Steel Cord Belt Research Articles

Dynamics modeling and simulation of steel cord conveyor belt based on dynamic elastic modulus

Steel cord conveyor belts are widely used in long-distance transportation of various materials. The steel cord belt is composed of rubber and steel cord core, exhibiting excellent viscoelasticity and complex dynamic characteristics during operation. The existing static elastic modulus cannot accurately reflect the real dynamic properties of the conveyor belt. In this paper, based on the catenary theory, the formula for the dynamic elastic modulus of the conveyor belt is derived by introducing the sag and elastic deformation of the steel cord conveyor belt on the basis of the static elastic modulus. The dynamic modeling of the steel cord conveyor belt is carried out using rigid belt block element + flexible beam method. Then, the RecurDyn software is used to establish the dynamic simulation system of the belt conveyor and conduct simulations, which are validated through a test bench. The results show that dynamics simulation based on the dynamic elastic modulus is closer to the real dynamic characteristics of the belt conveyor. Finally, the dynamic characteristics of belt conveyors under different start-up times, different start-up speeds, and idler spacing are analyzed using this modeling and simulation method. The results demonstrate that the dynamic elastic modulus can accurately reflect the real dynamic properties of the conveyor belt, providing a more accurate dynamic modeling and simulation method for the design of belt conveyors.

Automatic Procedure for Steel Cord Belt Splicing Preparation

Automatic Procedure for Steel Cord Belt Splicing Preparation

LITERATURE REVIEW ON TIRE COMPONENT REQUIREMENTS

This paper is a literature review about tire component requirements for innovation in tire construction. Herein are pointed out essential aspects expected in Tires’ structures from the mechanical point of view for future development of a realistic model for advanced simulation of tires (in miscellaneous operating conditions) and innovation in tire mechanics. Being composite structures, tires are made of many elements chosen with delicacy due to their intrinsic physical properties in regards to load effects. Since tires' mechanical behavior is directly linked to the parameters of its constituents (carcass, steel cord belt, and textile cord belt, namely), it is thereof imperative to grasp some solid pieces of knowledge about. Wherefore, the current contribution explored the mechanical requirements to be taken into account in the matrix (rubber) and reinforcements (steel cords and textile cords) for determining the inputs enabling to build up an accurate and simple computer model for improving tires simulation.

Aspects of Selecting Appropriate Conveyor Belt Strength

Breaks in the so-called “continuous” (unspliced) belt sections, and not in the spliced areas, are infrequent but do happen in practice. This article presents some aspects, which may account for such breaks in conveyor belts. It indicates the so-called “sensitive points” in design, especially in the transition section of the conveyor belt and in identifying the actual strength of the belt. The presented results include the influence of the width of a belt specimen on the identified belt tensile strength. An increase in the specimen width entails a decrease in the belt strength. The research involved develops a universal theoretical model of the belt on a transition section of a troughed conveyor in which, in the case of steel-cord belts, the belt is composed of cords and layers of rubber, and in the case of a textile belt, of narrow strips. The article also describes geometrical forces in the transition section of the belt and an illustrative analysis of loads acting on the belt. Attention was also devoted to the influence of the belt type on the non-uniform character of loads in the transition section of the conveyor. A replacement of a conveyor belt with a belt having different elastic properties may increase the non-uniformity of belt loads in the transition section of the conveyor, even by 100%.

Models of Transverse Vibration in Conveyor Belt—Investigation and Analysis

The transverse vibration frequency of conveyor belts is an important parameter describing the dynamic characteristics of a belt conveyor. This parameter is most often identified from theoretical relationships, which are derived on the basis of an assumption that the belt is a stationary elastic string. Belt vibrations have a number of analogies to other tension member systems, such as, for example, power transmission belts. Some research findings suggest that in the case of a limited length of the belt section, a more accurate description of its vibration can be obtained with a beam model rather than with a string model. Experimental research has so far mostly revolved around measurements of stationary belts. This article presents the results of vibration measurements performed for a moving belt and obtained for various operating parameters of the conveyor, as well as for several configurations of the distance between idler supports. The analysis was conducted on a moving steel-cord belt. Belts of this type are commonly used in the majority of mines and industrial plants. The measurement results were compared with the model of a string and with the model of a beam in tension. Both of the theoretical models allowed for the belt speed, whose influence was demonstrated in both theoretical calculations and experimental tests to be negligible. On the other hand, the tensile force in the belt was observed to have a significant impact on the vibration frequency. Depending on the idler spacing, the measurement results are approximate to those of the beam model or of the string model. For spacing smaller than 1.6 m, the belt shows properties approximate to an elastic beam, while for spacing greater than 1.6 m, the belt behaviour can be better represented through a string model. A beam model is, therefore, more applicable in analyses of vibrations in the upper strand of the belt, while a string model is more useful in analyses of vibrations in the lower strand.

