Browse Topic: Elastomers

Items (3,298)
This SAE Aerospace Information Report (AIR) summarizes data and background relative to age control of specific classes of those nitrile type synthetic elastomers used in sealing devices which are resistant to petroleum base hydraulic fluids, lubricating oils, and aircraft fuels. This includes, but is not limited to, those nitrile (NBR or BUNA-N) elastomers previously covered by Section I of MIL-STD-1523
AMS CE Elastomers Committee
ABSTRACT Additions of both carbon fiber (CF) and carbon nano-tubes (CNTs) as reinforcements to polyurea (PUr) based adhesives are computationally investigated. Both CF and CNTs show an increase in stiffness. The effect of CF reinforcements on the PUr is more pronounced than the CNT’s but this due to CNT loading being dramatically lower. On percent basis the CNT effect on strength was greater than the CF. Increasing hard segment content of PUr also had a positive effect on the joint strength, but a negative effect on the shear joint displacement. Finally the addition of CF reinforcements moved the performance of a PUr formulation from a Group IV adhesive into the Group III category. This paper illustrates the potential for commonly available reinforcements to be used to tailor the strength elongation characteristic of a PUr adhesive system. Citation: Demetrios A. Tzelepis, Robert Hart, “Optimization of Nano-Enhanced Elastomeric Adhesives Through Combined Experimental and Computational
Tzelepis, Demetrios A.Hart, Robert
ABSTRACT The first part of this paper will outline the conception of the testing apparatus (Figure 1), along with its operation and preliminary results. The second part of the paper will discuss a new methodology used to correlate the dependence of crack growth rate for strain crystallizing natural rubbers in terms of tearing energy. The tearing energy which depends on the type of elastomer, geometry and stress strain behavior of a particular specimen demonstrates a direct correlation with the crack growth rate at different R-ratios (= min tearing energy/max tearing energy). Figure 1 Schematic of the testing apparatus
Kujawski, DanielDiStefano, DarenBradford, William
ABSTRACT Rubber is the main element of tires and the outside layer of tracks. Tire and track heating is caused by hysteresis effects due to the deformation of the rubber during operation. Tire temperatures can depend on many factors, including tire geometry, inflation pressure, vehicle load and speed, road type and temperature and environmental conditions. The focus of this study is to develop a finite element approach to computationally evaluate the temperature field of a steady-state rolling tire and track. The 3D thermal analysis software Radtherm was applied to calculate the average temperature of tread and sidewall, and the results of Radtherm agreed with ABAQUS results very well. The distributions of stress and strain energy density of the rolling tracks were investigated by ABAQUS as well. The future works were finally presented
Tang, TianJohnson, DanielLedbury, EmilyGoddette, ThomasFelicelli*, Sergio D.Smith, Robert E.
ABSTRACT High life cycle costs coupled with durability and environmental challenges of tracked vehicles in South West Asia (SWA) have focused R&D activities on understanding failure modes of track components as well as understanding the system impacts on track durability. The durability limiters for M1 Abrams (M1, M1A1, and M1A2) T-158LL track systems are the elastomeric components. The focus of this study is to review test methodology utilized to collect preliminary data on the loading distribution of a static vehicle. Proposed design changes and path forward for prediction of durability of elastomers at the systems level from component testing will be presented
Ostberg, DavidBradford, Bill
ABSTRACT In this work, Abrams tank track system T-158LL backer pad elastomer self-heating and fatigue behavior was characterized experimentally, and the backer pad design was digitally twinned to show how complex in-service conditions can be evaluated virtually. The material characterization included measurement of the thermal properties and dissipative characteristics of the rubber compound, as well as its fatigue crack growth rate curve and crack precursor size. The analysis included 1) a structural finite element analysis of the backer pad in operation to obtain the load history, 2) a thermal finite element analysis to obtain steady-state operating temperature distribution within the backer pad, and 3) a thermo-mechanical fatigue analysis using the Endurica CL fatigue solver to estimate the expected service life and failure mode of the backer pad. As validation, experiments were conducted on the backer pad to measure operating temperature, fatigue life, and failure mode over a
