Steel Rubber Research Articles

Change of Axial Forces in Layered Rubber–Steel Base Isolators of High-Rise Buildings at Earthquake Impact

Change of Axial Forces in Layered Rubber–Steel Base Isolators of High-Rise Buildings at Earthquake Impact

Impact of Chatter Amplitude on Surface Roughness of Carbide Insert Tool Using Laminates among Tool and Tool Holder


 Chatter seems throughout the metallic reducing method as a result of resonance resulting from the interaction of the prominent natural frequencies of the gadget with the frequency of chip serration. Chatter leaves a lousy floor finish on the part and negatively affects dimensional tolerances, decreased productiveness, immoderate device wear and damaged device-device components. This paper provides an progressive approach to chatter suppression throughout turning manner by way of offering extremely-thin steel rubber laminates between carbide insert device and tool holder via growing the stiffness of the device. The dynamic behavior of the workpiece and device with laminates are simulated the usage of ANSYS and investigated experimentally. it's miles obvious that with the introduction of rubber brass laminates among tool and device holder the amplitude of vibration of tool decreased and thereby floor finish of workpiece advanced.

Impact of Chatter Amplitude on Surface Roughness of Carbide Insert Tool Using Laminates Among Tool and Tool Holder

Chatter seems throughout the metallic reducing method as a result of resonance resulting from the interaction of the prominent natural frequencies of the gadget with the frequency of chip serration. Chatter leaves a lousy floor finish on the part and negatively affects dimensional tolerances, decreased productiveness, immoderate device wear and damaged device-device components. This paper provides an progressive approach to chatter suppression throughout turning manner by way of offering extremely-thin steel rubber laminates between carbide insert device and tool holder via growing the stiffness of the device. The dynamic behavior of the workpiece and device with laminates are simulated the usage of ANSYS and investigated experimentally. it's miles obvious that with the introduction of rubber brass laminates among tool and device holder the amplitude of vibration of tool decreased and thereby floor finish of workpiece advanced.

Study on Shear Resistance Property of a New PBL Connector with Steel–Rubber Tenon

In order to improve the shear resistance and structural ductility of the perfobond rib (PBL) connector, a new PBL connector with steel-rubber tenon is proposed in this study, which aims to increase the shear load capacity of the connector while improving the ductility of the connector. First, models of new PBLs are established based on the validated finite element method, and their mechanical properties are compared with other shear connectors. The results show that the stiffness and shear load capacity of the proposed connector can be effectively improved when the steel ring is added, where the shear stiffness can be reduced, and the deformation capacity of the specimen can be improved when the rubber ring is added. When a steel ring with a thickness of 5 mm and a rubber ring with a thickness of 5 mm are involved, the shear load capacity of the connector with steel-rubber tenon is increased by 13.7%, and the shear stiffness is reduced by 37.3% compared to the conventional concrete tenon connector, while the ductility is increased by 75.1% compared to the connector with steel ring tenon. Subsequently, as for the connectors with steel-rubber tenon, the effects of the thickness of the steel ring, the thickness of the rubber ring, the diameter of perforated rebar, the strength of concrete and the strength of perforated steel plate are analyzed based on the finite element model of a PBL. The results show that an increase in the thickness of the steel ring, the diameter of the perforated rebar and the strength of the concrete will cause an increase in the shear stiffness and shear load capacity of the connector; however, an increase in the thickness of the rubber ring can cause a decrease in the shear stiffness and shear load capacity of the connector, while a change in the strength of perforated steel plate has little effect on the shear stiffness and shear load-carrying capacity. Finally, based on the finite element parametric analysis results and the damage mechanism of the proposed connector, a calculation equation applicable to the PBL connector with steel-rubber tenon is presented to predict the shear load capacity of the connector.

