Rope Systems Research Articles

Substantiation of Parameters of Cargo Movement by Car Rope Systems

Substantiation of Parameters of Cargo Movement by Car Rope Systems

Фундаментальний аналіз та оптимізація (мінімізація) динамічних навантажень у пружних елементах механізмів підйому вантажу кранів. Частина ІІ

A scientifically substantiated methodology of optimization of motion modes of machines and mechanisms (in particular, city-building cranes) based on minimization of integral functionals, which reflect undesirable properties of mechanical systems, and terminal (initial/final) conditions of motion of the mechanism of lifting cargoes by cranes have a physical meaning and are based on Newton's laws of mechanics, is proposed. The modes of motion of specific mechanical systems with a linear function of the position of elements are optimized on the example of mechanisms of load-lifting city-building cranes. It is shown that the influence of motion modes of drive mechanisms on dynamic loads in elastic elements of the mechanism of lifting mechanism of a city-building crane (ropes) is essential. The parameters of such modes of functioning/movement of such systems, at which exactly dynamic stresses of ropes at the stages of start-up of mechanisms of lifting mechanism of cranes are minimized, are determined. The results obtained in the work can further serve to clarify and improve the existing engineering methods of calculation of load lifting mechanisms of urban cranes in order to minimize the dynamic stresses of their rope systems at the start-up stage, as well as to prevent the occurrence of possible emergency situations. Such an approach can be realized both at the stages of design of the mentioned mechanisms and in the modes of proper operation.

Research of telescopic variable Boom length system for flat Boom tower crane

The telescopic principle of its boom section is investigated using the luffing system of the horizontal lifting boom with telescopic operation as the aim. In order to ensure that the normal lifting and luffing work of the trolley can be ensured when the horizontal boom is telescoped and retracted, the support method of the rope system on the horizontal boom, including the lifting rope system, the luffing rope system, and the telescopic rope system, is studied. The procedure for locating the supporting pulley of the three rope systems is investigated, and the alteration in the length of the three ropes caused by the extension or contraction of the horizontal boom is examined. The boom system's force analysis is conducted, and the force expressions of each force member with the expansion and contraction of the boom are obtained, and the force state diagram of each force member is drawn by MATLAB software.

Результаты научных исследований Брянского государственного университета в 2022 году в сфере создания мобильных канатных дорог и лесных канатных машин на базе самоходных колесных шасси

The results of the research activity of scientists of the Academician I.G. Petrovskii Bryansk State University in the field of developing promising domestic designs of mobile aerial rope systems of various functional purposes — mobile ropeways based on self-propelled wheeled chassis of high load capacity and cross-country ability, airmobile cable cars based on container and frame rope installations transported by air transport, forest rope units for logging. The description of the developed mathematical models and methods of modeling work processes during the operation of the specified rope equipment, including the creation of digital twins, traction calculation, analysis of dynamic processes, maintenance planning, etc. is given.

Influence of magnetic reconnection on the eruptive catastrophes of coronal magnetic flux ropes

Introduction: Large-scale solar eruptive activities have a close relationship with coronal magnetic flux ropes. Previous numerical studies have found that the equilibrium of a coronal flux rope system could be disrupted if the axial magnetic flux of the rope exceeds a critical value, so that the catastrophe occurs, initiating the flux rope to erupt. Further studies discovered that the catastrophe does not necessarily exist: The flux rope system with certain photospheric flux distributions could be non-catastrophic. It is noteworthy that most previous numerical studies are under the ideal magnetohydrodynamic (MHD) condition, so that it is still elusive whether there is the catastrophe associated with the critical axial flux if magnetic reconnection is included in the flux rope system.Methods: In this paper, we carried out numerical simulations to investigate the evolutions of coronal magnetic rope systems under the ideal MHD and the resistive condition.Results and discussions: Under the ideal MHD condition, our simulation results demonstrate that the flux rope systems with either too compact or too weak photospheric magnetic source regions are non-catastrophic versus varying axial flux of the rope, and thus no eruption could be initiated; if there is magnetic reconnection in the rope system, however, those flux rope systems could change to be capable of erupting via the catastrophe associated with increasing axial flux. Therefore, magnetic reconnection could significantly influence the catastrophic behaviors of flux rope system. It should be both the magnetic topology and the local physical parameters related to magnetic reconnection that determine whether the increasing axial flux is able to cause flux rope eruptions.

