Search Results

The hybrid structure of Engine Mounts made of rubber casing with cast iron reinforcing. Use of two materials made it unique both in application and testing. The rubber provides damping for engine vibrations and the cast iron provides necessary strengthening to hold the heavy engine in place. In this research paper the FEA (Finite Element Method) methodology is being discussed to evaluate and optimize the design analysis to enhance overall engine mount capacity. The existing and modified designs are validated and considerable improvement is being observed in modified design in physical testing. Accurate modeling of engine mounts assembly is presented in this paper. FEA analysis results have good correlation with physical validation for both designs. Impact of design parameters of rubber mounts has been presented.

With the significant amount of automation and electrification paving the way for the future of automobiles, the complexity and design of the electrical harnesses have evolved to a point where a minuscule discontinuity can cease the operation of a mechanically pristine vehicle. A vehicle equipped with the best-in-class systems does not always guarantee everlasting operations every time. The wiring harness of any vehicle by its design aspect is one of the most crucial and vulnerable components. Prone to succumbing to factors such as electrical overloading, physical impact, unprofessional handling, and even sabotage, presently there lies no backup system to compensate for the loss of functions of the main electrical network in the event of a failure. In the interest of rapid re-instating of primary functions in a vehicle to make it operational in the event of an electrical failure, the concept of an emergency piggyback electrical network is delineated.

With rising concerns on internal combustion engine noise levels in commercial vehicles, it is necessary to attenuate noises present in specific frequency bands. This can be achieved with the implementation of a quarter wave tube on the present exhaust system. Historically such passive attenuators have been efficient only at specific engine speeds and exhaust gas temperatures. A new folded adaptive quarter wave tube design is proposed here which can give significant noise attenuation at various engine operating conditions. The proposed design eliminates the requirement of complex electronic actuating mechanisms for the adaptive quarter wave tubes and replaces the same by perforated diaphragms and adjustable end plates, which are more robust and effective. The module can replace the turbo S-flow single chambered muffler which is installed on most of the commercial vehicles. A design is conceptualized and developed using CAD tools.

Vehicle life and performance is affected by many factors when in use. The most influential being the vibrations generated especially when the vehicle is in motion. These vibrations are directly experienced by the driver, whose performance goes down, if under continuous influence of these vibrations. This increases the fatigue and greatly reduces the return on investment done by the customer. There are two major sources of vibrations, the engine and the road on which the vehicle moves. To prevent such issues engine mounts are used in vehicles, which may seem simple but perform a critical role, of providing comfort to the driver. Therefore, it becomes important that thoroughly designed and examined mounts are being used in the vehicle. This paper focuses on the methodology to be followed for design and validation of an engine mount used in heavy duty vehicles.

In the current commercial vehicles market, ride-comfort and handling are crucial parameters for the customer and end user. There are various aspects which determine the vehicle behavior. One of aspects is the structural rigidity of the vehicle, which has its own effect on vehicle dynamics. To meet the required stiffness of the main structural component of the vehicle i.e. chassis frame, FEA analysis has to be done in current methodology. The number of iterations have to be done to build an appropriate model with low weight, which can meet the design requirements. At first, conceptual design mock-up unit is to be developed then FEA (CAE) analysis to be done on it. If any design criteria are not met, then this cycle repeats again until it fulfils the required stiffness. Today, the direct stiffness procedure is the basic principle of almost every FEA software package.

Most popular practice for analyzing the Subsystem failures in commercial vehicles is physical testing. These physical tests are carried out by three tests; Endurance testing, Accelerated Endurance Testing and Rig test simulation. All the three methods are costly and repetitive iterations of these tests is not economical. Therefore, in our organization, we established a method in virtual domain in order to reduce the repetitive iterations and also reduction in time consumed per iteration. General practice in our organization for Finite Element Analysis (FEA) calculation was inclusive of Model preparation, Transient analysis using Nastran. The results from the Transient analysis are used for performing fatigue analysis in fatigue software. In this process, Transient analysis and Model preparation are very much time consuming processes. Model preparation cannot be reduced, but to reduce the transient analysis time, we established a method in frequency domain (vibrational fatigue) [1].

Leaf spring is a vital suspension component, such that the failure of leaf spring could cause fatal accidents. Due to frequent failures of leaf springs on vehicles, a method is developed to perform the numerical analysis using explicit solver which provides insightful analysis of leaf springs to prevent the occurrence of failure during engineering design. Since fatigue life assessment of leaf springs is a significant aspect during the design stage and due to the limitation of non-compatibility of output file of explicit solver for fatigue analysis, various studies are conducted and implicit solver is considered to perform FEA simulation of leaf spring. The present study delineates comparison of non-linear analysis of semi-elliptical leaf spring using explicit solver with that of implicit solver. Analysis using implicit solver gives us an advantage to export the model in fatigue life estimation solver which is not possible using explicit solver.

