Steel Rubber Research Articles

EFFECT OF ENVIRONMENT ON BROMOBUTYL RUBBER–STEEL ADHESION

ABSTRACT Optimizing the maintenance cycles of rubber-lined components is of great importance. Especially for the industry sectors operating under demanding conditions, challenges in the lifetime evaluation of rubber linings may cause apparent premature failures. Thus, understanding the effect of environmental factors on the performance and durability of rubber linings, as well as on the weakest links of the structure in certain environments, is essential. The performances of bromobutyl rubber and rubber–steel interfaces after exposure to different environments, namely, high temperature (95 °C), moisture (95% relative humidity and immersion), and sulfuric acid (solution with 75 g/L of acid) were investigated. The weakest link of the rubber–metal structure and, consequently, the location of the fracture were mostly within the adhesive layer or at the primer–metal interface. However, the most degraded component of the adhesive system depends on the aging environments.

Concrete Containing Recycled Rubber Steel Fiber

To dispose waste rubber tire is one of the major environmental issue all over the world. Every year large number of tires are buried or discarded all over the world causing a serious threat to the environment. Mostly waste rubber tires are used by some industries as fuel but as we know this kind of waste utilization has hazardous effect and can be uneconomical. Therefore, it is needed to use this kind of waste in a such away so that it might not affect the environment at any cost. This paper presents the use of scrap rubber tires as an alternative to steel fiber in fiber reinforced concrete. Four types of concrete mix were prepared, the test batch and the control batch containing 1 % and 5 % replacement of steel fiber and recycled rubber steel fibers by volume of concrete respectively. W/c was kept constant so that the actual field condition can be replicated that are normally adopted at sites. Results showed a reduced compressive and split tensile strength up to 20% and 14% for 1% replacement of RRSF respectively. For 5% replacement of RRSF a reduction of 38% and 42% was observed for compressive and split tensile strength respectively. It was concluded that for replacement rates up to 1% of RRSF by volume of concrete did influence the compressive and split tensile strength of concrete but the samples with recycled rubber steel fibers has somehow showed ductile behaviour rather than brittle. Such behaviour can prove beneficial for structures that require good impact resistance properties. It is recommended to use such kind of concrete for the construction of light weight concrete structures.

Influence of different cord pitch on the pullout force of steel cord conveyor belt splice

The splice is the weakest part of the entire steel cord conveyor belt. And it occurs steel cord twitch fault frequently. If this fault cannot be dealt with timely and accurately, broken belt accidents would be occurred that affecting the safety of production seriously. In this paper, we investigated the different cord pitch pullout of the steel cord conveyor belt splice by using ABAQUS. The finite element model of the ST630 type steel cord conveyor belt was established, same as to the standard of the experimental sample. The pullout force of length 50.0, 70.0, 80.0 and 100.0 mm single steel cord impacted at steel cord conveyor belt splice was numerically computed respectively. The finite element model consists of rubber, steel cord and failure unit. Failure unit is used to simulate the bonding relationship between steel cord and rubber. Mooney-Rivlin hyper-elastic model for rubber was employed in the numerical simulations. Typical results obtained have been validated by experimental result and the relative error between simulation results and experimental results is within 10%. Simulations were also done for cord pitch of 4.0, 4.5, 6.0, 7.0 and 8.0 mm to study its effect on the pullout force of steel cord conveyor belt splice. The variation of cord pitch at normal impact was found to have influence as long as the cord pitch was different. It provides us the numeric value of the pullout force with the different cord pitch, and conducts us selecting the correct steel cord configuration spacing for the steel cord conveyor belt splice, as well for the steel cord conveyor belt. This is an efficient way for avoiding the steel cord twitch fault and the broken belt accident, while ensuring their high reliability and service life.

