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Automotive manufacturers are concerned about the safety of its customers. Safety critical components like wheel hub are designed considering the severe loads generated from various customer usage patterns. Accelerated tests, which are derived from Real World Usage Patterns (RWUP), are conducted at vehicle level to ensure the wheel hub meet the durability targets. Load and strain measurement are done to understand the critical lateral loading undergone by the wheel hub. Measured data is synthesized to drive the duty cycle. Finite Element (FE) Analysis of Wheel end is performed at module level considering measured loads to capture the exact load path in physical test. Simulation results are compared with the measured strain for validating the FE analysis procedure. FE analysis was repeated for different wheel hub designs, combinations of different flange radius (R) and flange width (t), to understand the effect of the two critical dimensions on wheel hub durability.

Use of Computer Aided Engineering (CAE) tools for virtual validation has become an essential part of every product development process. Using CAE tools, accurate prediction of potential failure locations is possible even before building the proto. This paper presents a detailed case study of virtual validation of Backhoe Loader (BHL) dipper arm using CAE tools (MBD: Multi Body Dynamics and FEA: Finite Element Analysis) and comparison of simulation results with test data. In this paper, we have illustrated the modelling of Backhoe Loader in MSc ADAMS software. The detail ADAMS model was created and validated. The component mass, Center of Gravity (C.G) and Mass Moment of Inertia (MOI) was taken from CAD data. Trenching is simulated by operating the different hydraulic cylinders of the BHL. Loader arm cylinders and stabilizer cylinders are operated to lift the machine tires above the ground level.

For Automatic transmission application, crankshaft torque is transferred to torque converter through flex plate. As the flex plate has no functional requirement of storing energy as in case of Manual Transmission (MT) flywheel, flex plate design can be optimized to great extent. Flex plate structure must have compliance to allow the axial deformation of torque convertor due to ballooning pressure generated inside the converter. Flex plate experiences dynamic torque and centrifugal forces due to high rotational speed. It should have compliance to accommodate the assembly misalignments with torque convertor in both axial and radial directions. In this paper, sequential and hybrid optimization techniques are described to optimize the flex plate design with stress, stiffness and mass as design constraints. The load path, corrugation length and axial stiffness of flex plate captured accurately using this hybrid optimization.

Precise control over mixture formation withhigh fuel pressure and multiple injections allows Gasoline Direct Injection (GDI) engines to be operated satisfactorily at extreme conditions wherePort Fuel Injection (PFI) engines wouldnormally struggle due to combustion instability issues. Catalyst heating phase is one such important condition which is initiated after a cold engine start to improve the effectiveness of the three-way catalyst (TWC). For a given TWC specification, fast light-offof TWC is achieved in the catalyst heating phase by increasing the exhaust gas temperature with higher exhaust mass flow. The duration of this phase must be as short as possible, as it is a trade-off between achieving sufficient TWC light off performance and fuel efficiency.

Automotive manufacturers are constantly working towards enhancing the driving experience of the customers. In this context, improving the static and dynamic gear shift quality plays a major role in ensuring a pleasant and comfortable driving experience. Moreover, the gear shift quality of any manual transmission is mainly defined by the design of the synchronizer system. The synchronizer sleeve strut detent groove profile plays a vital role in defining the performance of the synchronizer system by generating the minimum required pre-synchronization force. This force is important to move the outer synchronizer ring (blocker ring) to the required index position and to wipe-out the oil from the conical friction surfaces to build rapid high cone torque. Both these functional requirements are extremely critical to have a smooth and quick synchronization of the rotating parts under dynamic shift conditions.

Synchronizers are the most critical parts of a manual transmission. There are classical calculations available for the synchronizer design and studies are available for the normal functioning of synchronizer rings which describes how the synchronizer behaves in the event of gear shifting. The objective of this study is to describe the synchronizer behavior when synchronizers are not functional, i.e., in other gear engaged condition and the rings are free. This study describes the failure mechanism of the unused synchronizer rings which are moving freely in the packaging space. The findings of this synchronizer design cannot be limited only for synchronizer performance and standard durability calculations. To ensure proper function of synchronizer rings and to achieve the required life the external parameters like clearances, lubrication, clutch design for dampening torsional vibration from the engine are to be considered.

The global automotive industry is growing rapidly in recent years and the market competition has increased drastically. The engines with high torque delivery and deeper transmission ratios has become more and more common for a pleasant drivability experience. In a market highly driven from a comfort and an economic point of view, it is essential to develop a transmission and its components in an optimal way. One of the Unique Selling Point (USP) of a vehicle is the gear shift quality & it is highly important to have an optimum shift quality for an enhanced customer experience. Synchronizer plays a vital role for gear shifting performance in manual gearbox without any shifting assistance. The primary function of a synchronizer is to reduce the RPM difference between two gears before gear shifting with minimum time.

