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Dynamics,stability,and control of a four-cable mount system for wind tunnel test

Chinese Journal of Aeronautics 2023年第2期36卷 58-75页

作者： Zhenjun ZHAO Zhanwei ZHAO Yu YAN Kaichun ZENG Xiaojun SHI Han WU School of Mechanical and Materials Engineering North China University of TechnologyBeijing 100144China High Speed Aerodynamics Institute China Aerodynamics Research and Development CenterMianyang 621000China

A four-cable mount system is proposed for full-model wind tunnel flutter tests,which may adjust the pitch and roll attitude of the aircraft scaled model and ensure that the model is not subjected to cable tension.The system provides sufficient support to simulate the free flight of the aircraft by applying appropriate spring stiffness and cable tensions.The proposed fourcable mount system is modeled based on Lagrange mechanics,and its dynamics equations consider aerodynamic effects.The singularity of the system and its bifurcation characteristics under flow conditions are analysed to determine the supercritical bifurcation phenomenon for different tension levels and distances from the front suspension point to the mass centre of the model.The mathematical expressions of the longitudinal flight stability of the cable mount system are derived by linearising the system dynamics equations using small perturbations.The influence of the cable tension,spring stiffness,suspension point position,and other factors on the flight stability of the aircraft are analysed.A feedforward control algorithm is proposed to minimize the total elastic potential energy of the system.The results show that the model is in the level flight state when the elastic potential energy of the four-cable mount system is minimized.A feedback control design method is proposed based on the Lyapunov stability theory to derive the closed-loop stability conditions.The system dynamics model that includes the aircraft rigid body model,flexible cables,pulleys,springs,aerodynamic model,and servo motor control is established using the flexible multibody dynamics method.A multibody dynamics solver and Simulink are used to simulate the attitude adjustment of the model in the wind tunnel and verify the supercritical bifurcation characteristics of the system and the effectiveness of the feedback and feedforward control.

关键词： Bifurcation cable Flight dynamics Flutter Nonlinear control systems Wind tunnels

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Simulation research on cable-laying scheme of HIAF dipole power supply

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Radiation Detection Technology and Methods 2023年第1期7卷 149-158页

作者： Runzu Zhang Anhui Feng Ye Liu Zhongzu Zhou Yongbo Zhang Pengfei Liu Jiancheng Yang Daqing Gao Shuang Ruan Guodong Shen Hengmin Liu Institute of Modern Physics Chinese Academy of SciencesLanzhou730000China Tianshui Electric Drive Research Institute Group Co. LtdTianshui741020China

Background A strong electromagnetic force is the major cause of vibration in dipole power supply cables.Moreover,the long-term operation of cables under vibration conditions leads to structural fatigue failure.Purpose and methods To investigate the cable-laying scheme of a dipole power supply,a finite element model for the electromagnetic–structural coupling between cables and cleats was established.The electrodynamic forces were simulated for fixed-length cables in the horizontal,vertical,and bent models under pulse-current excitation.Subsequently,based on the optimized arrangement mode,the deformation of the cables and the stresses of the cleats were obtained.Results A small cable electrodynamic force was observed in the positive–negative interlace arrangement,and the cable deformation was caused by electrodynamic forces.The maximum cleat deformation occurred at the position with the largest electrodynamic force,where the cleats were reinforced.Moreover,the mechanical characteristics of the cables and cleats under pulse-current excitation are described intuitively and quantitatively,providing theoretical support for the cable-laying scheme of the dipole power supply.

关键词： cable Pulse current Laying scheme Electrodynamic force Vibration

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Underwater Monitoring Networks Based on cable-Structured Triboelectric Nanogenerators

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Research 2022年第2期2022卷 179-190页

作者： Yihan Zhang Yingying Li Renwei Cheng Shen Shen Jia Yi Xiao Peng Chuan Ning Kai Dong Zhong Lin Wang CAS Center for Excellence in Nanoscience Beijing Key Laboratory of Micro-Nano Energy and Sensor Beijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijing 101400China School of Nanoscience and Technology University of Chinese Academy of SciencesBeijing 100049China CUSTech Institute of Technology WenzhouZhejiang 325024China School of Material Science and Engineering Georgia Institute of Technology AtlantaGA 30332USA

The importance ofocean exploration and underwater monitoring is becoming vital,due to the abundant biological,mineral energy,and other resources in the ocean.Here,a self-powered underwater cable-based triboelectric nanogenerator(TENG)is demonstrated for underwater monitoring of mechanical motion/triggering as wllas searching and rescuing inthe sea.Using a novel double-layer winding method combined with ferroelectric polarization,a self-powered cable-structured sensor with a stable electrical output has been manufactured,which can accurately respond to a variety of external mechanical stimuli.A self-powered cable sensing network woven using smart cables can comprehensively transmit information,such as the plane osition anddivedhofasumersbeMorereiely,can analyzeitsdrtionfmovemnt,seedand pathaong w transmiting information such as the submersible's size and momentum.The developed self-powered sensor based on the cable-based TENG not only has low cost and simple structure but also exhibits working accuracy and stability.Finally,the proposed work provides new ideas for future seabed exploration and ocean monitoring.