PROSPECTS FOR THE INTRODUCTION OF CABLE CAR TRANSPORT

Objective. The main purpose of this article is to review and analyze the possibilities of integrating cableway transport into the urban environment for unloading and redistribution of passenger flows in large cities, taking into account current issues of energy efficiency and resource conservation. Methods. It is determined that the successful functioning of the state depends on the transport process. At the same time, road transportation is becoming increasingly important. Statistical data for 2020 and 2021 on freight and passenger transportation were used. Statistics on road accidents have been increasing in recent years. The issues of passenger and freight safety are relevant. When designing a modern alternative mode of transport, it is important to consider possible innovative solutions. One of such approaches is the position on energy efficiency and resource conservation. At the same time, energy efficiency concerns not only the engineering processes of these transport systems, but also the operation of cable cars. An innovative solution can be rope systems in which cabins move along the carrier rope and are equipped with their own drive. Results. The main functions and significance of the transport system of the country, the main modes of transport, including passenger, are considered. The transport problem of large cities due to congestion of roads is determined. A review and analysis of the possibilities of integrating ropeway transport into the urban environment for unloading and redistribution of passenger flows in large cities, taking into account current issues of energy efficiency and resource conservation. The prospects for the introduction of cable transport are considered. Scientific novelty. The problems of transport of Ukraine are determined. Statistical data on road accidents, volumes of freight and passenger traffic are used. The proposed solution to unload the roads of large cities, in order to improve the safety of passenger traffic and environmental friendliness in transport. The scheme of self-propelled cable car with individual drive is developed. Practical significance. The issue of energy efficiency concerns the rational use of energy resources, which means that the use of less energy resources will reduce the cost of transportation. The use of energy efficient technologies will allow less detrimental impact on the environment, which is of great importance in a large city.

Assessment of Kernmantle Ropes in terms of Sheath Slippage: Method and Results

Abstract Worksites at height require the protection of workers during both movement and task performance. The rope access technique involves the simultaneous use of working and backup textile rope systems. Currently, kernmantle ropes are most often used in conjunction with mechanisms that move along them and lock at the right moment. However, this mode of operation has a destructive effect on the rope. Ropes must therefore meet a number of specific requirements, one of the most important of which is sheath slippage. The paper presents a method for testing this parameter based on the requirements of EN standards, including the design and implementation of a test stand and a method for the verification of its operation. Test results for 11 types of ropes are presented and discussed. The paper also provides some guidelines for conducting tests.

Visual Sensing Inspection for the Surface Damage of Steel Wire Ropes With Object Detection Method

Nondestructive detection of the steel wire rope (SWR) is an essential scientific means to ensure the safe operation of rope systems, in which the visual sensing inspection method can directly grasp the surface damage condition of SWRs. However, due to the influence of algorithm performance, timely and accurate detection of SWR surface damage has always been a challenging task. At present, manual visual inspection is still the primary method in SWR maintenance. This article proposes an intelligent detection method of SWR surface damage based on an improved you only look once (YOLO) by introducing the object detection algorithm of deep learning (DL) for the first time, called WR-YOLO. The classic version-YOLOv3 was studied, and the backbone network was changed to improve its speed. To improve the algorithm adaptability under different working conditions, the dataset of SWR surface images, including three main states of health (HE), broken wire (BR), and wear (WE), was established. The proposed WR-YOLO was tested on the established dataset and compared with other YOLO algorithms. The results show that the proposed WR-YOLO can achieve a mean average precision (mAP) of 93.92% with a detection speed of 116 FPS, which is better than other YOLO algorithms in performance. Finally, the dynamic detection test was carried out, and the results show that it can achieve an accurate dynamic detection effect. Therefore, this method provides the most advanced visual inspection solution for rope surface damages, which can provide the basis for guiding engineering practice of HE maintenance.