T16. Imaging propagation of ictal spike-and-wave activity in the cerebral cortex over milliseconds with fast neural electrical impedance tomography

Introduction Electrical Impedance Tomography (EIT) is an emerging medical imaging modality in which the internal impedance of a subject can be imaged using boundary voltage measurements from non-penetrating surface electrodes. It can be used to image neuronal depolarisation over milliseconds as impedance falls when ion channels open during neuronal depolarization. EIT of fast electrical activity due to neuronal depolarisation in the rat cerebral cortex has previously been undertaken with a resolution of 2 ms and μ m using epicortical electrode arrays during evoked potentials and interictal spikes. The purpose of the current work was to use EIT to image ictal spike-wave discharges (SWDs) in the rat cortex and examine the possibility of determining the propagation pattern of this activity through cortical layers. Methods Adult female Sprague-Dawley rats (300–450 g) were anaesthetised with isoflurane; anaesthesia was maintained after surgery with isoflurane and intravenous fentanyl. A large craniotomy was performed on one hemisphere before implanting a 15 × 9 mm257-electrode array, fabricated from stainless steel and silicone rubber, on the cortical surface. Epileptiform events were induced by electrically stimulating the sensorimotor cortex with a 5-s train of 1–2 mA biphasic, charge-balanced square-wave pulses at 100 Hz. For EIT recordings, a 50 μ A sine-wave was injected at 1.7 kHz through a different electrode pair for each of ∼ 30 seizures. EIT images were produced with trigger markers at the peak amplitude of SWDs in the ECoG, averaging over time within one seizure, and over different current pair applications for successive seizures, demodulation of the EIT signal with a ± 500 Hz bandwidth and reconstruction of the processed voltages to produce images with a resolution of 300 μ m and Results There was a maximum impedance change of −0.31 ± 0.06% during the spike phase of averaged SWDs, the early focus of which was spatially confined to the infragranular layers of the primary somatosensory cortex (p Conclusion Fast neural EIT is a novel method which permits visualisation of the trajectory of propagation of ictal activity over milliseconds through the cerebral cortex. This has potential for improving understanding of the pathophysiology of such paroxysmal events and tracking the trajectory of ictal activity throughout the brain in 3D. This could provide a complementary clinical tool to help localise the epileptogenic zone in treatment-resistant focal epilepsies during presurgical evaluation.

FEM Modelling Techniques for Three Point Bend Test of Rubber Composites

This paper studies different modelling methodologies for a calculation of the three point bend test. Test samples are composed of a rubber matrix and either steel or textile cords reinforcement. Prior to the bending tests, all of the used materials including the matrix and the reinforcement were measured to find out their mechanical properties. Rubber materials were described using hyperelastic models. FEM software MSC Marc/Mentat is employed as a calculation tool and its various functionalities are utilized for a description of the test composite models. The main observed outcome is a dependence of the vertical force causing the test sample deformation on the amount of the deformation. Calculated results are compared to each other and to measurements. Then, all the modelling techniques are evaluated.

Steel Cord–Rubber Adhesion with SEM/EDX

ABSTRACTBrass-coated steel cords are widely used as reinforcement material for rubber composites. The adhesion between steel cord and rubber is critical throughout the lifetime use of steel cord/rubber composites; thus, the adhesion mechanism has been a focus of the rubber industry for several decades. Various modern analytical instruments, such as X-ray spectroscopy and mass spectroscopy, have been applied to the study of this bonding interface. In this paper, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX) was used to research the morphology of the steel cord surface and the adhesion mechanism. According to these morphology testing results, the rubber residue bands were observed be orientated and located mostly in Cu/Zn void areas. Further research reveals that macro-structure adhesion layer leads to interlocking mechanism for rubber residue.

REDUCTION OF DISC BRAKE SQUEAL NOISE USING CONSTRAINED LAYER DAMPERS

Brakes squeal has remained to be one of the major NVH challenges in brake system design and development. It has been a concern for automotive industry for decade. Brake researchers have proposed many brake squeal reduction and prevention methods in order to overcome and reduce the squeal that emanates from the brake disc systems. In this paper, the effectiveness of constrained layer dampers (CLD) in reducing disc brake squeal noise was investigated. CLD isolates the brake squeal noise through shear deformations of the viscoelastic materials. Two sets of brake tests were conducted using the brake test dynamometer with the application of CLD. Two different types of CLD were used which are three-layer constrained layer damper and four-layer constrained layer damper. Squeal tests were carried out using brake noise test rig based on the global standard procedure SAE J2521. From the test, four-layer CLD configuration works more efficient than three-layer CLD configuration. CLD made up of nitrile butadiene rubber, silicone rubber and mild steel proved to be the most effective noise insulator at hydraulic pressure range of 5 bar to 30 bar and temperature range of 50oC to 200oC with a maximum noise reduction of 11.3 dBA. Thus, CLD technique was proven to be an effective method in reducing brake squeal noise.

