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Groan is a low frequency noise generated when moderate brake pressure is applied between the surfaces of the brake disc and the brake pad at a low-speed condition. Brake groan is often very intense and can cause large numbers of customer complaints. During a groan noise event, vehicle structure and suspension components are excited by the brake system and result in a violent event that can be heard and felt during brake application. The cause of noise is friction variation of stick-slip phenomenon between friction material and disc. Creep groan is the structure-borne noise that is related to dynamic characteristic of the vehicle. However, it has been mainly improved through friction material modifications in the past. In this paper, transfer path of creep groan noise was analyzed by means TPA and structural countermeasure to creep groan noise was suggested. This paper discusses the approach for prediction and mitigation of brake groan noise for passenger vehicles having disc brakes.

Welding is one of the most convenient and extensively used manufacturing process across every industry and is recognized as a cost effective joining technique. The root cause of most of the fabricated structural failures lies in the uncertainties associated with the welding process. It is prone to generate high residual stresses due to non-volumetric changes during heating and cooling cycle. These residual stresses have a significant impact on fatigue life of component leading to poor quality joints. To alleviate these effects, designers and process engineers rely upon their experience and thumb rules but has its own limitations. This approach often leads to conservative designs and pre-mature failures. Recent advances in computational simulation techniques provide us opportunity to explore the complex phenomenon and generate deep insights. The paper demonstrates the methodology to evaluate the residual stresses due to welding in virtual environment.

This paper highlights the transition of multi-axis suspension test rig from fixed reacted type to semi-inertial type and the benefits derived thereof in simulation accuracies. The critical influence of ‘Mx’ and ‘Mz’ controls on simulation accuracies has been highlighted. The vital role of ‘Mz’ control in the resonance of wheel pan along ‘Z’ axis and thereof arresting unwanted failures modes in spindle has been duly emphasized. Finally, the role of constraints and boundary conditions on simulation accuracies has been demonstrated by replacing the reaction frame with vehicle body.

It is customary to select a twist beam rear suspension for front wheel driven small and medium range passenger cars. Besides better primary / secondary ride comfort, roll stiffness tuning ability, ease of assembly & good packaging solutions than the conventional semi trailing arm/ rigid axle suspensions, twist beam suspension system accentuate the concentration required in placing & orienting the cross beam to achieve certain imperative kinematical characteristics. In order to make the solutions of the required kinematical targets viable, it is vital to have the packaging space and stress concentration within yield limits given the weight & cost targets. This paper presents the work done on twist beam type suspension for a new generation entry level B-Class hatchback vehicle developed. To reduce the time consumed in validation of different design proposals a virtual validation process was developed.

This literature is in the field of communication networks where different Electronic Control Units (ECUs) communicate with each other over Controller Area Network (CAN) protocol. Typically these types of CAN networks are widely used in automotive vehicles, plant automations, etc. This proposed method is applicable in all such applications where controller area network is used as backbone electrical architecture. This literature proposes a new method of CAN signal packing into CAN frames so that network bus-load is minimized so that more number of CAN signals can be packed and more number of ECUs can be accommodated within a CAN network. The proposed method also ensures that the age of each CAN signal is minimized and all CAN signals reach the intended receiving ECUs within their maximum allowed age. Typically network designers are forced to design and develop multiple sub-networks and network gateways to get rid of network bus-load.

Among the key parameters that decide the success of a vehicle in today's competitive market are quietness of passenger cabin (in respect of both airborne and structure-borne noise) and low levels of disturbing vibration felt by the occupants. To control these values in body-on-frame construction vehicles, it is necessary to identify major transfer paths and optimize the isolation characteristics of the elastomeric mounts placed at several locations between a frame and the enclosed passenger cabin of the vehicle. These body mounts play a dominant role in controlling the structure-borne noise and vibrations at floor and seat rails resulting from engine and driveline excitations, and they are also a vital element in the vehicle ride comfort tuning across a wide frequency range. In the work described in this paper, transfer path tracking was used to identify root cause for the higher noise and vibration levels of a diesel-powered sports utility vehicle.

Integrating safety features may lead to changes in vehicle interior component designs. Considering this complexity, design guidelines have to take care of aspects which may help in package feasibility studies that consider systems performance requirements. Occupant restraints systems for protection in side crashes generally comprise of Side Airbag (SAB) and Curtain Airbag (IC). These components have to be integrated considering design and styling aspects of interior trims, seat contours and body structure for performance efficient package definition. In side crashes, occupant injury risk increases due to hard contact with intruding structure. This risk could be minimized by cushioning the occupant contact through provision of SAB and Inflatable IC. This paper explains the methodology for deciding the package definitions using Knowlwdge Based Engineering (KBE) tools.

