Search Results

In this era of engine downsizing, the powertrains with higher power densities are configured on next generation vehicles. The bare four cylinder engine without balancer shaft has higher surface velocities, sound pressure & power levels and nearly 10 to 15% higher base level vibration/forces over older generations. Adapting such engines on a new vehicle platform with stringent NVH targets is challenging. Powertrain mount modal analysis, 6DOF or 16DOF is a primary tool followed for initial mount positioning and stiffness definition. From our earlier experiences we have the knowledge that most of the 6DOF iterations lead to the mount positions which are less feasible as per vehicle architecture and packaging point of view, and further optimization is needed to arrive at suitable mount position through 6DOF analysis. In a drive to have first time right solution with minimal modifications, the study was conducted to understand the role of mount position & isolation on different vehicles.

Composite structures play a vital role in the automobile industry. Use of composites like CFRPs in automobiles poses various problems to engineers. CFRP components are not simple to model in comparison to traditional engineering materials like aluminium, steel etc. One of the main reason is that the composite materials generally do not behave in an isotropic manner but rather behave in an anisotropic or orthotropic manner. These anisotropic and orthotropic mechanical behaviors are more difficult to predict as compared to isotropic behaviors. This problem is solved using finite element analysis (FEA) packages to model complex composite material and predict their behavior. The paper discusses about the propagation of stresses within the composite laminates using FEA in Abaqus for different lamina stacking directions. The results obtained are verified using Theoretical Analysis in MATLAB.

Kinematic inputs such as camber, caster variation are very important for design of any suspension setup. Usual procedure is to get these inputs from kinematic software. But every designer cannot have this software & one has to learn them too. We have developed a method for kinematic analysis of McPherson strut type suspension which can be implemented on easily available and familiar software like MS Excel. Results obtained are in correlation with results from commercially available mechanism tools such as Pro mechanism. All links in suspension layout are considered as rigid. Vector calculus and other mathematical methods have been used to come up with final solution. Inputs required for mathematical program are suspension hardpoints, Lower arm angle from design orientation as wheel travel input and Rack stroke as steering input.

Exposure to high level of vibrations encountered in driver’s cabin of heavy duty truck over extended time causes driver fatigue and leads to serious health disorders. In most of the current heavy duty trucks in India, absence of proper vibration isolation system for driver’s seat results in transmission of high levels of vibration to the driver. A proper seat isolation system, combined with proper cushioning of seat can considerably reduce vibration transmissibility to the driver. The work presented here addresses the problem of vibration levels in a heavy duty truck and proposes solution for reducing vibration transmissibility to driver seat by using isolation and cushioning system. Vibration levels on floor, driver’s seat and seat back of an existing truck were measured using tri-axial accelerometer and 9 channel spectrum analyzer. Measured vibration levels in the vertical direction were found to be exceeding comfortable level.

Biodiesel can be considered as one of the alternative fuels for diesel engine vehicles in which the direct usage of biodiesel as a fuel is often restricted due to their high viscosity, poor atomization, incomplete combustion and carbon deposits on fuel injectors, more over biodiesels emits more NOx emissions owing to their high oxygen content. In order to reduce these effects biodiesel emulsion techniques have been used recently. This paper present the influence of adding Alumina nano particles to Karanja biodiesel emulsion fuel and study of performance and emission characteristics on a diesel engine. The investigations have been carried out in three phases on computerized single cylinder diesel engine using neat Karanja biodiesel (KBD), neat KBD emulsion fuel and Alumina blended KBD emulsion fuel. The KBD emulsion fuel has been prepared in the proportion of 93% KBD , 5% distilled water , 2% of surfactants (Span80 and Tween80) by volume to maintain hydrophilic-lipophilic balance.

In Modern Passenger Car Braking system, Disc brake plays a vital role in providing better performance and safety, in which brake pads are most critical part to decide the overall brake performance. In such brake pads, there are some technical challenges such as wear rate, abnormal noise & environmental issues with existing asbestos material. Hence we made a research to furnish suitable eco-friendly & cost effective solution. The main objective of this paper is to introduce asbestos-free automotive organic brake pad. Our research work intends to make organic brake pad by using natural fibre with organic ingredients such as kenaf and other composite materials in right proportion. Kenaf fibre is one of the natural fibres, which will improve heat resistance and strength of the brake pad. Initially, kenaf fibre is mixed with other composite materials and compacted at an optimal pressure by using hand-press machine.

