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Tippers used for transporting blue metal, construction and mining material is designed with different types of load body to suit the material being carried, capacity and its application. These load bodies are constructed with high strength material to withstand forces under various operating conditions. Structural strength verification of load body using FEM is conducted, by modelling forces due to payload as a pressure function on the panels of the load body. The spatial variation of pressure is typically assumed. In discrete element method (DEM) granular payload material such as gravel, wet or dry sand, coal etc., can be modelled by accounting its flow and interaction with structure of load body for prediction of force/pressure distribution. In this paper, coupled FE-DEM is used for determining pressure distribution on loading surfaces of a tipper body structure of a heavy commercial vehicle during loading, unloading and transportation.

This case study involves the failure analysis of the wheel arch structure for a commercial truck. The wheel arch is an important vehicle trim aggregate from both the regulatory perspective (spray suppression) as well as from the aesthetics of the truck. But, the durability of this part is affected by the vehicle architecture, vehicle load capacity as well as the operating conditions. This is more critical due to the nature of the overhang experienced by the mounting bracket assemblies that hold these wheel arches/mud flaps. This generally consist of tubular and sheet metal welded structures bolted on to the main chassis long members. These failures were observed in a legacy vehicle, where very little details of the complete vehicle digital simulation and testing performance were readily available.

High currents flowing through various traces of a printed circuit boards (PCB) causes thermal run away and PCB warpage due to the occurrence of high heat density. The present study discusses on steady state thermal analysis performed in a PCB kept inside an enclosure. Thermal analysis allows PCB designer to quickly move and confirm the component’s placement by examining the temperature plots predicted on the PCB surface. A PCB particularly designed for automated manual transmission (AMT) application employed in Ashok Leyland electric vehicle (EV) trucks is used for this present study. The performed simulations are preliminary level and carried out with commercially available software Altair Simlab ElectroFlo 2022.3. Simlab is a PCB level EDA (Electronic Design Automation) software suite used for design and analysis, and thus helps in minimizing the development cycles.

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.

Design decisions based on the virtual simulations leads to reduced number of prototype testing. Demonstrated correlation between the computer simulations and experimental test results is vital for designers to confidently take simulation driven design decisions. For the virtual design evaluation of durability, ride, handling and NVH performance, demonstration of correlation of structural dynamic characteristics is critical. Modal correlation between CAE and physical testing validates the stiffness and mass distribution used in the FE model by correlating mode shape and mode frequency in the desired frequency range. The objective of this study is to arrive at a method for establishing modal correlation between CAE and experimental test for a bare frame and thereby enabling evaluation of design iterations in virtual environment to achieve modal targets.

In today’s competitive world to stay in the commercial vehicle business, technological advancement is vital. Understanding the various operation modes of a vehicle considering the vibration becomes essential for developing a vehicle free from failures. ODS analysis is a method which is used to visualise the vibration pattern of a vehicle when influenced by known external operating forces. ODS provide very useful information for understanding and evaluating the behavior of the vehicle. This paper discusses about the experiments carried out in vehicle. It details the process of data collection at varying frequency input, understanding the modes at various frequencies, identifying the resonant frequency of various components, understanding the comparison between road inputs and resonance frequencies and the transfer of vibration (Transmissibility) from one component to another.

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.

Diesel engine pollutants include Oxides of Nitrogen (NOx) and Particulate Matter (PM) which are traditionally known for their trade-off characteristics. It’s been a challenge to reduce both pollutants at the source simultaneously, except by efforts through low temperature combustion concepts. NOx formation is dependent on the combustion temperature and thus the in-cylinder reduction of NOx formation remains of utmost importance. In this regard, water injection into the intake of a heavy-duty diesel engine to reduce peak combustion temperature and thereby reducing NOx is found to be a promising technology. Current work involves the use of 1-D thermodynamic simulation using AVL BOOST for modeling the engine performance with water injection. Mixing Controlled Combustion (MCC) model was used which can model the emissions. Initially, the model validation without the water injector was carried out with experimental data.

