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Shift quality of a manual transmission is a critical characteristic that requires utmost care while structuring the transmission. Shift quality is affected by many factors viz. synchronizer design, shifter design, gear design, transmission oil selection etc. This paper presents a correlation between stiffness of the shift fork in manual transmission with the gear shift quality using a gear shift quality assessment setup. Stiffness of shifter fork is optimized using contact pattern analysis and stiffness analysis on MSC Nastran. All the subsystem (i.e. synchronizer and the shift system component) are constrained to optimize the shift fork stiffness. A-5-speed manual transmission is used as an example to illustrate the same. A direct correlation of gear shift fork stiffness with the shift force experienced by the driver is established. The shift system was modeled in the UG NX 6.0 software to collate the synchronization force, shift system gap etc with the constraint on the shift fork.

Connected vehicle services have come a long way from the early days of telematics, both in terms of breadth of the class of vehicles, and in terms of richness or complexity of the data being handled for Enhancing Customer Experience. The Connectivity Control unit (CCU) is a gateway device for the vehicle to the outside world. While it enables transmission of vehicle data along with the location information. CCU is currently validated in the vehicle to check functionality. It has cost, time drawbacks and prevents effective testing of many scenarios. Bench level validation will not be able to complete functionality validation. There is subset of validation tools or semi-automated solutions are available in the market, but they are not fully functional, and critically cannot perform end to end validation. Automated Test setup for CCU in lab simulating the entire field data of the vehicle with modifiable characteristics.

In the era of fierce competition, launching a defect free product on time would be the key to success. In a modern automobile, the transmission system is designed with utmost care in order to transfer the maximum power from engine to driveline smoothly and efficiently. Optimized design of all the transmission components is necessary in order to meet the power requirement with the least possible weight. This optimization may require gear designs with different internal diameters. The assembly of these gears may not be possible on a solid transmission shaft. To facilitate assembling while retaining optimum design of transmission parts, a separate bush is designed to overcome this limitation. Some bushes may require a flange to restrict any free play of the mounted gear in its axial direction. During complete system level testing of one newly developed manual transmission, bush failure was observed.

Fuel efficiency is critical aspect for commercial vehicles as fuel is major part of operational costs. To complicate scenario further, fuel efficiency testing, unlike in passenger cars is more time consuming and laborious. Thus, to save on development cost and save time in actual testing, simulations plays crucial role. Typically, actual vehicle speed and gear usage is captured using reference vehicle in desired route and used it for simulation of target vehicle. Limitation to this approach is captured duty cycle is specific to powertrain and driver behavior of reference vehicle. Any change in powertrain or vehicle resistance or driver of target vehicle will alter duty cycle and hence duty cycle of reference vehicle is no more valid for simulation assessment. This paper demonstrates approach which uses combination of tools to address this challenge. Simulation approach proposed here have three parts.

The given paper presents the main elements of frictional power loss distribution in an automotive axle for passenger car. For reference two different axles were compared of two different sizes to understand the impact of size and ratio of gear and bearings on power loss characteristics. It was observed that ~50% of total axle power loss is because of pinion head-tail bearing and its seals, which is very significant. Roughly 30% of total power loss is contributed by pinion-ring gear pair and differential bearings and remaining ~20% by wheel end bearing and seals. With this study the automotive companies can take note of the area where they need to focus more to reduce their CO2 emissions to meet the stringent BS6, CAFÉ and RDE emission norms.

Currently the Automotive industry demands highly competitive product to survive in the global tough competition. Even if there is a slight reduction in product cost and time has a high significant impact on business. Engineers are under tremendous pressure to develop competitive and give better product concern resolution at the earliest. To arrest the failure of this thermostat vent, an innovative approach was used to relocate de-aeration restrictor on the hose to the thermostat root. Thus, resolving the product concern by increasing the strength of the vent at root and providing good business impact on cost savings. Physical testing has provided an effective way to smoothen product development for concern resolution. This Paper highlights approach on an attempt to field failure simulation with existing and modified design with lab test results.

The ever-increasing customer expectations put a lot of pressure on car manufacturers to constantly reduce the noise, vibration, and harshness (NVH) levels. This paper presents the holistic approach used to achieve best-in-class NVH levels in a modern high-power density 1.5 lit 4-cylinder diesel engine. In order to define the NVH targets for the engine, global benchmark engines were analysed with similar cubic capacity, power density, number of cylinders and charging system. Moreover, a benchmark diesel engine (considered as best-in-class in NVH) was measured in a semi-anechoic chamber to define the engine-level NVH targets of the new engine. The architecture selection and design of all the critical components were done giving due consideration to NVH behaviour while keeping a check on the weight and cost.