Rubber Dam Clamp May Cause Cortical Necrosis: A Case Report

Tooth isolation methods used during endodontic procedures are necessary to create an aseptic field and protect the patient’s alimentary tract from irrigation and instrument insult. This case details changes that can occur in mandibular cortical bone architecture after the use of a stainless steel rubber dam clamp during an endodontic procedure. A 22-year-old, otherwise healthy woman underwent nonsurgical root canal therapy on tooth #31 (mandibular right second molar, symptomatic irreversible pulpitis and periapical periodontitis.) Cone-beam computed tomographic imaging obtained between treatments revealed irregular erosive and lytic changes of the crestal-lingual cortical bone, resulting in sequestrum formation with infection and exfoliation. Continued monitoring and 6-month post-treatment CBCT imaging revealed complete resolution without further intervention. When a stainless steel rubber dam clamp is placed onto gingiva overlying mandibular alveolar bone, bony changes can occur presenting with radiographic signs of cortical erosion and may result in necrosis of the cortical bone with sequestrum formation. Knowledge of this potential outcome improves our understanding of the normal course progression after dental procedures using a rubber dam clamp for tooth isolation.

Experimental investigation on static compressive toughness of steel fiber rubber concrete

Abstract Recycled rubber particles can be produced by using waste tires. Adding recycled rubber particles to concrete can form rubber concrete (RC). RC can not only reduce the amount of natural sand and reduce the cost of concrete but also improve the static compressive toughness of concrete. Adding steel fiber into RC can improve the strength of concrete. In order to study the compressive toughness of steel fiber rubber concrete (SFRC), rubber particles washed with NaOH are added to steel fiber reinforced concrete. This can enhance the bonding performance between the recycled rubber particles and concrete. The volume ratio of recycled rubber is 5, 10, and 15%. Prismatic and cubic test blocks were prepared and their compressive tests were carried out. The results show that the stress interaction between the rubber particles and steel fiber in concrete significantly improves the compressive strength, elastic modulus, and stress–strain relationship of concrete. The compressive toughness and ductility of concrete are improved. When the content of rubber particles is 15–20%, the compressive toughness of SFRC is improved most obviously. Through experiments, the toughness index and specific toughness of rubber steel fiber reinforced concrete are calculated, which explores a new way and method for studying the compressive toughness of similar recycled material concrete.

An experimental study on mechanical behavior of nylon fabric laminated rubber bearings

Five samples of the nylon fabric laminated rubber bearing were manufactured with different rubber layer thickness and nylon cloth specifications. The compression and compression shear tests were conducted to evaluate the mechanical properties of the bearings. Results show the novel bearings’ vertical stiffness is significantly lower than that of laminated steel rubber bearings, but their vertical damping ratio can reach 7%. The effective horizontal stiffness decreases with increasing shear strain due to rollover deformation. The bearings do not get seriously damaged when the shear strain is 300%. The equivalent damping ratio of the bearings varies in the range of 9%–13%.

Use of Liquidambar Orientalis Mills in natural rubber compounds as an alternative to synthetic resins

Phenolic resins are useful additives that provide various functions for rubber compounds during compounding and vulcanization, as well as after cure. Natural resins are considered as strong alternatives to synthetic ones due to environmental concern. Liquidambar Orientalis Mills is an endemic plant and grows in many different geographies including Turkey. In this study, the phenolic resin obtained from Liquidambar Orientalis Mills has been studied regarding its functions in a generic natural rubber compound. It was incorporated into the rubber compound with and without selected gum and phenolic resins so that mainly obtaining competitive adhesion properties. Both individual and collaborative effects of the natural resin were evaluated. Rheological, thermal, morphological, mechanical and adhesion properties of the compounds were studied comparatively along with the non-linear cure kinetics. Liquidambar Orientalis Mills has been found to be a good alternative to both gum and phenolic resins in rubber compounds. Besides, significant improvement could be achieved for particularly rubber–steel adhesion.

A study on the use of fundamental antisymmetric-like guided wave for health monitoring of elastic–viscoelastic bilayer structures