Optimisation of Dynamic Loads of Rope Systems of Lifting Mechanisms of Bridge Cranes During Cargo Handling

Relevance. In this study, considerable attention is devoted to the analysis of dynamic loads that occur in the rope systems of lifting mechanisms of overhead cranes during start-up and braking, and the reduction of these loads.Purpose. To identify the magnitude and nature of changes in dynamic loads in the elements of lifting mechanisms of bridge cranes, a comprehensive dynamic analysis of the lifting mechanism of the bridge crane and its elastic elements (rope systems) was performed.Methods. The dynamic analysis of the above mechanisms and systems was performed on well-grounded mathematical models of bridge-type cranes (single- and double-mass).Results. The analysis of the obtained calculations of mathematical models of the mechanism of lifting the load of bridge cranes demonstrated that the dynamic loads applied to the structural elements and drive mechanisms are oscillatory and comparable to static loads. The analysis of the obtained calculations of mathematical models of the mechanism of lifting the load of bridge cranes demonstrated that the dynamic loads applied to the structural elements and drive mechanisms are oscillatory and comparable to static loads. To minimise the integral functionals, the methods of classical calculus of variations, mathematical physics and differential equations were used to model the dynamics of loading processes of rope systems and drives of bridge cranes, and the terminal (initial and final conditions of movement of such systems) were considered, which allowed solving the optimisation problem unambiguouslyThus, to reduce dynamic loads in structural elements (in particular, in ropes) during transients in such lifting mechanisms of bridge cranes, it is proposed to perform optimisation of the modes of movement of their drive mechanisms. An essential place in such optimisation is occupied by the choice of the optimisation criterion. Among such criteria, integral optimisation criteria were used. As such integral optimisation criteria, the RMS values of the current loads in the elastic elements (ropes) of overhead travelling cranes have been used.Conclusions. Such integral criteria are integral functionalities that usually reflect undesirable properties of machines and their mechanisms, thus, they are subject to minimisation

ДИСПЕРСІЙНИЙ АНАЛІЗ ПОЗДОВЖНІХ ІМПУЛЬСІВ ДЕФОРМАЦІЙ У КАНАТАХ МІНІМАЛЬНОЇ МАСИ ВАНТАЖОПІДЙОМНИХ МЕХАНІЗМІВ КРАНІВ

Dispersion analysis of longitudinal deformation pulses in minimum mass ropes of cranes load lifting mechanisms (which satisfy the conditions of equal strength in each specific cross section) is carried out in the article. The phase and group waveform velocities occurring in the ropes of this type are determined. The impulse dispersion by the method of lifting the load "with the pickup"/"from the base" ("from the ground") was investigated using the stationary phase method. Such methods are used in this work as: 1) classic methods of mathematical physics; 2) complex Fourier transform over time; 3) stationary phase method for the calculation of the integral which characterizes the deformations in the remote field during its asymptotic schedule. It is shown that the asymptotic schedule reduces the analysis of stress and deformation wave fields arising in the rope to the using of the Airy function with a complex argument. The sign of this argument is determined by the sign of the third derivative of the frequency by the wave vector for mentioned above fields near stationary points of the group velocity of wave formations (hear, in accordance, the second derivative is equal to zero). It is substantiated that Airy function is responsible for reproducing the nature of perturbations before and after the wave front moving inside the rope system. The phase velocity with which the constant phase plane of the exponential multiplier is carried in the rope is determined. This multiplier the spatial-temporal dependence of the emerging waveform describes. Near the pulse front (load/deformation of the rope), its duration increases, but the amplitude decreases in proportion to the cubic root of the distance to the observation point. The formula is established, according to which the asymptotic of this problem solution should be built, in the case of the curve extreme of waveform propagation group velocity in the rope. A similar approach gives the possibility to explore the main patterns of no stationary wave fields generated in the ropes of cranes load lifting mechanisms. The results obtained in the work can be used for establishing cranes rope systems loads and deformations quantities estimates under the condition of their transience. Such loads/deformations usually cause of the above systems overstrain when lifting or lowering loads with different types cranes (particularly, bridge, gantry, portal), which work in operation modes (real operation mode) and can lead to emergencies (for example, breaks in rope systems).

