Behavior Of Cables Research Articles

Relaxation behavior of a three-layered wire cable under a combined tension and bending load

Relaxation behavior of a three-layered wire cable under a combined tension and bending load

Burning characteristics of power cables with cone calorimeter

Power cables consist of insulation, padding and sheathing, which are highly susceptible to ignition. Power cables are an important factor affecting fire risk in urban utility tunnels (UUTs). In this paper, the combustion characteristics of four types of power cables (YJV, ZR-YJV, ZR-VV, and ZR-PE) in UUTs were investigated using a cone calorimeter. In this paper, laboratory experiments were conducted to investigate the combustion characteristics of power cables with two different parameters including two heat fluxes (35 kW/m2 and 75 kW/m2) and two sheath thicknesses (3 mm and 5 mm). The effects of heat release rate (HRR), effective heat combustion (EHC), optical density index (ODI) and smoke production rate (SPR) on ignition and combustion were investigated. The results showed that ZR-VV power cables have lower TTI, lower average HRR, lower EHC, higher MLR, and lower SEA than YJV and ZR-YJV power cables.With a conical calorimeter and heat flux of 35 kW/m2, the HRR of the power cables increased within 200 s, while for ODI, the total smoke output of ZR-YJV cables was minimized. Heat flux has a significant effect on HRR, SPR and EHC of ZR-PE cable. Sheath thickness has little effect on HRR, SPR and EHC of ZR-PE cables. In addition, one of the most important parameters, the ignition time, which depends on the composition and structure of the cable, was identified. Finally, the effect of external heat flux is complex and depends on the combustion characteristics of the power cable. Laboratory tests provide useful information for understanding the combustion behavior of power cables, including heat release rate, effective thermal burn, optical density index, and smoke production.

High frequency Modelling of Cables in PWM Motor Drives by Using Polynomial Functions based Parameters

- The high frequency behaviour of the cables in pulse width modulation (PWM) motor drives is of a crucial importance in the analysis of transient overvoltages and conducted electromagnetic interference (EMI) propagation, both common and differential mode. In order to give a tool for simulation of the above cited phenomena, a new method for high frequency cable modelling is proposed in this paper. The method is based on the measurement of the impedance frequency responses of the cables in short and open circuit conditions. The lumped parameters cable behaviour is described by polynomial functions in frequency domain. For a given frequency a simple equivalent circuit representation of the cable is obtained. The proposed model is easily implemented in Matlab/Simulink and it is validated comparing the computed frequency impedance responses of the cable, loaded by either a resistive load or an induction motor, to the corresponding measured ones. Moreover, the prediction, by the model, of the overvoltage at the motor terminals in a long-cable PWM drive is performed. The proposed model are also compared with some commonly used high frequency cable models presented in technical literature.

Multibody dynamic modeling of the behavior of flexible instruments used in cervical cancer brachytherapy.

The steep radiation dose gradients in cervical cancer brachytherapy (BT) necessitate a thorough understanding of the behavior of afterloader source cables or needles in the curved channels of (patient-tailored) applicators. The purpose of this study is to develop and validate computer models to simulate: (1) BT source positions, and (2) insertion forces of needles in curved applicator channels. The methodology presented can be used to improve the knowledge of instrument behavior in current applicators and aid the development of novel (3D-printed) BT applicators. For the computer models, BT instruments were discretized in finite elements. Simulations were performed in SPACAR by formulating nodal contact force and motion input models and specifying the instruments' kinematic and dynamic properties. To evaluate the source cable model, simulated source paths in ring applicators were compared with manufacturer-measured source paths. The impact of discrepancies on the dosimetry was estimated for standard plans. To validate needle models, simulated needle insertion forces in curved channels with varying curvature, torsion, and clearance, were compared with force measurements in dedicated 3D-printed templates. Comparison of simulated with manufacturer-measured source positions showed 0.5-1.2mm median and<2.0mm maximum differences, in all but one applicator geometry. The resulting maximum relative dose differences at the lateral surface and at 5mm depth were 5.5% and 4.7%, respectively. Simulated insertion forces for BT needles in curved channels accurately resembled the forces experimentally obtained by including experimental uncertainties in the simulation. The models developed can accurately predict source positions and insertion forces in BT applicators. Insights from these models can aid novel applicator design with improved motion and force transmission of BT instruments, and contribute to the estimation of overall treatment precision. The methodology presented can be extended to study other applicator geometries, flexible instruments, and afterloading systems.