Mars, William V.Castanier, MatthewOstberg, DavidBradford, William
ABSTRACT Tracked vehicles are known to provide excellent off-road mobility, but traditional steel tracks do come with some important compromises. The recent introduction of Composite Rubber Tracks (CRT) on the CV90 IFV (77,000 lb) has shown that this robust and operationally proven CRT technology significantly reduces the vehicle weight, fuel consumption, noise, and vibration levels. Inspired by this new enthusiasm for tracked vehicles, provided by CRT, armies and original vehicle manufacturers initiated a series of independent trials confirming the benefits and reliability of CRT. The author’s objective is to present the conclusions of these independent CRT trials, more specifically focusing on the Warrior IFV, providing substantiation data on how CRT technology enhances tracked vehicle performance
Marcotte, Tommy
ABSTRACT In this study, a styrene butadiene rubber, which is similar to the rubber used in road wheel backer pads of tracked vehicles, was investigated experimentally under monotonic and fatigue loading conditions. The monotonic loading response of the material was obtained under different stress states (compression and tension), strain rates (0.001/s to 3000/s), and temperatures (-5C to 50C). The experimental data showed that the material exhibited stress state, strain rate and temperature dependence. Fatigue loading behavior of the rubber was determined using a strain-life approach for R=0.5 loading conditions with varying strain amplitudes (25 to 43.75 percent) at a frequency of 2 Hz. Microstructural analysis of specimen fracture surfaces was performed using scanning electron microscopy and energy dispersive x-ray spectroscopy to determine the failure mechanisms of the material. The primary failure mechanisms for both loading conditions were found to be the debonding of particles on
Brown, H.R.Bouvard, J.L.Oglesby, D.Marin, E.Francis, D.Antonyraj, A.Toghiani, H.Wang, P.Horstemeyer, M.F.Castanier, M.P.
ABSTRACT Militaries worldwide are increasing their Research and Development (R&D) into RAS. Within the next 10 – 15 years RAS will play an active part in operations as the future battlefield becomes more complex. CRT technology can significantly reduce platform weight, fuel consumption, noise and vibration levels[1][2][3]. Armies and vehicle manufacturers have initiated a series of independent trials that confirmed the benefits and reliability of CRT on a tracked military vehicle. With the increase in RAS technologies comes a desire to utilize the proven benefits identified from manned platforms. The author’s objective is to highlight the findings of these trials[1][2][3] and provide substantiated data on how CRT technology can benefit RAS in terms of weight saving, whilst reducing maintenance and vibration. Citation: Fabien Lagier, Ing. MBA, “Composite Rubber Track (CRT) for Robotic & Autonomous System (RAS)”, In Proceedings of the Ground Vehicle Systems Engineering and Technology
Lagier, Fabien
This specification covers a silicone (MQ/VMQ/PVMQ) elastomer that can be used to manufacture product in the form of sheet, strip, tubing, extrusions, and molded shapes. This specification should not be designated for use in molded O-rings and molded O-ring cord, molded rings, compression seals, molded-in-place gaskets, and plate seals for aeronautical and aerospace applications
AMS CE Elastomers Committee
Elastomeric bushings are common components in vehicles, used to reduce noise, vibration, and harshness. Rubber bushings are employed in suspension components such as control arm bushings, subframe bushings, and motor mount bushings, each with varying static and dynamic stiffness requirements depending on vehicle weight and ride and handling performance. Traditional rubber bush simulations typically use simple material models like hyperelastic or viscoelastic models. However, recent advancements have introduced more sophisticated material models to capture the nonlinear and time-dependent behavior of rubber materials. These advanced models may incorporate nonlinear viscoelasticity, strain rate dependency, and damage mechanics. Rubber bushings experience multiple physical phenomena simultaneously, such as mechanical loading, thermal effects, and fluid-structure interaction. New simulation techniques enable the coupling of different physics domains, allowing for a comprehensive analysis
Hazra, SandipMore, VishwasTangadpalliwar, Sonali