Synchronizer is the key element for the smoother gear shift operation in the constant mesh transmission. In the gear shift operation, the double bump occurs at the contact between the sleeve teeth and the clutch body ring teeth after the full synchronization. The double bump is random in nature and the dynamics is difficult to predict. The double bump gives a reaction force to the driver and affects the gear shift quality. This paper focus on the sensitivity analysis of the synchronizer ring index percentage and the clutch body ring asymmetric chamfer angle to reduce the occurrence and magnitude of the double bump. The system level simulation model is developed using 1D simulation tool. The modeling is done after complete declutching event so that there is no power supply to the transmission. The model can handle both upstream and downstream reflected inertia depending upon the gear shift event.

One of the key factors driving the automotive world is emission regulations. Zero emissions, clean engine concept are some buzz words being used extensively in the automotive industry. Stringent emission regulations throughout the world mean that automotive manufacturers have to pay attention to minimizing engine out emissions. Electronic engine management systems allow flexibility in controlling injection parameters & provide a means for optimizing engine performance. This paper presents work carried out on a 2.49L common rail direct injection diesel engine to achieve Euro IV emission targets. Without after-treatment devices, it is difficult for engine management alone to meet Euro IV and further stringent emissions. To overcome this, two type of after-treatment technologies are adopted by OEM's Selective Catalyst Reduction Diesel Particulate Filter Huge amount of research is being done on the application, cost aspect and availability of component samples for series production.

In the move towards cleaner diesel emissions, the European On Board Diagnostics (EOBD) legislation mandates monitoring of drift of air mass flow sensor. Drift of a sensor is defined as the phenomenon in which output signal slowly deviates independent of the measured property. Long term drift usually indicates a slow degradation of sensor properties over a long period of time. Drift monitoring of the air mass flow sensor involves comparing the signal from the sensor with a reference signal under special operating conditions. Boost pressure sensor, which measures absolute intake manifold pressure and intake air temperature, is used to calculate the reference signal. For engines with constant geometry turbo charger, boost pressure sensor is solely used for drift monitoring. Therefore, it was a challenge to come up with a means of finding the drift in air flow mass sensor without boost pressure sensor.

Material selection is based on Process such as forging, die-casting, machining, welding and injection moulding and application as type of load for Knife Edges and Pivots, to minimize Thermal Distortion, for Safe Pressure Vessels, Stiff, High Damping Materials, etc. In order for gears to achieve their intended performance, durability and reliability, the selection of a suitable gear material is very important. High load capacity requires a tough, hard material that is difficult to machine; whereas high precision favors materials that are easy to machine and therefore have lower strength and hardness ratings. Gears are made of variety of materials depending on the requirement of the machine. They are made of plastic, steel, wood, cast iron, aluminum, brass, powdered metal, magnetic alloys and many others. The gear designer and user face a myriad of choices. The final selection should be based upon an understanding of material properties and application requirements.

The scope of the project is to achieve SUV structural performance improvement to meet the offset frontal crash safety requirements as per ECE R 94 Regulation by design modifications in different Sub-systems of the vehicle structure suggested with the help of CAE crash simulations. The study can be classified in four main phases mentioned below. The first phase of the development is to conduct a crash test and CAE simulation for the baseline design. The second phase includes correlation activity among baseline test and CAE. The third phase is to achieve improvement by vehicle structure design modifications and new parts in chassis and BIW guided with CAE simulations and design iterations. Finally the forth phase deals with validation of new crashworthy vehicle design by last crash test.

In the recent past a lot of emphasis is given for the overall weight reduction of the sound package used in the vehicles. The paper presents a study of one of such materials used in the automotive market. The dash panel is a primary area for the engine noise transmission to the cabin. Hence the material selection of the dash inner acoustic insulation is critical. In the conventional method a barrier (EVA) and a decoupler (foam) is used. In the conventional design the surface weight of the barrier has to be substantially high for the dash insulation to perform effectively and hence adds to more weight. In the present application of light weight material also known as dual density absorbers and barrier is used for the dash acoustic insulator. The study reveals the good acoustic performance of the light weight dash mat in terms of passenger cabin noise reduction and improved sound quality along with weight reduction.