Response Characteristics and Suppression of Vortex-Induced Vibration of the Flexible Cable

To investigate the vortex-induced vibration (VIV) of a flexible cable in the uniform flow, experiments were conducted using a flexible cable with an external diameter of 80[Formula: see text]mm and a length of 10.48[Formula: see text]m in the wind tunnel. The characteristics of multi-modal VIV, time-frequency and traveling wave behavior of the flexible cable were analyzed. Moreover, the effects of twist direction, diameter and the single/double helical wire on the VIV characteristics of the flexible cable were investigated. It is found that the flexible cable experiences single and multi-modal VIVs in uniform flow at different incoming wind speeds, respectively. For the multi-modal VIV of the flexible cable, the vibration over the time history is dominated by two adjacent modal frequencies and shows a phenomenon of beat vibration. The multi-modal VIV responses of the flexible cable show a mix of standing and traveling wave behaviors, in which the effects of standing wave are more pronounced near both ends and the effects of traveling wave are more dominant in the middle region of the flexible cable. The twist direction of the helical wire has little effect on the VIV responses of the flexible cable. The VIV amplitudes of the flexible cable can be reduced by a single helical wire. With the diameter of the helical wire increases, the suppression effects of the single or double helical wire on the VIV of the flexible cable can be improved. Particularly, the double helical wire with diameter 0.10D can effectively suppress the VIV of the flexible cable.

Experimental Study on High-Temperature Creep Behavior of Full-Locked and Galfan-Coated Steel Cables

Experimental Study on High-Temperature Creep Behavior of Full-Locked and Galfan-Coated Steel Cables

Nonlinear Coupled Vibration Behavior of BFRP Cables on Long-Span Cable-Stayed Bridges under Parametric Excitation

Based on the cable-stayed beam model, this paper studies the nonlinear coupled vibration behavior of basalt fiber-reinforced polymer (BFRP) cables on long-span cable-stayed bridges under parametric excitation. Considering the sag, damping of BFRP cables, and the coupled interactions between stayed cables and the main girder, the nonlinear coupling vibration model of the BFRP cable–beam composite structure has been established. Taking the longest cable of Sutong Bridge as a case study, the nonlinear coupled vibration behavior of BFRP cables under parametric excitation has been numerically analyzed using the finite difference method. The analysis results indicate that (1) under parametric excitation, the large amplitude nonlinear vibration of the BFRP cable will be induced with an evident “beat” phenomenon. (2) Under the same parametric excitation, the nonlinear coupling vibration response and the beta frequency of the BFRP cable were both smaller than that of the traditional steel cable. (3) The nonlinear coupling vibration response of the BFRP cable increased with an increment in excitation amplitude and a decrement in cable force. With the increase in the excitation frequency, weight per unit length, and axial stiffness, the nonlinear vibration response of the BFRP cable increased first and then decreased. Meanwhile, the damping ratio of the BFRP cable had no significant influence on the nonlinear coupling vibration.

Grain size effects on the behavior of silicone rubber high voltage power cables using seagull optimization algorithm

&lt;p&gt;High voltage insulation is one of the most important components of electrical power systems. Polymeric materials have lately supplanted ceramic materials as insulating materials due to their low weight, straightforward structure, high mechanical strength, good performance in the presence of pollution, ease of transportation, and ability to enhance voltage. The purpose of this thesis is to add micro and nano-sized aluminum oxide (Al2O3) fillers to silicone rubber (SIR) to enhance its electrical characteristics. Micro Al2O3filler with contents of 10wt%, 20wt%, 30wt%, and 40wt% was combined with nano Al2O3with contents of 1wt%, 3wt%, 5wt%, and 7wt% to create samples of SIRcomposites. The composites’dielectric strength is evaluated in a variety of environments, including dry, wet, low-salt wet, and high-salt wet circumstances. In order to boost the insulator’s dielectric strength under diverse environmental conditions, this research aims to develop a weight ratio composition for such a composite. The ideal concentration of nano or micro Al2O3fillers has been calculated using the whale optimization algorithm (WOA) and seagull optimization algorithm (SOA).&lt;/p&gt;

