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Crankshaft is one of the critical components of an engine (5C: cylinder head, connecting rod, crankshaft, camshaft and cylinder block). It is subjected to repetitive and dynamic loads due to cyclic operation of an engine and inertia forces. Due to uneven mass distribution, failure zones occur near fillets and holes in journal locations during operation of the engine. Hence, this topic was chosen because of increasing interest in higher payloads, lower weight, higher efficiency and shorter load cycles in crankshaft equipment. Calculation of Crankshaft strength consists initially in determining the nominal alternating bending and nominal alternating torsional stresses, which multiplied by the appropriate SCF (Stress Concentration Factor), result in an equivalent alternating stress. This equivalent alternating stress is then compared with the fatigue strength of the selected crankshaft material. This comparison will show whether or not the crankshaft concerned is dimensioned adequately.

Assessment of cooling performance in the design stage of vehicle allows a reduction in the number of needed prototypes and reduces the overall design cycle time. Frontend cooling and thermal management play an essential role in the early stages of commercial vehicle design. Sufficient airflow needs to be available for adequate cooling of the under-hood components. The amount of air mass flow depends on the under-hood geometry details, positioning and size of the grilles, fan operation and the positioning of the other components. Thermal performance depends on the selection of heat exchanger. This paper describes the effects of several design actions on engine cooling performance of a commercial vehicle with the help of Computational Fluid Dynamics (CFD) simulation tool Fluent™. Front of vehicle design is captured in detailed FE model, considering front bumper, grille, cabin, cargo and surrounding under-hood and underbody components.

In today's competitive world, vehicle with light weighting is the most focused area. Vehicle light weighting can be done either by using light weight materials or by reducing the size of the existing components. In present paper later approach of vehicle light weighting is followed. It will help in design lay outing and reduce weight will add benefit to Fuel Efficiency (FE) too. Scope for light weighting is identified in exhaust system where muffler volume is optimized using Computational Fluid Dynamics (CFD) commercial tool FLUENT™. The back pressure, exhaust gas temperature, sound noise level & sound quality are chosen as design verification parameters. The muffler volume is reduced by 14.1%; resultant system become 14.1% compact with 2% lighter weight. Initially CFD analysis is performed on existing muffler and correlated with available test results. Accordingly parameters like pressure drop and flow induced noise are set as target values for new design.

Market driven competition in global trade and urgency for controlling the atmospheric air pollution are the twin forces, which have urged Indian automobile industries to catch up with the international emission norms. Improvement in the fuel efficiency of the vehicles is one way to bind to these stringent norms. It is experimentally proven that almost 40% of the available useful engine power is being consumed to overcome the drag resistance and around 45% to overcome the tire rolling resistance of the vehicle. This as evidence provides a huge scope to investigate the influence of aerodynamic drag and rolling resistances on the fuel consumption of a commercial vehicle. The present work is a numerical study on the influence of aerodynamic drag resistance on the fuel consumption of a commercial passenger bus. The commercial Computational Fluid Dynamics (CFD) tool FLUENT™ is used as a virtual analysis tool to estimate the drag coefficient of the bus.

The safety of the heavy duty commercial vehicle (HCV) occupants in an accident is an imperative task and should be considered during the design and development of cabins. The sufficient cabin survival space must be remained after the accident. The main aim of this study is to develop a Finite Element (FE) model of HCV cabin and validate to the test as per AIS029. The present study also includes the assessment of the energy absorption capabilities of the HCV cab during the pendulum impact test. Initially a detailed 3D FE model of a fully suspended HCV cabin was developed and then pendulum impact test simulation was carried out using LS-Dyna explicit solver. Simulation results were compared with the test results and were found in a great agreement in terms of survival space and overall deformation behavior. The load transfer path was described at the time of pendulum impact. The largest amount of impact energy was absorbed by the frontal region of the cabin.

The main emphasis for a commercial vehicle design which was focused on fuel-economy and durability does not fulfill the increasing customer expectations anymore. Commercial vehicle designers need to focus on other vehicle aspects such as steering, ride comfort, NVH, braking, ergonomics and aesthetics in order to provide car like perception to truck, bus drivers and passengers during long distance drives. Powertrain mounting system must perform many functions. First and foremost, the mounting system must maintain & control the overall motion of the powertrain, to restrict its envelope reasonably, thereby avoiding damage to any vehicle component from the potential impact. This requires the mount to be stiff. Second the mount must provide good vibration isolation to have a comfortable ride to the vehicle occupant. This requires the mount to be soft.

Advanced Non-linear topology optimization methods have been addressed as the most promising techniques for light weight and performance design of Powertrain structures. The theoretical achievements are obtained both mechanically and mathematically. Nowadays, the great challenge lies in solving more complicated engineering design problems with multidisciplinary objectives or complex structural systems. The purpose of this paper is to provide a forum to present new developments in structural Non-linear topology optimization. The advantage of the proposed method is that structural optimization on irregular design domains can be carried out easily. Furthermore, this method integrates the stress analysis and the boundary evolution within the framework of finite element methods. In this paper, mainly focused on the Commercial Vehicles Powertrain component i.e. Transmission Housing.

To compete with the current market trends there is always a need to arrive at a cost effective and light weight designs. For Commercial Vehicles, an attempt is made to replace existing Gear Shift Fork from FC Iron (Ferro Cast Iron) to ADC (Aluminum Die Casting) without compromising its strength & stiffness, considering/bearing all the worst road load cases and severe environmental conditions. ADC has good mechanical and thermal properties compared to FC Iron. Feasible design has been Optimized within the given design space with an extra supporting pad for load distribution. Optimization, Stiffness, Contact pattern has been done using OptiStruct, Nastran & Ansys for CAE evaluation. A 6-speed manual transmission is used as an example to illustrate the simulation and validation of the optimized design. Advanced linear topology optimization methods have been addressed as the most promising techniques for light weighting and performance design of Powertrain structures.