Metal Rubber Research Articles

Ballistic performance of composite structure configurations with high elongation calendered rubber layer laminated to AA5083-H112 aluminum alloy

This study aims to determine the ballistic performances of laminated composite plates produced with AA5083-H112 series aluminum and rubber material with high elongation capacity under impact loading. To investigate the effect of rubber compounds, two types of rubber with calendered and damping were prepared. Thanks to the surface treatment applied to the aluminum plates, the rubber–metal adhesion strength was adjusted, and four different laminated composite plate samples were prepared. Calendered rubber was used on the bullet impact surface of all samples, and damping rubber was used on the back. It has been observed that the pressure barrier created by the calendered rubber bullet on the front face provides high performance to absorb energy. A detailed study was carried out on the total thickness of laminated composite plates, the interface adhesion strength between rubber and aluminum layers, and the ballistic performance of aluminum-rubber combinations. It was concluded that the laminated composite plate’s energy absorption would increase, especially by increasing the thickness of the dumping rubber layer on the back of the aluminum sheets. In the strong metal-rubber interface interaction between the rubber and aluminum layer, the bullet is stopped before the pressure barrier is formed. The penetration depth and bulging height increase, and most of the energy are transmitted through the aluminum plate. In the weak metal-rubber interface interaction, a significant portion of the energy is absorbed by the rubber and air thanks to the pressure barrier.

Strategies for Implementing the Jakobsson-Floberg-Olsson Cavitation Model in EHL Simulations of Translational Seals

The numerically stable simulation of cavitation effects is mandatory for predicting the friction and wear behavior of translational hydraulic seals. This contribution provides a comparison of two different implementations of the Jakobsson-Floberg-Olsson (JFO) cavitation model, an investigation of their properties and possible options for their stabilization. These methods are tested and compared both within a simple divergent gap test case as well as within an EHL simulation of a rubber metal contact. Based on these comparisons and theoretical investigations, the strengths and weaknesses of the different methods are summarized and discussed with respect to an application in EHL simulations of translational hydraulic seals.

Research on Dynamic Cumulative Damage Effect of Metal Rubber and Stress Wave Propagation Characteristics of Layered Composite Structure

The development of protective materials and structures is of great significance for improving the impact resistance, penetration resistance and spalling resistance of military equipment. At present, the layered composite structure has been widely used due to its good protective performance. In this paper, a special elastic porous material-metal rubber (MR) with excellent cushioning and damping properties was used to prepare high-performance layered composite structures. To begin with, the dynamic mechanical response and the dynamic cumulative damage effect of MR were studied through Split-Hopkinson Pressure Bar (SHPB) tests. Then, the failure form and stress wave propagation characteristics of the layered composite structures were investigated through SHPB tests and finite element method. The results show that repeated impacts can enhance the compactness of MR, thereby increasing the ultimate bearing capacity and energy absorption capacity, which is beneficial for MR to resist repeated impacts. The MR in composite structures can reduce ceramic damage, attenuate stress wave and smooth stress distribution. The titanium alloy on the back of the ceramic will aggravate the damage of the ceramic, and ultra-high molecular weight polyethylene on the back of the ceramic provides cushioning for the ceramic. Therefore, the impact resistance of the composite structure can be improved by adding MR and the reasonable arrangement of materials, and the SiC/UHMWPE/MR/TC4 composite structure has relatively reasonable stress distribution and better protection performance.

Macro–Microstatic Stiffness Prediction Model of Metal Rubber

AbstractAn accurate prediction to the macro–microstatic stiffness of metal rubber (MR) is necessary when introduced into the novel hybrid metal rubber‐bump foil bearings (HMR‐BFBs) as the supporting components. However, the deficiency in theoretical models describing the static stiffness limits MR's engineering applications. This study presents theoretical and experimental characterization for the mechanical properties of MR samples. The microstatic stiffness prediction models are proposed based on the radial and axial deformation mechanisms of helix wire units. The constitutive static stiffness model for predicting the macromechanical properties of MR samples is developed with consideration of the separation state, the sliding contact state, and the extrusion contact state between the metal wires based on the force interaction and the Coulomb friction. Moreover, an orthogonal experiment is designed, and subsequently the static stiffness tests of MR samples are carried out. Based on static stiffness tests, a semiempirical stiffness model with consideration of the material and process parameters, including the relative density of MR samples, the wire diameter, and the Young's modulus of metal wires is developed. Results show a good agreement between the theoretically predicted and experimental static stiffness of MR specimens with a correlation index R2 of 0.9692.