This study investigates the ultrasonic guided wave propagation in an elastic–viscoelastic (steel–rubber) bilayer structure. 2D finite element models are developed in the frequency domain to simulate the wave propagation in the steel–rubber bilayer structure. The guided wave A0 mode is generated in the bilayer with a contact L-wave probe and detected with an out-of-plane laser vibrometer. Several wave features, such as amplitude, phase velocity and phase delay, are measured and compared to determine the characteristic changes of the A0 wave mode in the steel layer alone as well as in the bilayer structure. Studies are also performed for the bilayer structure when excited from the steel and rubber surfaces. The amplitude and phase velocity of the A0 mode are reduced in the bilayer compared to the steel layer alone. The phase velocity of the A0 wave mode in the bilayer does not depend on the viscoelastic properties of the rubber layer, rather depends only on the elastic properties of the rubber layer. The viscoelastic rubber layer in the bilayer structure does not sustain any independent wave mode; instead, it carries the A0 mode of the steel layer alone as a modified A0 wave mode in the bilayer structure. A parametric numerical study of the viscoelasticity of the rubber layer in the bilayer structure shows that the attenuation of the modified A0 mode in the bilayer is more affected by the bulk S-wave attenuation than the bulk L-wave attenuation. The rate of attenuation of the modified A0 mode in the bilayer is faster on the rubber surface than on the steel surface. A study on the A0 wave mode interaction with the interfacial disbond between steel and rubber layers is also carried out.

Graphene Nanoplatelets Modified Chemlok® Adhesive System for Natural Rubber – Aluminium Bonded Component in Engine Mount

Generally, the engine mount is made from rubber and mild steel bonded with a Chemlok® adhesive system. It could be modified to provide sufficient bonding between natural rubber and aluminum. Therefore, this work aims to study a nano-manipulated adhesive system by modifying the existing Chemlok® adhesive system at different weight percentages of graphene nanoplatelets (GNPs) loading via two steps ultrasonic-assisted stirring process by ultrasonic bath and hot plate. The natural rubber (NR)-aluminum (Al) substrates were bonded using a hot press machine under the pressure of 100 kgf/cm2 for 20 minutes at 140 °C temperature. The samples were subjected to a 90-degree peel test based on ASTM D429 by the UTM machine, and the peel-fractured surfaces were evaluated both physically and under SEM. The adhesive strength increased with the increment of GNPs in the modified Chemlok® 205/220 system. The GNPs modified Chemlok® system achieved 30% improvement than the existing adhesive. The analyses proved the modification was successful. The modified system with GNPs dispersed at certain intercalation levels showed active functional groups, reinforcing effects, and thermal stability.

Studying Seismic Stability of Buildings Constructed Using Lift-Slab Method and Equipped with Rubber-Steel Seismic Isolators

As the construction industry develops, unique unconventional methods of improving the seismic stability of buildings are used. One of these methods is the seismic isolation of buildings using special isolating supports. Rubber steel supports with high damping ability can improve the seismic stability of the building by 1.5 times on average. Since the seismic stability of the buildings constructed using the lift-slab method was set at up to 7 points, we expect to increase it to 8-9 points through the installation of the rubber steel supports in these buildings. The implementation of the current seismic resistance improvement methods for the existing buildings and structures shall help achieve the following: improve the preparation of the authorities and residents to major earthquakes; significantly reduce seismic risks and the consequences of both major earthquakes and industrial disasters caused by earthquakes; provide the economic and social stability of the country in case of emergencies.

Investigating the Vacuum Extractors of Biomedical Devices of Different Materials and Pressures on the Fetal Head during Delivery

Operative delivery requires the use of a vacuum extractor; obstetricians can choose the appropriate vacuum extractor to make the delivery process smoother and safer. However, there is no biomechanical literature focused on the imposed effects of a vacuum extractor prepared with different materials and vacuum pressure on the fetal head during the process of delivery. Therefore, we first established and performed the finite element analytical model to explore the influences of vacuum extractors manufactured from different materials on the fetal head under various extractive pressures. The model of the vacuum extractor was designed as a hemispherical shape, and the material of the vacuum extractor was composed of silicone rubber and stainless steel for comparison. Four different vacuum pressures (500 cm H2O, 600 cm H2O, 700 cm H2O, and 800 cm H2O) were applied as the factors for investigation. The reaction force on the fetal head, von Mises stress of vacuum extractor, and von Mises stress on the skull of fetal head were measured and analyzed to evaluate the effects. The results revealed that subtle divergent influences of different vacuum pressures were observed, and the stainless-steel vacuum extractor induced a larger reaction force (358.04–361.37 N), accompanied with stress (13.547–13.675 MPa), on the fetal head than non-metallic or relatively softer materials. The results provide a reliable basis for selecting proper vacuum extractor during operative delivery to avoid obstetrical complications, such as scalp scratch, cephalohematoma and even intracerebral hemorrhage.