Investigation on dynamic performance of concrete column crumb rubber steel and fiber concrete

In general the Normal Concrete (NC) are by quasi-brittle failure, where, the nearly complete loss of loading capacity, once failure is initiated especially under dynamic loadings. The significance of this study is to improve the damping properties of concrete structure by utilization of the recycled materials from waste tires to be used in concrete as structural materials that improve seismic performance. In this study, the concrete containing 10% of fine crumb rubber and 1 % volume fraction of steel fiber from waste tires is use to investigate the dynamic performance (natural frequency and damping ratio).A small scale column were fabricated from Treated Crumb Rubber and Steel Fiber Concrete (TCRSFC) and NC were cast and cured for 28 days to investigate the dynamic performance. Based on analysis, dynamic modulus, damping ratio and natural frequency of TCRSFC has improved considerably by 5.18%, 109% and 10.94% when compared with NC. The TCRSFC producing concrete with the desired properties as well as to introduce the huge potential as dynamic resistance structure from severe damage especially prevention on catastrophic failure.

Detection of Interfacial Debonding in a Rubber-Steel-Layered Structure Using Active Sensing Enabled by Embedded Piezoceramic Transducers.

Rubber–steel-layered structures are used in many engineering applications. Laminated rubber–steel bearing, as a type of seismic isolation device, is one of the most important applications of the rubber–steel-layered structures. Interfacial debonding in rubber–steel-layered structures is a typical failure mode, which can severely reduce their load-bearing capacity. In this paper, the authors developed a simple but effective active sensing approach using embedded piezoceramic transducers to provide an in-situ detection of the interfacial debonding between the rubber layers and steel plates. A sandwiched rubber–steel-layered specimen, consisting of one rubber layer and two steel plates, was fabricated as the test specimen. A novel installation technique, which allows the piezoceramic transducers to be fully embedded into the steel plates without changing the geometry and the surface conditions of the plates, was also developed in this research. The active sensing approach, in which designed stress waves can propagate between a pair of the embedded piezoceramic transducers (one as an actuator and the other one as a sensor), was employed to detect the steel–rubber debonding. When the rubber–steel debonding occurs, the debonded interfaces will attenuate the propagating stress wave, so that the amplitude of the received signal will decrease. The rubber–steel debonding was generated by pulling the two steel plates in opposite directions in a material-testing machine. The changes of the received signal before and after the debonding were characterized in a time domain and further quantified by using a wavelet packet-based energy index. Experiments on the healthy rubber–steel-layered specimen reveal that the piezoceramic-induced stress wave can propagate through the rubber layer. The destructive test on the specimen demonstrates that the piezoceramic-based active sensing approach can effectively detect the rubber–steel debonding failure in real time. The active sensing approach is often used in structures with “hard” materials, such as steel, concrete, and carbon fiber composites. This research lays a foundation for extending the active sensing approach to damage detection of structures involving “soft” materials, such as rubber.

The Reduction of Static Friction of Rubber Contact under Sea Water Droplet Lubrication

In this work, a series of experimental tests is carried out in laboratory conditions which set the rubber compound (soft and stiff), the normal load, and the direction of propagation of sea water droplets into the interface of rubber–steel pipe contact as variables. The results show that the maximum static frictions (F) of rubber–pipe contacts increase as the normal load increases in both dry and lubricating conditions, and the values of F for the softer rubber are higher than that for the stiffer rubber. However, significant reduction in static friction is found due to the lubrication of sea water droplets. The influence of lubrication is stronger when the droplets propagate into the contact interfaces at the tail edge than that at the front edge. Capture sequences of the contact region facilitate the lubrication of seawater droplets by accelerating the progress of separation in the contact interfaces, thus reducing the static friction force. This investigation improves our understanding of the lubrication of sea water droplets during pipe-laying operation, and it will help us to conduct further research on the accuracy and safety of offshore engineering.

