Rubber – a loosely cross-linked network of polymer chains that when strained to high levels will forcibly return to at or near it original dimensions. This course is designed to provide the participant with a thorough understanding of rubber’s engineering characteristics. This class will introduce the various sources of rubber, both natural and synthetic. The class will contrast the differences between rubber and plastics; including thermoplastic rubber. Detailed discussions on how to select the correct rubber polymer for the application, highlighting the pros and cons of each major rubber type.
The Indian economy is developing at good pace, hence sign of significant growth can be seen in transportation industry. The transportation industry comprises of two main verticals, one is goods transportation & other is public transportation. As India is country with dense traffic conditions, the driving is very fatiguing affair. The studies have shown that the driving efficiency has a significant effect on operating economy. The current paper work focuses on the improvement in ergonomic improvements in the driver station of a bus which is used as mode of transportation for public. In India the buses are deployed for school, staff, city & intercity application. All these application are exposed to different driving conditions. In the available literature of driver comforts major focus given to truck application. The present study focuses on bus application in Indian traffic conditions.
Engine mounts are an integral part of the vehicle that help in reducing the vibrations generated from the engine. Engine mounts require a simple yet complicated amalgamation of two very different materials, steel and rubber. Proper adhesion between the two is required to prevent any part failure. Therefore it becomes important that a comprehensive study is done in order to understand the mating phenomenon of both. A good linking between rubber and metal substrate is governed by surface pretreatment. Various methodologies such as mechanical, chemical are adopted for the same. The aim of this paper is to present a comparative study as to which surface pretreatment has an edge over other techniques in terms of separation force required to break the bonding between the two parts. The study also presents a cost comparison between the techniques so that best possible technique can be put to use in the commercial vehicle industry.
Present day truck cab suspension comprises fully floating linkage type cab suspension to facilitate ride comfort. Fully floating cab has certain limitations in terms of stability of cab in dynamic articulations during vehicle running especially in off-road terrain applications. Presence on linkages leads to more wear and tear of joints and bushes which will in turn provide detrimental effect on vibration levels of cab that affects ride comfort and of cab for occupants. There is a dire need to develop a system that provides improvement in lateral and vertical stability of cab without compromising ride comfort of occupants. Durability of the product also to be met till life of vehicle. Anti-Vibration Stability Cab Mount is a unsymmetrical mount designed by compounding of elastomeric(rubber) metal bonded outer sleeves sandwiched between multistage inner mount bonded on aluminum casing.
In upcoming generation of automobiles industry we are major focusing on optimization of tyre design. Tyres are the only medium which are responsible for moving a vehicle back and forth. Conventional tyres does the quite firmly and are currently in their best era. Few of the drawback of pneumatic tyres are they all suffer getting puncture, pressure maintenance, operating atmosphere can change the air density which causes pressure loss etc., these problems pushes industry to create new tyres which doesn’t carry same problems. The scope for improvement is always exist in the designing processes. Airless tyres are an option which doesn’t have any of the issues. Airless tyres are rubber structure which support the vehicle load during its all maneuverability. The structural design of the tyre decides the properties of tyre such as tyres stiffness, lateral stiffness, load bearing capacity and more. In this tyre design we have utilized properties of arc of a circle.
In-cylinder surface temperature is of heightened importance for Homogeneous Charge Compression Ignition (HCCI) combustion, as the combustion mechanism is thermo-kinetically driven. Thermal Barrier Coatings (TBCs) selectively manipulate the in-cylinder surface temperature, providing an avenue for improving thermal and combustion efficiency. This thermal phenomenon sidesteps charge preheating during gas exchange, while a surface temperature swing during combustion/expansion reduces heat transfer losses, leading to more complete combustion and reduced emissions. The magnitude and profile of the dynamic surface temperature swing was found to be affected by the material properties and TBC thickness. This study is the continuation of the author’s work to systematically engineer coatings that are best suited for HCCI. A parametric study was used to assess the impacts of various TBC material properties (density, specific heat, thermal conductivity) on the temperature swing effect.