Silicone elastomers have become a vital material in the medical device industry due to their unique properties, including biocompatibility, durability and chemical inertness. Silicone materials are categorized based on their unvulcanized consistency, which significantly affects their processability and their physical properties. This article compares high consistency silicone rubbers (HCRs), liquid silicone rubbers (LSRs), and low consistency elastomers (LCEs), analyzing their characteristics and the implications in selecting each during different phases in the development of silicone medical devices
This document establishes age limit and guidance for acceptance of hose and hose assemblies containing elastomeric materials for use in aircraft, space vehicles, missiles and component assemblies thereof at time of delivery to the contractor, procuring activity, or contracting officer. This document does not establish limitations on storage times for military/civil activities nor operating life
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
This specification covers a fluorocarbon (FKM) rubber in the form of O-rings, O-ring cord, compression seals, and molded-in-place gaskets for aeronautical and aerospace applications
AMS CE Elastomers Committee
This specification covers a fluorosilicone (FVMQ) elastomer that can be used to manufacture product in the form of sheet, strip, tubing, extrusions, and molded shapes. This specification should not be used for molded rings, compression seals, molded O-rings, molded O-ring cord, and molded-in-place gaskets for aeronautical and aerospace applications
AMS CE Elastomers Committee
For engineers working on soft robotics or wearable devices, keeping things light is a constant challenge: heavier materials require more energy to move around, and — in the case of wearables or prostheses — cause discomfort. Elastomers are synthetic polymers that can be manufactured with a range of mechanical properties, from stiff to stretchy, making them a popular material for such applications. But manufacturing elastomers that can be shaped into complex 3D structures that go from rigid to rubbery has been unfeasible until now
Innovators at NASA Johnson Space Center have developed a method using low-viscosity RTV silicone to form durable seals between polymer bladder and metal bulkhead interfaces to be used for inflatable space habitats
A method of overall modeling and step-by-step solution was proposed to verify and analyze the strength of the mount shell. First, a reliable finite element simulation model was established based on testing of the mechanical properties of rubber materials, constitutive model construction, and stiffness tests of the mounts. Second, the displacement of the mount system under preloading and crash loads was calculated separately through the modeling of the powertrain mount simulation, which provided accurate load conditions of the mount for the following work. Finally, the strength calculation and evaluation of the mount shell was completed with the quasi-static solution method. This calculation method could consider the influence of complex factors comprehensively, such as assembly load distribution, large deformation of rubber, and contact nonlinearity on the stress distribution of the mount shell. In addition, the calculation method could solve the problem of balance between solution
Li, KeliangChen, GuozhengSun, WanyuYan, ShanhengLi, MingLiu, Baoguo
This specification covers a fluorosilicone (FVMQ) elastomer that can be used to manufacture product in the form of sheet, strip, tubing, extrusions, and molded shapes. This specification should not be used for molded rings, compression seals, molded O-rings or molded O-ring cord, and molded in place gaskets for aeronautical and aerospace applications
AMS CE Elastomers Committee
Electric trucks and off-highway vehicles weigh about 30% more than their gasoline- and diesel-powered counterparts. That's a challenge for OEMs who want to reduce vehicle weight to increase range but are bound by the limits of current battery technology. To reduce vehicle weight, OEMs can make design changes in other areas, such as by replacing steel with thermoformed plastics, aluminum alloys and composite materials. What manufacturers may overlook, however, is the weight savings that can be achieved with industrial rubber products. Rubber is already lightweight, but there are heavier-than-necessary elastomeric components used throughout vehicle interiors and exteriors, typically with metal or plastic fasteners
