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Highway transportation using truck is an important transport mode of goods and product to their destination. Commercial vehicle is expensive mode of transportation so it will be protected from failure. For Heavy duty truck they are fully loaded at one side of transportation and other side empty transportation. In such case lift axle grounded when truck is loaded and when truck is empty it is in lift condition. Lift axle is play important role while loading so it is important that it should not fail. Many times lift axle fails at weld location due several load come on the axle. In this paper study of weld failure to vertical, braking and lateral load come on lift axle when truck is in loading condition. Weld failure check in CAE analysis with various load cases and compare with actual physical vehicle failure. Weld failure correlation well correlate when actual loading are consider in analysis. For analysis loading data is measure from RLDA data that will be used for analysis.

Downsizing and Light weighting is the latest trend in the automotive industry to achieve more fuel efficient, compact and cost effective design of vehicles. Powertrain components compromise of more than 45% of the total vehicle weight. Automakers are putting significant efforts to reduce the weight of power train components. Integrated design of aluminum Engine Head and Intake manifold has been successfully implemented. Now currently we have identified the gear box housings for downsizing in light duty trucks i.e. Existing light duty trucks Cast Iron transmission. This design has been successfully modified with integrated clutch housing and transmission housing, using lightweight aluminum as the new material, using simulation tools. This lead to weight savings of up to 30% and cost savings of 20-25% as compared to existing cast iron designs. Using an integrated design reduces the assembly cost, makes the design more compact and gives better weight balance.

Virtual validation of automobile components poses a huge challenge and needs continuous process improvements. One of such challenge in FE modelling of welds and understanding its behavior with respect to physical behavior. With the ongoing development of BSVI line of products in commercial vehicle industry, the virtual validation needs to be accurate and close to the physical behavior of the components. The learning and challenges faced during the previous development is implemented in the current study for weld simulation and correlation activity. The brackets welded to the power train components is taken as a challenge in the present work. Initially weld model was depicted in the CAD and was analyzed in CAE by providing proper FE connection. This practice had lot of flaws, approximations due to perpendicularity and flatness concerns in the models leading to consuming a lot of time in model preparation.

The main driving force behind recent innovations in automotive sector is the need to decrease the dependability on fossil fuels and move towards alternative sources for energy. While there is still substantial scope for improvement in conventional diesel and petrol engine based powertrains, the inherent dependency on limited and rapidly depleting carbon based fuels make their long term usage impractical highlighting the need for alternative non-conventional powertrain setups. In the recent past, electric powertrains have come out as favorable alternative as they are extremely flexible in adopting to scenarios where energy for use might be drawn from multiple sources such as solar power, hydroelectric, nuclear reaction, etc. The advantages can further be magnified by adopting the electric power based powertrains in mass transportation application such as bus application.

Brake drum in commercial vehicles is very important aggregate contributing towards major weight in brake system module. The main function of brake drum is to dissipate kinetic energy of vehicle into thermal energy, as a results in braking operation major load comes on brake drum. Hence this is very critical component for vehicle safety and stability [1]. Objective of this paper is to increase the pay load, which is utmost important parameter for commercial vehicle end customers. To achieve the light weighing target, alternate materials such as Spheroidal graphite iron (SGI) has been evaluated for development of brake drum. Many critical parameters in terms of reliability, safety and durability, thickness of hub, wheel loading, heat generation on drum, manufacturing and assembly process are taken into consideration. The sensitivity of these parameters is studied for optimum design, could be chosen complying each other’s values.

The planetary gear system is a critical component in speed reduction of gear system. It consists of a ring gear, set of planetary gears, a sun gear and a carrier. It is mainly used in high speed reduction transmission. More speed variation can be achieved using this system with same number of gears. This speed reduction is based on the number of teeth in each gear. The size of new system is compact. A theoretical calculation is performed at concept level to get the desired reduction of speed. Then the planetary gear system is simulated using ANSYS software for new development transmission system. The final validation is done with the testing of physical parts. This concept is implemented in 9speed transmission system. Similar concept is in development for the hub reduction with planetary gears. The maximum 3.67 reduction is achieved with planetary system. The stresses in each pin is calculated using FEA.

This paper presents theoretical calculation, analysis and simulation (validation and verification) of driveshaft torsion vibration. The vibration measurement validation verification has been carried out on vehicle (4x2) having four cylinder engine 85kw@2800 rpm and six speed manual transmission for getting correlation between values of theoretical calculations and CAE results. This analysis has been done in order to achieve vehicle good performance in terms of driving comfort as well as smooth functionality with zero vibration frequency at high speed. The propeller shaft series selection and refinement has been done using theoretical iteration with operating angle of prop shaft which exits in between the universal joint planes. A frequency of vibration analysis has evaluated at different propeller shaft layout and duty cycle. The vibration performance predictions for vehicles with these design is rigorously done.

In manual driven vehicle, gear change mechanism is a component that is too often taken granted but it is one of the most important feature of the vehicle. Customer touches, feels the entire vehicle through gear shift mechanism hence it must be quick and smooth in action, efficient and totally reliable. In cab over engine type truck configuration, the mechanical single rod is preferable and best efficient option for gear shift mechanism. In conventional single rod design, one end of gear shifting linkage is mounted on the engine through bracket and the lever comes inside from the cabin, beside the driver seat for changing the gears. Another end of this linkage is connected to vehicle transmission shift lever. In this conventional design, gear shift lever is having huge induced vibration, which is irritating and frustrating in nature. And during the cabin tilting at its axis, a cut out is required on cabin floor which allows cab tilting when GSL is mounted on engine.

