Cable Length Research Articles

Erection strategy for main cable based on unstrained length of parallel wire strands

This paper presents a construction scheme aimed at achieving one-time erection of strands through precise control of the unstrained length. The scheme entails correcting system errors through the initial strand erection and reducing the influence of random errors by improving manufacturing conditions and increasing field measurements. The key objective is to control cable erection using cable length. A reliability analysis program was developed to assess the accuracy of the main cable installation. A case study of an actual bridge was conducted to verify the feasibility of the scheme. First, an assessment of the distribution characteristics of the random variables was performed. Subsequently, a comparative analysis was performed to evaluate the reliability of the proposed scheme against conventional erection methods. Finally, the new method was validated by on-site installation of several strands. Results revealed that while the reliability of cable formation shape was comparable between the traditional method and the proposed scheme, the latter exhibited superior uniformity of internal force among cable strands after formation. In addition, the average value of the cable length correction for Nos. 2 to 15 strands closely aligns with that of the reference strand, suggesting that the systematic error correction determined by the reference strand exhibits relatively high accuracy. Furthermore, strands erected with cable length as the control objective effectively maintained sag errors within the range of [− 4 mm, 8 mm], demonstrating a high level of precision.

Automatic Cable Harness Layout Routing in a Customizable 3D Environment

Designing cable harnesses can be time-consuming and complex due to many design and manufacturing aspects and rules. Automating the design process can help to fulfil these rules, speed up the process, and optimize the design. To accommodate this, we formulate a harness routing optimization problem to minimize cable lengths, maximize bundling by rewarding shared paths, and optimize the cables’ spatial location with respect to case-specific information of the routing environment, e.g., zones to avoid. A deterministic and computationally effective cable harness routing algorithm has been developed to solve the routing problem and is used to generate a set of cable harness topology candidates and approximate the Pareto front. Our approach was tested against a stochastic and an exact solver and our routing algorithm generated objective function values better than the stochastic approach and close to the exact solver. Our algorithm was able to find solutions, some of them being proven to be near-optimal, for three industrial-sized 3D cases within reasonable time (in magnitude of seconds to minutes) and the computation times were comparable to those of the stochastic approach.

SPH-DEM modeling of cable-controlled ROVs: Underwater mobility and path planning

Remotely operated vehicles (ROVs) are commonly used in water conservation initiatives to inspect underwater structures. However, significant issues remain in guaranteeing the safety of ROVs during field testing, such as loss of control in complex flow regimes and cable breakage. An SPH-DEM numerical model is constructed in this paper to characterize the motion properties of cable-controlled ROVs in complex flow scenarios such as flood discharge, gate leakage, and wave impact. Two dam underwater detection tests are carried out to reveal the damage mode or loss of the cable-controlled ROV. Furthermore, simulations of two benchmark scenarios are used to validate the SPH-DEM coupling model. In the water entry test for a sphere, our simulated depth has a maximum relative error of 12.38% compared to the experimental value, and a maximum relative error of 7.52% compared to the theoretical value. Following that, the interaction mechanism between the submersible vehicle, current, cable, and hydraulic structure is investigated. The findings highlight the importance of flow velocity near the underwater gate and cable length in impacting the precise attitude control of cable-controlled ROVs. Furthermore, it is clear that most occurrences of cable-controlled ROV damage or loss result from the ROV becoming entrapped or from cable breakage. This numerical investigation provides critical insights into guaranteeing the safe operation of cable-controlled ROVs in real-world detection situations.

Mechanical response of tensegrity-origami solar modules

This work studies the mechanics of novel origami solar modules with tensegrity architecture for integration in the dynamic solar façades of energy-efficient buildings. The analyzed modules are deployed by adjusting the rest lengths of cables attached to given nodes, so as to form a tensegrity origami. Their stiffness is tuned by adjusting the pretension of the actuation cables, when the deployment motion is locked. The insertion of solar thermal or photovoltaic panels into the rigid elements of the module makes it possible to form positive-energy solar systems. The work studies the kinematics and the mechanics of the investigated structures through analytic and numerical methods. Two folding motions are examined: to open and close the modules and to track sun rays. The rapid prototyping of a physical mock-up permits an experimental validation of the force–displacement response in a given configuration of the sun-tracking motion. A procedure for the computation of the fundamental vibration modes and vibration frequencies of a quadrangular solar module is also given, and the expected response of the system under wind loading is outlined.