Towards realistic nonlinear elastic bending behavior for cable simulation

AbstractThis contribution aims to characterize and model the nonlinear elastic behavior of cables for reliable simulations. To simulate the nonlinear elastic behavior of cables, we use an iterative method, where at each step, an algorithmic local bending stiffness constant is used and updated according to the current cable state. We also formulate an inverse problem to determine the properties of real cables. By solving the inverse problem, the nonlinear elastic behavior for given measurement data is identified, yielding a curvature‐dependent bending stiffness characteristic. In addition, we propose an alternative method based on the balance equations for rods in static equilibrium to identify the bending stiffness characteristic. We apply both methods to experimental data, and the results are compared and discussed.

Improving composite cable performance: Nonlinear thermo-elastic analysis with temperature-dependent pretension and 3D cable elements

Composite cables are widely used in various engineering applications due to their high strength-to-weight ratio and versatility. However, their performance is highly influenced by temperature changes and the application of pretension, which must be considered to perform accurate analysis. Fibrous materials, characterized by their high strength and flexibility, are incorporated into the cable structure to enhance its performance. This research paper presents a comprehensive study on the nonlinear analysis of cable structures made of fibrous materials considering temperature-dependent effects and pretension. A three-dimensional cable element model is employed to accurately capture the complex behavior of composite cables. The proposed approach allows for a more realistic representation of the cable's response, accounting for both mechanical and thermal effects. In order to effectively solve nonlinear equations, the Newton-Raphson (NR) method, a powerful iterative technique for solving nonlinear equations, is employed. This technique is employed to analyze the behavior of composite cables under various loading conditions, accounting for factors such as temperature dependence and pretension. Through extensive numerical simulations, the effects of temperature variation and pretension on the structural performance of composite cables are evaluated. The results provide valuable insights into the behavior of composite cables and offer guidelines for optimizing their performance in real-world applications. This research contributes to advancing composite cable design and engineering practices by considering the intricate interplay between temperature-dependent behavior, pretension, and nonlinear thermo-elastic analysis.

Influence of coiling behavior on axial stress in steel wires of submarine power cables: A numerical study

Coiling processes that are commonly employed to lay submarine power cables to static tanks on ships cause twisting and bending deformations of the cables, potentially affecting the integrity and safety. This study investigates the mechanical behavior of submarine power cables subjected to combined torsional and bending loads using analytical models and finite element method-based software. The objective of the numerical analysis was to evaluate compressive stresses generated within the armor wires of submarine power cables. Additionally, the investigation was extended to assess the potential risk of wire buckling, i.e., bird-caging. The influence of wire pitch length and tank diameter on the magnitude of compressive stress was examined, and the findings revealed a decrease in the likelihood of wire buckling with longer pitch lengths and larger tank diameters. The results of this study will offer valuable insights into the cross-sectional design and the mechanical behavior of submarine power cables subjected to coiling operation.

A nonlinear finite element framework and Gaussian process-based prediction of stick/slip behaviour in semi-parallel wire cables

This paper addresses the effect of wire slipping on the mechanical properties of structural cables. Based on parameter calibration with experimental data, the paper proposes a Finite Element modelling framework aimed at enhancing the prediction accuracy of the stick/slip behaviour of semi-parallel wire (SPW) cables. The model considers the specific arrangement of the SPW cable composition, interwire friction, and residual interlock between wires. Gaussian Process regression is employed as a surrogate model to reduce the model’s computational cost, optimise parameters and quantify uncertainty. The results show high prediction accuracy when compared with experimental data for different pretension forces. The study finds that wire slip varies considerably between wire layers and is significantly influenced by residual interlock between wires. Additionally, cyclic loading under high bending curvatures reveals that the hysteresis behaviour is dependent on wire slip and loading history. The proposed model accurately predicts the stick/slip behaviour of SPW cables, emphasising the importance of accounting for wire slipping in cable analysis models for various applications.