Identification of damage development in the core of steel cord belts with the diagnostic system

Belt conveyors are used for transporting bulk materials over distances. The core of the belt, by transferring the longitudinal stresses and ensuring proper frictional coupling of the belt, enables belt movement and transportation of materials on its surface. As the belt cover and edges are used, the belt becomes abraded, and the core is subject to fatigue. The result is the development of cracks in rubber covers across the belt, which leads to the development of damage not only along the cables (the natural direction of water migration and corrosion) but also in the direction transverse to the belt axis. Conducting a series of scans of the St-type belt operating in one of the underground copper ore mines in Poland allowed identifying the number of failures as well as their size and changes over time. These data were in turn used to determine the measures defining the condition of the belt such as the density of defects (the number of defects per 1 m of the belt), the density of the area of damage (the area of damage per 1 m of the belt) and the change in the average area of a single defect over time. By determining the regression of these measures in time and the rate of damage development in both directions (along the axis of the belt and across the belt), it was possible to forecast future states of the belt, as well as to evaluate the costs of different belt replacement strategies and the economic rationalization of the decision to replace them. This research has become possible owing to the development of the DiagBelt system for two-dimensional imaging of the damage to the core of steel-cord belts with resolution sufficiently high to allow tracking the development of single core defects.

The material parameters for computational modeling of long-fibre composites with textile

In this contribution, the composites with textile fibre (cord) and an elastomer matrix are studied based on computational modeling of car tires in combination with experiments. These composite are applied in tire casings for cars, conveyor belts etc. The aim of this research work of authors is creation of computational models namely for stress-strain analyses of selected parts of radial tire casing. The typically passenger car radial tire casing consists of one or two polyester plies in tire carcass and two steel-cord belts and one polyamide 66 cap ply below tread. The finite element method using the program system ANSYS is applied to the computational modeling. For the determination of the material parameters of elastomer and textile cords as input data to the computational models, it was necessary to perform tests as statically tensile tests. Also the experiments of composites as tests of low cyclic loading of composites are needed for verification analyses between computational results and experimental data. For computational modeling, the modulus of elasticity and Poisson ratio are used as material input parameters of textile reinforcements. The results from the computational modeling and selected results from the tests are presented in this contribution.

Random Deterioration Process of Conveyor Belt Evaluated by Statistical Analysis of Core Failures Detected Along Belt Axis and Elapsed Time

Magnetic diagnostic methods are used for steel cord belt condition evaluation since the beginning of 1970s. Initially they generated an analogue signal for several tens of centimetres of conveyor belts scanned sequentially with one measuring head in several cycles or the whole width of the belt at one time thanks to the installation of many measuring heads across the entire cross section. This did not allow identification of single centimetre failures, but rather an aggregate assessment of the state of quite wide waist. Modern diagnostic devices, thanks to miniaturization, allow up to 200 heads per belt width to identify damage of individual cords. Instead of analogue signals, they generate a zero-one digital signal corresponding to a change in the magnetic field sign, which can illustrate damage on 2D images. This makes it easier to identify the location and size of the damage in the belt image. Statistical analysis of digital signals summed up for consecutive sections along the belt axis allows to present both the source signal and its aggregation for band of a given width to form aggregate measures of belt damage such as the damage density per 1 meter of belt. Observation of changes in these measurements at different times allows on evaluation of its rate of change over time, which can be used to forecast future belt condition and to select the proper moment of preventive belt replacement to another one to avoid emergency downtimes (egg in underground mines) or to recondition of belts (egg. in lignite surface mines). The paper presents the results of investigations of the damage condition of a core of a single belt segment working in one of the copper ore underground mines. Scanning of the belt condition was performed few times at intervals of several months. The paper presents the results of the analysis of the changes in core condition, showing the random character of the damage process along the axis and its change over time.