Robust adaptive vibration control of a gantry crane system with flexible cable

SummaryIn this paper, a robust adaptive vibration control method for gantry crane system is proposed considering unknown parameters brought by unknown payload, cable length and tension. The control objective is to transport the cargo to the desired position while suppressing the vibration of the cable in the presence of unknown parameters. For this purpose, a boundary controller is designed with an adaptive law to compensate the parameter uncertainty of the system. The well‐posedness of the closed‐loop system is proved by means of operator semigroup theory and the asymptotic stability of the closed‐loop system is analyzed. Finally, the effectiveness of the proposed control approach is demonstrated through both numerical simulation comparisons and physical experiments.

Design, self-calibration and compliance control of modular cable-driven snake-like manipulators

The high flexibility of cable-driven snake-like manipulators (CDSM) makes them well-suited for tasks in narrow and unstructured spaces. However, ensuring both stiffness and load capacity while maintaining good compliance for safe human-robot interaction is challenging. We design a modular cable-driven snake-like manipulator (MCDSM) and improve its active compliance through impedance control. Firstly, the detachable arm segments of the MCDSM can adapt to multiple tasks. The modular drive units and plug-in drive boxes facilitate quick installation and maintenance. Furthermore, the modified kinematic model considers the torsion angle information of the detachable arm segments. Based on this model, a self-calibration method using redundant cable length is proposed for cable space to joint space. Moreover, a dynamic model for the MCDSM is established. An optimization method for cable tension in joint space is proposed to eliminate the coupling phenomenon during tension control. Finally, a compliant control method for the MCDSM is presented by combining the inner loop for the cable tension control. The feasibility of the proposed methods is demonstrated through simulations and experiments with a prototype.

The Global DAS Month of February 2023

Abstract During February 2023, a total of 32 individual distributed acoustic sensing (DAS) systems acted jointly as a global seismic monitoring network. The aim of this Global DAS Month campaign was to coordinate a diverse network of organizations, instruments, and file formats to gain knowledge and move toward the next generation of earthquake monitoring networks. During this campaign, 156 earthquakes of magnitude 5 or larger were reported by the U.S. Geological Survey and contributors shared data for 60 min after each event’s origin time. Participating systems represent a variety of manufacturers, a range of recording parameters, and varying cable emplacement settings (e.g., shallow burial, borehole, subaqueous, and dark fiber). Monitored cable lengths vary between 152 and 120,129 m, with channel spacing between 1 and 49 m. The data has a total size of 6.8 TB, and are available for free download. Organizing and executing the Global DAS Month has produced a unique dataset for further exploration and highlighted areas of further development for the seismological community to address.

DEVELOPMENT OF A HIGH CAPACITY THREE HEADED COIL-SPOOL WINDING MACHINE

Cable packaging machines are machines that can automatically wrap long and thin materials such as wires, cables and pipes into regular packages. These machines play an important role in cable production and save time and labour in the production process. There are many types of cable packaging machines and they have different features, but in general, all of them ensure that the materials are wrapped in the correct size, tightly packed and transported quickly. In the machine designed and manufactured in this study, cables are packed in perforated spool, slotted spool and coil form. The system consists of 7 sections as unloader, traverse unit, dancer, cable winding heads, spool feeding, pliers group and main control panel. In the designed and manufactured machine, the number of cable winding heads was increased to 3 for the first time and the lost time during the cable winding process was minimized. In the research, the performance of the designed and manufactured machine was tested. As a result of the experiments, it was determined that the machine winds 10-12 coils/min at a cable length of 16,5-25 m and 4,5-5 spools/min at a cable length of 100 m.