Experimental Study on Combustion Behavior of U-Shaped Cables with Different Bending Forms and Angles

Cables are usually bent into a U-shape to cross obstacles during installation: this includes the upward-bending mode (UBM) and the downward-bending mode (DBM). An experimental study was conducted to investigate the combustion behavior of U-shaped cables with the above bending forms and different angles. The ignition point was set in the middle of the U-shaped cables and the temperature distribution, flame spread rate (FSR), mass loss rate (MLR), flame dimensional characteristics, etc. were measured and analyzed. The results showed that FSR and MLR are positively related to the bending angles, and the FSR is the highest in UBM 90°, close to 6.51 cm/min, which is four times higher than that in the bending angle 0° condition. In the UBM, the heat radiation and convection from the cable flame to the unburned region were more intense and the “eruptive fire phenomenon” occurred during the combustion process, leading to a sharp increase in the FSR in a short time. However, the thermal convection and radiation from the burning region to the unburned region were weakened in the DBM. Meanwhile, the molten outer sheath (PE) would flow along the cables, heating and igniting the unburned region in the DBM. In addition, the FSR, MLR, and peak temperature increased in the UBM compared to the DBM. The highest flame temperature occurred in UBD 90°, approximately 1023 °C.

Analytical and Numerical Study of Underwater Tether Cable Dynamics for Seabed Walking Robots Using Quasi-Static Approximation

In this study, the dynamics of tether cables (TCs) that connect a surface ship and a walking robotic vehicle on the seabed are numerically investigated. The main aim of this study is to develop a reliable prediction model for the dynamic behavior of TCs attached to a seabed walking robot. This system consists of a surface ship, underwater manned seabed walking robot (UMSWR), TC, and winch. The study is comprised of mathematical modeling and numerical simulations of the developed governing equations for the TC dynamics. A relatively simple and efficient mathematical analysis method is proposed to determine the configuration and forces on the TC under a steady state. The problem is solved using the quasi-static technique and lumped mass parameters for discretizing and modeling the dynamics of the TC. Based on the static analysis of the Morrison equation and finite segment method, analytical formulas of the steady-state equation of TC were obtained and solved. The effects of variable water density and variable underwater currents are included in the cable behavior. Consequently, the two-dimensional TC profile and axial tension were estimated in a steady-state configuration. The developed equations were simulated in MATLAB software. Several numerical simulation examples were worked out, demonstrating the accurate performance of the method. Various input parameters of the system and their relationships with the output values were investigated, thereby demonstrating the versatility of the method.

Active control strategy for low frequency vibration of space flexible cables based on improved sliding mode controller

Effective vibration control of flexible cables is increasingly demanded for space flexible structure. For the low frequency dynamics of flexible cables, a novel vibration control strategy based on sliding mode control is proposed in this paper. First, the complex dynamical behavior of flexible cables is modeled using D’Alembert’s principle. Second, an improved dual power reaching law is put forward to better address the chattering problem of the sliding mode controller. Then, an extended state observer (ESO) with the radial basis function (RBF) neural network is designed to compensate for internal uncertainties and external disturbances as well as further improve the control accuracy. Lyapunov function is employed to analyze the stability of the system. Finally, considering the large number of parameters of the proposed controller, an improved particle swarm optimization (PSO) algorithm is designed to automatically adjust these parameters. The effectiveness of the proposed method is demonstrated by simulation results.

Interfacial behavior of soil-embedded fiber optic cables with micro-anchors for distributed strain sensing

Interfacial behavior of soil-embedded fiber optic cables with micro-anchors for distributed strain sensing

Fatigue Analysis of Inter-Array Power Cables between Two Floating Offshore Wind Turbines Including a Simplified Method to Estimate Stress Factors

The use of floating offshore wind farms for electrical energy supply is expected to rise significantly over the coming years. Suspended inter-array power cables are a new design to connect floating offshore wind turbines (FOWTs) with shorter cable lengths than conventional setups. The present study investigates the fatigue life of a suspended power cable with attached buoys connecting two spar-type FOWTs. Typical environmental conditions for the North Sea are applied. The nonlinear bending behavior of the power cable is considered in the analysis. Fatigue assessment is performed using the numerical software OrcaFlex based on stress factors obtained from cross-section analysis. An effective method for obtaining the stress factors is proposed for early engineering design stages and compared with the finite element software UFLEX simulation results. The simplified method delivers similar results for axial tension loads and conservative results for bending loads compared with results obtained from the finite element software. Stress components resulting from curvature variation are identified as the main contributors to fatigue damage. The most critical locations along the power cable for fatigue life are close to the hang-off points.