Child injury performance evaluation is becoming critical part of almost all legal and consumer ratings-based vehicle safety evaluation protocols. Most of New CAR Assessment Programs (NCAP) now have separate ratings exclusively to evaluate child restraint system effectiveness and child dummy performance under various crash testing modes. OEM’s have need and challenge to maximize injury performance. Sled tests are conventionally used for tuning restraints like seat belts and airbags for driver and co-driver under various frontal type test conditions. However, second row seats are used for CRS/ Child injury performance evaluations. In the present study an attempt is made to simulate child injury performance of P3 dummy positioned on second row seat on defined child seat for 64 kmph frontal Offset deformable barrier type test conforming to Global NCAP. Sled pulses are carefully tuned to capture key injury patterns. Thence restraint parameters are tuned to improve child dummy injuries

In automotive Body-In-White (BIW) structures, stiffness and the fatigue behavior is greatly influenced by the properties of its joints. Spot welding is one of the most widely used process for joining of sheet metals in BIW. Spot weld fatigue life under Accelerated Durability Test (ADT) is crucial for durability performance of BIW structures. Experience of BIW validations highlighted more number of spot weld failures in CAE when compared to actual tests. Hence, lot of iterations in the form of design modifications are required to be carried out to make these spot welds meet the targets which increases design & development time as well as cost. Current practice uses force-based approach for predicting spot weld fatigue life in CAE. To improve the spot weld fatigue life correlation, extensive study has been carried out on the approaches used for calculating spot weld fatigue life, namely force & stress-based approaches.

Structural durability of different components and systems for a Utility Vehicle is critical to design, due to severe customer usage in rural zones and off road driving conditions. Physical validation of new component designs is time consuming, costly and iterative. Also, this process does not ensure an optimized structure. Through virtual validation it is possible in the initial phase of design to validate the structure and optimize the design. The core of a virtual validation process is to obtain accurate correlation which can replace developmental laboratory testing. Hence, only a confirmatory test can be carried out. This enables design optimization based on simulations. This paper presents the systematic approach used for optimization of SUV rear bumper and bumper mounting structure. Dynamic correlation is obtained for bumper structure subjected to the vibration levels as mapped from the proving ground test. The objective of new bumper development is for value engineering.

Reducing the vibrations in the powertrain is one of the prime necessities in today's automobiles from NVH and strength perspectives. The necessity of 4×4 powertrain is increasing for better control on normal road and off-road vehicles. This leads to bulky powertrains. The vehicle speeds are increasing, that requires engines to run at higher speeds. Also to save on material costs and improve on fuel economy there is a need for optimizing the mass of the engine/vehicle. The reduced stiffness and higher speeds lead to increased noise and vibrations. One more challenge a powertrain design engineer has to face during design of its transmission housings is the bending / torsional mode vibrations of powertrain assembly. This aggravates other concerns such as shift lever vibrations, shift lever rattle, rise in in-cab noise, generation of boom noise at certain speeds, etc. Hence, reducing vibrations becomes an important and difficult aspect in design of an automobile.

This paper describes application of Design of Experiments (DOE) technique and optimization for mass reduction of a Sports utility vehicle (SUV) body in white (BIW). Thickness of the body panels is taken as design variable for the study. The BIW global torsion, bending and front end modes are key indicators of the stiffness and mass of the structure. By considering the global modes the structural strength of the vehicle also gets accounted, since the vehicle is subjected to bending and twisting moments during proving ground test. The DOE is setup in a virtual environment and the results for different configurations are obtained through simulations. The results obtained from the DOE exercise are used to check the sensitivity of the panels. The panels are selected for mass reduction based on the analysis of the results. This final configuration is further evaluated for determining the stiffness and strength of the BIW.

The ECE R-14, AIS015 safety standard specifies the requirements of the safety belt anchorages namely, minimum numbers, their locations, static strength to reduce the possibility of their failure during accidental crashes for effective occupant restraint and the test procedures. This standard applies to the anchorages of safety belts for adult occupants of forward facing or rearward facing seats in vehicles of categories M and N. ECE R14 ensures the passenger safety during sudden acceleration/retardation and accidents. Early simulations revealed some structural short falls that demanded cabin improvements in order to fulfill regulation requirements for the seal belt anchorage test. This paper describes the innovative design modifications done to meet the seat belt anchorage test. Good correlation with the test is achieved in terms of deformations. These simulation methods helped in reducing the number of intermediate physical tests during the design process.

In today's competitive automobile marketplace with reduced vehicle development time and fewer prototypes/tests, CAE is playing very crucial role in vehicle development. Automobile environment demands ever improving levels of vehicle refinement. Performance and refinement are the key factors which can influence the market acceptance of vehicle. Driveline is one of the key systems whose refinement plays critical role in improved customer satisfaction. Because of the virtue of the driveline functionality, driveline induced noise and vibration are the most common issues in the AWD vehicle development programs. Refinement of the drive line needs complicated nonlinear full vehicle CAE MBD models for the evaluation of driveline induced noise and vibration responses at different operating conditions [1]. In this paper a simplified approach is adapted for solving the Noise & Vibration issue which has been identified at the prototype testing level of an AWD vehicle development.