Research on the Construction Technology of Self-Monitoring Asphalt Concrete

Combined with the paving of the test section of Self-monitoring Asphalt Concrete, the electrode burying mode of pavement construction is designed according to its characteristics, and the best mixing method and spreading rolling construction technology are compared and analyzed. The results show that the construction structure of the test section is reasonable and feasible, the best mixing effect can be obtained by adding conductive phase material and asphalt at the same time, and the rolling process. The order of rubber wheel and steel wheel compaction has no significant effect on compaction degree.

Mechanical properties and freeze-thaw resistances of bronze-concrete composites

Studies in the literature show that the physical and mechanical properties of concrete could be improved by the incorporation of different kinds of industrial waste, including waste tire rubber and tire steel. Recycling of waste is important for economic gain and to curb environmental problems. In this study, finely ground CuAl10Ni bronze is used to improve the physical and mechanical properties, and freeze-thaw resistances of C30 concrete. The density, cold crushing strength, 3-point bending strength, elastic modulus, toughness, and freeze-thaw resistances of concrete are determined. In addition, the Schmidt Rebound Hammer (SRH) and the ultrasonic pulse velocity (UPV) tests, which are non-destructive test methods, are applied. SEM/EDX analyses are also carried out. It is noted that a more compacted structure of concrete is achieved with the addition of bronze sawdust. Then higher density and strength values are obtained for concretes that are produced by bronze addition. In addition, concretes including bronze sawdust generally show higher toughness due to high plastic energy capacities than pure concrete.

Study on Mechanical Properties of Steel Fiber Rubber Recycled Brick Concrete

In order to study the mechanical properties of steel fiber rubber recycled brick concrete, ten groups of recycled brick concrete specimens with the strength of 15MPa were tested , one group was purely recycled brick concrete, the remaining nine groups mixed with different rations of admixture. Three groups mixed with steel fiber, another three groups mixed with rubber granules, the last three groups mixed with both steel fiber and rubber granules. These concrete specimens were tested by pressure testing machine respectively, the maximum strength is calculated by its maximum stress value. The results proved that: when adding steel fiber to recycled brick concrete can improve the strength of concrete, the higher the percentage of steel fiber was added, the more obvious the increases in strength. The recycled brick concrete mixed with rubber granules showed a reduced strength of the concrete, the higher percentage of rubber granules were added, the more significant drop in strength. When added the same percentage of both steel fiber and rubber granules, the result showed an increased strength of recycled brick concrete, as the percentage of two kinds of admixture dosage increases simultaneously, the strength increases rapidly.

Optimizing Viscoelastic Properties of Rubber Compounds for Ballistic Applications

Using interlayers of rubber adds a positive effect to the synergy of disruptor–absorber armors. Emerging from its viscoelasticity the material is able to transform mechanical stress into heat. The dynamic mechanical properties of elastomers depend on both ambient temperature and frequency of an applied mechanical load. The damping shows a maximum in the glass transition area. If the frequency of the glass transition is in the magnitude of the mechanical stress rate applied by ballistic impact, the elastomer will undergo the transition and thus show maximized damping. An ideal material for ballistic protection against small calibers is developed by making use of dynamic mechanical analysis and the time–temperature superposition principle. The material is later analyzed by ballistic experiments and compared to other nonideal rubbers with regard to glass transition temperature, hardness and damping. It is shown that by choosing a material correctly with certain glass transition temperature and hardness, the ballistic properties of a steel–rubber–aluminum armor can be enhanced. The chosen material (butyl rubber) with a hardness of 50 °ShA is able to enhance energy absorption during ballistic impact by around 8%, which is twice as good as other rubber with non-optimized properties.

Eco-efficient preplaced recycled aggregate concrete incorporating recycled tyre waste

This experimental study explores the development of highly eco-efficient concrete. This concrete incorporates 50% higher coarse aggregate content compared with normal concrete, thus reducing cement demand, and its granular skeleton is entirely recycled. Moreover, it adopts a unique energy-efficient placement technique whereby the granular skeleton is first preplaced in the form and then injected with a flowing grout, which considerably reduces the energy of mixing and placement. Various mixtures incorporating recycled concrete aggregate along with recycled rubber granules and steel wire fibres retrieved from scrap tyres were made. The mechanical strength and post-cracking behaviour of the eco-efficient concrete were evaluated. While tyre rubber decreased mechanical strength as expected, scrap tyre steel wire fibres enhanced the tensile and flexural behaviour, exhibiting superior energy absorption and ductility compared to the brittle failure of the control mixture. The results provide an insight into the level of recycled tyre rubber and steel wire that could be combined with recycled concrete aggregate to achieve durable and cost-effective eco-efficient preplaced recycled aggregate and rubberised concrete for sustainable non-structural applications.