Результаты научных исследований Брянского государственного университета в 2021 году в сфере проектирования и моделирования рабочих процессов в мобильных транспортно-перегрузочных канатных комплексах

The results of scientific research activities of scientists of the Academician I.G. Petrovskii Bryansk State University in the development of promising domestic samples of designs of mobile transport and reloading rope systems and ropeways based on self-propelled wheeled chassis of high carrying capacity and cross-country ability and the creation of scientifically substantiated methods for their design and computer simulation of work processes during operation. The description and analysis of the effectiveness of new technical solutions of mobile passenger and cargo aerial ropeways are given.

Исследование нагруженности линейно-протяженных конструкций при использовании обжимных устройств

The article presents scientific approaches to the study of the stress-strain state of linearly extended structures containing crimping devices. Examples of such structures include rope systems, pipelines for transporting media under pressure. The study of the stress-strain state of a gas pipeline on which a steel coupling used for the repair of substructures is installed is considered in detail.

Fatigue resistance of steel ropes: failure criterion: Background to the verification in prEN 1993‐1‐11:2020

AbstractMany steel rope systems are subjected to fluctuating tensile loads and therefore can fail due to fatigue. Available fatigue test data indicate that rope diameter, mean stress, socket type, lay angle and rope length influence the fatigue resistance. Most of the tests were terminated before full failure of the ropes. This paper shows that the test termination criterion, such as fracture of the first wire, fracture of 5 % of the wires or full rope fracture, has a large influence on the resulting fatigue resistance. A probabilistic analysis is carried out for a rope system in a bridge, demonstrating that the required structural reliability levels are met when considering full failure as the end‐of‐life criterion for ropes.

S‐N curve for full‐locked coil ropes: Background to the verification in prEN 1993‐1‐11:2020

AbstractMany steel rope systems are subjected to fluctuating tensile loads and therefore can fail due to fatigue. There are indications that the fatigue resistance of full‐locked coil ropes is somewhat lower than that of other types of rope. Fatigue test data on full‐locked coil ropes have been collected, but they terminate at different conditions. A semi‐empirical model is employed to extrapolate the test results to full failure of the rope. The resulting S‐N curve is being adopted for the revision of European standard prEN 1993‐1‐11.

Результаты научных исследований Брянского государственного университета в сфере мобильных транспортно-перегрузочных канатных систем и комплексов

The results of scientific research activities of scientists of the Academician I.G. Petrovskii Bryansk State University in the development of promising domestic samples of designs of mobile transport and reloading rope systems and ropeways based on self-propelled wheeled chassis of high carrying capacity and cross-country ability and the creation of scientifically substantiated methods for their design and computer simulation of work processes during operation. The description and analysis of the effectiveness of new technical solutions of mobile passenger and cargo aerial ropeways are given.

The failure analysis of the drilling rig hoisting steel wire rope

Drilling rigs belong to the lowest-safety level of hoisting rope systems. The valid regulation for drilling permits the usage of steel ropes on condition that their permanent safety does not decrease under the value 2.5. Considerable dynamic and cyclic stresses, abrasion and corrosive environment generated during the operation cause rapid fatigue and rope damage. The stress of the rope in operation leads to the specific precautions ensuring the safety rope work. The specific precautions include monitoring of the rope tractive work measured in tonne-kilometres (ton-kilometres services). The working part of the hoisting ropes of the drilling rigs - after the stated number of tonne kilometres was worked off - is slipped and a regular non-destructive rope test (NDT) is recommended. Rope under sizing, failing in rope slipping program and non- implementation of NDT controls led to the situations endangering the drilling crew safety. After the critical situations the operator decided to perform the analysis of the condition of all ropes.