As aerospace engineers push the boundaries of new frontiers, the need for advanced materials that can withstand the rigorous demands of these advanced applications is relentless. These materials go beyond functionality; it is about ensuring reliability in the skies, where failure is not an option. Fluorosilicone can help do exactly that. In the 1960s, the U.S. Air Force noticed that conventional silicone-based sealants, coatings, and other components degraded rapidly when exposed to fuels, de-icing fluids, and other hydrocarbon-based solvents. Dimethyl-based silicones are non-polar and easily absorb hydrocarbon-based solvents, which may result in material swelling, mechanical weakening, and ultimately, failure
This specification covers polythioether rubber fuel-resistant sealing compounds supplied as a two-component system that cures at room temperature
AMS G9 Aerospace Sealing Committee
The global medical device market offers opportunities for innovation-driven growth. Demand for smart, new lifesaving and life-enhancing technologies is perhaps stronger than ever. Manufacturers around the world looking to capitalize on this eager global market face a long list of challenges — some big, some small. Supply-chain disruptions, labor shortages, rising materials costs, and other headwinds are leading to delays in both engineering and manufacturing processes. Despite these challenges, the world demands medical device manufacturers’ best. A surging geriatric population, implications of a global pandemic, and the mortality rates for heart disease, cancer, obesity, and other conditions are all contributing to strong and sustained market demand. One study predicts a compound annual growth (CAGR) of 5.4 percent will push global sales of medical devices to nearly $658 billion (USD) by 2028. Of course, the road to success will be littered with familiar roadblocks — and some that are
The present study discusses the determination of the Seal drag force in the application where an elastomeric seal is used with a metallic interface in the presence of different fluids. An analytical model was constructed to predict the seal drag force and an experimental test was performed to check the fidelity of the analytical model. A Design of Experiment (DoE) was utilized to perform an experimental test considering different factors affecting the Seal drag force. Statistical tools such as the Test for Equal Variances and One Way Analysis of Variance (ANOVA) were used to draw inferences for the population based on samples tested in the DoE test. It was observed that Glycol fluids lead to lubricant wash-off resulting in increased seal drag force. Additionally, non-lubricated seals tend to show higher seal drag force as compared to lubricated seals
Yarolkar, MakrandTelore, MilindPatil, Sandip
This specification covers an acrylonitrile-butadiene (NBR) elastomer that can be used to manufacture product in the form of sheet, strip, tubing, extrusions, and molded shapes. For molded rings, compression seals, O-ring cord, and molded-in-place gaskets for aeronautical and aerospace applications, use the AMS-P-83461 specification or the MIL-PRF-25732 specification
AMS CE Elastomers Committee
This specification covers a silicone (MQ/VMQ) elastomer that can be used to manufacture product in the form of sheet, strip, tubing, extrusions, and molded shapes. This specification should not be used for molded rings, compression seals, molded O-ring cord, and molded-in-place gaskets for aeronautical and aerospace applications
AMS CE Elastomers Committee
This study delves into the dynamic properties of hybrid composite materials, specifically focusing on the natural frequency and modal damping characteristics of Coir Fiber-Rubber Particles Reinforced Polymer Composites (CRP). Comprehensive experimental investigations were conducted utilizing an FFT analyzer. Initial experiments involved the preparation of specimens with varying rubber content, ranging from 2% to 5%. Coir, known for its cellulose-rich composition, was selected due to its innate damping properties, making it highly effective in mitigating vibrations. The primary motivation behind this research is to provide cost-effective solutions for reducing vibrations in mobility vehicles, addressing challenges associated with passenger comfort, durability, and overall performance. The study yielded promising results, with CRP exhibiting substantial reductions in vibrations. The findings of this research are expected to serve as valuable inputs for the design and engineering of
Mache, AshokKulkarni, AparnaShah, SwapnilGujar, AdeshHujare, Pravin
