启闭,传统的采用人工目视和触摸的方法可靠性差且危险。介绍了一种采用基于虚拟仪器的电磁检测技术对钢丝绳进行检测的案例,如仪器的检测原理、检测路径的设计、检测结果以及判断标准。实例证实了钢丝绳电磁虚拟检测技术的可行性。最后,基于目前日益增长的钢丝绳检测需求,以及并不广泛的检测现状,建议应该重视钢丝绳检测技术的猿产及应踊。     

钢丝绳定量无损检测现状

钢丝绳无损检测的目的是保证钢丝绳的安全运行，并在安全运行的前提下尽量减少因过早报废而产生的浪费。对目前主流的钢丝绳无损检测方法的检测原理及特点进行分析比较，给出各种方法的研究现状和实践效果，包括20世纪90年代以后提出的新检测方法，如磁致伸缩法和声发射一超声法。最后讨论目前钢丝绳定量无损检测面临的问题。     

矿井提升钢丝绳磨损原因的分析

钢丝绳是矿井提升设备以及井下牵引轨道运输设备的重要组成部分,是连接容器和传递动力的重要部件.钢丝绳的损坏不仅对提升运输的安全构成威胁,也会导致钢丝绳的使用寿命大大缩短,增加了生产成本.将现场采集的斜井提升钢丝绳上的油垢制成粉末试样进行XRF射线分析,将多个磨损部位制成金相试样进行扫描电镜分析,得出钢丝绳受磨损的种类,提出了必要的预防措施.     

多绳缠绕式提升系统纵向振动特性仿真分析

以超深井多绳缠绕式矿井提升机试验台为研究对象,考虑风阻的影响建立了提升过程中容器的振动和钢丝绳张力的微分方程。并利用MATLAB-Simulink软件对试验台提升过程中的钢丝绳纵向振动特性进行了仿真分析,得到了在最大速度一定的情况下,提升系统以不同加速度提升运行时,钢丝绳的绳端变形、绳端变形速度、天轮处钢丝绳张力以及张力变化速度的变化规律,对提升过程加速度的输入设计有一定的指导意义。     

索道钢绳缺陷的磁性检测信号辨识

索道钢绳是索道设备的关键部件,对索道钢绳状态的监测是保障生命、财产安全的重要环节。对锈蚀、断丝等几种常见钢绳缺陷做检测,分析了其各自的LF及LMA谱线,并由实际检核验证了监测结果的准确性。总结了在钢绳探伤中的一些经验,如探伤仪的校准、缺陷的定性与定量分析等,对钢绳探伤工作有一定借鉴价值。     

电梯钢丝绳拉伸过程中的声发射特征

采用声发射技术对电梯钢丝绳拉伸过程进行监测,获取钢丝绳断丝信号,并对断丝信号进行参数分析和波形分析。试验结果表明:声发射检测技术能很好地定性辨识断丝信号。断丝信号具有高幅值高能量的特点,信号幅值在80~100 dB之间或绝对能量在2×10~6 mV·s以上的信号可定性认定为断丝信号。通过对具有这些特征的信号进行统计,可对钢丝绳断丝情况定量计算,从而推断出钢丝绳的剩余强度。钢丝绳断丝信号为突发型信号,对信号进行快速傅里叶变换可得知断丝信号的频率主要分布在0~220 kHz之间,且在25~50 kHz之间有明显的能量峰值。     

Experimental investigation of embedding high strength reinforcements in extrusion profiles

Embedding reinforcement or functional wires in extruded profiles offers the potential to increase mechanical properties as well as the field of application. With improved strength and stiffness and an integrated function as deformation sensor or data transmitter the weight of space frame structures can be reduced substantially. To comprehend the general conditions when embedding the reinforcement and functional elements during the extrusion process, experimental extrusion investigations have been carried out for the analysis of significant process and tool geometry parameters.Extrusion with porthole dies, i.e. by feeding the elements over bridges inside the die in the aluminum base material flow, was studied to manufacture continuous reinforced, thin-walled, and hollow profiles. Special care was taken to ensure an accurate positioning in the transient material flow to prevent a loss of functionality by insufficient covering and loss of positioning caused by the die geometry or unequal temperature distribution inside the die. Studies on different reinforcement wires and wire ropes based on high strength steel are presented, showing an increasing process stability when using solid wires. General process restrictions are analyzed and process guidelines are presented based on exemplary extrusions.     

钢丝绳探伤仪的模块化设计与研究

对钢丝绳探伤仪进行了模块化分析,并根据模块化设计的思想和概念,阐述了钢丝绳探伤仪功能模块的划分和模块化设计的方法及步骤。对小型工业产品的模块化设计具有一定的参考意义。     

拉索局部腐蚀检测与评估分析

在检测斜拉索腐蚀程度的基础上,分析和探讨拉索腐蚀失效与寿命估算.进而提出索力对于局部应力腐蚀的不敏感性和应定期对服役中的拉索进行全面防护状态检测的建议.      