The potential of hydrogen-battery storage systems for a sustainable renewable-based electrification of remote islands in Norway

Remote locations and off-grid regions still rely mainly on diesel generators, despite the high operating costs and greenhouse gas emissions. The exploitation of local renewable energy sources (RES) in combination with energy storage technologies can be a promising solution for the sustainable electrification of these areas. The aim of this work is to investigate the potential for decarbonizing remote islands in Norway by installing RES-based energy systems with hydrogen-battery storage. A national scale assessment is presented: first, Norwegian islands are characterized and classified according to geographical location, number of inhabitants, key services and current electrification system. Then, 138 suitable installation sites are pinpointed through a multiple-step sorting procedure, and finally 10 reference islands are identified as representative case studies. A site-specific methodology is applied to estimate the electrical load profiles of all the selected reference islands. An optimization framework is then developed to determine the optimal system configuration that minimizes the levelized cost of electricity (LCOE) while ensuring a reliable 100% renewable power supply. The LCOE of the RES-based energy systems range from 0.21 to 0.63 €/kWh and a clear linear correlation with the wind farm capacity factor is observed (R2 equal to 0.87). Hydrogen is found to be crucial to prevent the oversizing of the RES generators and batteries and ensure long-term storage capacity. The techno-economic feasibility of alternative electrification strategies is also investigated: the use of diesel generators is not economically viable (0.87–1.04 €/kWh), while the profitability of submarine cable connections is highly dependent on the cable length and the annual electricity consumption (0.14–1.47 €/kWh). Overall, the cost-effectiveness of RES-based energy systems for off-grid locations in Northern Europe can be easily assessed using the correlations derived in this analysis.

Applying Screw Theory to Design the Turmell-Bot: A Cable-Driven, Reconfigurable Ankle Rehabilitation Parallel Robot

The ankle is a complex joint with a high injury incidence. Rehabilitation Robotics applied to the ankle is a very active research field. We present the kinematics and statics of a cable-driven reconfigurable ankle rehabilitation robot. First, we studied how the tendons pull mid-foot bones around the talocrural and subtalar axes. We proposed a hybrid serial-parallel mechanism analogous to the ankle. Then, using screw theory, we synthesized a cable-driven robot with the human ankle in the closed-loop kinematics. We incorporated a draw-wire sensor to measure the axes’ pose and compute the product of exponentials. We also reconfigured the cables to balance the tension and pressure forces using the axis projection on the base and platform planes. Furthermore, we computed the workspace to show that the reconfigurable design fits several sizes. The data used are from anthropometry and statistics. Finally, we validated the robot’s statics with MuJoCo for various cable length groups corresponding to the axes’ range of motion. We suggested a platform adjusting system and an alignment method. The design is lightweight, and the cable-driven robot has advantages over rigid parallel robots, such as Stewart platforms. We will use compliant actuators for enhancing human–robot interaction.

Elastoplastic coupling analysis of surrounding rock-prestressed yielding anchor bolts/cables based on unified strength theory

A whole-process analytical theory for the coupled deformation of deep circular tunnel surrounding rock and prestressed yielding anchor bolt (cable) system is derived based on the unified strength theory and non-associated flow rule. This theory considers the strain softening characteristic of rock mass, the yielding reinforced characteristics of anchor bolt (cable), and the support timing. An analytical method is proposed to calculate the difference in displacement of anchor bolts (cables). This study highlights the importance of monitoring anchor bolts (cables) elongation rate in high-stress tunnels by integrating theoretical analysis with engineering practice. The displacement difference that occurs during the coordinated deformation of the bolts (cables) and the surrounding rock provides the support resistance. Therefore, the safety margin standard of elongation rate can be used to assess the integrity and effectiveness of the support structure during the real-time bolts (cables) action. The present study aims to validate the rationality of the analytical theory by conducting numerical simulations using ABAQUS software. Specifically, we focus on analyzing the ground response curves (GRC) underthe bolt (cable) support and the elongation rate of the bolt (cable). Various factors such as prestress, yielding amount, support timing, intermediate principal stress coefficient, radial/longitudinal spacing, and length are considered tocompare and analyze their effects on the GRC. The results showed that anchor bolts (cables) can significantly reduce the surrounding rock convergence. With prestressed bolt (cable) support, the GRC exhibits a stepwise drop, significantly and timely reducing the support force required for the surrounding rock equilibrium. After setting the yielding structure, the increase in anchor cable stress was limited, thereby slightly increasing the surrounding rock displacement. However, the anchor cable elongation rate significantly decreased, thereby greatly enhancing the support structure safety. The support timing affects the starting point of bolts (cables) function. The displacement control effect is more pronounced when support is provided earlier. However, this also leads to an increase in the elongation rate of the bolt (cable). The intermediate principal stress coefficient reflects the self-bearing capacity of the surrounding rock, and increasing this value can improve the deformation control performance of the surrounding rock under anchor bolt (cable) support as a whole and reduce the elongation rate through the coupled function of the surrounding rock–anchor bolt (cable) system. The spacing between anchor cables significantly impacts the convergence control of surrounding rock. Smaller spacing leads to better control of the surrounding rock deformation and lower stress of the anchor cables. As the length of the anchor cables increases, the elongation rate and stress of the anchor cables continuously decrease. However, the surrounding rock deformation exhibits an initially decreasing and increasing pattern. This paper presents a theoretical and computational approach to analyze the effect of prestressed yielding anchor bolt (cable) support and the safety of support structures in tunnel engineering. The findings of this study can serve as a valuable reference for the convergence analysis of circular tunnels in underground engineering.