Prediction of Cable Behavior Using Finite Element Analysis Results for Flexible Cables

In actual industrial sites, verifying the framework for cable manipulation is crucial. Therefore, it is necessary to simulate the deformation of the cable to predict its behavior accurately. By simulating the behavior in advance, it is possible to reduce the time and cost required for work. Although finite element analysis is used in various fields, the results may differ from the actual behavior depending on the method of defining the analysis model and analysis conditions. This paper aims to select appropriate indicators that can effectively cope with finite element analysis and experiments during cable winding work. We perform finite element analysis of the behavior of flexible cables and compare the analysis results with results from experiments. Despite some differences between the experimental and analysis outcomes, an indicator was developed through trial and error to align the two cases. Errors occurred during the experiments depending on the analysis and experimental conditions. To address this, weights were derived through optimization to update the cable analysis results. Additionally, deep learning was utilized to update the errors caused by material properties using the weights. This allowed for finite element analysis even when the exact physical properties of the material were unknown, ultimately improving the analysis performance.

A computationally efficient finite element model for the analysis of the non-linear bending behaviour of a dynamic submarine power cable

This paper proposes a numerical approach based on a detailed 3D FE model to calculate the global mechanical behaviour and local stress state of dynamic submarine power cables. The method is applied to a three-core dynamic submarine power cable under a cyclic bending load. The numerical approach is based on the homogenization theory of periodic structures. The 3D computational domain is thus reduced to the helical period of the internal cable components, which allows the geometrical complexity and contact interactions between the components to be fully considered. In addition, the mesh size is reduced by using beam element modelling of the armour components. The study investigates the sensitivity of the cable bending behaviour to frictional interactions and manufacturing residual stresses. To validate the numerical model, the results are compared with experimental data and analytical results. The first comparison focuses on the overall behaviour of the cable under a cyclic bending load, while a local analysis compares quantities such as displacement and stresses with the results of analytical models available in the literature. The close agreement between the numerical, experimental and analytical results demonstrates the accuracy of the model in predicting the non-linear bending behaviour and local stresses that are essential for the cable design process.

A nonlinear finite element framework for static and dynamic analysis of structural cables with deviating supports

Structural cables are important load-bearing members in many light-weight and slender structures. The mechanical behaviour of tension cables is complex as it is dominated by geometric nonlinearities, complex support conditions and uncertainties arising from the composition of the cable cross section. Numerous models to describe static and dynamic cable behaviour were developed, differing in the model assumptions and the simplifications made. Most common are geometrical linearisation, dimensional reduction, and the disregard of localised support and stiffness effects. Some models take a combination of some geometric nonlinearities, cable bending stiffness and certain boundary effects into account. This paper first presents a literature review aimed at systematically categorising cable force identification models. Based on this, the paper proposes a novel numerical cable modelling framework that allows for accurate predictions of static and dynamic cable response, e.g. for the use in the inverse system identification techniques of Structural Health Monitoring. The saddled cable model is based on a nonlinear Finite Element formulation to account for the geometric and mechanical effects of deviating supports on structural cables even for very large sag cables. After validation with analytical solutions, the models show that the effect of self-weight distribution and cable bending stiffness considerably affects the identified internal force distribution, contact length on the saddle and cable form. Further, the model is used to predict the tension force based on the identified natural frequencies of an external tendon installed on a bridge. Compared with the actual tension force, the saddled cable model provided very high prediction accuracy, even when compared with other cable models. Therefore, it is shown to be very accurate and can be used to determine force-response relationships used in system identification techniques when increased accuracy is needed for such complex cable arrangements.