In an automobile, main function of the steering system is to allow the driver to guide the vehicle on a desired course. Steering system consists of various components & linkages. Using these linkages, the torque from steering wheel is transferred to tyre which results in turning of the vehicle. Over the life of vehicle, these steering components are subjected to various loading conditions. As steering components are safety critical parts in the vehicle, therefore they should not fail while running because it will cause vehicle breakdown. In commercial vehicle segment, vehicle breakdown means delay in freight delivery which results in huge loss to costumer. Therefore, while designing steering components one should consider all the possible loadings condition those are possible. But, it can’t be done through theoretical calculation. Therefore, physical tests have to be carried out to validate design of steering system, which is very costly & time-consuming process.

The job of a suspension system is to maximize the friction between the tires and the road surface, to provide steering stability with good handling and to act as a cushioning device ensuring the comfort of the driver & passengers. The suspension also protects the vehicle itself and any cargo or luggage from damage and wear. Almost all heavy duty vehicles use inverted type suspension system which is also called as bogie type suspension system. The design of this type of suspension is a complex and difficult science which has evolved over many years. It was recognized very early in the development of suspensions that the interface between vehicle body and wheel needed some sort of cushioning system to reduce the vibration felt as the vehicle moved along. This was already part of road coach design and took the form of leaf (laminated) steel springs mounted on the axles, upon which the vehicle body rested.

At the time of invention of road coaches, the vehicle consisted only of an axle with wheels and a body attached. Smooth roads were built for a better ride comfort however they were not consistent. The road coaches were too bumpy and uncomfortable for the passenger along with the driver who was not able to control the vehicle. That's why the engineers had to shift their attention to the suspension system for a better ride comfort and handling. The technology has advanced with time so as the suspension system. Rubber ended type leaf spring is one of the suspension system types available in the industry. The main function of a suspension in order of importance is as below: 1 Acts as a cushioning device ensuring the comfort of the driver and passengers; 2 Maximizes the contact between the tires and the road surface to provide steering stability with good handling; 3 Protects the vehicle itself and any cargo or luggage from damage and wear.

The job of a suspension system is to maximize the friction between the tires and the road surface, to provide steering stability with good handling and to act as a cushioning device to ensure the comfort of the driver and passengers. The suspension system also protects the vehicle and any cargo or luggage from damage and wear. Commonly the strength of these suspension systems is evaluated by endurance trials on field or Rig testing which are time consuming and costly. On the other hand, virtual testing methods for strength and stiffness evaluation provide useful information early in the design cycle and save significant time and cost. However, the virtual method also needs validation, which can be achieved by physical co-relations (via rig tests). A study has been done to predict the behavior of Leaf Spring Suspensions entirely through the FEA (Finite Element Analysis) route and correlating those results with physical test.

Wheel end bearing is one of the critical components of the vehicle as it directly faces the road loads for harsh operating environment. Bearing being a precisely manufactured component and rotating at high speed, utmost care is required while assembling as well as during operation. In operating condition wheel end is directly exposed to outside environment making it prone to entry of contamination. This contamination if not prevented from entering into wheel end through proper sealing it would cause lubricant contamination and consequently bearing failure. Bearing replacement and overall wheel end service is time consuming activity reducing the turn out time of the vehicle. In wheel ends, one side is sealed with the help of seal while the other side is protected by cap and gasket. This cap-gasket interface is very critical from sealing perspective and utmost importance needs to be taken while designing the same.

Ever-increasing operational cost, reducing profit margins & increase in competition, it is of upmost significance for fleet owners & drivers to opt for a vehicle having maximum uptime. OEM's are under immense pressure to design & develop vehicles/subsystems which are reliable enough to minimize downtime & withstand heavy overloading plus extreme operating conditions especially tippers. Vehicle systems like Wheel end (hub, bearing, and grease) which are designed & packaged according to a very stringent envelop & operate as a closed system facing all the extremities of operating conditions. This undoubtly make them prone to no. of failure modes which are resulting in vehicle unplanned stoppages, so any failure mode related to the same must be taken care with utmost importance. In commercial vehicles the bearing outer cup is in interference fit with the hub. These bearings of wheel hub have to be maintained at the wheel end play of few microns.