Sex-specific dendritic morphology of hippocampal pyramidal neurons in the adolescent and young adult rats.

CA1 and CA3 pyramidal neurons are the major sources of hippocampal efferents. The structural features of these neurons are presumed to be involved in various normal/abnormal cognitive and emotional outcomes by influencing the pattern of synaptic inputs and neuronal signal processing. Although many studies have described hippocampal structure differences between males and females, these reports mainly focused on gross anatomical features in adult or aged models, and such distinctions on neuronal morphology and dendritic spine density during adolescence, a period of high vulnerability to neurodevelopmental disorders, have received much less attention. In this work, we analyzed dendritic architecture and density of spines in CA1 and CA3 neurons of male and female rats in early adolescence (postnatal day, PND 40) and compared them with those in late adolescence/young adulthood (PND 60). On PND 40, CA1 neurons of male rats showed more Sholl intersections and spine density in apical and basal dendrites compared to those in females. The Sholl intersections in basal dendrites of CA3 neurons were also more in males, whereas the number of apical dendrite intersections was not significantly different between sexes. In male rats, there was a notable decrease in the number of branch and terminal points in the basal dendrite of CA1 neurons of young adults when compared to their sex-matched adolescent rats. On the other hand, CA1 neurons in young adult females also showed more Sholl intersections in apical and basal dendrites compared to adolescent females. Meanwhile, the total cable length, the number of branches, and terminal points of apical dendrites in CA3 neurons also exhibited a significant reduction in young adult male rats compared to their sex-matched adolescents. In young adult rats, both apical and basal dendrites of CA3 neurons in males showed fewer intersections with Sholl circles, but there were no significant differences in dendritic spine density or count estimation between males and females. On the other hand, young adult female rats had more Sholl intersections and dendritic spine count on the basal dendrites of CA3 neurons compared to adolescent females. Although no significant sex- and age-dependent difference in neuronal density was detected in CA1 and CA3 subareas, CA3 pyramidal neurons of both male and female rats showed reduced soma area compared to adolescent rats. Our findings show that the sex differences in the dendritic structure of CA1 and CA3 neurons vary by age and also by the compartments of dendritic arbors. Such variations in the morphology of hippocampal pyramidal neurons may take part as a basis for normal cognitive and affective differences between the sexes, as well as distinct sensitivity to interfering factors and the prevalence of neuropsychological diseases.

Three-dimensional distributed acoustic sensing at the Sanford Underground Research Facility

Distributed acoustic sensing (DAS) is a valuable tool for monitoring seismic signals as it provides high spatial and temporal resolution strain sensing along the length of a fiber-optic cable. DAS records the seismic wavefields essentially synchronously at each sensing location (i.e., sensing channel with gauge lengths) because the interrogator senses the distributed strain at the speed of light in the fiber. Unlike traditional seismic sensors, DAS has an intrinsic directional sensitivity to the axial strain change along the fiber, leading to difficulties when using standard seismic analysis and interpretations that rely on 3D particle velocity sensing. In addition, cable deployments on the surface can be dominated by high-amplitude wind or urban noise, impeding the detection of low-amplitude distant seismic sources. Here we investigate the capabilities of a unique 3D array with spiral-like portions in the Sanford Underground Research Facility (SURF), the former Homestake Mine, between 1250 m (4100 ft) and 1488 m (4850 ft) in depth for detecting local, regional, and teleseismic sources of ground vibrations. Our pilot array finds that DAS records high frequency (above 5 Hz) vibration sources well, such as mine activities and local and regional blasting events. Furthermore, our deployment method (fiber resting on the surface with rocks placed every meter or so) may contribute to low-frequency noise that contaminates the interpretation of teleseismic waves, particularly lower frequency S-wave arrivals. Nevertheless, this 3D DAS array provides significant data for future analysis as well as the basis for improving and expanding the array in SURF.