Verification of Vibration Isolation Effectiveness of the Underwater Vehicle Power Plant

In order to enhance the vibration isolation effectiveness of an underwater vehicle power plant, and alleviate the mechanical vibration of the outer housing, initially discrete vibration isolators were improved, and three new types of ring vibration isolators designed, i.e., ring metal rubber isolators, magnesium alloy isolators and modified ultra-high polyethylene isolators (MUHP). A vibrator excitation test was carried out, and the isolation effectiveness of the three types of vibration isolators was evaluated, adopting insertion loss and vibration energy level drop. The results showed that compared with the initial isolators and the other two new types of isolators, MUHP showed the most significant vibration isolation effectiveness. Furthermore, its effectiveness was verified by a power vibration test of the power plant. To improve the vibration isolation effectiveness, in addition to vibration isolators, it is essential to carry out investigations on high-impedance housings.

Research on the dynamic mechanical properties and constitutive model of metal rubber under impact loading

The development of lightweight, impact-resistant and high energy dissipation materials is of great significance to reduce the hazards of explosions and impacts. Metal rubber (MR) has the characteristics of low density, high damping performance and high elasticity, which shows great potential in the field of protection. However, there are few studies on the dynamic mechanical response of MR under high-speed impact. A series of experiments were carried out to study the mechanical properties of MR. It is found that the deformation mechanism of the metal wire inside the MR determines the mechanical properties. Under quasi-static conditions, the stress-strain of MR includes an elastic stage, a softening stage and a hardening stage, and the stress-strain under high-speed impact includes an elastic stage, a softening stage and a failure stage. In addition, the smaller the wire diameter, the higher the load-bearing capacity of the MR. The damage characteristics of MR under high-speed impact are divided into expansion failure and compaction failure, which will affect mechanical performance in the failure stage. The calculated energy absorption and ideal energy absorption efficiency show that MR is a material with excellent energy absorption properties. The dynamic elastic modulus and dynamic peak stress of MR have strain rate effect and density effect. A constitutive model based on Sherwood-frost equation was established, which can precisely forecast the dynamic mechanical properties.

Study on Friction Characteristics of Laser Textured Metal Rubber Microfilaments under Solid Lubricating Grease

Study on Friction Characteristics of Laser Textured Metal Rubber Microfilaments under Solid Lubricating Grease

A solvent-responsive robust superwetting titanium dioxide-based metal rubber for oil-water separation and dye degradation

The sewage treatment technology of oil-water separation based on superwetting materials has been widely employed. However, the stability of substrates was rarely considered in the past few years, which greatly limited the application of superwetting materials in engineering field. As a new robust, three-dimensional porous material, metal rubber (MR) has attracted significant attention for solving this problem. To treat the wastewater containing insoluble heavy/light oil and soluble dyes, herein, MR capable of degrading organic dyes with switchable wettability and high oil-water separation efficiency was prepared. Firstly, the superhydrophilic MR was obtained by anodizing. Then, the wettability of MR surface was reversibly switched between superhydrophilic and superhydrophobic via alternate immersion in stearic acid ethanol solution and tetrahydrofuran (THF) solvent to achieve switchable oil-water separation of MR. The superwetting MR displayed excellent abrasion resistance and retained outstanding oil-water separation performance after 100 times of sandpaper abrasion. Besides, the surface of pure titanium MR was rich in titanium dioxide (TiO2) after anodic oxidation, which could effectively degrade the organic dyes under ultraviolet light. Therefore, the as-prepared superwetting MR possesses the ability to treat complex wastewater and have applications prospects in controllable oil-water separation and self-cleaning surfaces.