Anti-Bourdon tube pressure gauge

Abstract A novel pressure transducer is investigated in this paper, which works on an anti-Bourdon tube (ABT) principle due to dual effect of differential expansion of the tube at various points and the end moment induced due to asymmetry of cross section. Different materials such as rubber, stainless steel, nickel, brass, copper etc. and different geometries of tubes and bellows are investigated experimentally and analysed using theoretical formulation and Finite Element Analysis. Prototypes of the pressure gauges using rubber, nickel and stainless steel bellow as sensing elements are fabricated and tested. The proposed sensing element will behave similar to the asymmetric metallic tubes but will have about three times higher flexibility and grater rate of expansion and deflection under internal pressure. Comparative results with the existing Bourdon pressure gauge show that the ABT pressure gauge is simple in construction, economical for fabrication, reliable and promising pressure gauge in future. At the end, various design configurations of the pressure sensing element are discussed. By proper selection of geometry, materials and manufacturing of the asymmetric metallic tubes or bellows as sensing element, an ABT pressure gauge can be fabricated to measure pressure ranging from low to high or very high pressures for various potential applications which is not possible using Bourdon tube pressure gauge.

Naval-vessel on board equipment base to minimize structure-borne noise

In order to reduce the structure-borne noise of naval-vessel onboard equipment to meet imposed standards, the equipment exciting force should be restricted and additional anti-vibration devices such as resilient mounts and bellows should be applied. Since the structure-borne noise is dependent on the design of the equipment base, the realization of a low-vibration base design is important. In this study, a typical pump base is optimized using Design of experiment (DOE) and Computer-aided engineering (CAE) techniques, in order to minimize the vibration transferred from the equipment base to the floor. In addition, a sandwich panel consisting of a steel plate and rubber material is applied to the pump base between an anti-vibration mount and the base, so as to reduce the vibration transferred from the pump using the double-mounting-system principle. Consequently, the structure-borne noise reduction achieved by applying the proposed base design is verified via experiment.

Optimization of isolation structure under wind load excitation and experimental study of the wind resistant bearing

The method of collaborative work between steel plate anti-wind bearing (AWB) and rubber isolation bearing is proposed to study the vibration reduction effect of isolation structure under stronger wind load, and the function mechanism is explained. Based on a practical project, three kinds of schemes with different isolation layers are put forward, the finite element software ETABS is used for time history analysis, and comparison is made on the seismic response of different isolated structure and aseismic structure. Comparison result shows that the isolation layer with rubber bearing and AWB can work reasonably, but further optimization on the designed parameters is needed. Moreover, the design value of horizontal bearing capacity of lead rubber bearing (LRB) is appropriate to be close to the seismic isolation layer under wind load excitation. Finally, numerical simulation and comparative analysis of shear test of the AWB are conducted. With a very small yield displacement and yield strength over 80% of the set of horizontal bearing capacity, the AWB is validated to satisfy the working conditions which provide the horizontal bearing capacity under normal operating conditions and designed earthquake. The AWB yields and malfunctions, when the maximum displacement is less than the displacement of the isolation layer.

Experimental Investigation of Static and Dynamic Properties of Steel–Rubber, Cast Iron–Rubber and Epoxy Granite–Rubber as IC Engine Mount

The effective way of reducing the vibration transmitted from the engine to the supporting structures is use of mounts. The mounts are used not only to isolate the vibration but also to withstand the static and dynamic loads of the engine. In this work, the mount structural materials are prepared from steel, cast iron and epoxy granite and tested for the structural properties and damping ratio. The mounts manufactured using these materials and natural rubber are tested using the experimental setup for the dynamic behavior with harmonic excitations. The results of the reaction forces exerted and the respective phase angles during the harmonic excitations showed that the epoxy granite–rubber mount has improved natural frequency and vibration isolation.

Impact-acoustic evaluation method for rubber–steel composites: Part I. Relevant diagnostic concepts

Recycling and retreading is critical for reducing costs and energy consumption for the manufacture of tire casings. An effective retread requires tire casings with good structural integrity and no internal damage. This paper presents an impulse-acoustic nondestructive technique to investigate internal defects in rubber–steel composites such as truck tires. The technique employs a light impactor that taps the structure to be inspected, measuring the impact force with a load cell and analyzing the resulting sound recorded with a microphone in order to discriminate defective regions from defect free regions. Acoustic signatures of both the defective and non-defective side walls of a tire were recorded. The acoustic signatures of were analyzed and the peak amplitude and decay rates demonstrated a suitable correlation in the presence of internal delaminations. This paper seeks to presents an understanding of the fundamental principles underlying the individual measurement and analysis techniques. The results of this investigation show that the acoustic responses can be used to identify the presence of internal delaminations and also may potentially be used to determine their size and location. The effort is part of a project to develop an automated inspection system for truck tires to determine the integrity of the base structure before a retreading operation is performed.