Aerodynamic simulation using commercial CFD (Computational Fluid Dynamics) codes is now an integral part of the vehicle design process. Aerodynamic prediction and vehicle development program runs in parallel. This requires a good agreement between experimental measurements and CFD prediction of aerodynamic behavior of a vehicle. The comparison between experimental and simulation results show differences, as it may not be possible to replicate effect of all the wind tunnel parameters in the simulation. This paper presents the details of aerodynamic simulation process of a Crossover and its validation with the experimental results available from the wind tunnel tests. The results are compared for different configurations such as- closing the grille openings, removing the rearview mirror, adding ski-rack and using different tyres. This study also includes the effect of different wind speeds and yaw angles on the coefficient of drag.

This paper presents a simulation for the gear shift process of a manual transmission, implemented using a library function. All the subsystem (i.e. synchronizer and the shift system) are correlated to generate a gear shift curve for optimum shift ability prediction of a manual transmission. A 5-speed manual transmission is used as an example in the paper to illustrate the simulation, co-relation and the validation of the gear shift performance curve on the vehicle. The dynamic behavior of the shift system and synchronizer in engaging and disengaging the gear is simulated through the gear shift characteristics to generate the shift rail's ramp profile. The synchronizer travel is co-related with the shift rail ramp profile to get a negative force after synchronization is over. The profile indicates the role of the detent ball diameter, radius on the shift rail ramp's profile etc and how it affects synchronizer force over the shift rail travel.

Continually increasing customer demands and legislative Requirements regarding fuel economy, emissions, Performance, drive ability and comfort need to be met by every OEM's developing vehicles worldwide. There is a serious pressure to reduce CO2 emission from automotive application which contributes to around 15.9% of the total CO2 production based on the Surveys done time to time. In a developing market like India, many foreign players are entering with lots of option for offering to this market. The parameters of prime importance here are fuel efficiency with good drive ability and at the same time affordable price. Diesel engines are finding these benefits and attracting the buyer over its counterpart (Gasoline). The road condition and the driving pattern in India compared with developed countries differ to a major extent. In India, the Low speed uses are predominating in Cities and in Ghats.

Reducing the vibrations in the powertrain is one of the prime necessities in today's automobiles from NVH and strength perspectives. The necessity of 4×4 powertrain is increasing for better control on normal road and off-road vehicles. This leads to bulky powertrains. The vehicle speeds are increasing, that requires engines to run at higher speeds. Also to save on material costs and improve on fuel economy there is a need for optimizing the mass of the engine/vehicle. The reduced stiffness and higher speeds lead to increased noise and vibrations. One more challenge a powertrain design engineer has to face during design of its transmission housings is the bending / torsional mode vibrations of powertrain assembly. This aggravates other concerns such as shift lever vibrations, shift lever rattle, rise in in-cab noise, generation of boom noise at certain speeds, etc. Hence, reducing vibrations becomes an important and difficult aspect in design of an automobile.

This paper describes application of Design of Experiments (DOE) technique and optimization for mass reduction of a Sports utility vehicle (SUV) body in white (BIW). Thickness of the body panels is taken as design variable for the study. The BIW global torsion, bending and front end modes are key indicators of the stiffness and mass of the structure. By considering the global modes the structural strength of the vehicle also gets accounted, since the vehicle is subjected to bending and twisting moments during proving ground test. The DOE is setup in a virtual environment and the results for different configurations are obtained through simulations. The results obtained from the DOE exercise are used to check the sensitivity of the panels. The panels are selected for mass reduction based on the analysis of the results. This final configuration is further evaluated for determining the stiffness and strength of the BIW.

Stringent emission norms by government and higher fuel economy targets have urged automotive companies to look beyond conventional methods of optimization to achieve an optimal design with minimum mass, which also meets the desired level of performance targets at the system as well as at vehicle level. In conventional optimization method, experts from each domain work independently to improve the performance based on their domain knowledge which may not lead to optimum design considering the performance parameters of all domain. It is time consuming and tedious process as it is an iterative method. Also, it fails to highlight the conflicting design solutions. With an increase in computational power, automotive companies are now adopting Multi-Disciplinary Optimization (MDO) approach which is capable of handling heterogeneous domains in parallel. It facilitates to understand the limitations of performances of all domains to achieve good balance between them.

Plenum is the part located between the front windshield and the bonnet of an automobile . It is primarily used as an air inlet to the HVAC during fresh air mode operation. It’s secondary functions include water drainage, aesthetic cover to hide the gap between windshield to bonnet, concealing wiper motors and mechanisms etc. The plenum consists mainly two sub parts viz. upper plenum and lower plenum. Conventional plenum design which is found in majority of global OEMs employ a plastic upper plenum and a metal lower plenum which spans across the entire width of engine compartment. This conventional lower plenum is bulky, consumes more packaging space and has more weight. In this paper, we propose a novel design for the plenum lower to overcome above mentioned limitations of the conventional design. This novel design employs a dry and wet box concept for its working and is made up of complete plastic material.