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In a current competitive automotive market, weight and cost optimization is the need of an hour. Therefore it is important to explore use of alternative material which has less weight, low manufacturing cost and better strength. This paper presents methodology to achieve cost & weight reduction through use of Austempered Ductile Iron (ADI) instead of alloy forging. ADI casting has lower density, physical properties at par with alloy forgings and lower manufacturing cost. Pivot arm is the one of the critical component of twin axle steering system which transfers the hydraulic torque from steering gearbox to second forward axle via linkage system. In order to design lightweight pivot arm, existing chromium alloy steel material is replaced with the Austempered ductile iron (ADI). Pivot arm is designed and validated digitally as well as bench test and results are found to be meeting cost and weight targets.

This paper discusses the test setup and methodology required to validate complete lift axle assembly for simulating the real time test track data. The correlation of rig vs track is discussed. The approach for reduction of validation time by eliminating few of the non-damaging tracks/events, its correlation with real life condition is discussed, and details are presented. With increased competition, vehicle development time has reduced drastically in recent past. Bench test procedure using accelerated test cycle discussed in this paper will help to reduce development time and cost. Process briefed in this paper can also be used for similar test specification for other structural parts or complete suspension system of heavy commercial vehicles.

The public transport in India is gradually shifting towards electric mobility. Long range in electric mobility can be served with High Voltage Battery (HVB), but HVB can sustain for its designed life if it’s maintained within a specific operating temperature range. Appropriate battery thermal management through Battery Cooling System (BCS) is critical for vehicle range and battery durability This work focus on two aspects, BCS sizing and its coolant flow optimization in Electric bus. BCS modelling was done in 1D CAE software. The objective is to develop a model of BCS in virtual environment to replicate the physical testing. Electric bus contain numerous battery packs and a complex piping in its cooling system. BCS sizing simulation was performed to keep the battery packs in operating temperature range.

With the advent of BS VI regulations, automotive manufacturers are required to innovate the powertrains, fuel systems, exhaust and its after treatment systems to meet the regulatory requirements. The exhaust regulations can be met either by reducing the exhaust gases being generated by the engine (attacking the source) or by treating the exhaust gases in after treatment devices. The choice of the opted system varies with the manufacturer. The after-treatment devices such as catalytic converters are generally mounted in the engine compartment to take advantage of high temperature of exhaust gases to yield the reactions. Such an arrangement imposes a lot of thermal load on the peripheral components such as gearshift cables, bearings, oil seals, driveshafts etc. Thermal shields or thermal sleeve are used to address thermal issue and to protect transmission components.

The automotive sector is going through a phase of stiff competition among various Original Equipment Manufacturers for increasing their profitability while ensuring highest levels of customer satisfaction. The biggest challenge for such companies lies in minimizing their overall cost involving investments in Research and Development, manufacturing, after sales service and warranty costs. Higher warranty costs not only affect the net profit but in turn it also affects the brand image of the company to a large extent in the long run. An effort is made here to target such warranty costs due to frequent tail pinion and hub seal leakages on single reduction/hub reduction axles of Heavy Commercial Vehicles in the field. A preliminary study involving the severity analysis of such failures is followed by a step by step investigation of these failures.

The entire commercial vehicle industry is moving towards weight reduction to leverage on the latest materials available to benefit in payload & fuel efficiency. General practice of weight reduction using high strength steel with reduced thickness in reference to Roark’s formula does not consider the stiffness & dent performance. While this helps to meet the targeted weight reduction keeping the stress levels within the acceptable limit, but with a penalty on stiffness & dent performance. The parameters of stiffener like thickness, section & pitching are very important while considering the Stiffness, bucking & dent performance of a dumper body. The Finite Element Model of subject dumper body has been studied in general particularly on impact of dent performance and is correlated with road load data to provide unique solution to the product. The impact of payload during loading of dumper is the major load case.

Automotive Audio Signaling system is very vital and is controlled by local regulatory requirements. In India, usage of horn is very frequent due to highly congested traffic conditions, and is in the order of 10 to 12 times per kilometer. This results in the deterioration of the “contact”, which enables the functioning of the device. Hence the device requires premature replacement or frequent tuning, which are time consuming and results an increase in warranty costs and cost of service as well. Thus, to overcome this problem a unique and novel approach is proposed in this paper which enhances the life of the automobile horn, by implementing an additional pair of Contacts on circuit breakers, providing a parallel path for the power supply. This effort ensures that the life of the horn is increased by 5 times than the existing design.