Fuzzy c-means clustering recognition in ultrasonic fault detection in bonding steel plate and rubber material

The article elaborates the use of ultrasonic in testing the quality of the bonding of a steel plate and rubber. We also analyse information such as the echo signal’s attenuation coefficient, harmonic amplitude and frequency, and extract the signal energy, signal duration and the product of singular peak value and quantity, which are regarded as the characteristic values. We use the fuzzy c-means clustering algorithm to make a quantitative analysis on steel plate and rubber bonding quality. The results show that the recognition correct rate of the algorithm is 97·5%, and this method can effectively classify and identify the quality in bonding steel plate and rubber material.

Contribution from the Use of Alternative Materials in Concrete for Accessibility on Sidewalks

This study aims to address the question of accessibility on sidewalks in accordance with Rule 9050 of the Brazilian Association of Technical Standards (ABNT NBR 9050:2004) and analyze the feasibility of using alternative materials (steel fibers, construction waste and rubber) to produce Interlocking tactile concrete paver. It was performed an experimental dosage of concrete with 04 specimens: reference, with steel fiber, with rubber and with steel fiber and construction waste. The pavers molded with conventional concrete and with the addition of alternative materials were tested as for compression strength and water absorption and the results were satisfactory, meeting the specifications of the Brazilian standard.

Modeling of a new semi-active/passive magnetorheological elastomer isolator

This paper presents theoretical modeling of a new magnetorheological elastomer (MRE) base isolator and its performance for vibration control. The elastomeric element of the traditional steel–rubber base isolator is modified to a composite layer of passive elastomer and MRE which makes the isolator controllable with respect to its stiffness and damping. The proposed variable stiffness and damping isolator (VSDI) is designed based on an optimized magnetic field passing through MRE layers to achieve maximum changes in mechanical properties. The controllability of the VSDI is investigated experimentally under double lap shear tests. A model employing the Bouc–Wen hysteresis element is proposed to characterize the force–displacement relationship of the VSDI. An integrated system which consists of four VSDIs is designed, built and tested. Dynamic testing on the integrated system is performed to investigate the effectiveness of the VSDIs for vibration control. Experimental results show significant shift in natural frequency, when VSDIs are activated and the possibility of using the VSDIs as a controllable base isolator.

대중교통수단 특성의 중요도를 고려한 신교통시스템 평가 실증분석

This paper presents an evaluation method that considers the weights of many characteristics of a public transportation system; this method facilitates the selection of suitable advanced transit system in a transportation investment plan. The method sets up twelve evaluation items separated by the following influence factors: users, community, government and operators. It then evaluates the advanced transportation system by analyzing the weights. For an empirical analysis, the urban advanced transportation systems for the main transit of small and medium sized cities were evaluated using the AHP method. The result revealed that the weight order is safety, rapidity and punctuality, convenience, and regional activation, and the priority order is steel wheel-type AGT, LIM, and rubber wheel-type AGT.

Role of Sn on the adhesion in Cu–Sn alloy-coated steel–rubber interface

Cu–Sn coatings with varying Sn content were deposited on steel substrate by immersion route and the effect of variation of Sn content and the substrate roughness on the interfacial adhesion strength of Cu–Sn-coated steel substrates vulcanized with styrene butadiene rubber were investigated. The surface roughness of the coatings did not vary compared to pristine steel substrate with change in Sn weight% in the coatings. The coated surfaces exhibited bare spots or deep trough as micro-discontinuities in the coatings, where formation of Fe2O3 was evident from SEM-EDS, AES, and XPS analysis. Microstructural study of the coating cross-section and coating-substrate interface by transmission electron microscopy of cross-sectioned samples revealed inadequate penetration of coating inside these troughs. Peel test carried out on the Cu–Sn-coated steel–rubber joints showed mixed mode i.e. adhesive and cohesive mode of interfacial fracture irrespective of the coating composition. The peel test further indicated higher interfacial adhesion strength for Cu–Sn-coated samples than pure Cu-coated samples, with an optimum adhesion strength for the coatings containing 3–4 wt.% Sn.