New noise regulations, with reduced noise limits, have been proposed by UN-ECE. A new method which aims at representing urban driving of the vehicles more closely on roads is proposed and is considerably different from the existing one (IS 3028:1998). It is more complex; we also found that some of the low powered vehicles can not be tested as per this method. The paper proposes ways of improvement in the test method. The new noise reduction policy options will have a considerable impact on compliance of many categories of vehicles. Technological challenges, before the manufacturers, to meet all performance needs of the vehicle along with the cost of development will be critical to meet the new noise limits in the proposed time frame.

Micro Hybrid Systems are a premier approach for improving fuel efficiency and reducing emissions, by improving the efficiency of electrical energy generation, storage, distribution and consumption, yet with lower costs associated with development and implementation. However, significant efforts are required while implementing micro hybrid systems, arising out of components like Intelligent Battery Sensor (IBS). IBS provides battery measurements and battery status, and in addition mission critical diagnostic data on a communication line to micro hybrid controller. However, this set of data from IBS is not available instantly after its initialization, as it enters into a lengthy learning phase, where it learns the battery parameters, before it gives the required data on the communication line. This learning period spans from 3 to 8 hours, until the IBS is fully functional and is capable of supporting the system functionalities.

Spot welding is the primary joining method used in automobiles. Spot-weld plays a major role to maintain vehicle structural integrity during impact tests. Robust spot weld failure definitions is critical for accurate predictions of structural performance in safety simulations. Spot welds have a complex metallurgical structure, mainly consisting of fusion and heat affected zones. For accurate material property definitions in simulation models, huge number of inputs from test data is required. Multiple tests, using different spot weld joinery configurations, have to be conducted. In order to accurately represent the spot-weld behavior in CAE, detailed modeling is required using fine mesh. The current challenge in spot-weld failure assessment is developing a methodology having a better trade-off between prediction accuracy, testing efforts and computation time. In view of the above, cohesive zone models have been found to be very effective and accurate.

Gasoline engines with Multi point fuel injection (MPFI) technology are being developed with naturally aspirated and/or turbocharged engines. Wherein a MPFI and turbo charged combination engines have certain challenges during development stages. One of the important challenge is design of air intake and exhaust system. With MPFI turbocharged engine combination, the under bonnet heat management is crucial task for drivability. The heat management of air intake plays a vital role in drivability part therefore a design layout of air intake path is an important aspect. Drivability can be categorized as low end, mid-range and top end drivability. Turbocharged MPFI engines have a typical phenomenon of ‘Lag in response’ in the low-end region. This ‘Lag in response’ phenomenon at low-end drivability region can be overcome through optimization of air intake system and optimization of exhaust back pressure.

Use of adhesives in automotive require in-depth material, design, manufacturing & engineering knowledge. It is also necessary to understand functional requirements. For perfect and flawless adhesive joinery, the exact quantity of adhesive, its material composition, thickness of adhesive layer, substrate preparation methods for adhesive bonding, handling and curing time of the adhesive have to be studied & optimized. This paper attempts to describe different aspects of adhesive bonding in automotive industry to include: Selection of adhesives based on application and design of the components, surface preparation of adherend, designing of adhesive joint, curing conditions of adhesives, testing and validation of adhesive joints. Emphasis was given to study & verify the performance of different adhesive joints to meet end product requirements. Samples were prepared with a variety of adhesive and adherend combinations.

Structural adhesive is a good alternative to provide required strength at joinery of similar and dissimilar materials. Adhesive joinery plays a critical role to maintain structural integrity during vehicle crash scenario. Robust adhesive failure definitions are critical for accurate predictions of structural performance in crash Computer Aided Engineering (CAE) simulations. In this paper, structural adhesive material characterization challenges like comprehensive In-house testing and CAE correlation aspects are discussed. Considering the crash loading complexity, test plan is devised for identification of strength and failure characteristics at 0°, 45°, 75°, 90°, and Peel loading conditions. Coupon level test samples were prepared with high temperature curing of structural adhesive along with metal panels. Test fixtures were prepared to carryout testing using Instron VHS machine under quasi-static and dynamic loading.