Lift axles of heavy commercial vehicles are deployed to handle increased payload. These axles of Commercial vehicles are made of low alloy carbon steel materials. Lift axles are designed in hollow condition for weight reduction opportunity. Two types of tube materials are used for the manufacturing of lift axles. These are either Cold Drawn Seamless (CDS) tubes or Hot Finished Seamless (HFS) tube material. The vanadium micro-alloyed steel grade, 20MnV6 is an excellent choice for the manufacturing of lift axles. The 20MnV6 has favorable mechanical properties for lift axles and also offers good weldability. However, lift axles made of 20MnV6 when manufactured in hot-finished condition, shows significant scatter in terms of durability performance. This requires further heat treatment of 20MnV6 to be deployed for reducing the scatter in the material properties to reduce scatter in durability performance and thus increasing the reliability of the lift axles.

The changing mobility landscape of India reveals that the erstwhile transport modes of the 20th century i.e., railways and road buses are making way for airlines, personal vehicles, shared mobility, metro rails. Rapid technological changes, stricter regulations, new transport cultures autonomous, connected, electric and shared (ACES), state-of-the-art and environmental concerns are shaping up the eco-system for automobiles. Despite these challenges roadways and automobiles will continue to be most prominent solution in India for future. But for that, the automobile sector should be agile, innovative, and adaptable to changing eco-system, vigilant to thwart threat of alternate mobility solutions and must provide sustainable solutions for the future. The purpose of this paper to evaluate various mobility solutions, ascertain prominence of upcoming automobile solutions and their sustainability for future in India.

Vehicle floor vibration is the resultant of different road inputs damped through various transfer paths. Seat comfort, which depends on these floor vibrations, can be evaluated with a single input signal “Pink noise”; which constitutes various road inputs. Transmissibility of seat structure on a vibration shaker with pink noise input includes all possible responses of road inputs. Still, transmissibility profile at vehicle end and component level varies. This is due to the utilization of “dummy” on component level testing on vibration shaker, which acts as a dead weight with dissimilar damping characteristics of human. A transmissibility correlation between human and dummy is attained by replacing the dummy in place of human and actuating it to find the difference in contribution between them for different class of vehicles. This contribution extrapolation from the damping effects of human and dummy is applied on dummy transmissibility.

Subject paper focuses primarily on non uniform tire wear problem of front steered wheels in a pickup model. Cause and effect analysis complemented with field vehicle investigations helped to identify some of the critical design areas. Investigation revealed that steering geometry of the vehicle is undergoing huge variations in dynamic condition as compared to initial static setting. Factors contributing to this behavior are identified and subsequently worked upon followed by a detailed simulation study in order to reproduce the field failures on test vehicles. Similar evaluation with modified steering design package is conducted and results are compared for assessing the improvements achieved. In usual practice, it is considered enough if Steering Geometry parameters are set in static condition and ensured to lie within design specifications.

Currently, automotive industries are using Advanced High-Strength Steels (AHSS) sheet grades to achieve key requirements like light weighting and improved crash performance. But forming of AHSS grades becomes key challenge due to its lesser ductility and edge fracturing tendency during forming. In general, most of the automotive components undergoes shearing operations like blanking and punching which affects the edge ductility of the steel. AHSS grades possess limited edge ductility compared with conventional steel grades which results in edge fracturing due to tensile strain during stretch flanging operation. Stretch flange-ability is an important formability characteristic, which aids in material selection to avoid edge fracturing of complex shaped parts. Material with better stretch flange-ability possess better edge ductility and hence perform better in stretch flanging of sheet metal.

IC Engine manufacturers are constantly in pursuit of better sealability of cylinder head and engine block interface for meeting performance and durability targets. In order to overcome variation in torque - tension characteristics of cylinder head bolt because of friction variations, yield based clamping are being extensively adopted. Current study is done on torque - tension characteristics of a cylinder head bolt with a controlled quality. The paper enumerates the experimental setup representing a sub 1 liter all aluminum engine's head-block joinery. Studies on torque - tension characteristics of cylinder head bolt and the effect of sealing interface using a cost effective single layer steel gasket are being discussed in the paper. Subject work has led to a successful implementation of angular torque parameters on head bolts to meet functional and durability targets.

Today, noise perceived by the occupants is becoming an important factor driving the design standards for the design of most of the interior assemblies in an automotive vehicle. Buzz, Squeak and Rattle (BSR) is a major contributor towards the perceived noise of annoyance to the vehicle occupants. An automotive vehicle consists of many chassis assemblies which are the potential sources of BSR noise. The potential locations of critical BSR noise could be contained within such assemblies as well as across their boundaries. Engine mount design is major area where BSR noises can be heard inside cabin on various road conditions. Natural rubber is regular rubber used in engine mount applications but in this paper BSR problems are solved by changing the rubber compound i.e., NR+BR (slippery compound). Detailed case study is presented where slippery rubber compound is used which is solving BSR issue and also meeting durability targets.