Driveline (DL) is one of the major sources of noise and vibration which excites the vehicle structures across a wide band of frequencies in commercial vehicles (CV). Current work focuses on the driveline noise source identification and its reduction in a heavy commercial vehicle. An abnormal noise is perceived in a CV in high gears at high speeds. This annoying DL noise is subjectively perceived in geared and neutral coast down conditions. Objective NVH assessment including near source noise and vibration of the driveline components was performed to quantify the noise. Initial test results revealed that the DL excitations are aggravated in auxiliary gear box as broadband rattle noise. The design configuration of the DL components and related subsystems such as propeller shafts and gearbox etc. was studied to the find root cause of the excitations. The driveline configuration including the auxiliary gearbox tooth geometry is also scrutinized and modified.

A major activity of any new vehicle development program, is to meet legal requirements of local markets. Pass by noise (PBN) test is one of the standardized tests and is used to certify new vehicles/variants for their Noise emissions. Certification for noise emissions of commercial vehicles is achieved by measuring external sound levels according to procedures defined by standards such as IS: 3028 for Indian market. Before a physical proto-vehicle is assembled, various systems and subsystems are readily made available by suppliers off the shelf. During final design validation of the vehicle by mule-vehicle testing, PBN target compliance need be assured for all these systems in order to meet overall PBN target. The PBN on an Intermediate commercial vehicle (ICV) migrated to the latest Exhaust emission standard, was the subject of this study. This vehicle emitted PBN greater than accepted threshold.

In the emerging commercial vehicle sector, it is very essential to give a product to customer, which is very reliable and less prone to the failures to make the product successful in the market. In order to make it possible, the product is to be validated to replicate the exact field conditions, where it is going to be operated. Lab testing plays a vital role in reproducing the field conditions in order to reduce the lead time in overall product life cycle development process. This paper deals with the design and fabrication of the steering column slip endurance test rig. This rig is capable of generating wear on the steering column splines coating which predominantly leads to failure of steering column. The data acquired from Proving Ground (PG) was analyzed and block cycles were generated with help of data analyzing tools.

All automotive components undergo stringent testing protocol during the design validation phase. Nevertheless, there are certain components in the field which are seldom captured during design validation. One of these components is the battery isolator switch. This project aims at optimizing a validation methodology for this component based on field usage and conditions. The isolator switch is the main control switch which connects and disconnects the electrical loads from the battery. This switch is used in the electrical circuit of the vehicle to prevent unwanted draining of battery when it is not needed and when the vehicle is in switched off. An electrical version of this switch uses electromagnetic coils to short the contacts. The failure mode being investigated is a high current load causing the input and output terminal to be welded.

Natural gas has been considered and implemented as alternative fuel to gasoline and diesel powered vehicles worldwide. Although natural gas belongs to petroleum fuel family, it has considerable recourses worldwide to ensure long energy security and comparatively lower carbon to hydrogen ratio that make it more environment friendly. This paper presents the effect of long duration endurance test on gas engine oil along with performance and emission characteristics of 5.8 L turbocharged heavy duty natural gas engine. The six cylinder engine was chosen due to its importance for urban bus transportation. The engine was subjected to long duration endurance test of 800 hrs with closed loop monitoring and controlled conditions as per 6 mode engine load cycle. During the complete endurance test of 800 hours, performance and emission characteristics of the engine were analyzed after completion of every 100 hours as per Full Throttle Performance Test and European Transient Cycle (ETC).

Exterior noise reduction of a vehicle has become important nowadays in order to meet the stringent pass by noise regulations. First step in this process is the identification of dominant noise sources. There are several noise sources which can contribute to the pass by noise like gearbox, turbocharger, oil sump, exhaust muffler, air intake etc. The dominant noise sources can be identified with the near field noise, component vibration measurements combined with experimental modal analysis. This paper discusses about the noise source identification and exterior noise reduction of a shortest wheel base intermediate commercial vehicle, which is having a 4-cylinder inline diesel engine.