Laboratory measurement of the indentation rolling resistance of conveyor belts

Abstract The indentation rolling resistance of conveyor belts is an important design consideration for long belt conveyors and can also be important for heavily loaded belt conveyors. Indentation rolling resistance is dependent on the properties of the conveyor belt, including the carcass and bottom cover as well as properties of the belt conveyor including induced loads, belt speed, ambient temperature and idler roll diameter. A purpose built laboratory test facility is described to measure the indentation rolling resistance of conveyor belts. The test facility is designed to accept both fabric and steel cord belts and test over a range of typical operating parameters and conditions. Results are presented for a range of test parameters, including; load, belt speed, idler roll diameter, ambient temperature and bottom cover compound. Application of the test data to conveyor design is also presented with the aim being to show how the test facility can be used to improve the accuracy of conveyor belt tension calculations by more accurately evaluating the performance of different rubber compounds and belt constructions.

Replacement of Belt Structure for FEA of Tire

The paper deals with computational modeling of radial tire for cars. The authors used FEA (Finite Element Analysis) utilizing program ANSYS. The authors are oriented not only to the strain-stress analyses of tire. In relation to the tire computational models, the composite structure parts (textile carcass, steel-cord belt and textile belt) cannot be implemented up to the level of reinforcing cords because of the time difficulty as well as the large number of the finite elements. The composite structure parts are partially replaced with some specified stiffness. The paper describes the different ways of replacement of structure represented by the steel-cord belt. These replacements are used for FEA of tire.

Evaluation of the Effectiveness of an Eco-Friendly Technology for Splicing Steel Cord Conveyor Belts

A new eco-friendly method of splicing steel cord conveyor belts without the use of noxious materials has been developed by the Mining Institute at Wrocław University of Technology in collaboration with the Bełchatów Lignite Mine – the two leaders in implementing state-of-the-art and environment friendly technologies in mining in Poland [1,2,3]. Polish lignite mines use belts with steel cords. Such belts are spliced through high temperature vulcanization, which is not safe for the environment and has an adverse impact on human health. Strength and durability are the two main properties of belt splices, having a bearing on the failure-free operation of the belt conveyors used for the haulage of stripped rock or muck in open pit mines [4,5,6]. This means that properly made steel cord belt splices should have the strength and durability parameters similar to the ones of the belt without splices. Many factors contribute to the quality of the splice, including the ones connected with the splicing technology, workmanship and with the fact that splices are made directly on conveyors in heavy mine conditions.

Study on the Steel Cord Belt Joint Monitoring Based on Force Displacement Curve

This paper, based on an analysis into the approaches, at home and abroad, of the conveyor belt joint monitoring, provides an in-depth investigation into the causes and conditions of the belt conveyor tension overload and fractures, finding that the fractures of the joint are random, and are among the most frequently occurring problems, along with steel-cordbelt conveyor belt deviation, drum slipping, roller life, fire, and the steel-cored belt longitudinal tearing etc Therefore, based on the fact that the joint length can be measured by detecting its tension with an senor, this paper investigates the technology of belt joint monitoring by means of the F-L curve,, so as to provide an early warning. This method the system practice shows that: the technology has good application value in production and application, has the vital significance to the enterprise safety production.

Singularity Detection of Magnetic Memory Signal of Steel-Cord Conveyor Belt

Metal magnetic memory technology was an important method for detecting the steel-cord conveyor belt early fault, characteristics of magnetic memory signal extraction is critical for judging of the conveyor belt failure. Generally using of magnetic memory signal maximum gradient value can quickly judge the stress concentration zone, but the magnetic memory signal is susceptible to effected by environmental and noise; In view of the weak and non-stationary characteristics of magnetic memory signal, this paper has proposed the singularity detection method based on wavelet transform modulus maximum for metal magnetic memory signal, the method could exactly judged the stress concentration zone of joints and located the fault points of the steel-cord belt, the characteristic gradient of magnetic memory signal and the Lipschitz exponent were extracted. The result of simulation indicated the technology was effectively for judging the stress concentration zone and fault point. DOI: http://dx.doi.org/10.11591/telkomnika.v11i9.2866