The commercial vehicle market in India is shifting to higher payload capacity vehicles due to a lower transportation cost per unit goods. To cater this requirement, the vehicle manufacturers are designing the heavy multi-axle commercial vehicles and with higher per axle loading capacity. One of such a vehicle design involves five-axle vehicle with non-steerable, twin tire, lift axle. Though using a twin tires have increased loading capacity of lift axle compared to a single tire self-steerable lift axle, it can cause tire scrub while vehicle is turning and leads to a significant tire wear. The tire wear possibility due to use of non-steerable lift axle is estimated through simulation using full vehicle model in ADAMS. The operating zone of the vehicle, where maximum tire wear can occur, is identified through simulation. Different alternatives to reduce tire wear for this scenario are also discussed.

Vehicle refinement from point of view reduction in its Noise, Vibrations and Harshness (NVH) affects customer’s buying decision and it also directly influences his/her driving experience on road at different speeds. Customer voice, however, indicates that a traditional process of developing design solutions is not aligned with the customers’ expectations. Traditionally the load cases for NVH development are focused only on quietness of passengers’ cabin at idling and in 3rd gear wide open throttle cruising on smooth roads. In reality, the Driver of a premium sedan car or a Sports Utility Vehicle (SUV) or a Compact Utility Vehicle (CUV) expects something different than merely the low sound pressure level inside the cabin. His/her driving pattern over a day plays a crucial role. A vehicle-owner wishes to balance various attributes of the in-cab sound and tactile vibrations at a time.

The automotive industry is facing a challenge as efficiency improvements are required to address the strict emission norms which in turn requires high performance downsized, lightweight IC engines. The increasing demand for lightweight engine needs high strength to weight ratio materials. To meet high strength to weight ratio, castings are preferable. However due to strength limitations for critical crankshaft applications, it forces to use costly forgings such as micro alloyed forging steel and Martensitic (after heat treatment) forging steel. To reduce the cost impact, high strength Austempered Ductile iron (ADI) casting is developed for crankshaft applications to substitute steel forgings. Austempered Ductile Iron is having an excellent mechanical properties due to aus-ferritic structure. The improved properties of developed ADI Crankshaft over steel forged crankshaft offers additional weight advantage.

Leaf springs are used for vehicle suspension to support the load. These springs are made of flat sections of spring steel in single or in stack of multiple layers, held together in bracketed assembly. The key characteristics of leaf spring are defined as ability to distribute stresses along its length and transmit a load over the width of the chassis structures. The most common leaf spring steels are carbon steels alloyed with Cr and micro-alloyed with Ti, V and Nb. The specific thermomechanical process and alloying elements result in specific strength and fatigue properties for spring steels. The unique properties which facilitate use of spring steel in leaf spring suspensions are ability to withstand considerable twisting or bending forces without any distortion. The microstructure of these steel determines the performance and reflects the process of steel manufacturing. The performance is mainly determined by evaluating fatigue life durability.

Electric vehicles (EV’s) are very much noise, vibration and harshness (NVH) sensitive due to the absence of engine noise. The outline of this paper is based on vehicle level turning noise evaluation. The impact of the driveshaft angle in the frequency range of 1000-2000Hz. The level of noise while turning at driver and co-driver side is evaluated first. Then the possible countermeasure to address such noise issues are also discussed. The impact on the angular adjusted roller (AAR) joint and driveshaft angle is studied along with the impact on other parameters like powertrain mount stiffness, ground clearance and vehicle architecture.

The usage of forging a preformed, near net shape, compacted and sintered metal powder has been widely accepted since the eighties and is now one of the mainstays for producing Connecting rods in North America. However, its use in Indian subcontinent is limited as its counterpart i.e. conventional steel forging is still the most dominant. Powder metallurgy route has many advantages like good dimensional accuracy; minimum scattering of weight etc. Despite these advantages, the Powder metallurgy process is still not preferred predominantly due to technical (endurance) and infrastructural limitations. This work envisages combining the benefits of powder metallurgy process with the required mechanical properties viz. tensile and fatigue strength alongside design modifications to meet the requirements of a connecting rod for a 2-cylinder diesel engine. The connecting rods met the fatigue life at the required FOS equaling the performance of a conventionally forged connecting rod.