A tractor is vehicle specifically designed to deliver a high tractive effort at slow speeds for carrying out various agriculture operations like ploughing, rotavation etc. using implement. Hydraulic system is a key feature which connects these implements with the tractor. It controls the position and draft of the implement depending upon the type of crop, farming stage, implement type and soil conditions. These variations induces extreme range of load on the hydraulic system, thus making it challenging to design these components. Bell crank assembly is one of the main components of hydraulic system which controls the draft (thus, the loads experienced by tractor) through load sensing mechanism. Often bell crank assembly failures are reported from field due to uneven soil hardness and presence of rocks. This paper studies one of such bell crank assembly failures in the field. The failure was reported after half life cycle of usage during agriculture Operation.

Over the ages of automotive history, expectations of the customers increases vastly starting from driving comfort, better fuel economy and a safe vehicle. Requirement of good vehicle drivability from customers are increasing without any compromise of fuel economy and vehicle features. To enhance the product, it is a must for every OEM’s to have better drivability to fulfill the needs of the customer. This paper explains Objective Drivability Evaluation done on compact SUV vehicle and comparison with subjective drivability. Vehicle manufacturer usually evaluate drivability based on the subjective assessments of experienced test drivers with a sequence of certain maneuvers. In this study, we have used the objective drivability assessment tool AVL drive to obtain the vehicle drivability rating. The vehicle inputs from the accelerometer sensor which captures the longitudinal acceleration and CAN bus signals such as engine speed, vehicle speed, accelerator pedal, are fed into the software.

Twist beam is a type of suspension system that is based on an H or C shaped member typically used as a rear suspension system in small and medium sized cars. The front of the H member is connected to the body through rubber bushings and the rear portion carries the stub axle assembly. Suspension systems are usually subjected to multi-axial loads in service viz. vertical, longitudinal and lateral in the descending order of magnitude. Lab tests primarily include the roll durability of the twist beam wherein both the trailing arms are in out of phase and a lateral load test. Other tests involve testing the twist beam at the vehicle level either in multi-channel road simulators or driving the vehicle on the test tracks. This is highly time consuming and requires a full vehicle and longer product development time. Limited information is available in the fatigue life comparison of multi-axial loading vs pure roll or lateral load tests.

By reducing overall noise emanating from Engine at design phase, permits to reduce both time-to-market and the cost for developing new engines. In order to reduce vibration and radiated noise in engine assembly, oil pan is one of the most critical components. This study explains the key-steps that are executed to optimize the oil pan design for 4-cylinder diesel engine by improving Normal Modes, modified Topology, reduced Forced Frequency Response and ATV analysis for reducing its noise radiation. Using Multi-body tool crankshaft forces were generated and the FE model of Base Design was analysed for its noise radiation and panel contribution was done for finding the most radiating panels using Boundary Element Method approach. A series of iterative optimization were carried out with commercial software. Parameters like Stiffness, material property, Ribbing patterns and Shape of the Oil pan was modified to shift the natural frequencies of the component and reduce the sound radiation.

This paper presents a simulation of the stiffness of the shift fork of a manual transmission using contact pattern analysis and optistrut. All the subsystem (i.e. synchronizer and the shift system component) are constrained to optimize the shift fork stiffness. A-5-speed manual transmission is used as an example to illustrate the simulation, co-relation and validation of the optimization of the gear shift fork stiffness. The shift system was modeled in the software to collate the synchronization force, shift system gap etc with the constraint on the shift fork. It is constrained by the synchronizer sleeve and the fork mounting on the gear shift rail. The synchronizer force is then applied on the gear shift fork pads which are translated to the synchronizer sleeve. It has a number of pads which come into contact at different occasion of the synchronization because of the varying stiffness of the fork.

Today’s automotive industry in the process of better fuel efficiency and aiming less carbon foot print is trying to incorporate energy saving and hybrid technologies in their products. One of the trends which has been followed by Original Equipment Manufacturers (OEMs) is the usage of Electric Power Steering (EPS) system. This has been an effective option to target fuel saving as compared to hydraulically assisted power steering system. EPS has been already tested successfully, not only on system level but also on vehicle level for endurance and performance by OEMs as per their norms and standards. Over the decade, NVH (noise, vibration & harshness) have become one of the touch points for customer perception about vehicle quality. This leads us to a commonly perceived problem in EPS or manual type steering system i.e. rattle noise.