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In current scenario, virtual validation is one of the important phase for any new product development process. The initial step for virtual validation for durability analysis of vehicle is to understand the loads which are transmitted to body from the roads. In current methodology standard 3g load cases are considered. These are worst load cases which show more number of high stress locations on vehicle. In actual vehicle running condition, dynamic loads are coming on vehicle structure. These dynamic loads can be obtained by measuring the loads coming on the vehicle through road load data acquisition system. The use of measured loads posed challenges due to the non-availability of representative mule in the initial phase of vehicle development. To overcome these challenges, Mahindra & Mahindra developed a new approach which enabled the direct substitution of analytically synthesized loads for measured data.

This paper describes vinyl ester based SMC (Sheet molding composite) material for oil sump part in automotive application. This sheet moulding composite is a ready to mould glass-fibre reinforced vinyl ester material primarily used in compression moulding process. This vinyl ester resin is compounded with glass fibre to meet the product functional requirements. Oil sump is a structural component under bonnet that forms the bottommost part of the crankcase and also contain the engine oil before and after it has been circulated through the engine. Generally, metals are preferred material for this application. In this paper, fibre filled vinyl ester based thermoset resin (SMC) material has been explored for oil sump application. They possess excellent properties in terms of tensile strength, modulus, impact strength, dimensional stability, high/low temperature resistance and oil resistance.

Squeak and rattle concerns accounts for approximately 10% of overall vehicle Things Gone Wrong (TGW) and are major quality concern for automotive OEM’s. Objectionable door noises such as squeak and rattle are among the top 10 IQS concerns under any OEM nameplate. Customers perceive Squeak and rattle noises inside a cabin as a major negative indicator of vehicle build quality and durability. Door squeak and rattle issues not only affects customer satisfaction index, but also increase warranty cost to OEM significantly. Especially, issues related to door, irritate customers due to material incompatibilities. Squeaks are friction-induced noises generated by stick-slip phenomenon between interfacing surfaces. Several factors, such as material property, friction coefficient, relative velocity, temperature, and humidity, are involved in squeak noise causes.

Technology is one of the key determinants of the outcome in today's wars. Many targeting systems today use infra-red imaging as a means of acquiring targets when ambient light is insufficient for optical systems. Reducing thermal signatures offers an obvious tactical advantage in such a scenario. One way to reduce thermal emission of combat vehicles is to adopt highly efficient electrical power trains instead of internal combustion engines that tend to reject a sizeable amount of the input energy as heat. The tractor is one of the most versatile vehicles that are used in the theatre of combat for various operations such as haulage, clearing terrain, deploying bridges, digging trenches etc due to its excellent abilities in handling difficult terrain. A tractor powered by an all-electric power train was developed for civilian applications. The traction characteristics are identical to that of a conventional diesel powered tractor of comparable size.

Automotive clutches are rotary components which transmits the torque from the engine to the transmission. During the engagement, due to the difference in speed of the shafts the friction lining initially slips until it makes a complete engagement. Enormous amount of heat is generated due to the slippage of the friction lining, leading to poor shift quality and clutch failure. Depending on the road & traffic conditions, and frequency of engagement and disengagement of the clutch, it generates transient heating and cooling cycles. Hill fade test with maximum GVW conditions being the worst case scenario for the clutch. A test was conducted to understand the performance of the clutch, in which clutch burning was observed. The clutch lining got blackened and burning smell was perceived. The friction coefficient drops sharply to a point until it cannot transmit the torque required to encounter the slope. This further worsen clutch slippage and lead to more severe temperature rise.

Due to recent advancements in interior noise level and the excessive use of different grade leathers and plastics in automotive interiors, squeak noise is one of the top customer complaints. Squeak is caused by friction induced vibration due to material incompatibility. To improve costumer perception, interior designs are following zero gap philosophy with little control on tolerances leading to squeak issues. Often manufacturers are left with costly passive treatments like coatings and felts. The best option is to select a compatible material with color and finish; however, this will reduce the design freedom. Material compatibility or stick-slip behavior can be analyzed with a tribology test stand. However, this test is performed on a specimen rather than actual geometry. There were instances, when a material pair was found incompatible when tested on a specimen, but never showed any issue in actual part and vice versa.

In the conceptualization phase of vehicle development, for achieving reasonable dynamics performance, proper selection of steering system meeting all the requirements is necessary. This requires accurate prediction of major steering performance attributes like steering effort, steering torque, Turning Circle Diameter (TCD), %Ackerman and steering returnability. However, currently available models majorly depend on Computer Aided Engineering (CAE)-analysis or physical trials which requires system detailing and the same cannot be used for early prediction of the steering performances in the concept phase. This paper aims to address this deficiency with the help of a new steering performance calculator. In the calculator, performance attributes namely steering effort, steering torque, TCD and %-Ackerman has been modelled with engineering calculations and other attributes namely steering returnability&precision has been modelled through machine learning techniques.

