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The sequence of manufacturing processes involved in the making of truck frame rail sections leave a certain amount of imperfections in the form of plastic deformation and residual stresses in it. These residual stresses along with the externally induced loading stresses together should not be allowed to cross the yield limit of the frame material as it leads to premature failure of frame rail before giving its expected life. One such manufacturing process inducing premature failure is studied in detail using experimental analyses and presented in this paper. The kink bending process employed on the already formed and bolt hole punched C section frame rail, leads to plastic deformation and material crowding around the bolt hole located near the kink bend area of the frame flange.

Due to recent infrastructural development and emerging competitive automotive markets, there is seen a huge shift in customer’s demand and vehicle drivability pattern in commercial vehicle industry. Now apart from ensuring better vehicle durability and best in class tyre life and fuel mileage, a vehicle manufacturer also has to focus on other key attributes like driver’s safety and ride comfort. Thus, for ensuring enhanced drivability, key parameters for ensuring better vehicle handling includes optimization of bump steer and brake steer. Both bump steer and brake steer are vehicle’s undesirable phenomenon where a driver is forced to constantly make steering wheel correction in order to safely maneuver the vehicle in the desired path.

CNG has proven to be a concrete alternative to gasoline and diesel fuel for sustained mobility. Due to stringent emission norms and sanctions being imposed on diesel fuel vehicles, OEMs have shifted their attention towards natural gas as an efficient and green fuel. Newly implemented BS VI emission norms in India have stressed on the reduction of Nitrogen Oxides (NOx) from the exhaust by almost 85% as compared to BS IV emission norms. Also, Indian Automotive market is fuel economy cautious. This challenges to focus on improving fuel economy but without increase in NOx emissions. Exhaust Gas Recirculation (EGR) has the potential to reduce the NOx emissions by decreasing the in-cylinder temperature. The objective of the paper is to model a CNG TCIC engine using 1D simulation in order to optimize the NOx emissions and maintain exhaust temperatures under failsafe limits.

Bogie-type suspensions for trucks are comprised of two axles and a central spring pack on each side of the truck chassis. Bogie suspensions have a good load distribution between the axles and are used for severe applications in trucks, in off-road conditions thereby subjecting them to extreme stain and load. In today’s competitive market scenario, it of utmost importance to minimize down time in commercial vehicles as it directly corresponds to loss in business which leads to customer dissatisfaction. It is therefore essential to optimize and select the right material for each component in the bogie suspension system. This paper deals with the material selection and testing of one such component - Bogie Wear Pad. The bogie wear pad undergoes sliding friction throughout its lifetime during loading and unloading of bogie suspension. Three different materials are selected and their wear is measured under the same conditions of loading.

Due to increasing pollution and climatic cries, newly implemented BS-VI emission norms in India have stressed the reduction of emission. For which many automobiles have been shifted to alternate fuels like CNG. Also, the Indian Automotive market is fuel economy cautious. This challenges to focus on improving fuel economy but without an increase in emissions. Crankcase blow-by gases can be an important source of particulate emission as well as other regulated and unregulated emissions. They can also contribute to the loss of lubricating oil and fouling of surface and engine components. Closed Crankcase Ventilation (CCV) or Open Crankcase Ventilation (OCV) is capable to reduce particulate emissions by removing the oil mist that is caused mainly due to blow-by in the combustion chamber. This paperwork is focused, to measure the effectiveness of the CCV and OCV systems on the engine-out emissions, primarily on the particulate emissions.

The suspension system in a vehicle isolates the frame and body from road shocks and vibrations which would otherwise be transferred to the passengers and goods. Heavier goods vehicles use tandem axles at the rear for load carrying. Both the axles should be inter-connected to eliminate overloading of any one axle when this goes over a bump or a ditch. One of the inter-connecting mechanism used is leaf spring with tie rod, bell crank & linkages, when the first rear axle moves over a bump, the linkages equalize the loading on the second rear axle. This paper details about the failure analysis methodology to simulate the tie rod field failure using a six poster road simulator and to identify the root cause of the failure and further corrective actions.