Water transport at high current densities is of main concern for polymer electrolyte membrane fuel cells. The water content of the membrane has to be high enough to provide maximum electrical conductivity and thus optimal stack performance. Dry-out may also lead to membrane degradation. However, a too high level of humidity leads to cell flooding, blocking the air and fuel flows to the catalyst sites and thus the reactions, resulting in a drop in efficiency. Fuel cells water transport physics requires further investigation due to its complexity [1,2] and numerical modelling can improve the fundamental understanding of the phenomena. In this work, an optimization algorithm is used to optimize a fuel cells geometry to improve the temperature distribution and the pressure drop. In addition, the effect of the several geometric configurations on the water management is discussed. The PEM fuel cell is modelled in Siemens Simcenter STAR-CCM+ .
Reliability of electronic components is of increasing importance for further progress towards automated driving. Thermal ageing processes such as electromigration is one factor that can negatively affect reliability of electronics. Resulting failures are mainly depending on components’ thermal load within vehicle lifetime - called temperature collective, which is described by the temperature frequency distribution of the components. At present, the only possibility to examine the temperature collective is performed by vehicle endurance testing. Knowledge about the temperature frequency distribution in early development stages is one of the key factors to ensure electronics’ reliability in future vehicles. Vehicle Thermal Management (VTM) tools, which provide numerical simulation, allows lifetime thermal prediction in early development stages, but also challenges current VTM processes.
Light-weighting fiber composite materials introduced to reduce vehicle mass and known as innovative materials research activities since they provide high specific stiffness and strength compared to contemporary engineering materials. Nonetheless, there are issues related automation strategies and handling methods. Material handling of flexible textile/fiber components is a process bottleneck and it is currently being performed by setting up multi-stage manual operations for hand layups. Consequently, the long-term research objective is to develop semi-automated pick and place processes for flexible materials utilizing collaborative robots within the process. The immediate research is to experimentally validate innovatively designed grippers for efficient material pick and place tasks.
In this study, the formation and decomposition of ammonium nitrate (AN) on a state-of-the-art extruded vanadium-based SCR catalyst (V-SCR) under simulated exhaust conditions has been evaluated. Results show that AN readily forms and accumulates at temperatures below 200°C when exposed to NH3 and NO2. The rate of AN accumulation increases with decreasing temperature. A new low temperature NH3 storage site (not present following NH3 storage conditions with NH3 only) becomes apparent after AN accumulation at 100 and 125°C for an extended duration (e.g., t > 30 min). This new NH3 storage site, with a peak release temperature of approximately 185°C, is then evaluated in detail to better determine its origin. BET surface area, diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS), thermal gravimetric analysis (TGA), and reactor-based experiments are all used to characterize AN formed on the V-SCR catalyst in comparison to pure AN powder.
Recently, graphene has attracted both academic and industrial interest because it can produce a dramatic improvement in properties at very low filler content. This review will focus on the latest studies and recent progress in the swelling resistance of rubber compounds due to the addition of graphene and its derivatives. This work will present the state-of-the-art in this subject area and will highlight the advantages and current limitations of graphene for potential future researches.
Gearbox failure is the most common failure, which is being detected in vehicles, turbines and other applications. It is not possible to detect every fault manually because gearbox failure depends on various factors like gearbox oil temperature, uncertain driving patterns, engine components and other various gearbox parameters. In recent decades, a lot of research has been done in detecting gearbox failure and various methods and techniques have been proposed to predict failure and also to reduce maintenance and failure costs. To predict the behaviour of the gearbox, robust and efficient algorithms are required. In this work, an effective and accurate algorithm to predict gearbox failure after analysing various symptoms arising on gearbox oil temperature is proposed. Gearbox oil temperature variations are caused by different factors like viscosity, water saturation, dielectric constant and conductivity.
This quantitative research study was conducted to illustrate the relationships between Metal-Organic Frameworks and Covalent Organic Frameworks. Research on hybrid materials has been going on for decades and the results are quintessential. In modern times, surplus researches are being undertaken to keep the material more efficient and long-lasting for a suitable price to industrialize. To overcome the influence of the essential factors, MOF’s and COF’s play a substantial role in its properties and applications for critical fields of engineering. Conventional materials are limited to their manufacturing methods and equipment. This paper illustrates a predominant case where the use of the modern materials in various applications like the gas storage tank, high-tech battery technology, catalyst for multiple chemical reactions, gas purification reactions, efficient semiconductors, and supercapacitors are observed.