Brake drum is an important component in automotive, which is a link between axle and wheel. It performance is of utmost importance as it is related to the safety of the car as well to the passengers. Many design parameters are taken into consideration while designing the brake drum. The sensitivity of these parameters is studied for optimum design of brake drum. The critical parameters in terms of reliability, safety & durability could be the cross section, thickness of hub, interference & surface roughness between bearing and hub, wheel loading, heat generation on drum, manufacturing and assembly process. The brake drum design is derived by considering these parameters. Hence the sensitivity of these parameters is studied both virtually & physically, in detail. The optimum value of each parameter could be chosen complying each other's values.

To meet different target of light-weighting, lower fuel economy, crash safety and emission requirement, advanced high strength steel (AHSS) is commonly used in automotive vehicles and has become popular now a days. AHSS material up-to 1500 MPa is commonly used for structural components and major reinforcement of automotive BIW. Manufacturing of AHSS material requires precise control of chemical composition, and subsequent rolling and heat treatment to get optimum combination of required phases In most of the AHSS material microstructure, martensite is present along with ferrite or other phases. Hot stamp steel with strength level 1500 MPa strength also have martensite phase in microstructure after press hardening. However during heating and cooling cycle in resistance spot welding, martensite phase tempering affects hardness at Heat Affected Zone (HAZ).

NVH is of prime importance in buses as passengers prefer comfort. Traditionally vehicle NVH is analysed post completion of proto built however this leads to modifications, increases cost & development time. In modern approach physical validation is replaced by CAE. There are many sources of NVH in vehicle however this article is focused about the methodology to improve NVH performance of bus by analysing and improving the stiffness and mobility of various chassis frame attachment points on which source of vibrations are mounted or attached. In this study chassis frame attachment stiffness of Engine mounts and propeller shafts is focused.

Nowadays, friction welding is recognised as a highly productive and economic joining process for similar as well as dissimilar welding of automobile and aerospace components. Friction welding is the viable solution to offset the challenges of dissimilar fusion welding due to varying thermal and physical properties as well as limited mutual solubility. This study investigated interface microstructure and bonding strength of dissimilar rotary friction welding of 3.15 mm E46 plate and 45 mm AA6061-T6 rod. The direct drive rotary friction welding of E46 and AA6061-T6 is performed at combinations of two different friction times (4 sec and 7 sec) and forging pressure (108 MPa and 125 MPa). Mechanical bonding strength at the interface is evaluated based on the push-off and multistep shear tests. Further, a fractured steel surface was visually examined to understand the failure mechanism of welded joints.

High strength aluminium alloys are an ideal material in the automotive sector leading to a significant weight reduction and enhancement in product safety. In recent past extensive development in the field of high strength steel and aluminium was undertaken. This development has been propelled due to demand for light weight automotive parts. The high strength to weight ratio possessed by Al alloy helps in reducing the total weight of the vehicle without effecting the overall performance, thereby increasing the fuel economy, and reducing the carbon emission level. Joining of high strength aluminium alloy is critical to develop durable automotive products. Joining of high strength aluminium alloy for mass production in automobile industry is a challenging task. Laser welding is recognized as an advanced process to join materials with a laser beam of high-power, high- energy density.

The stress concentration at welded joints and small crack propagation from some pre-existing discontinuities at notched regions control the fatigue life of typical welded structures. There are numerous FEM stress-based weld fatigue assessment approaches available commercially which unify FEM stresses with various fatigue software codes embedded with international weld standards. However, FEM stress-based approaches predict extensively conservative results. Considerable efforts & subjective decision making is required to arrive at desired level of weld life correlation with physical test results, in terms of weld life and failure location. This is majorly because of inconsistency & inaccuracy in capturing the hot spot stress results due to stress singularities occurring at the notched regions owing to the mesh sensitivity, modeling complexity.

A bus is integral part of public transportation in both rural and urban areas. It is also used for scheduled transport, tourism, and school transport. Buses are the common mode of transport all over the world. The growth in economy, the electrification of public transport, demand in shared transport, etc., is leading to a surge in the demand for buses and accelerating the overall growth of the bus industry. With the increased number of buses, the issue of safety of passengers and the crew assumes special importance. The comfort of driver and passenger in the vehicle involves the vibration performance and therefore, the structural integrity of buses is critically important. Bus safety act depicts the safety and comfort of bus operations, management of safety risks, continuous improvement in bus safety management, public confidence in the safety of bus transport, appropriate stakeholder involvement and the existence of a safety culture among bus service providers.