Engine mounts and mounting brackets play a critical role in determining NVH performance of a vehicle. A lot of work has been done in the area of virtual simulation using FE models to study engine mounting system performance and its impact on vehicle level performance. An overall approach towards engine mounting system validation at vehicle level is also very critical to validate simulation results in a prototype based on which further refinement work will be carried. In this paper a detailed procedure for engine mount and mounting bracket physical validation at vehicle level is presented. Various tests to be performed at vehicle level to quantify engine mount and mounting bracket performance parameters is discussed in detail along with measurement procedures and techniques. Test results are interpreted and its impact on overall performance is also explained. These test results will help design engineers to further improve engineering parameters of mounts and mounting brackets.

The modern day automobile customers’ expectations are sky-high. The automotive manufacturers need to provide sophisticated, cost-effective comfort to stay in this competitive world. Air conditioning is one of the major features which provides a better comfort but also adds up to the increase in operating fuel cost of vehicle. According to the sources the efficiency of internal combustion engine is 30% and 70% of energy is wasted to atmosphere. The current Air conditioners in automobiles use Vapour compression system (VCS) which utilizes a portion of shaft power of the engine at its input; this in turn reduces the brake power output and increases the specific fuel consumption (SFC) of the engine. With the current depletion rate of fossil fuels, it is necessary to conserve the available resources and use it effectively which also contributes to maintain a good balance in greenhouse effect thus protecting the environment.

E85 (85% Ethanol + 15% Gasoline), as an alternative fuel has been widely used in spark ignited engines used in light duty vehicles. However, they are rarely used in spark ignited heavy duty engines. In this study, we used E85 in a 5.8 litre, multi cylinder, turbocharged, multi point - port injected, spark ignited heavy duty engine, to analyze the performance capability. As E85 has higher octane rating, the compression ratio was increased to 11.5:1. Experimental investigation of In-cylinder pressure was done and the engine’s ignition timing and injection duration was calibrated to operate the engine below peak firing pressure limits, without knocking. The experimental results showed that exhaust gas recirculation resulted in lower peak firing pressure and rate of heat release. The results of the engine test showed that E85 can be used in heavy duty spark ignited engines. The scope for future work is on addressing the higher BSFC and cold start from subzero temperature levels.

A full-bodied validation of automotive system emphasis on a comprehensive coverage of failure modes of component on one hand and evaluation with full system for the intended function of single component on the other has for long been cumbersome to most commercial vehicle manufacturers. This paper focuses on optimizing the test method in rig testing to relieve the complexity in the structural validation as whole system level. The methodology proposed by authors focuses on accelerating the vibration testing of component by compressing the validation timelines by using CSCPV (Combined Systematic Calculated and Pre Validation) method. This method selects the components of the system for validation by VFTM (Vital Few and Trivial Many) approach from existing testing database failure data and selects the worst predominant failure cases. This CSCPV method uses systematically calculated representing mass from analysis to validate the intended component alone instead of entire system.

In heavy commercial vehicle segment in India, driver comfort and feel was largely ignored. Fierce competition in the recent years and buyer’s market trend is compelling the designers of heavy truck to focus more on the finer aspects of attribute refinements. Steering is one driver-Vehicle interface which the driver is engaged throughout. Comfort and feel in steering wheel is defined by parameters like steering effort, manoeuvrability, on-center feel & response, cornering feel & response, Torque dead band, return-ability etc. and is influenced by a long list of components and systems in the truck. This study focuses on the influences of jacking torque and steering system friction on the on-center driving performance. Experiments to measure the Jacking torque and steering system friction were conducted in the lab and subjective and objective assessments of on-center driving performance were later conducted at test track in two similar 12 Ton truck to correlate their effects.

Steering gear box function is one of the important requirements in heavy vehicles in order to reduce driver fatigue. Improper functioning of steering gear box not only increases the driver fatigue, also concerns the safety of the vehicle. In this present investigation, the engine oil mixing up with steering oil has been identified and steering gear box failure has been observed in the customer vehicle. The root cause of failure has been analyzed. Based on the investigations, in particular design of steering pump has been failed at customer end. The same design of steering pump were segregated and analyzed. Initial pressure mapping study has been conducted. The pressure mapping results revealed that the cavity pressure obstructs the flow of suction pressure. It indicates that obstacle at suction port due to the existence of internal leakage that causes back pressure in the internal cavity of steering pump which sucks engine oil.