Wire Cable Failures in Climbing Anchor Chocks

2007 ◽  
Vol 348-349 ◽  
pp. 165-168
Author(s):  
Jeffrey Vogwell ◽  
Jose Maria Minguez

Anchor chocks are used in the sport of rock climbing for providing secure attachment to a rock face. They are used at regular intervals and must be light weight (since many are carried) and also sufficiently strong to withstand an impact force should a climber fall from a height. In chock design, steel wire cable is widely used for connecting the nut component, which is wedged into a rock crevice, to the free end which attaches, via a karabiner link, to the safety rope. However, the wire cable is vulnerable to failure as it can fray with use at exposed ends - especially when folded into a loop using tight bends. Also, the ferrule end connections are considered a potential design weakness. In a research programme tests have been carried out on new and also some well used anchor chocks and has revealed very different, and some unpredicted, failure modes – depending on the state of the wire rope and whether the applied load at failure was static or impact. This paper presents the results of test failures for a range of chocks and discusses the benefits of using single lengths of wire cable with suitably swaged end ferrules.

2013 ◽  
Vol 655-657 ◽  
pp. 207-210
Author(s):  
Ming Xi Hu ◽  
Sheng Jun Liu ◽  
Yan Jun Zhang ◽  
Zhen Jie Du ◽  
Feng Tian ◽  
...  

Aiming at the damage of package caused by emergency rescue and other severe transportation environment, a multi-level cushioning packaging storage box is proposed in this paper, the precise instrument is fixed in the box, which achieves the box-instrument integration. At the moment when air-dropped box touches the ground, the impact force is absorbed and cushioned through plastic cork base, rubber absorber, box body, steel wire rope spring, hydraulic damper for five times, which could provide effective cushion protection for the precise instrument which fragility value is not less than 15G. Simulation airdrop tests are performed to the storage box with different cushion levels, and the test shows that the result of five-level cushion method proposed in the paper is the best, and overload values are all within 12G, which could provide enough cushion space for precise instrument to avoid touchdown damage.


2021 ◽  
Vol 13 (6) ◽  
pp. 168781402110280
Author(s):  
Genlin Mo ◽  
Jing Liu ◽  
Yongxi Jin ◽  
Wenmin Yan

Stainless steel wire rope isolator is widely used in engineering. To optimize design of the isolator, loading, and unloading characteristics of the 6 × 19 6 mm wire rope under compression are investigated. Ropes of different lengths are tested to get the force-displacement relations. The stiffness, the equivalent damping ratio, and the hysteresis loop of the wire rope are derived. The stiffness decreases with both the length of the rope and the vibration amplitude. It has an approximate linear relationship with the reciprocal of length and amplitude. The equivalent damping ratio has an approximate quadratic relationship with the reciprocal of length and amplitude. The hysteresis loop of the wire rope is described using the proposed quadrilateral model. The loading stage is found to be determined by the length of the rope. The unloading stage is influenced by both the vibration amplitude and the length of the rope. Influences of the excitation amplitude and the frequency on the isolation performance for both steady-state vibration and transient impact vibration are revealed based on the models. The work would help engineers to design the isolators and predict responses of the structures.


Sensors ◽  
2019 ◽  
Vol 19 (17) ◽  
pp. 3763 ◽  
Author(s):  
Zhang ◽  
Jing ◽  
Xu ◽  
Zhan ◽  
Tan

Electromagnetic testing is the most widely used technique for the inspection of steel wire ropes. As one of the electromagnetic detecting approaches, the magnetic flux leakage (MFL) method has the best effect for the detection of broken wires. However, existing sensors based on MFL method still have some problems. (1) The size of the permanent magnet exciter is usually designed according to experience or rough calculation, and there is not enough depth analysis for its excitation performance; (2) Since the detectable angular range for a single Hall component is limited, Hall sensor arrays are often employed in the design of MFL sensors, which will increase the complexity of the subsequent signal processing due to the extensive use of Hall components; (3) Although the new magneto-resistance sensor has higher sensitivity, it is difficult to be applied in practice because of the requirement of the micron-level lift-off. To solve these problems, a sensor for the detection of broken wires of steel wire ropes based on the principle of magnetic concentration is developed. A circumferential multi-circuit permanent magnet exciter (CMPME) is employed to magnetize the wire rope to saturation. The traditional Hall sensor array is replaced by a magnetic concentrator to collect MFL. The structural parameters of the CMPME are optimized and the performance of the magnetic concentrator is analyzed by the finite element method. Finally, the effectiveness of the designed sensor is verified by wire breaking experiment. 1–5 external broken wires, handcrafted on the wire rope with a diameter of 24 mm, can be clearly identified, which shows great potential for the inspection of steel wire ropes.