Proper lubrication is essential for any gear box & axle to get optimized performance. For getting desired life of gear train, we have to maintain minimum oil level inside the gear box or axle, whereas in case of rotating parts such as bearings and shafts, we have to provide sealing such as o rings & oil seals to stop oil coming out from the housing. But, if sealing is not proper seepage & leakage start and reduce the oil level inside the gear box. Oil deficiency leads to scuffing failure in gears and later occurrence of gear & bearing seizure ultimately fails the system. To sustain proper lubrication, we must seal the interfaces appropriately. There are different types of sealing available. Sealing is also depended on application and its location. To protect seal from external environment, we adopt a unique arrangement called slinger which enhances the life of seal.

The noise and vibration performance of diesel fueled automotives is critical for overall customer comfort. The stationary vehicle with engine running idle (Vehicle Idle) is a very common operating condition in city driving cycle. Hence it is most common comfort assessment criteria for diesel vehicles. Simulations and optimization of it in an early stage of product development cycle is priority for all OEMs. In vehicle idle condition, powertrain is the only major source of Noise and Vibrations. The key to First Time Right Idle NVH simulations and optimization remains being able to optimize all Transfer paths, from powertrain mounts to Driver Ear. This Paper talks about the approach established for simulations and optimization of powertrain forces entering in to frame by optimizing powertrain mount hard points and stiffness. Powertrain forces optimized through set process are further used to predict the vehicle passenger compartment noise and steering vibrations.

With increase in demand for quieter product and reduction in masking noise, axle whine management plays a crucial role in the early product development process. Whine is tonal in nature and humans are more sensitive to tonal memory, hence this makes user to experience a very unpleasant ride which in turn results in bad product credibility. Dynamic mesh force excitation is the cause of the axle whine noise. Critical factors in consideration are gear micro geometry variability, misalignments, temperature of operation and resulting bearing pre-load, operating loads, and structural resonances that carry the excitation to the occupant’s ear. The variability associated with gear micro-geometry plays crucial role during optimization in the quest for robust gear design.

During the cold start conditions engine must overcome higher friction loss, at the cost of fuel penalty till the optimum temperatures are reached in coolant and lubrication circuits. The lower thermal capacity of the lubrication oil (with respect to the coolant) inverses the relation of viscosity with temperature, improves engine thermal efficiency benefit. Engine oil takes full NEDC test cycle duration to reach 90°C. This leads to higher friction loss throughout the test cycle, contributing a significant increase in fuel consumption. Increasing oil temperature reduces viscosity, thereby reducing the engine friction. This helps to identify the focus for thermal management in the direction of speeding up the temperature rise during a cold engine starting. This work aims at the study and experiment of an exhaust recovery mechanism to improve the NEDC fuel economy.

Light weighting in modern automotive powertrains call for use of plastics (PP, PA66GF35) for cam covers, intake manifolds and style covers, and noise encapsulation covers. Conventionally, in early stage of design these components are evaluated for static assembly loads & gasket compression loads at component level. However, engine dynamic excitations which are random in nature make it challenging to evaluate these components for required fatigue life. In this paper, robust methodology to evaluate the fatigue life of engine style cover assembly for random vibration excitations is presented. The investigation is carried out in a high power-density 4-cylinder in-line diesel engine. The engine style cover (with Polyurethane foam) is mounted on cam cover and the intake manifold using steel studs and rubber isolators to suppress the radiated noise.

With recent advancements to create light weight engines and therefore, to design stronger and lighter connecting rods, automobile manufacturers have looked upon vanadium micro-alloyed steels as the material of choice. These materials have been developed keeping in mind the strength and manufacturing requirements of a connecting rod. Since, 36MnVS4 has been the most popular of this category, the same has been discussed in this paper. The transition of manufacturers from the traditional C70S6 grade to the new 36MnVS4 must be dealt with in-depth study and modification of processes to adapt to new properties of the latter. C70S6 is a high carbon grade with superior fracture split whereas 36MnVS4 is a medium carbon grade with superior strength and ductility owing to the presence of vanadium.