Constitutive model of disordered grid interpenetrating structure of flexible microporous metal rubber

In this study, the disordered grid interpenetrating structure (DGIS) of wire turns in flexible microporous metal rubber (FMP-MR) for vibration and noise reduction is investigated, and an effective constitutive model is developed to dynamically capture the nonlinear mechanical behavior of FMP-MR. In this model, a micro spring element with adaptive deformation (MSEAD) model with random spatial distribution is employed, based on the phenomena of irregular overlapping and interlacing of material turns. The spatial distribution of micro springs and the evolution of the contact area morphology in FMP-MR are taken into consideration and introduced as key variables in model development. The concept of combined probability distribution (CPD) of micro spring pairs between wire turns in FMP-MR is proposed to characterize the random combination mode of material turns. Eventually, based on the micro-patterns of wire turns in FMP-MR, a constitutive model including macroscopic parameters, such as shape, density, wire diameter, helix pitch, and wire elastic modulus, and microstructure parameters, such as spatial distribution of wire turns, contact shape, and friction coefficient is developed for the first time. By analyzing and discussing the fitting degree of quasi-static compression experimental results and the model constitutive curves, the validity of the proposed constitutive model is quantitatively confirmed by residual analysis. According to the results, the FMP-MR constitutive model based on DGIS can effectively reflect the nonlinear mechanical behavior and complex micro-contact friction phenomena of the material.

Dynamic Performance of Laminated High-Damping and High-Stiffness Composite Structure Composed of Metal Rubber and Silicone Rubber.

In this study, a laminated composite damping structure (LCDS) with metal rubber (MR) as matrix and silicone rubber (SR) as reinforcement has been designed. The embedded interlocking structure formed by the multi-material interface of the LCDS can effectively incorporate the high damping characteristics of traditional polymer damping materials and significantly enhance the adjustable stiffness of the damping structure. Based on the periodic cyclic vibration excitation, dynamic tests on different laminated structures were designed, and the damping performance and fatigue characteristics under periodic vibration excitation of the LCDS, based on MR and SR, were explored in depth. The experimental results exhibited that, compared to single-compound damping structures, the LCDS with SR as reinforcement and MR as matrix has excellent stiffness and damping characteristics. The incorporation of the silicon-based reinforcement can significantly improve the performance of the entire structure under cyclic fatigue vibration. In particular, the effects of material preparation and operating parameters on the composite structure are discussed. The effects of MR matrix density, operating frequency, amplitude, and preload on the stiffness and damping properties of the MR- and SR-based LCDS were investigated by the single factor controlled variable method. The results demonstrated that the vibration frequency has little effect on the LCDS damping performance. By increasing the density of the MR matrix or increasing the structural preload, the energy dissipation characteristics and damping properties of the LCDS can be effectively improved. With the increase in vibration excitation amplitude, the energy consumption of the LCDS increases, and the average dynamic stiffness changes at different rates, resulting in the loss factor decreasing first and then increasing. In this study, a damping structure suitable for narrow areas has been designed, which overcomes the temperature intolerance and low stiffness phenomena of traditional polymer rubber materials, and provides effective guidance for the design of damping materials with controllable high damping and stiffness.

Experimental and Constitutive Model Study on Dynamic Mechanical Behavior of Metal Rubber under High‐Speed Impact Loading

The development of lightweight, impact‐resistant, and high energy‐consuming materials is of great significance for improving the defense capabilities of military equipment. As a new type of damping material, metal rubber has demonstrated great potential for application in the field of impact protection. In this paper, the dynamic mechanical response of metal rubber under a high strain rate is studied, which provides a new idea for developing high‐performance protective materials. The stress‐strain curves, energy absorption performance, and wave transmission performance of metal rubber at various strain rates were investigated based on a split‐Hopkinson pressure bar (SHPB) device. The dynamic stress‐strain curve of metal rubber is divided into three stages: elastic stage, plastic stage, and failure stage. The optimal energy absorption efficiency is greater than 0.5, and the maximum value can reach 0.9. The wave transmittance is less than 0.01. The dynamic mechanical tests have proved that metal rubber has excellent energy absorption capacity and impact resistance property. A constitutive model based on Sherwood–Frost was established to predict the dynamic mechanical behavior of metal rubber. The results of comparison between the calculation and the experiment show that the constitutive model can accurately predict the dynamic mechanical performance of metal rubber.