New wiggles from old cables: Acquisition, cable, and data aspects

Seismic imaging is essential for detailed characterization and understanding of the subsurface. Traditionally, marine seismic data have been acquired either using towed streamers or ocean-bottom receivers. Distributed acoustic sensing (DAS) is a novel and fast-emerging technology that makes it possible to use fiber-optic cables for acoustic measurements. The technology turns the fiber-optic cable into a densely sampled receiver array. A controlled source experiment comparing DAS and conventional towed streamer data for seismic imaging purposes is described. An existing 130 km telecommunication fiber-optic cable was interrogated to acquire DAS data to analyze the signal at long distances and for subsurface imaging. A seismic source vessel was used to create seismic data along the full cable length, while at the same time acquiring conventional towed streamer data for comparison. In addition, the telecommunication fiber-optic cable was used to acquire passive DAS data. The results show that seismic signals in the telecommunication fiber-optic cable are detectable at distances above 100 km from the source point. Furthermore, comparisons of the DAS data and towed streamer data show that the DAS technology allows for the acquisition of large offset seismic data that are comparable with conventional seismic data. Analysis of the passive DAS data shows that the infragravity waves correlate with the observed weather conditions during the acquisition.

The intelligent Photomultiplier Tubes for OSIRIS

The dimensions of liquid scintillator neutrino detectors have grown over the years. Thus, the analog cable length required for the readout increases. In consequence, the signal loss increases as well. With the intelligent Photomultiplier Tube this problem can be solved. The digitiser is moved as close as possible to the Photomultiplier Tube. This concept allows nearly lossless digitisation of the analog signal. Furthermore, a computing unit next to the analog-to-digital converter enables implementation of on-the-fly data processing and control algorithms. This paper presents the detailed concept and the performance of the intelligent Photomultiplier Tube.

Research on the influence of the connection and withdrawal of a 35 kV bypass system on the power quality of transmission lines

Uninterrupted power supply maintenance has become a trending issue with the increasing reliability requirements for 35 kV power transmission. The bypass operation holds significant importance in 10 kV and 100 kV power transmission maintenance. However, research on live maintenance of a 35 kV bypass system remains scarce and requires urgent supplementation. Therefore, this paper aims to determine the feasibility of live operation for the 35 kV bypass system by studying the impact of its connection and disconnection on the voltage and current of the transmission lines. The existing 35 kV bypass live maintenance system is analyzed and studied concerning the operational process. When the bypass system is connected or disconnected during the maintenance of transmission lines, it may cause changes in the voltage and current, which could affect the safety of power transmission. To address this phenomenon, the paper performs calculations and analysis for different scenarios, including moments of varying voltage amplitudes in the lines and different maintenance cable lengths in the bypass system. Through theoretical analysis and simulation, a comprehensive study of voltage and current variations in two different scenarios of transmission lines has been conducted during the simulation process, including equivalent capacitance and initial conditions for the transmission lines and bypass systems, enabling the simulation of the switching process. Based on calculations and analysis, this paper presents a safety assessment of live operation in the 35 kV bypass live maintenance system.

Dynamic modeling and stability analysis of parafoil traction cable for high altitude wind power generation

In high altitude wind parafoil power generation (HAWPG), parafoil traction cable plays an important role. The cable, which is stretched by the parafoil, is prone to excite vibration even under small disturbances, which affects the stability of the entire HAWPG system. In view of this problem, this paper establishes parafoil traction cable dynamic model and analyzes the unstable regions of the cable parametrically excited vibration. The cable dynamic model, which has axial time-varying velocity and tension, is established based on Hamilton principle. Based on the cable ordinary differential equation, a second-order cable Mathieu–Hill differential equation can be obtained. Then, solve the vibration instability regions caused by changing parameters, the boundaries of different regions on the parameter plane can be directly determined by constructing the periodic solution. Finally, numerical examples and phase portraits are provided to verify the proposed method. The parameters, which includes the cable material properties, length and axial velocity, determined the boundedness of cable vibration. Therefore, the parafoil traction force on the cable should be set appropriately when determining the cable material properties to avoid the unstable vibration.