High fuel efficiency, low ownership/ maintenance cost and favorable driving climate are the major reasons for the increasing demand for low-power commuter motorcycles and scooters, particularly in developing countries like India, Brazil and China. Noise Vibration and Harshness (NVH) has now become a new subject for the battle between competing manufacturers in attracting customers. Valvetrain noise is quite significant in the engines of these cost gasoline vehicles as they don't incorporate a Hydraulic Lash Adjuster (HLA) to keep the manufacturing costs less. The aim of this study was to understand how the cam ramp velocity and height affects the noise generated by the engine and what effect they have on its performance.For this study, a small scooter gasoline engine with an Over Head Camshaft (OHC) and a rocker arrangement with a roller-follower was considered. A commercially available numerical code was used to simulate the kinematic and dynamic behaviour of the valvetrain system.

There is a higher demand for quieter tractors in the agri-industry, as the continued exposure to noise levels have disastrous effects on operator’s health. To meet the world-wide regulatory norms and to be the global market leader, its mandatory to develop the comfortable tractor which meets homologation requirements and customer expectations. Typically, Operator Ear Level (OEL) noise has been evaluated in the test, after First Proto has been made. This approach increases cost associated with product development due to late changes of modifications and testing trails causing delay in time-to-market aspect. Hence, there is a need to develop the methodology for Predicting tractor OEL noise in virtual environment and propose changes at early stage of product development. At first, full vehicle comprising of skid, sheet metals and Intake-exhaust systems modelled has been built using Finite Element (FE) Preprocessor.

In today’s scenario, internal combustion engines have conflicting requirements of high power density and best in class weight. High power density leads to higher loads on engine components and calls for a material addition to meet the durability targets. Lightweight design not only helps to improve fuel economy but also reduces the overall cost of the engine. Material change from cast iron to aluminium has a huge potential for weight reduction as aluminium has 62% lesser mass density. But this light-weighting impacts the stiffness of the parts as elastic modulus drops by around 50%. Hence, this calls for revisiting the design and usage of optimization tools for load-bearing members on the engine to arrive at optimized sections and ribbing profiles. This paper discusses the optimization approach for one of the engine components i.e., the FEAD (front end accessory drive) bracket.

Rear axles are subjected to bending and torsion loads out of which Bending loads are predominant. In case of Off road vehicles Bi Axial- combination of Bending and torsion loads were predominant, because of axle construction and vehicle usage pattern. Defined test procedures are available for bending durability and torsional durability evaluation of axles. In this experiment, new test methodology was developed for Bi Axial durability evaluation of Off road vehicle rear axle with single servo hydraulic linear actuator. For creating Bi Axial load condition, we may need multiple actuators and complicated fixtures. Axle wheel end is constrained at an angle with suitable fixtures for creating the bending and torsional forces together in the axle. Servo hydraulic linear actuator with suitable loading arm is used for applying the test torque in the axle input flange.

Being a safety critical aggregate, every aspect of brake system is considered significant in vehicles operations. Along with optimum performance of brake system in terms of deceleration generation, brake pedal feel or brake feel is considered as one of the key elements while evaluating brake system of vehicles. There are many factors such as liner and drum condition, road surface, friction between linkages which impress the pedal feel. Out of these, in this paper we will be discussing the factors which influence the brake pedal feel in relation to the driver comfort and confidence building. Under optimum braking condition, brake operation must be completed with pedal effort not very less or not very high, brake pedal feel must be firm throughout the operation, in such a way that it will not create fatigue and at the same time it will give enough confidence to the driver while operating with acceptable travel.

Globally, automotive sector is moving towards improving off-road performance, durability and safety. Need of off-road performance leads to unpredictable overload to powertrain system due to unpaved roads and abuse driving conditions. Generally, shafts and gears in the transmission system are designed to meet infinite life. But, under abuse condition, it undergo overloads in both torsional and bending modes and finally, weak part in the entire system tend to fail first. This paper represents the failure analysis of one such an incident happened in output shaft under abuse test condition. Failure mode was confirmed as torsional overload using Stereo microscope and SEM. Application stress and shear strength of the shaft was calculated and found overstressing was the cause of failure. To avoid recurrence of breakage, improvement options were identified and subjected to static torsional test to quantify the improvement level.

Weight reduction in automotive applications have led to the processing of thermoplastic polymers by foam injection molding. The density of the foamed polymer can be reduced up to 20%. Whilst, work has been reported on the weight reduction of the foamed polymer by using different types of blowing agent technologies, there has been limited studies in the areas of the sound transmission loss and sound attenuation properties of these materials. The present study is intended to understand the effect of chemical blowing agent (CBA) on the properties of polypropylene. The molded specimens were characterized using density, Differential scanning colorimetry (DSC), Thermogravimetric analysis (TGA), Fourier transform infra-red spectroscopy (FT-IR) and sound transmission loss (STL) measurements. Specimens were also tested for tensile properties, flexural properties, Izod impact strength and Heat deflection temperature (HDT) as per standard test protocol.