scholarly journals Nonlinear isolation performance of 6 × 19 wire rope of different lengths under compression

2021 ◽  
Vol 13 (6) ◽  
pp. 168781402110280
Author(s):  
Genlin Mo ◽  
Jing Liu ◽  
Yongxi Jin ◽  
Wenmin Yan
Keyword(s):  
Hysteresis Loop ◽  
Vibration Amplitude ◽  
Steel Wire ◽  
Damping Ratio ◽  
Excitation Amplitude ◽  
Wire Rope ◽  
Equivalent Damping ◽  
Wire Rope Isolator ◽  
The Wire ◽  
Isolation Performance

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.

Beneficial performance of a quasi-zero stiffness vibration isolator with generalized geometric nonlinear damping

2020 ◽  
pp. 095745652097238
Author(s):  
Chun Cheng ◽  
Ran Ma ◽  
Yan Hu
Keyword(s):  
Damping Ratio ◽  
Nonlinear Damping ◽  
Vibration Isolator ◽  
Equivalent Damping ◽  
Frequency Responses ◽  
Geometric Nonlinear ◽  
Resonant Region ◽  
Force Transmissibility ◽  
Isolation Performance ◽  
Force And Displacement Transmissibility

Generalized geometric nonlinear damping based on the viscous damper with a non-negative velocity exponent is proposed to improve the isolation performance of a quasi-zero stiffness (QZS) vibration isolator in this paper. Firstly, the generalized geometric nonlinear damping characteristic is derived. Then, the amplitude-frequency responses of the QZS vibration isolator under force and base excitations are obtained, respectively, using the averaging method. Parametric analysis of the force and displacement transmissibility is conducted subsequently. At last, two phenomena are explained from the viewpoint of the equivalent damping ratio. The results show that decreasing the velocity exponent of the horizontal damper is beneficial to reduce the force transmissibility in the resonant region. For the case of base excitation, it is beneficial to select a smaller velocity exponent only when the nonlinear damping ratio is relatively large.

Shock isolation characteristics of a bistable vibration isolator with tunable magnetic controlled stiffness

2021 ◽  
pp. 1-28
Author(s):  
Bo Yan ◽  
Peng Ling ◽  
Yanlin Zhou ◽  
Chuan-yu Wu ◽  
Wen-Ming Zhang
Keyword(s):  
Damping Ratio ◽  
Excitation Amplitude ◽  
Relative Displacement ◽  
Vibration Isolator ◽  
Maximum Acceleration ◽  
Vibration Isolators ◽  
Displacement Ratio ◽  
Shock Isolation ◽  
Maximum Relative Displacement ◽  
Isolation Performance

Abstract This paper investigates the shock isolation characteristics of an electromagnetic bistable vibration isolator (BVI) with tunable magnetic controlled stiffness. The theoretical model of the BVI is established. The maximum acceleration ratio (MAR), maximum absolute displacement ratio (MADR) and maximum relative displacement ratio (MRDR) are introduced to evaluate the shock isolation performance of the BVI. The kinetic and potential energy are observed to further explore the performance of the BVI. The effects of the potential barrier, shape of potential well, damping ratio on the BVI are discussed compared to the linear vibration isolators (LVI). The results demonstrate that the intrawell oscillations and snap-through oscillations are determined by the excitation amplitude and duration time of main pulse. MADR and MRDR of the BVI are smaller than those of the LVI. The maximum acceleration peak amplitude of the BVI is far below that of the LVI, especially when the snap-through oscillation occurs. In brief, the proposed BVI has a better shock isolation performance than the LVI and has the potential to suppress the shock of space structures during the launch and on-orbit deploying process.

Wire Cable Failures in Climbing Anchor Chocks

2007 ◽  
Vol 348-349 ◽  
pp. 165-168
Author(s):  
Jeffrey Vogwell ◽  
Jose Maria Minguez
Keyword(s):  
Failure Modes ◽  
Impact Force ◽  
Steel Wire ◽  
Research Programme ◽  
Wire Rope ◽  
Rock Climbing ◽  
Light Weight ◽  
Secure Attachment ◽  
Rock Face ◽  
The Wire

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.

scholarly journals Theoretical Design and Characteristics Analysis of a Quasi-Zero Stiffness Isolator Using a Disk Spring as Negative Stiffness Element

2015 ◽  
Vol 2015 ◽  
pp. 1-19 ◽  
Author(s):  
Lingshuai Meng ◽  
Jinggong Sun ◽  
Wenjuan Wu
Keyword(s):  
Damping Ratio ◽  
Low Frequency ◽  
Harmonic Balance Method ◽  
Steady State Solution ◽  
Excitation Amplitude ◽  
Response Curves ◽  
Disk Spring ◽  
Performance Effects ◽  
Characteristics Analysis ◽  
Isolation Performance