Damping in stay cable with damper: Practical universal damping curve and full-scale measurement

This paper includes two main parts which are the development of a universal damping curve for cables of cable-stayed bridges with dampers and a full-scale measurement of cable damping. In the first part, the universal damping curve is derived for cables with viscous dampers or High Damping Rubber (HDR) dampers. The proposed damping curve is a single curve which incorporates several cable-damper parameters like cable bending stiffness, boundary conditions at cable ends (hinged, fixed or restraint ends), damper stiffness, damper support stiffness and added negative stiffness. A numerical approach by a finite difference method (FDM) is also developed to verify the proposed universal damping curve. In addition to FDM, the accuracy of the proposed curve was confirmed with damping formulations in literature over ten different damper types. The results showed a good agreement of estimated damping between proposed damping curve and others. Additionally, a significant improvement in estimating cable damping was observed through two available full-scale tests, which compared the results between proposed curve and current curve. The second part in this study presents a full-scale measurement of cable vibration and a real application of the proposed damping curve for the identification of damping in cables of Shinminato Bridge (cable lengths from 100 to 200 m). Both HDR and viscous dampers were used for the cable vibration control of the bridge. The results of damping analysis indicated that the HDR damper effectiveness was higher than 0.7 whereas this effectiveness was smaller than 0.4 for the viscous damper.

Simulations of Deformation Failure Process and Refinement of Reinforcement Scheme in the Dabenliu Quarry Slope Using Discontinuous Deformation Analysis

For this study, the geological engineering features and possible failure modes of the Dabenliu quarry slope in the Jinping-I Hydropower Station were qualitatively analyzed before a method for setting viscous boundary and an algorithm for modeling pre-stressed cables were embedded into a DDA (Discontinuous Deformation Analysis) computer code to analyze the deformation of the slope under seismic loading. Our simulation results revealed that the middle and upper parts of the slope slipped along the bedding joints (interlayer shear zones) and that the lower part buckled and collapsed after the slope was excavated. This is a typical slipping–buckling failure mode characterized by upper-slipping followed by lower-buckling. Based on the distribution of the simulated internal force of the anchor cables, the reinforcement scheme was adjusted by strengthening the support for the middle and lower parts of the slope, whereas the length and pre-stress of the anchor cables were reduced for the upper part of the slope. The adjusted reinforcement scheme can ensure the stability of the slope under the action of a magnitude 7 earthquake, and the slope may lose stability with no evident collapse under the action of a magnitude 8 earthquake. Finally, the simulation results were verified via a comparison with the monitoring data regarding the slope.

Experimental study of a travelling fire along a cable tray assembly in a mechanically ventilated enclosure

This study investigates the behaviour of a fire propagating over a long length of electrical cables, in order to assess the maximum burning length and the associated heat release rate of the travelling fire. It is part of the research work conducted in the framework of the OECD/NEA PRISME 3 project for a better assessment of fire propagation over cable trays in nuclear installations. The fire scenario consists of a set of 3 horizontal cable trays 6 m long, positioned in the corridor of a mechanically ventilated large-scale compartment. The parameters of the study are the nature of the cables (thermoset or thermoplastic types) and the distance of the cable trays from the ceiling. The determination of the fire heat release rate (HRR), the total burning length, the velocity of the flame front, the heat release rate per unit area (HHRPUA) and the effective heat of combustion (EHC) of the cable fires are given. For the configuration studied (3 cable trays and a given load), fire HRRs of 160 kW and 520 kW corresponding to burning lengths of 2 m and 3 m and corresponding to velocities of 0.4 mm/s and 0.9 mm/s are obtained for thermoset cables. For thermoplastic type cables (made of polyvinyl chloride), a power of 730 kW corresponding to a burning length of 3.5 m and corresponding to a velocity of 1.9 mm/s is reported. The order of magnitude for HRRPUA and EHC were respectively ranged between 50 kW/m2 and 150 kW/m2 and 20 MJ/kg and 25 MJ/kg for the two cable types.