关键词： cable polarization underwater

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Numerical and analytical simulation of the structural behaviour of fully grouted cable bolts under impulsive loading

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International Journal of Mining Science and Technology 2018年第5期28卷 807-811页

作者： Faham Tahmasebinia Chengguo Zhang Ismet Canbulat Onur Vardar Serkan Saydam School of Minerals and Energy Resources Engineering University of New South Wales

Designing reliable yielding support system to mitigate the effect of the kinetic energy in burst-prone conditions in mining and tunneling excavations is one of the challenges for geotechnical engineers. A combination of the support elements can be used to increase rock strength and minimise the displacement of unstable rock mass. It is important to understand how the support system works to ensure the stability of underground excavations. cable bolts have been commonly used as an effective underground support system and an element of reinforcement to improve rock stability. cable bolts are usually considered to be subjected to static loads under relatively low stress environments, however, in burst-prone conditions, they might be subjected to dynamic loads. cable bolts as well as other support elements are used in burst-prone conditions to absorb the kinetic energy of the removed rock to avoid sudden and violent failures. This paper develops numerical and a novel analytical simulation technique for cable bolts to assess their structural behaviour under static and dynamic loading conditions. The numerical and analytical models are then validated against experimental observations reported in the literature, which demonstrates the reliability of the proposed models.

关键词： cable bolts Yielding support Coal burst Shear dynamic loading

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Modelling and control of a spatial dynamic cable

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Acta Mechanica Sinica 2019年第4期35卷 866-878页

作者： Bo Tian Subhrajit Bhattacharya Department of Mechanical Engineering and Mechanics Lehigh University Bethlehem PA 18015 USA

We study the problem of dynamically controlling the shape of a cable that is fixed at one end and attached to an actuated robot at another end. This problem is relevant to unmanned aerial vehicles (UAVs) tethered to a base. While rotorcrafts, such as quadcopters, are agile and versatile in their applications and have been widely used in scientific, industrial and military applications, one of the biggest challenges with such UAVs is their limited battery life that make the flight time for a typical UAVs limited to twenty to thirty minutes for most practical purposes. A solution to this problem lies in the use of cables that tether the UAV to a power outlet for constant power supply. However, the cable needs to be controlled effectively in order to avoid obstacles or other UAVs. In this paper, we develop methods for controlling the shape of a cable using actuation at one end. We propose a discrete model for the spatial cable and derive the equations governing the cable dynamics for both force controlled system and position controlled system. We design a controller to control the shape of the cable to attain the desired shape and perform simulations under different conditions. Finally, we propose a quasi-static model for the spatial cable and discuss the stability of this system and the proposed controller.

关键词： Lagrangian mechanics Discrete model of cable Control of under-actuated systems

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Dynamic properties analysis of a stay cable-damper system in consideration of design and construction factors

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Earthquake Engineering and Engineering Vibration 2014年第2期13卷 317-326页

作者： Dan Danhui Chen Yanyang Xiao Rong Department of Bridge Engineering Tongji University Henan Provincial Communications Planning Survey & Design Institute Co. Ltd

A numerical solution based on the Steffensen stable point iterative method is proposed to resolve the transcendental frequency equation of a stay cable-damper system. The frequency equation, which considers clamped supports and fl exural rigidity of the cable, is intended to investigate the infl uence of the parameters of the cable damper system on its dynamic characteristics. Two factors involved in the design and construction phases, the damping coeffi cient induced by external dampers and the cable tension, are the focus of this study. Their impact on modal frequencies and damping ratios in these two phases of cable-damper systems are investigated by resolving the equation with the proposed solution. It is shown that the damping coeffi cient and cable tension exert more noticeable effects on the modal damping ratios than on the modal frequencies of stay cable-damper systems, and the two factors can serve as design variables in the design phase and as adjustment factors in the construction phase. On the basis of the results, a roadmap for system-level optimal design of stay cable-damper systems that can achieve global optimal vibration suppression for the entire bridge is proposed and discussed.

关键词： cable damper damping coeffi cient cable tension dynamic property optimal design

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Use of a coded voltage signal for cable switching and fault isolation in cabled seafloor observatories

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Frontiers of Information Technology & Electronic Engineering 2018年第11期19卷 1328-1339页

作者： Zhi-feng ZHANG Yan-hu CHEN De-jun LI Bo JIN Can-jun YANG Jun WANG State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang University

cabled seafloor observatories play an important role in ocean exploration for its long-term, real-time, and in-situ observation characteristics. In establishing a permanent, reliable, and robust seafloor observatory, a highly reliable cable switching and fault isolation method is essential. After reviewing the advantages and disadvantages of existing switching methods, we propose a novel active switching method for network configuration. Without additional communication path requirements, the switching method provides a way to communicate with a shore station through an existing power transmission path. A coded voltage signal with a distinct sequence is employed as the communication medium to transmit commands. The analysis of the maximum bit frequency of the voltage signals guarantees the accuracy of command recognition. A prototype based on the switching method is built and tested in a laboratory environment, which validated the functionality and reliability of the method.