Primary function of the inverter in an Electric or Hybrid Electric vehicle (EV/HEV) is to generate required AC voltage from high voltage battery to drive Electrical machine (EM). Being part of power-train of the vehicle, inverters (or hybrid control units (HCU)) are safety related electronic control units (ECU) due to the severity of the accidents/incidents that could result if the ECU is not functional as intended. Therefore it is necessary to develop the inverter in accordance with applicable safety standards. The standard ISO 26262 in particular addresses the complete development cycle of safety related automotive products. OEMs now mandate the strict adherence to ISO26262 standard for such ECUs. This paper describes how safety principles are realized in the hardware modules of inverter, which are responsible for the functional safety adherence.

Increasing demand of Electric and Hybrid vehicles questions more about Reliability and Lifetime of electronic circuits associated with them. It is very important for a hardware circuit designer to evaluate if module will last the expected lifetime. This paper elaborates the methods and steps to find the expected lifetime of critical components; and to decide whether Hybrid Power Electronics Unit (PEU) will meet the OEM requirements on lifetime. Accelerated thermal stress method is used to determine the required High Temperature Operational Life (HTOL) hours for given thermal profile of Hybrid vehicle passenger car in driving (8,000Hrs), charging(30,000Hrs) and total lifetime (38000Hrs ≈ 15Years). Example calculation of required HTOL hours against expected lifetime for critical component from Hybrid ECUs is explained in this paper. Also inclusions and exclusions of this method in evaluating lifetime assessment are also discussed here.

With increasing growth of vehicular population, there is an increasing demand for raw materials. This has added strain to the available resources, which is becoming more and more unsustainable. As a result, search for sustainable materials are continuously happening in our industry and there is a strong focus from everyone to incorporate more and such materials. One way of doing so, is by blending naturally available materials like fibers, with polymers. In this study, naturally available Coconut fibers have been blended successfully with Polyurethane foam, thereby improving the green footprint of the vehicle. Coconut fibers are naturally occurring fiber extracted from the husk of the coconut. Polyurethane foam is the most versatile polymeric foam used in several places of automobile for reducing the Noise, Vibration & Harshness. The composite was manufactured using reaction injection molding technique by reacting polyol with iso-cyanide.

Biodiesel is an alternative fuel for diesel which is made through a chemical process which converts vegetable oils and fats of natural origin into fatty acid methyl esters (FAME). The most usual method to transform Bio-oil into biodiesel is Transesterification that can be carried out using different catalyst systems. Jatropha is second generation, non-edible oil and can be used for producing biodiesel. The Transesterification reaction consists of heating jatropha oil with proper concentration of methanol at appropriate temperature in the presence of catalyst. After reaction, the mixture is allowed to settle down for 8-10 hrs. Two separate layers, top layer of biodiesel and lower layer of glycerol will form, which can be separated. Reaction temperature, amount of methanol, catalyst and reaction time are important parameters which decide yield and quality of biodiesel.

Vegetable oils and its esters are being considered seriously for internal combustion engines. It has many advantages such as it is renewable, nontoxic, sulphur free and biodegradable. But there are several problems associated with its use in diesel engines such as lower thermal efficiency and higher smoke levels compared to diesel. One of the methods by which these problems can be tackled is by blending of diesel (DSL) with biodiesels. In this work coconut oil biodiesel and castor oil biodiesel which are obtained from different sources are chosen, considering the wide variation in properties such as viscosity and degree of unsaturation. For coconut oil biodiesel (COBD) and castor oil biodiesel (CSBD), iodine value, which is an indication of the degree of unsaturation, was determined experimentally. The property influence on the performance of COBD and CSBD and its blends with equal volume with diesel was studied.

Unburned hydrocarbon (HC) emission results because part of the fuel inducted into the engine escapes combustion. HC emission is dependent on many mechanisms such as adsorption and desorption of fuel in oil layer, flame quenching, fuel escaping into crevices and accumulation of fuel in engine deposits, etc. Out of these, the oil layer adsorption/desorption mechanism contributes to about 25-30% of total engine-out HC emissions. In this work adsorption/desorption mechanism is studied considering the engine to be fueled with different fuels. The fuel adsorbed/desorbed in lubricating oil is modeled with a one-dimensional partial differential equation (PDE). One dimension PDE is chosen as the transverse flow across the oil film is considered to be negligible. The PDE is solved using finite difference explicit scheme in which the space derivatives and the time derivatives are approximated with a second order central difference method and forward Euler method, respectively.

The performance of any automotive engine depends not only upon its core engine parts but also on the effectiveness of the sub-systems attached to the engine, like the intake, fuel, engine cooling and exhaust systems. The exhaust system being a critical system of any automotive vehicle plays a responsible role of improving the ride quality of the vehicle and fuel economy. The effective design of exhaust system is critical in order to ensure the required exhaust gas is exited from the engine and at the same time the noise is attenuated. In this paper a novel approach is developed in order to characterize the flow through the cold end exhaust system and reduce the pressure drop to achieve desired performance. The exhaust system attenuates the noise from the engine without deteriorating the engine performance by ensuring an optimum value of exhaust back pressure.