In heavy duty diesel engines, exhaust gas recirculation is often preferred choice to contain NOx emissions, in this a part of exhaust gas is tapped from exhaust manifold or later and recirculated to air intake pipe before intake manifold. Critical to such engines is the design of air intake pipe and intake manifold combination in view of proper exhaust gas mixing with intake air. The variation in exhaust gas mass fraction at each intake port should be as minimal as possible and this variation must be contained within +/− 10% band to have a minimal cylinder to cylinder variation of pollutants. Exhaust gas homogeneity for various intake configurations was studied using three-dimensional computational fluid dynamics for a 4 cylinder, 3.8 L, Diesel fuelled, common rail, turbocharged and intercooled heavy duty engine. Flow field was studied in the computational domain from the point before exhaust gas mixing till all the four intake ports.

With advancement of technology, better safety and higher vehicle reliability is primary requirement of end customer especially in public transportation. Hence there exist challenges in design and development of steering system for long haulage and tipper application. In the steering system, track rod is used to steer both the front tyre under different operating condition assisted by power steering system. This paper deals with the failures observed on track rod in long haulage and tipper application with loading conditions. Also the methodology adapted to resolve the field failures.

Commercial vehicle industry is presently striving towards development of buses with enhanced passenger safety and comfort. This calls for additional components and aggregates that eventually lead to increase in the overall length and gross vehicle weight (GVW) of the bus for the same passenger capacity. Usually, steering system of longer front overhang (FOH) vehicles have multiple linkages such as bevel box arrangement or intermediate pivot arm arrangement instead of single direct draglink because of packaging and design constraints. In this work, an attempt has been made to design the steering system for one of the longer FOH bus with single direct draglink arrangement. Here, single draglink was packaged and designed with commercially available higher strength tube material. Design optimisation of steering geometry was carried such that the steering performance was atleast on par with existing performance.

Commercial vehicles have steering systems with one or more steering links connecting the steering gear box pitman arm and front axle steering arm. In case of twin steer vehicles, intermediate pivot arm is used to transfer the motion proportionately between the two front axles. Intermediate pivot arm is also used in some longer front over-hang vehicles to overcome their packaging constraints and to optimize the mechanical leverage. The pivot shaft is a mechanical part of the intermediate pivot arm assembly upon which pivot arm can swivel in one axis. Steering forces transferred through the drag links generates resultant forces and bending moments on the pivot shaft. In this work, study has been carried out on premature failure of the pivot shaft in city bus application model (Entry + 1 step). Metallurgical analysis of failed part indicated the failure to be due to fatigue. Pivot shaft was tested in rig with similar load conditions in order to replicate the failure.

The automotive industry needs sustainable seating products which offer good climate performance and superior seating comfort. The safety requirement is always a concern for current seating systems. The life of the present seating system is low and absorbs moisture over a period of time which affects seat performance (cushioning effect). Recycling is one of the major concerns as far as polyurethane (PU) is concerned. This paper presents the development of an alternative material which is eco-friendly and light in weight. Thermoplastic Polyolefin (PO) materials were tried in place PU for many good reasons. It is closed cell foam which has better tear and abrasion resistance. It doesn't absorb water and has excellent weathering resistance. Also it has a better cushioning effect and available in various colours. Because of superior tear resistance, it is possible to eliminate upholstery and would reduce system level cost.

In mining tippers, rear suspension plays a major role in defining vehicles ride and handling characteristics, stability and load carrying capacity. Bogie type of suspension is well suited for these applications. Bogie suspension mainly consists of bogie bracket, leaf springs and radius rods. Nonlinear static analysis is performed for a bogie bracket assembly considering bolt pretension and contacts to evaluate the static strength of bogie bracket. Since bogie bracket is connected to frame with several bolts, a sensitivity analysis is carried out to study the effect of bolt loosing on bogie bracket. The surface contact interaction (stick-slip) behavior between frame and bogie suspension mounting bracket is also studied. Good correlation is achieved with testing results.

Oil strainer is used in engine oil sump, which prevents dirt, scale and other particle from clogging downstream orifice. In this paper, dynamic analysis was carried out using FEA tool. As a part of dynamic analysis, constrained modal analysis and frequency response (steady state dynamics) analysis was done. Frequency response analysis was done for different engine exciting frequency at different service load (vibration amplitude). Modal superposition method is used for doing frequency response analysis and load is applied as base excitation. The natural frequency from modal analysis and stress response from frequency response analysis is well correlated with test results. Based on achieved good correlation with test, several design modification could be carried out in CAE before finalizing the final design.