关键词： cabled seafloor observatories cable switching and fault isolation Coded voltage signal Maximum bit frequency

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Free vibration of a sagged cable with attached discrete elements

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Applied Mathematics and Mechanics(English Edition) 2019年第5期40卷 631-648页

作者： W.PAKOS Faculty of Civil Engineering Wroc law University of Science and Technology

An algorithm is presented to analyze the free vibration in a system composed of a cable with discrete elements, e.g., a concentrated mass, a translational spring, and a harmonic oscillator. The vibrations in the cable are modeled and analyzed with the Lagrange multiplier formalism. Some fragments of the investigated structure are modeled with continuously distributed parameters, while the other fragments of the structure are modeled with discrete elements. In this case, the linear model of a cable with a small sag serves as a continuous model, while the elements, e.g., a translational spring, a concentrated mass, and a harmonic oscillator, serve as the discrete elements. The method is based on the analytical solutions in relation to the constituent elements, which, when once derived, can be used to formulate the equations describing various complex systems compatible with an actual structure. The numerical analysis shows that, the method proposed in this paper can be successfully used to select the optimal parameters of a system composed of a cable with discrete elements, e.g., to detune the frequency resonance of some structures.

关键词： free vibration sagged cable with attachments continuous discrete model

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Finite element modeling of cable sliding and its effect on dynamic response of cable-supported truss

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Frontiers of Structural and Civil Engineering 2019年第5期13卷 1227-1242页

作者： Yujie YU Zhihua CHEN Renzhang YAN School of Civil Engineering Central South UniversityChangsha 410000China Department of Civil Engineering Tianjin UniversityTianjin 300072China College of Civil Engineering Chongqing Jiaotong UniversityChongqing 400000China

The cable system of cable-supported structures usually bears high tension forces, and clip joints may fail to resist cable sliding in cases of earthquake excitations or sudden cable breaks. A analytical method that considers the dynamic cable sliding effect is proposed in this paper. cable sliding behaviors and the resultant dynamic responses are solved by combining the vector form intrinsic finite element framework with cable force redistribution calculations that consider joint frictions. The cable sliding effect and the frictional tension loss are solved with the original length method that uses cable length and the original length relations. Then, the balanced tension distributions are calculated after frictional sliding. The proposed analytical method is achieved within MATLAB and applied to simulate the dynamic response of a cable-supported plane truss under seismic excitation and sudden cable break. During seismic excitations, the cable sliding behavior in the cable-supported truss have an averaging effect on the oscillation magnitudes, but it also magnifies the internal force response in the upper truss structure. The slidable cable joints can greatly reduce the ability of a cable system to resist sudden cable breaks, while strong friction resistances at the cable-strut joints can help retain internal forces.

关键词： sliding cable explicit solution framework original length method seismic response cable rupture

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Control mechanism of a cable truss system for stability of roadways within thick coal seams

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Journal of Central South University 2017年第5期24卷 1098-1110页

作者：严红何富连李林玥冯锐敏邢鹏飞 Key Laboratory of Deep Coal Resource Mining Ministry of Education of China (School of Mines China University of Mining & Technology) Faculty of Resources and Safety Engineering China University of Mining and Technology (Beijing) Guizhou Xinlian Blasting Engineering Group Co. Ltd. Department of Mining and Mineral Resources Engineering Southern Illinois University

cable truss systems have been widely applied in roadways with complicated conditions, such as the large cross-sections of deep wells, and high tectonic stress. However, they are rarely applied to roadways with extremely thick coal seams because the control mechanism of the system for the deformation of the roof and the separation between coal rock segments is not completely understood. By using the relationship between the support system and the roof strata, a mechanical model was established to calculate the deformation of the roof in a thick coal seam with bedding separation under different support conditions: with an anchor truss support and without support. On this basis, the research was used to deduce a method for computing the minimum pre-tightening forces in the anchor truss, the maximum amounts of subsidence and separation with, and without, anchor truss support under the roof, and the maximum subsidence and the decreasing amounts of the separation before and after adopting the anchor truss. Additionally, mechanical relationships between the minimum pre-tightening force and the anchoring force in the anchor were analyzed. By taking a typical roadway with thick coal roof as an example, the theoretical results mentioned above were applied in the analysis and testing of a roof supporting project in a roadway field to verify the accuracy of the theory: favorable experimental results were achieved. In addition, the relationships among other parameters were analyzed, including the minimum pre-tightening forces applied by the anchor truss, the angle of inclination of the anchor cable, and the array pitch. Meanwhile, the changing characteristics of the amounts of roof separation and subsidence with key parameters of the support system(such as array pitch, pre-tightening force, and inclination angle) were also analyzed. The research results revealed the acting mechanism of the anchor truss in control of roadway stability with a thick coal seam, providing a theoretical basis of its application in coal mining.

关键词： cable truss system thick coal seam roof separation pre-tightening force

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