The OEM's aim is to reduce development time and testing cost, hence the objective behind this work is to achieve a flexible stateflow model so that changes in the application during supply chain or development, on adding/deleting any switches, varying timer cycle, changing the logic for future advancements or else using the logic in different application, would end in minimal changes in the chart or in its states which would reflect least changes in the code. This research is about designing state machine architecture for chime/buzzer warning system and wiper/washer motor control system. The chime/buzzer stateflow chart includes various input switches like ignition, parking, seat belt buckle, driver door and speed accompanied with warning in the form of LED, lamp and buzzer. The logic is differentiated according to gentle and strong warning. Various conditions and scenarios of the vehicle and driver are considered for driver door and seat belt which is resolved in the chart.

Design of vehicle structure to provide safe structural environment for occupants of vehicles involved in high speed (> 15 km/h) collisions has drawn considerable resources as safety of humans is at stake. Low speed impacts, since these do not cause severe injuries to the occupants, do not generate much concern. However, structural design for this situation has generated a lot of interest among insurance companies as the structural damage caused by these types of collisions is substantial, requiring significant payments by the insurance companies. In this work alternative designs for crash-box have been assessed for RCAR (Research Council of Automotive Repairs) requirement for frontal crash. Using structural details of an existing sedan, various designs of crash-box that can be fitted within the packaging space have been assessed for low speed impact.

This article delineates the importance of infrastructure and its related aspects on sustainability of transportation on global and local context. Almost 7% of the GDP in India is spent on transportation and 6% of the CO2 emissions in the world is due to transportation. In countries like India, the road transport has significantly grown over other forms of mobility. This articles introduces different forms of transportations that exists today and the importance of sustainability in transportation sector. Sustainable transportation depends on development of infrastructure to enable smart transport solutions involving intelligent transport system, electric mobility, information management, vehicle health monitoring, advanced traffic management system and driver assistance system in a vehicle. The challenges includes existing transport operations, environmental impact and complexity of existing transport network.

This paper describes static and fatigue behavior of resistance spot welds with the stack-up of conventional mild and advanced high strength steels, with and without adhesive, based on a set of lap shear and coach peel coupon tests. The coupons were fabricated following specified spot welding and adhesive schedules. The effects of similar and dissimilar steel grade sheet combinations in the joint configuration have been taken into account. Tensile strength of the steels used for the coupons, both as-received and after baked, and cross-section microstructure photographs are included. The spot weld SN relations between this study and the study by Auto/Steel Partnership are compared and discussed.

This paper depict the difference in the endurance factor of safety with usage of static and quasi static FE analysis and corrective measures take to solve the problem. The importance of the dynamic loading and subsequent effect of it on the multi axial fatigue analysis. Considering the modern trend prevailing among the vehicle manufacturers and specifically talking about two wheeler industry, it is clear that while the engine remains the same but the frame is changed to cater the market with new models to cut down on the development time. Initially the crankcase was designed for a double cradle frame where the crankcase was mounted on the frame. Later, the frame design was changed to single cradle where engine acts as a stress member link. This kind of arrangement makes the crankcase mountings participate in the chassis loads. Therefore, the crankcase mounting experiences road loads when the vehicle encounter the road irregularities.

Since the inception of the IIHS Small Overlap Impact (SOI) test in 2012, automotive manufacturers have implemented many solutions in the vehicle body structure to achieve an IIHS “Good” rating. There are two main areas of the vehicle: forward of vehicle cockpit and immediately surrounding the vehicle cockpit, which typically work together for SOI to mitigate crash energy and prevent intrusion into the passenger zones. The structures forward of vehicle cockpit are designed to either 1) absorb vehicle energy from impact to the barrier, or 2) provide enough strength and rigidity to aid deflection of the vehicle away from the barrier. The structures which are immediately surrounding the vehicle cockpit (known as pillars and rocker/sills) are traditionally components designed to be highly rigid sheet metal panels to protect the occupant during crash events.

In this paper, a new beam element is developed for the purpose of capturing thin-walled beam’s collapse mechanisms under dynamic load such as impact load and will be validated in the next phase. Such beam element can be used to create simplified finite element models for crashworthiness analysis and simulation and, therefore, will significantly reduce the modeling effort and computing time. The developed beam element will be implemented into LS-DYNA and validated through crashworthiness analysis and simulation. This paper introduces the approach of deriving the new element formulation.