This paper presents a novel quasi-zero stiffness (QZS) isolator designed by combining a disk spring with a vertical linear spring. The static characteristics of the disk spring and the QZS isolator are investigated. The optimal combination of the configurative parameters is derived to achieve a wide displacement range around the equilibrium position in which the stiffness has a low value and changes slightly. By considering the overloaded or underloaded conditions, the dynamic equations are established for both force and displacement excitations. The frequency response curves (FRCs) are obtained by using the harmonic balance method (HBM) and confirmed by the numerical simulation. The stability of the steady-state solution is analyzed by applying Floquet theory. The force, absolute displacement, and acceleration transmissibility are defined to evaluate the isolation performance. Effects of the offset displacement, excitation amplitude, and damping ratio on the QZS isolator and the equivalent system (ELS) are studied. The results demonstrate that the QZS isolator for overloaded or underloaded can exhibit different stiffness characteristics with changing excitation amplitude. If loaded with an appropriate mass, excited by not too large amplitude, and owned a larger damper, the QZS isolator can possess better isolation performance than its ELS in low frequency range.

scholarly journals A Sensor for Broken Wire Detection of Steel Wire Ropes Based on the Magnetic Concentrating Principle

Sensors ◽  
2019 ◽  
Vol 19 (17) ◽  
pp. 3763 ◽  
Author(s):  
Zhang ◽  
Jing ◽  
Xu ◽  
Zhan ◽  
Tan
Keyword(s):  
Permanent Magnet ◽  
Structural Parameters ◽  
Steel Wire ◽  
Sensor Arrays ◽  
Wire Rope ◽  
Hall Sensor ◽  
Wire Ropes ◽  
Depth Analysis ◽  
The Wire ◽  
Lift Off

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.

scholarly journals Design and Characteristics Analysis of a Nonlinear Isolator Using a Curved-Mount-Spring-Roller Mechanism as Negative Stiffness Element

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Han Junshu ◽  
Meng Lingshuai ◽  
Sun Jinggong
Keyword(s):  
Damping Ratio ◽  
Harmonic Balance Method ◽  
Excitation Amplitude ◽  
Negative Stiffness ◽  
Response Curves ◽  
Restoring Force ◽  
Characteristics Analysis ◽  
Stiffness Softening ◽  
Isolation Performance ◽  
Cubic Stiffness

The characteristics of a passive nonlinear isolator are developed by combining a curved-mount-spring-roller mechanism as a negative stiffness corrector in parallel with a vertical linear spring. The static characteristics of the isolator are presented, and the configurative parameters are optimized to achieve a wider displacement range at the equilibrium position where the isolator has a low stiffness and the stiffness changes slightly. The restoring force of the isolator is approximated using a Taylor expansion to a cubic stiffness. Considering the overload and underload conditions, a dynamic equation is established as a Helmholtz-Duffing equation, and the resonance response of the nonlinear system is determined by employing the harmonic balance method (HBM). The frequency response curves (FRCs) are obtained for displacement excitations. The absolute displacement and acceleration transmissibility are defined and investigated to evaluate the performance of the nonlinear isolator, and they are compared with an equivalent linear isolator that can support the same mass with the same static deflection as the proposed isolator. The effects of the amplitude of the excitation, the offset displacement, and the damping ratio on the dynamic characteristics and the transmissibility performance are considered, and experiments are carried out to verify the above analysis. The results show that the overload and underload system can outperform the counterparts with the linear stiffness, softening stiffness, softening-hardening stiffness, and hardening stiffness with the magnitude of the excitation amplitude, and that its isolation performance is generally better than that of a linear system. The transmissibility, response, and resonance frequency of the system are affected by the excitation amplitude, offset displacement, cubic stiffness, and damping ratio. To obtain a better isolation performance, an appropriate mass, not-too-large amplitude, and larger damper are necessary for the proposed isolator.

scholarly journals PENGARUH CAIRAN ALUMINIZING TERHADAP KEKERASAN KAWAT BAJA

2017 ◽  
Vol 3 (2) ◽  
Author(s):  
Dwi Putranto N ◽  
Dody Prayitno
Keyword(s):  
Room Temperature ◽  
Steel Wire ◽  
Intermetallic Layer ◽  
Hardness Test ◽  
Wire Rope ◽  
Heavy Load ◽  
Steel Wires ◽  
The Wire ◽  
Wire Strand ◽  
The Impact

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.

scholarly journals Finite element analysis on the wire breaking rule of 1×7IWS steel wire rope

2017 ◽  
Vol 108 ◽  
pp. 01002 ◽  
Author(s):  
Du Wenzheng ◽  
Ma Baozhu ◽  
Xie Zheng ◽  
Cao Dazhi ◽  
Wu Peng
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Steel Wire ◽  
Wire Rope ◽  
Element Analysis ◽  
The Wire

scholarly journals Multi-Body Dynamics Simulation of Hoisting Wire Rope and Its Stress Analysis

2020 ◽  
Vol 38 (3) ◽  
pp. 485-493
Author(s):  
Zhi Qin ◽  
Qing Huang ◽  
Hongrui Jin ◽  
Hongqian Xue
Keyword(s):  
Tensile Stress ◽  
Cross Section ◽  
Contact Stress ◽  
Stress Amplitude ◽  
Steel Wire ◽  
Geometric Model ◽  
Maximum Tensile Stress ◽  
Wire Rope ◽  
Dynamics Simulation ◽  
The Wire

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.

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