“探空飞梭”游艺机钢丝绳在线检测和评估的解决方案

＂探空飞梭＂游艺机的安全直接关乎游客生命,其中的钢丝绳又是＂探空飞梭＂安全的最关键部件之一。文章通过实践提出了依据标准,应用MTC钢丝绳电脑探伤仪定期在线检测钢丝绳的解决方案。该仪器可现场检测,由电脑采集数据经过处理,对缺陷作出钢丝绳的断丝、松股、跳丝和变形等缺陷作出定性判断,继而算出钢丝绳磨损的百分数,实现钢丝绳的定性、定位和定量的检测要求。其将为特种设备基于科学仪器的监督检验、风险评估和建立预警系统提供示范和参考。     

Corrosion behaviour of steel ropes for snow and rockfall barriers

Abstract

During service, steel ropes can suffer from corrosion, which can reduce their mechanical properties. This degradation is particularly important in the case of structural ropes, or barriers, for snow and rockfall protection because it is not easy to detect any significant degradation over time due to the locations of these structures, which are often difficult to reach. Moreover, rockfall barriers are frequently used in marine environments to reduce the instability of rocks and cliffs, where corrosive attack by chlorides can be very dangerous. This study has characterised the effects on corrosion of the geometrical configurations of the strands and wires in the ropes, and the benefits of zinc and zinc alloy protective coatings on the wires for reducing the degradation of structural ropes. The aim of the research was to obtain information useful for the design of high durability barriers and the selection of an appropriate rope and coating. An approach based on an electrochemical testing has been compared with one based on classical tests involving the exposure of ropes in aggressive environments (salt spray, humidity chamber, etc.) in order to find an electrochemical method able to distinguish the performance of different materials as well as to monitor the corrosion degradation of barriers in the field.

Using electrochemical techniques it was possible to quantify the corrosion rate and demonstrate the better behaviour of ropes coated with zinc–aluminum alloys in comparison with pure zinc. Moreover it was possible to evaluate the actual reactive area, and therefore the protective geometry effect when comparing two ropes with different geometries. This approach should be extended to further kinds of ropes in order to improve basic corrosion understanding of this important structural component.     

关于钢丝绳电磁检测和强度评估的一些看法

电磁检测是一种可靠的钢丝绳损伤检测方法，但是以钢丝绳破断强度损失作为钢丝绳报废的依据是不合理的。而采用金属横截面损失（LMA）作为报废标准更科学、准确。     

悬索桥主缆缠丝涂装防护

主缆是悬索桥的主要承重受力构件。主缆由高强度镀锌钢丝组成。由于处在跨江、跨海的环境中,主缆可能产生腐蚀。为了保证悬索是安全用使用寿命,必须对主缆进行特殊涂装保护。结合国内已建成的几座特大型悬索桥主缆防护工程,介绍几种主缆缠丝、涂料涂装方案,并对其特点进行分析讨论。     

Wear Evolution in a Stranded Rope Subjected to Cyclic Bending

Wire ropes, due to their construction, combine two very interesting properties: high axial strength and flexibility in bending. However, the assemblage of wires to form flexible ropes results in the sliding of contacting wires and the creation of wear scars, which can act as stress risers and reduce the fatigue life of ropes. Therefore, in order to understand the fatigue behavior of wire ropes, the degradation that occurs between the wires and the strands has to be studied first. In this study, after identifying the main wear patterns for a polymer-covered stranded rope, the wear evolution along the number of cycles and the effect of the sheave diameter in the preferential wear sites were analyzed. The tests were carried out in a custom-made Bending over Sheave (BoS) fatigue test bench and short segments of the rope were analyzed by Scanning Electron Microscope (SEM) and confocal imaging profilometry in order to characterize the wear scars. The worn volume and the wear scar depth were selected as the most suitable parameters to characterize the wear behavior of wires. In addition, the importance of the polymeric cover and sheave diameter was proved: a reduction of the sheave diameter results in a bigger wear rate (μm³/cycle).     

钢丝绳锈蚀、磨损缺陷识别研究

目的发展高性能、低成本基于图像处理技术的钢丝绳缺陷识别方法,实现钢丝绳磨损、锈蚀缺陷的检测。方法首先采用邻域平均法提取钢丝绳的灰度区域特征,接着建立了基于熵统计函数以描述、量化灰度分布特征与灰度波动特征,在此基础上,选取良品、锈蚀缺陷与磨损缺陷三种类型的样品进行区域灰度、灰度分布、灰度波动特征的量化与提取。结果经观测得到不同类型的样品在三维特征空间分布中具有明显的可区分性,基于该特点,可通过设置三维特征的阈值实现对钢丝绳合格品,锈蚀缺陷,磨损缺陷进行识别与区分。结论该基于图像处理的检测方法可高效、准确地实现了对钢丝绳的锈蚀、磨损缺陷的识别,不仅具有学术价值,更具有实用意义,非常适用于在线检测。