2017 ◽  
Vol 3 (2) ◽  
Author(s):  
Dwi Putranto N ◽  
Dody Prayitno

Wire rope is made from several steel  wires a combined form a strand, a couple of strands twisted around the core to form a steel rope. One example of its usage is on the bridge to provide support for a heavy load. The steel wire is composed of several parts that is, steel wire, core and wire strand. Increasing the hardness of steel wire have the impact, the hardness of the steel wire. In an effort to improve the hardness of steel wire, there are opportunities to increase the hardness of steel wire with aluminizing method. The aim of this research is to find out the hardness of Wire in aluminizing process with alloys Al - Cu - Sn. Moreover to the research also aims to focus on the addition of Sn element in Al - Cu liquid. The methodology research was preceded by spliting wires from the wire rope. After that cut the wire into the sample wire. Then soak the wire into Al - Cu – Sn liquid at a temperature of 700ºC for ± 3 minutes. Elements of Sn which contained in the composition of Al - Cu - Sn vary from 0 % , 10 % and 20 % , while for CU’s component is 10 % and the rest of is Al, and the latter only elements of Al - Sn, without adding Cu element. Wire samples were then take away and cooled at room temperature, then test the wire by using micro hardness test, the test data was analyzed with Anova and finally made a conclusion. The results of this of this research showed that for the violence that occurs in the intermetallic layer shows the increase in value of hardness obtained on steel wire.


2017 ◽  
Vol 108 ◽  
pp. 01002 ◽  
Author(s):  
Du Wenzheng ◽  
Ma Baozhu ◽  
Xie Zheng ◽  
Cao Dazhi ◽  
Wu Peng

Author(s):  
Zhi Qin ◽  
Qing Huang ◽  
Hongrui Jin ◽  
Hongqian Xue

As a key component of the hoisting system of the crane, the steel wire rope will bear a variety of loading actions such as stretching, bending, vibration and impact in the process of traction hoisting. Therefore, it is important to determinate the dynamic characteristics of the steel wire rope under complex loads and understand the stress-strain state to predict the risk of hoisting operation in advance. This article takes the bridge crane as the engineering background, first, a dynamic model of a steel wire rope lifting system based on ADAMS/Cable was established, and the dynamic stress spectrum of the steel wire rope during the lifting process was calculated and obtained. Secondly, by establishing the geometric model and finite element model of the wire rope, the tensile stress and wire displacement distribution of the wire rope and the contact stress between the wire rope and the pulley and the wires inside the wire rope are analyzed during the lifting process of the crane. The final results show that the instantaneous acceleration of the steel wire rope increases the maximum tensile stress of the steel wire rope by 37% compared with the stable lifting stage at the instant of starting the steel wire rope, causes an increase in the stress amplitude of the wire rope cross section, and the lifting process of the steel wire rope is accompanied by unstable vibration loads. The analysis found that the outermost cross-section of the steel wire rope's outer strand was subjected to the greatest stress, and its local maximum tensile stress amplitude was increased by 56% compared to the stable lifting stage. The contact stress generated by the contact between the steel wire rope and the pulley causes contact wear on the external and internal strands of the steel wire rope, and promotes fatigue fracture of the steel wire rope.


Author(s):  
Ryan M. Woodward ◽  
Margaret M. Cowie ◽  
Tamar J. Caplan ◽  
Jennifer A. Mahan ◽  
Devin McManus

<p>A footbridge was built in 2013 in rural Morocco using lightweight polyester rope, spanning 64 meters (210 feet) across a deep ravine. The area is prone to perennial flash flooding, cutting off access to schools, the local clinic, and the market for weeks at a time. After five years of service, the design team returned to inspect the structural condition, and replace one of the main ropes. The decommissioned rope was subjected to load testing and dissection, and was found to be in excellent condition.</p><p>The novel use of synthetic rope offered some advantages over steel wire rope typically used for this type of project, and the team developed strategies to work efficiently with this unusual material. Particularly, its light weight makes it substantially less costly and simpler to transport to the construction site (the rope was procured in the U.S. and shipped to Morocco in backpacks). As it is less sensitive to the effects of twisting, the rope does not require the level of care typical of wire rope.</p><p>The paper will discuss unique aspects of construction, and challenges related to ongoing maintenance of this type of infrastructure in a developing country.</p>


2015 ◽  
Vol 713-715 ◽  
pp. 122-125
Author(s):  
Li Jun Qiu ◽  
Su Ying Xu

Tire crushing body is divided for the purpose of separating the wire. Wheels of Steel Shares will be made by a single, Stripping the wire and colloidal by roll extrusion. The tread belt layer composed of steel wire rope is made. Peel method using a roll extrusion method can not. It is after stripping tread peeling rope belt layer to peel. Tread was cut into strips at first, then stripped from steel tread belt layer surface,.With a layered approach to rope belt layer stripped from the carcass . You can use sliced ​​or milling method to release the rope. Sliced ​​on the rope can form a sheet body peeling. Milling peeling green tape layer is formed on the wire cutting and tearing. Dividing the body on the fixed milling peeling easier.


2013 ◽  
Vol 483 ◽  
pp. 382-385 ◽  
Author(s):  
Jun Jie Chen ◽  
Hui Wang ◽  
Jing Sheng Lin ◽  
Chao Fu ◽  
Lu Tang

In order to improve the service life of wire rope used n tensile stringing, an automatic cleaning, detection and maintenance integration system was designed. Through the simulation analysis of elastic plates that fix the fixed brushes and the design of the rotating brushes driving system, a wire rope decontamination device assembled fixed brushes and rotating brushes was developed according to the demand of steel wire decontamination. The brush head adopts the design concept of elastic device, which makes the wire rope pressing force adjustable, ensures the wire connectors passable and makes the axial dirt sweeping of different diameter wire rope possible. The overall rotation mechanism with multiple brushes can circumferentially sweep the dirt in the wire rope gap. Then, the wire ropes were comprehensively sweeped with no dead cleanup. The device has been actually used, and the results showed that the decontamination effect is good.


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