Damping Energy Dissipation and Parameter Identification of the Bellows Structure Covered with Elastic‐Porous Metal Rubber

In order to improve damping energy dissipation of a U‐shaped bellows structure, elastic‐porous metal rubber as a cover layer was adopted and the corresponding vibration parameters were identified. First, the evolution of energy dissipation characteristics with respect to the changes of amplitude and frequency was investigated through a dynamic experimental test in the bending direction of the covered bellows structure. Second, the conspicuous hysteresis loop characteristics were described while the nonlinear constitutive relation was analytically modelled based on the exact decomposition method. Third, the corresponding parameters on dynamic properties of the covered bellows structure were determined by generalized least‐squares estimation. Finally, the prediction results were compared with the measured displacement‐restoring force curves to verify the accuracy of the developed dynamic model. The results indicate that the proposed dynamic model associated with the nonlinear constitutive relation for the covered bellows structure can well describe the evolution of the restoring force in terms of amplitude and frequency.

Research on Damping Mechanism with Resetting Capability for Axial Vibration Control of Satellite Antenna

With the development of space technology, the large scale space deployable antennas gradually become one of the key research themes of research. The basic requirements for large scale satellite antennas are the characteristics of light in weight and high in profile accuracy. The low-frequency and large-amplitude vibration of the large scale antennas is easily excited when working in an environment with zero gravity. In order to suppress the vibration of large scale deployable satellite antenna, a new type of damping mechanism with resetting capability is presented to improve the ability of vibration energy consumption and ensure the dynamic characteristics of the radial rib structure containing the presented profile accuracy of the antenna. The rod making up the deployment mechanism of the antennas is divided into two parts which connected by using the shape memory alloy (SMA) wires through guiding mechanism. Meanwhile, a metal rubber is fixed and pressed between two parts of the rod by SMA wires. The ability of the friction energy dissipation of the metal rubber is utilized to suppress the axial vibration of the rods. The super elasticity of the SMA wires is used to provide the restoring force for ensuring the dimensional stability of the rod. In this paper, the design principle of the axial self-resetting damping structure is introduced in detail. And, the dynamic characteristics of the radial rib structure containing the presented damping mechanism are investigated by using the software ANSYS. The simulation results show that the vibration amplitude of the radial rib of antennas has been reduced significantly.

Soft strain gauge tactile sensor array using liquid metal

In recent years, soft tactile sensors comprising liquid metal and silicone rubber have been studied for tactile sensing of soft robots. In order to obtain detailed information about objects, the sensor array was configured by utilizing crossing of orthogonal microchannels filled with liquid metal as sensing elements in previous research. In this study, we propose the soft tactile sensor array with independent sensing elements. This sensor embeds narrow microchannels standing vertically in silicone rubber. Microchannels are filled with liquid metal and used as sensing elements. This structure realizes miniaturization and high-density placement of sensing elements while maintaining the independence of the sensing elements. We fabricated the sensor with 16 sensor elements of 0.4mm width embedded at 2.0mm intervals.

Numerical analysis of rubber tire/rail contact behavior in road cum rail vehicle under different inflation pressure values using finite element method

With the advent of Rail cum road motors there are great demanding situations earlier than Indian railways. Railway Engineers had been for all time interested by the metal wheel-Rail and Rubber tire-Rail contacts. These tiny interfaces govern the dynamic overall performance of avenue cum rail motors via the masses it transmits and, like every high-strain attention sector, it's far subjected to severe damage phenomena. The paper deals with modelling and simulation of the static behaviour of a radial mini truck tire of a proposed road cum rail automobile in touch with rails. The Finite element technique via the ANSYS software program is used to obtain the static behaviour of the rubber tire in contact with rail underneath inflation stress values. The primary goal is to carry out a finite detail analysis and computationally compare the overall performance of a stationary rubber tire along with rim on rails with the aid of changing the inflation stress so that corresponding overall performance parameters like equivalent strain in rubber tire and rims, deformation and call patch of rubber tire are expected and the effect of inflation pressure on these parameters can be understood.