Rubber isolators are widely used under random vibrations. In order to predict their fatigue life, a study on the fatigue analysis methodology for rubber isolators is carried out in this paper. Firstly, taking a mount used for isolating air conditioning compressor vibrations as studying example, accelerations versus time of rubber isolator at both sides are acquired for a car under different running conditions. The acceleration in time domain is transformed to frequency domain using the Fourier transform, and the acceleration power spectral density (PSD) is the obtained. Using the PSD as input, fatigue test is carried for the rubber isolator in different temperature and constant humidity conditions. A finite element model of the rubber isolator using ABAQUS is established for estimating fatigue life, and model validity is verified through static characteristic testing. Dynamic responses of the rubber isolator at frequency domain are calculated if a unit load is applied. The estimated
Yao, QishuiLi, MinZhang, LichengYue, ZaiqinShangguan, Wen-Bin
This paper investigates the tire-road interaction for tires equipped with two different solid rubber material definitions within a Finite Element Analysis virtual environment, ESI PAMCRASH. A Mixed Service Drive truck tire sized 315/80R22.5 is designed with two different solid rubber material definitions: a legacy hyperelastic solid Mooney-Rivlin material definition and an Ogden hyperelastic solid material definition. The popular Mooney-Rivlin is a material definition for solid rubber simulation that is not built with element elimination and is not easily applicable to thermal applications. The Ogden hyperelastic material definition for rubber simulations allows for element destruction. Therefore, it is of interest and more suited for designing a tire model with wear and thermal capabilities. Both the Mooney-Rivlin and Ogden-equipped Mixed Service Drive truck tires are subjected to a simulated static vertical stiffness test to validate their static domain characteristics against
Ly, AlfonseEl-Sayegh, ZeinabEl-Gindy, MoustafaOijer, FredrikJohansson, Inge
Compared to other age groups, older adults are at more significant risk of hip fracture when they fall. In addition to the higher risk of falls for the elderly, fear of falls can reduce this population’s outdoor activity. Various preventive solutions have been proposed to reduce the risk of hip fractures ranging from wearable hip protectors to indoor flooring systems. A previously developed rubberized asphalt mixture demonstrated the potential to reduce the risk of head injury. In the current study, the capability of the rubberized asphalt sample was evaluated for the risk of hip fracture for an average elderly male and an average elderly female. A previously developed human body model was positioned in a fall configuration that would give the highest impact forces toward regular asphalt. Three different rubber contents with 14, 28, 33 weight percent (% wt.) were implemented as the ground alongside one regular non-rubberized (0%) asphalt mixture, one baseline, and one extra-compliant
Sahandifar, PooyaWallqvist, VivecaKleiven, Svein
This specification covers a neopentyl polyol ester fluid
AMS CE Elastomers Committee
This specification provides requirements for the identification and packaging of sheet, strip, extrusions, and molded parts made of natural rubber, synthetic rubber, reclaimed rubber, and combinations of the above with other materials such as asbestos, cork, and fabrics. AMS2817 covers preferred requirements for identification and packaging of preformed packings
AMS CE Elastomers Committee
For more than a century, pneumatic (air-inflated) tires have totally dominated the market for road vehicle tires. However, in the recent two decades, interest has grown in developing airless tires. Some of the authors were involved in design of an early version in composite material 15-30 years ago for passenger cars. Presently, the EU project LEON-T (Low particle Emissions and lOw Noise Tyres) includes a part in which prototypes for innovative heavy goods vehicle (HGV) tires are developed, with the main purpose to reduce noise emission by 6 dB. To reduce noise that much it is believed that airless tires are needed. A special challenge is to get a durable design able to carry typical truck tire loads. This paper introduces the principal design of airless tires. Airless tire prototypes are intended to be developed by partner Euroturbine, in cooperation with mainly Applus+ IDIADA, VTI and subcontractor Lightness by Design. The tire consists of a rim, load-carrying spokes, composite belt
Anantharamaiah, BharathFagerberg, LinusSandberg, UlfHansson, Hans-ErikGarcia, Juan J.