Research on Steel Cord Belt Electromagnetic Testing Real Time Monitoring Technology

Based on the principle of magnetic flux leakage, this paper researches and develops the steel cord belt online testing real-time monitoring system. It take magnetizing and receiving sensor in integrated intensive arrangement, adopt mining intrinsic safe single box-type structure, the temperature is adaptive, free maintenance and avoid debugging. The master control board has two kinds of media communication interface; the transmission distance can be 20km. This system has self-check, parameter setting, data analysis and inquires, report printing, and other functions. Field application show that the system realized high speed, online testing and accurate positioning in steel cord rusting in belt, rope breaking, joint twitch, shifting, zinc coating aging etc. conditions, the judge accuracy rate is more than 99.9 percent.

Research on the Working Condition Monitoring and Protecting System for Mine Belt Conveyor

A new distributed computer system used for real-time monitoring and protecting of mine steel-cord belt conveyor is developed and introduced in this paper. It can accomplish the on-line monitoring of some faults of the conveyor, such as splice breaking, longitudinal rip, fire and tension super-threshold etc. Simulation experiments and industrial experiments show that this system possesses many advantages such as general, high reliability, lower cost, easy installation, evidential suitability, etc. So it is feasible.

Research on the Double-Drum Drive Power Balance of the Hemicycle Deep Trough Belt Conveyor

Under the same output torque of the drive system, the imbalanced degree formula of the motor power was inferred, which expressed with elastic deformation, drum diameter and motor external characteristics. The reason and the main influence factors to the motor power imbalance were analysed. The results show that the best choice of belt conveyor on multi-drum drive occasion is steel cord belt, and the first drum diameter should be slightly bigger than the second drum diameter, in order to make sure the distribution of motor power is relatively balanced.

Dynamic rolling process of tires as layered structures

Due to inner pressure the tire is a prestressed system of cord layers. The cord layers are covered by rubber layers. The whole structure is coated by a wear-resistive thread and a soft side wall coating. Serving as a boundary condition at the cord ends is a steel ring at both sides of the wheel rim. To stiffen the thread the structure has a steel cord belt with a ply angle of ±20° to the circumferential direction. The rolling system works like a spring with changing contact forces, and to compute the car dynamics it is necessary to take into account a high frequency and nonlinear varying contact. The forces between tire and road are limited by friction which gives rise to high frequency friction oscillations. Also the structural dynamics of the tire is nonconservative and self-excited, and an appropriate damping of cords and rubber is needed to stabilize the system dynamically. The computing static equilibrium and equations of motion of a continuum mechanics membrane model are treated, and the discretization to a multi-masspoint model is shown. The resulting nonlinear system of Newtonian equations is solved by using the predictor-corrector integration method in time. The time step of integration is due to the highest frequency of the system, and it is ten times shorter than the minimum of oscillation time in the system. All the nonlinearities, the hysteretic damping, and small bending moments of the rubber layers are taken into account to compute the nonstationary rolling with slip and spin on uneven roads or soft ground.

A failure model for corded composite plates with edge fractures

The tensile strength of composite plates with unidirectional cords depends on the way the load is distributed within the matrix by the cords. Of particular interest is the effect of a broken edge cord or a number of in-line fractured edge cords on the breaking strength of the plate when it is subjected to axial loading. This paper describes a model for estimating the maximum allowable number of broken tensile members in a bonded composite plate before catastrophic failure occurs. The model has application to the analysis of steel-cord and Kevlar-cord elastomer belts containing broken edge cords as the result of impact damage.

Testing steel-cord belt splices with a magnetic conveyor belt monitor

Steel-cord belt splices fail for a variety of reasons, including corrosion, poor vulcanising, and incorrect construction. The latter often leads to early failure. A conveyor belt monitor (CBM) has been used to evaluate the splice lay-up. The mass of the overlapping cords and their magnetic signature are used to rapidly locate suspect splices in the belt. The general shape of the magnetic signature for ideal splices will be discussed.

Steel cord belt reinforced transmission belt: Abatemarco, M.R. US Pat 4 022 071 (10 May 1977)

Steel cord belt reinforced transmission belt: Abatemarco, M.R. US Pat 4 022 071 (10 May 1977)