The effect of cyclic loading on the rubber bearing with slit damper devices based on finite element method

In this paper, slit steel rubber bearing is presented as an innovative seismic isolator device. In this type of isolator, slit steel damper is an energy dissipation device. Its advantages in comparison with that of the lead rubber bearing are its simplicity in manufacturing process and replacement of its yielding parts. Also, slit steel rubber bearing has the same ability to dissipate energy with smaller value of displacement. Using finite element method in ABAQUS software, a parametric study is done on the performance of this bearing. Three different kinds of isolator with three different values of strut width, 9, 12 and 15 mm, three values of thickness, 4, 6 and 8 mm and two steel types with different yield stress are assessed. Effects of these parameters on the performance characteristics of slit steel rubber bearing are studied. It is shown that by decreasing the thickness and strut width and by selecting the material with lower yield stress, values of effective stiffness, energy dissipation capacity and lateral force in the isolator reduce but equivalent viscous damping is not affected significantly. Thus, by choosing appropriate values for thickness, strut width and slit steel damper yield stress, an isolator with the desired behavior can be achieved. Finally, the performance of an 8-storey frame with the proposed isolator is compared with the same frame equipped with LRB. Results show that SSRB is successful in base shear reduction of structure in a different way from LRB.

Quantitative analysis of bond and splice strength of steel cord conveyor belt

Steel cord conveyor belt has the advantages of high tensile strength, high friction resistance and strong impact resistance. It is widely used in coal, mining, port, electric power and other fields. The splice area is the weakest link in the whole steel cord conveyor belt, and the splice deformation often occurs. In order to prevent a serious belt breakage accident, we need know the quantitative relationship between splice deformation and splice strength clearly. In this paper, the finite element simulation analysis is carried out on the relationship between deformation and strength of steel cord conveyor belt splices. The change of the bond strength between steel cord and rubber under the action of external force is mainly studied. The emphasis is on the influence of length, number and diameter of steel cords. In these three different factors, the value of A is different. At the same time, we have also analyzed each situation accordingly. Finally, the quantitative relationship between the splice deformation and the overall strength of the splice was summarized. The research results can provide theoretical basis for safety inspection, splice performance analysis, maintenance and renewal of steel cord conveyor belt.

Application of in vitro porcine gastric model of submucosal eminence lesion in endoscopic submucosal dissection

Objective To establish the in vitro porcine gastric model of submucosal eminence lesion and to evaluate its application to endoscopic submucosal dissection(ESD). Methods Silicone rubber impression materials and steel balls with diameters of 1 cm, 2 cm, and 3 cm were used to make three pairs of spherical cavities. And then raw ground beef was put into spherical cavities and boiled for 20 minutes to make spherical mass models. Six isolated porcine stomach with esophagus and duodenum were selected. The mass models with diameters of 1 cm, 2 cm and 3 cm were imbedded respectively into the submucosa of fundus, body, and antrum of porcine stomach through the incision on serosal layer. The submucosal masses were observed by endoscopy and endoscopic ultrasonography and ESD was performed. Results A total of 18 mass models were constructed in 6 porcine stomachs, of which 17 models were successfully established and 1 failed. Typical endoscopic characteristics of gastric submucosal eminence lesions were found in 17 models. Endoscopic ultrasonography showed that these models originated from submucosal layer and demonstrated mixed echo. There were no significant differences between mucosa of lesions and that of surrounding areas. ESD was successfully performed in the porcine gastric models of submucosal eminence lesions, and all models were not broken or detached. Conclusion The in vitro porcine gastric model of submucosal eminence lesions can well replicate disease status and provide a suitable model for study on endoscopic therapy of submucosal eminence lesion and training of endoscopists. Key words: Disease model, animal; Isolated porcine stomach; Gastric submucosal eminence lesions; Endoscopic submucosal dissection