The Indian passenger vehicle market has grown by more than 40% by volume in the last decade and has reached a record high in FY23. This has created a more diverse and demanding customer base that values interior design and quality. The modern customer expects a high level of aesthetics and sophistication in their vehicle interiors - including in the luggage area. The Luggage Cover (Parcel Tray) is a component in the luggage area of a passenger vehicle that is used to conceal the luggage & improve its aesthetics. The cover is generally made of thermoplastic material with rotating hinges and is held in its place by the compression from the back door, which is frequently opened and closed. The parts that connect the cover to the door (usually an elastomer interface on the thermoplastic tray) tend to change over a period due to climatic conditions and leads to rattling concerns over a period. The change in elastomer interface with the back door (due to repeated compression & climatic
Sreejith, M PKhandelwal, LokeshSandilya, ArnabNatu, Mandar RRay, Amulya KaliHanda, Rajat
Silicone and rubber composite, often called Ceramifiable Silicone Rubber Composites(CSRCs), has proven to show excellent mechanical and thermal properties. CSRC materials have been mainly used in industrial applications like electrical insulating cables, decorations, and fire-proof materials. The mechanical and ceramifiable properties of CSRC can be altered by changing the silicone rubber matrix and by adding the right additives or fillers. In this work, we prove the potential of CSRCs as thermal insulating materials in battery packs. Specifically, we explore the usage of CSRC inside the battery pack to improve safety during thermal events. We also characterize the material properties before and after exposing the CSRC to elevated temperatures and flame. Finally, we investigate the effectiveness of the CSRC sheet in preventing or delaying cell-to-cell thermal propagation during a thermal runaway event inside the battery pack. Our experiments show that the CSRC sheet significantly
Nambisan T M, Praveen KumarH, ManjunathaR, PavanP, Hari Prasad ReddyG M, BharathKulkarni, Mukund AravindSundaram, Saravanan
The art of rubber formulation science always has a scope for fine-tuning with changing the parameters like base polymer grade selection, filler selection, curing system/cross link density, manufacturing methods, and many. Hence forth the filler manufacturer arrived differentiation of the filler already, this paper provides a description of rubber formulation tuning for damped vibration automotive applications. Acicular spiky spherical and hollow spherical nano silica selected as filler. With the thorough knowledge of elastomeric formulation and with doping different new selected silica grades, an optimized DOE was done. New formulation development was focused on isolation characteristics without affecting other necessary properties. The different inputs for finite element calculations was studied with the effects of doping different fillers and also studied the resultant virtual output in damping coefficients. Quad lap shear specimen was used as a standard part in which virtual and
Murugesan, AnnarajanSathaye, Asmita
Rubber is one of the most used materials currently selected to produce automotive parts, but, for specific applications, some improvement is required in its properties through the addition of some components to the rubber compound formulation. Because of that, mechanical, thermal, and chemical properties are enhanced in order to meet strict requirements of the vast range of application of the rubber compounds. In addition to improving material properties, the combination of different substances, also aims to improve processability and reduce the costs of the final product. Recently, the use of nanofillers has been very explored because of their distinctive properties and characteristics. Among the nanofillers under study, graphene is known for its high-barrier property, thermal and electrical conductivities, and good mechanical properties. A large number of researches on rubber/graphene compounds preparation methods and applications can be found in literature and results are promising
Veloso, VerônicaPinto, EduardoSantiago, MarceloBortoli, BrunaRibeiro, WillianPolkowski, Rodrigo
This specification covers an ethylene propylene rubber in the form of molded rings, molded compression seals, molded O-ring cord, and molded-in-place gaskets for aeronautical and aerospace applications
AMS CE Elastomers Committee
Vehicles equipped with rubber track systems feature a high level of performance but are challenging to design due to the complex components involved and the large number of degrees of freedom, thus raising the need to develop validated numerical simulation tools. In this article, a multibody dynamics (MBD) model of a continuous rubber track system developed in Part 1 is compared with extensive experimental data to evaluate the model accuracy over a wide range of operating conditions (tractor speed and rear axle load). The experiment consists of crossing an instrumented bump-shaped obstacle with a tractor equipped with a pair of rubber track systems on the rear axle. Experimental responses are synchronized with simulation results using a cross-correlation approach. The vertical and longitudinal maximum forces predicted by the model, respectively, show average relative errors of 34% and 39% compared to experimental data (1–16 km/h). In both cases, the average relative error is lower for
Duhamel, OlivierFaivre, AntoinePlante, Jean-Sébastien
Continuous rubber track systems for farming applications are typically designed using multiple iterations on full-scale physical prototypes which is costly and time consuming. The development of numerical design tools could speed up the design process and reduce development costs while improving product performance. In this article, a rigid multibody dynamics (MBD) model of a continuous rubber track system is presented. This article is the first part of a two-part study: Part 1 focuses on the model description and part 2 describes the experimental evaluation of the MBD model. The modeling methodology is based on a track discretization as a set of rigid body elements interconnected by 6 degrees-of-freedom bushing joints. The mathematical formalism and experimental characterization of all critical subsystems such as the roller wheels, tensioner, suspensions, and contact models are also presented. Several simulation results are presented to illustrate the capability of MBD models in
Faivre, AntoineDuhamel, OlivierHemmatian, MasoudPlante, Jean-Sébastien
Items per page:
1 – 50 of 3298