Numerical simulation of contact behavior between rail wheel and rails of a new road cum rail vehicle

The railway transportation system in today’s transport scenario is of utmost importance owing to its increased load carrying capacity, high speed, low costs, connectivity and ecologic features. Due to this, the railways are subjected to additional loads which in turn produce a higher level of strains and stresses. With the advent of Rail cum Road vehicles, there are enormous challenges before Indian railways. Railway Engineers have been forever interested in the Metal wheel-Rail and Rubber tire-Rail contacts and this rolling contact of a wheel/Tire on a rail is the basis of many rail-wheel related problems including the rail corrugation, wear, plastic deformation, rotating interaction fatigue, thermo-elastic–plastic behavior in contact, fracture, creep, and vehicle dynamics vibration. The paper deals with modeling and simulation of the static behavior of a small rail wheel of a proposed road cum rail vehicle in contact with rails. The Finite Element Method and ANSYS software are used to obtain the static behavior of the rail wheel in contact with rail. The aim is to evaluate numerically the performance of a stationary small rail wheel on rails so that corresponding performance parameters like equivalent stress, deformation and contact patch can be predicted. In this study, three cases have been discussed viz. The case 1 is about the development of the simulated environment/ model for the big rail wheel on the rail track and its validation from previous published research work; in Case 2 same modeled environments is used evaluate the performance of small rail wheel on rail track. The developed rail cum road vehicle is friction driven vehicle, so all the eight wheels (4 small rail wheels and 4 rubber tire) are used while the vehicle moves on the rails.

Application of metal rubber vibration absorber in coaxial dual-reflection space camera

Application of metal rubber vibration absorber in coaxial dual-reflection space camera

ХАРАКТЕРНЫЕ СЛУЧАИ УДАРНОГО НАГРУЖЕНИЯ ВИБРОЗАЩИТНЫХ СИСТЕМ АГРЕГАТОВ И УЗЛОВ ТРАНСПОРТНЫХ СРЕДСТВ

Using the previously developed mathematical model of a vibration isolator with an elastic–hysteresis element made of metal–rubber material and the obtained approximate solutions of the nonlinear differential equation of the aircraft motion based on the Bubnov–Galerkin methods and a small parameter, the dependences for constructing shock–insulating characteristics for rectangular and semi–sinusoidal pulses are derived. It is shown that the error of these solutions in comparison with the exact solutions for some elastic characteristics, in particular, with a significant nonlinearity in the form of a cubic parabola, does not exceed 3.5%.

ИССЛЕДОВАНИЕ ОКОЛОРЕЗОНАНСНЫХ РЕЖИМОВ ВЫНУЖДЕННЫХ КОЛЕБАНИЙ ВИБРОЗАЩИТНЫХ СИСТЕМ С КОНСТРУКЦИОННЫМ ДЕМПФИРОВАНИЕМ ПРИ ГАРМОНИЧЕСКОМ ВОЗБУЖДЕНИИ

Using the previously developed mathematical model of a vibration isolator with an elastic – hysteresis element made of metal–rubber material and on the basis of the Bubnov–Galerkin method, the solution of the equation of forced vibrations of vibration protection systems (VS) under harmonic excitation is obtained. The obtained theoretical results are used to construct generalized dynamic characteristics of vibration isolators with structural damping, in particular, vibration isolators with an elastic–hysteresis element made of MR material. As a result, a simple and fairly general procedure for calculating the generalized vibration–isolating characteristics of the aircraft for the case of harmonic linearization is obtained.

Damage Quantification of Frame-Shear Wall Structure with Metal Rubber Dampers under Seismic Load

The seismic load can bring serious damages to the coupling beams and frame beams in the frame-shear wall structure. Such damages can hardly be repaired, causing functional loss to the structure. One of the best ways to consume seismic energy input, rationalize the damage mode of structure, and prevent serious damages to the main components is to install metal rubber (MR) dampers materials in the frame-shear wall structure. Based on Park and Ang’s damage model, this paper presents pertinent formulas of damage indexes, and uses them to quantify the failure mode. Then, the correspondence was established between damage level of the target structure, reasonable damage mode, and damage index. Finally, two ABAQUS models of an 18-floor frame-shear wall structure were constructed: an uncontrolled structure (traditional frame-shear wall structure) and a controlled structure (frame-shear wall structure with MR dampers). Through comparative analysis, the characteristic parameters of the damper were determined for the reasonable damage mode, and the failure mechanism of the target structure was identified accurately under seismic load.