Manual Gear shifting mechanism is a customer touch point in vehicle driving conditions and it is a frequently used functional part of the vehicle. Inherent challenges exist to develop a gear shifting system that achieves better comfort shifting gears in manual transmissions, i.e. gear shift levers should be comfortable, efficient and reliable. There are several traditional concepts available for designing a mechanical interface for gear shift system like cable GSL (Gear Shift Linkages), mechanical GSL, engine mounted SRGSL (single rod gear shift linkages), directly transmission mounted GSL. All are having pros and cons over another. A unique attempt is made to provide an efficient single rod type gear actuation system for commercial vehicle where one end is directly mounted on the cowl floor of the bus/Truck and another end is connected to transmission lever.

A propeller shaft is a mechanical component of drive train that connects transmission to drive wheels/axle with the goal to transfer rotation and torque. It is used when the direct connection between transmission and drive axle is not possible due to large distance between their respective assigned design spaces. In commercial vehicles especially in heavy duty (GVW/GCW>15 tons) a single piece propeller shaft is seldom used due to its inherent disadvantages and therefore, most if not all, of the setups consists of multiple pieces of propeller shaft which are directly mounted on to frame cross members with the help of mounting brackets. As such the mounting bracket assembly undergoes various dynamic and static loading conditions and should be able to withstand these loads. This paper will focus on the FEA analysis of propeller shaft mounting assembly system. Furthermore, these results will be correlated with physical tests results collected from test rig and physical vehicle testing.

As the commercial vehicle engine heads towards the next generation of stringent emissions and fuel economy targets, all aspects of the internal combustion engine are subject to close scrutiny. Inherently, ICE’s are very inefficient, with efficiency varying between 18 ~ 40%. This efficiency is a function of friction losses, pumping losses and wasted heat. Currently, automotive OEM’s globally are hard at work trying to attack these issues with various solutions to achieve incremental gains. The leading trend is getting more power from less space, also known as downsizing. Due to the importance of downsizing, direct injection and other technologies, it is imperative to highlight another key area, where OEM’s are expanding their limits to gain those extra few kilometers per liter of fuel i.e. weight reduction. From an emissions perspective, it is estimated that every 50 kg of weight reduced from an average 1,500 kg vehicle cuts CO2 emissions by 4 ~ 5 grams.

Flex Connectors are intended for mitigating the relative movement of exhaust system components along the axis of the system arising from the thermal expansion due to intermittent engine operation. Flex connectors must not be installed in locations, where they will be subjected to destructive vibration. Hence, the stiffness of the flex connector plays an important role, while designing or selecting the right design. It consists of a multi-ply bellows combined with an inside and an outside steel braid. The liner is included to reduce the temperature of the bellows and improve flow conditions. The braid is included for mechanical protection and to limit the possible extension of the joint. It has only axial translational motion.

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 decrease weight of the current design without compromising its strength & stiffness, considering/bearing all the worst road/engine load cases and severe environmental conditions. The topic was chosen because of interest in higher payloads, lower weight, and higher efficiency. Automotive cylinder head must be lighter in weight, to meet increasingly demanding customer requirements. The design approach for cylinder head has made it difficult to achieve this target. A designer might make some judgment as to where ribs are required to provide stiffness, but this is based on engineering experience and Finite Element Analysis (FEA) of the stand-alone head.

The existing head cover is having external oil and blow by separation unit, which is not only costlier but also complex and leads to increase in overall height of engine which was difficult to integrate in new variants of vehicles. A new head cover has been designed with internal baffle type oil and blow by separation system to ensure efficient separation and proper packaging of the system in new variants. The new system has been finalized after 26 DOE’s of different wire mesh sizes and different baffle plate size and positions. The final system has two bowl shaped separation unit with wire mesh, two cup type oil separation passages and one baffle plate for separating blow by. The system works on condensation and gravity method. The blow by is guided through a well-defined passage integrated in aluminum cylinder head cover itself. The passage angle is maintained to ensure minimum oil flow with blow by.

Three on the tree, four on the floor. The gear change mechanism is a component that is too often taken for granted but it is one of the more important features of the vehicle. It must be quick and smooth in action, efficient and totally reliable. Modern driving conditions demand that the driver makes frequent gear changes and a mechanism that is temperamental or inaccurate can be both frustrating and dangerous as well as physically tiring. The gear changing mechanism starts, quite obviously, with the gear lever. Most stem from the fact that a gear lever must move in two planes, forward and back and then from side to side to move across the gear "gate". A good many drivers think of gear changing as one simple action. This is more a tribute to the design of gear changing mechanisms than a reality. There are multiple gear selector mechanisms that are available for use in commercial vehicle industry.

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.

To compete with the current market trends there is always a need to arrive at a cost effective and light weight designs, hence the need for upgrading the existing/proven integral connecting rod to fracture split connecting rod. This technique provides gains as weight reduction and consequently reducing noise and vibration due to the decrease of the oscillating mass from the system. Using the proposed fracture split connecting rod, it is estimated that cost savings of up to 10%, reduction in weight and better fatigue performance (25% - 30%) can be achieved. For this, we have used simulation tools to reduce number of physical tests and thereby achieving considerable reduction in design and development time and cost. High carbon alloy steel used for manufacturing fracture split connecting rod and it doesn’t require additional heat treatment after hot forging.

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, inertia forces due to uneven mass distribution with failure zones as fillets and holes in journal locations. Fatigue is most common cause in failure of the crankshaft. Its failure will cause serious damage to the engine so its reliability verification must be performed. The load is applied as per the firing order of the cylinder for 2 revolutions of crankshaft, to cover firing condition of each cylinder. Loads with respect to crank angle or time are applied at respective locations and results are taken on 360 steps for 2 complete revolutions of crank. The topic was chosen because of increasing interest in higher payloads, lower weight, higher efficiency and shorter load cycles in crankshaft equipment.

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.