CHARACTERISTICS OF ELECTRIC MOTORS, SYSTEMS OF HOISTING AND TRANSPORT, CONSTRUCTION, ROAD VEHICLES AND EQUIPMENT. THE THIRD LECTURE

The material for the third lecture on the subject “Theory of hoisting and transport, construction, road vehicles and equipment” is the main focus of the paper including the most important issues for the characteristics of electric motors of hosting and transport, construction, road facilities and equipment, for the calculation of power of electric motors with the criterion of the activation duration and selection of engines for RMS power. In addition, it considers systems of hosting and transport, construction, road facilities and equipment, namely their power and speed tackle gears and concerns the efficiency of movable and fixed blocks of rope systems.

The effects of ascent technique and the presence of leaves on loading of a tie-in point during climber ascents

The use of throwlines has made it easier for climbers on the ground to set a tie-in point (TIP) near the top of the tree. But doing so may increase the likelihood of TIP failure because smaller branches have less load-bearing capacity and close inspection of the TIP from the ground is difficult. We measured rope tension during climber ascents on stationary rope systems on ten TIPs from two species. The climber ascended using three techniques and we repeated trials when trees were in- and out-of-leaf. From the load time history of each trial, we computed the magnitude and frequency of loading, and we counted the number of peak loads. Ascending with two foot ascenders and a hand ascender induced greater loads than footlocking or using two foot ascenders and gripping the rope by hand, and there were distinct loading frequencies when using two foot ascenders but not footlocking. The presence of leaves was associated with more peak loads, but not when footlocking. The presence of leaves increased the maximum load induced when ascending on foot and hand ascenders, but decreased the maximum load when footlocking. Our results both align with and address important limitations of previous work.

Loads borne by a tie-in point during ascents and descents on a basal-anchored stationary rope system

Previous studies that quantified or simulated loads on a tie-in point (TIP) during climber ascents, abrupt stops during descents, and falls considered crown-anchored stationary rope systems (SRS). But climbers also use basal-anchored SRS when working in trees, and because both parts of the rope—lead and fall—carry a load, the TIP presumably bears a greater load than on a crown-anchored SRS. In this study, tension in the fall and lead of a rope used in a basal-anchored SRS was measured during climber ascents and abrupt stops during descents. As expected, loads borne by the TIP were greater than on a crown-anchored SRS. Loads also varied among three species selected for varying degrees of bark roughness; greater loads were borne on the TIPs of a smooth-barked species. It was also noteworthy that pre-loading a TIP to determine its safety, which climbers do before ascending, increased the total load during ascents, presumably because tension set during the pre-load was not released in the fall of the rope prior to the ascent. To reduce the likelihood of TIP failure, climbers are advised to take care when selecting a TIP that will support a basal-anchored SRS.

Ideal MHD instabilities for coronal mass ejections: interacting current channels and particle acceleration

We review and discuss insights on ideal magnetohydrodynamic (MHD) instabilities that can play a role in destabilizing solar coronal flux rope structures. For single flux ropes, failed or actual eruptions may result from internal or external kink evolutions, or from torus unstable configurations. We highlight recent findings from 3D magnetic field reconstructions and simulations where kink and torus instabilities play a prominent role. For interacting current systems, we critically discuss different routes to coronal dynamics and global eruptions, due to current channel coalescence or to tilt-kink scenarios. These scenarios involve the presence of two nearby current channels and are clearly distinct from the popular kink or torus instability. Since the solar corona is pervaded with myriads of magnetic loops -- creating interacting flux ropes typified by parallel or antiparallel current channels as exemplified in various recent observational studies -- coalescence or tilt-kink evolutions must be very common for destabilizing adjacent flux rope systems. Since they also evolve on ideal MHD timescales, they may well drive many sympathetic eruptions witnessed in the solar corona. Moreover, they necessarily lead to thin current sheets that are liable to reconnection. We review findings from 2D and 3D MHD simulations for tilt and coalescence evolutions, as well as on particle acceleration aspects derived from computed charged particle motions in tilt-kink disruptions and coalescing flux ropes. The latter were recently studied in two-way coupled kinetic-fluid models, where the complete phase-space information of reconnection is incorporated.