This study looked into the application of active thermal coatings on the surfaces of the combustion chamber as a method of improving the thermal efficiency of internal combustion engines. The combination of low thermal conductivity and low heat capacity that these coatings are offering, reduces the temperature gradient between the hot combustion gases and the cooler surroundings during the engine cycle thus leading to lower heat transfer losses and increased piston work. The use of such coatings also results in increased exhaust temperatures which has the potential to improve the cold start performance of after-treatment systems. The active thermal coating was applied to a production aluminium piston and its performance was compared against a reference aluminium piston on a single-cylinder diesel engine.
This paper studies the latest trend in transmission hydraulic controls development which involves the integration of the solenoid hydraulic element into the hydraulic valve body and attaching the magnetic part of the solenoid to the assembled valve body. This practice has been adopted by multiple automotive OEMs. Integrated direct acting control solenoids are key enablers for OEMs to meet more stringent fuel economy requirements in competitive environments. In the meantime, there are unique challenges in both integration and packaging due to the limited useful stroke of the armature and the fact that the solenoid armature can only act upon the spool valve in an outward motion. Both normally low and normally high functionality can be achieved with direct acting solenoids, but there are more challenges for the normally high functionality, especially spool valve porting and high hysteresis.
Polymers as viscoelastic material grab a grate attention in industry due to their high strength, light weight and low manufacturing cost. Therefore, studying the properties of polymers has a great importance. In several applications the analytical tools are used to simulate the situation due to its lower cost and time consumption than experiments. In order to simulate the viscoelastic material properties in analytical tools, theoretical models such as such as Generalized Maxwell Model (GMM) are used. Usually the viscoelastic constitutive parameters for GMM are calculated by fitting the model to the master curve obtain from a Dynamic Mechanical Analysis (DMA) test. DMA is a testing method for viscoelastic material characterization by applying the stress or strain to a viscoelastic material and measure the response.
Abstract: In vehicle development process, closures slam durability is one of the important measurement for BIW & closure design. In Closure slam simulation event, the majority of dynamic forces absorbed through rubber seals and rubber bump-stops which are typically mounted in-between the closure system and BIW. These auxiliary components also provide the cushioning to the structure and protect it from the panel interaction during abusive closure slam. In conventional CAE Simulation process, the stiffness of rubber bumpstop oftenly represented with linear stiffness data which does not capture rubber behavior during loading and unloading for both static and dynamic event. Thus, it provides an opportunity to develop the numerical material model for better rubber behavior simulation. This paper details the experimental testing of rubber material coupons under different states of strain rate.
Thermal comfort and safety of automotive passengers are the most important factors in the development of the automotive HVAC system. HVAC system is responsible for the demisting and defrosting of the vehicle’s windows and for creating/maintaining a pleasant environment inside the cabin by controlling airflow and temperature. Fog or ice which forms on the windshield is the main reason for invisibility and leads to major safety issue to the customers while driving. It has been shown that proper clear visibility for the windshield could be obtained with a better flow pattern and uniform flow distribution in the defrost mode of the HVAC system and defrost duct. Defroster performance has received significant attention from OEMs to meet the specific global performance standards of FMVSS103 and SAE J902. Therefore, defroster performance is seriously taken into consideration during the design of HVAC system and defroster duct.
Cast irons are widely used for combustion engine/exhaust system applications, not only because they are less expensive but also because they offer some attractive properties such as good thermal conductivity, relatively high specific yield strength, and good oxidation resistance. Cast irons can be made with a wide variety of microstructures containing either flake-like graphite (FG), nodular graphite (NG) or vermicular graphite (VG), or mixing of the above, which control their mechanical and fatigue properties. In this paper, a microstructure-fatigue property relationship model is developed, combining the Tanaka-Mura-Wu’s fatigue crack nucleation model with Eshelby’s solution for materials containing ellipsoidal inclusions. This applies to cast irons considering its microstructural graphite characters (shape, size, elastic modulus and Poisson’s ratio).