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Technical Paper

Fatigue Durability Development for Cab of Light Truck Based on Virtual Proving Ground Technology

2022-03-29
2022-01-0319
The boundary load of the light truck cab fatigue analysis is the force of the cab mounting system, which cannot be directly measured. In the absence of a physical prototype, the fatigue load of the cab cannot be extracted through virtual iteration. Aiming at the problem of fatigue analysis in the early stage of the car-free cab, the virtual proving ground technology is used to extract fatigue load and do fatigue analysis in this paper. Using the virtual road as the excitation, the simulation analysis of the whole vehicle virtual proving ground is carried out, and the wheel center load and the cab mounting force are obtained. Comparing the simulation load with the signal required on the proving ground, it is found that the extracted virtual load is consistent with the actual vehicle load in the time domain and frequency domain. The retention of pseudo-damage of the six-component load of the wheel center can meet the precision control requirements of the vehicle load decomposition.
Technical Paper

A Multi-axle and Multi-Type Truck Classification Model for Dynamic Load Recognition

2022-03-29
2022-01-0137
Overloading of trucks can easily cause damage to roads, bridges and other transportation facilities, and accelerate the fatigue loss of the vehicles themselves, and accidents are prone to occur under overload conditions.In recent years, various countries have formulated a series of management methods and governance measures for truck overloading.However, the detection method for overload behavior is not efficient and accurate enough.At present, the method of dynamic load identification is not perfect.
Book

Automobile Wheel Alignment and Wheel Balancing

2021-12-22
With over thirty years of experience in the design, development, and patenting of some products in the field of wheel alignment, the author shares his knowledge on the importance of wheel maintenance to the overall performance of a vehicle. From the ancient bullock carts to chariots to automobiles, wheels have undergone many changes to serve the purpose of mankind's mobility. Mobility is inevitable in today's life. A world without wheels is unimaginable. Every vehicle owner expects his tires to last longer and perform better. But improper wheel alignment and wheel balancing can drastically impact the wear and tear on a tire. This book walks the readers through the basics to techniques for wheel alignment on light vehicles, commercial vehicles, and trailers. In addition, illustrations present various types of tire wear and the cause of each. Finally, the author delves into tire safety from understanding how air pressure effects a tire to the importance of tire rotation.
Standard

Heavy-Duty Electrical Connector Performance Standard

2021-12-14
WIP
J2030
This SAE Standard encompasses connectors between two cables or between a cable and an electrical component and focuses on the connectors external to the electrical component. This document provides environmental test requirements and acceptance criteria for the application of connectors for direct current electrical systems of 50 V or less in the majority of heavy-duty applications typically used in off-highway machinery. Severe applications can require higher test levels, or field-testing on the intended application.
Technical Paper

Divergence of Thickness Losses and Weight Losses of Disc Pads for Passenger Cars: High-Copper NAOs and Copper-Free Low Mets

2021-10-11
2021-01-1290
The current investigation was undertaken to find out if lighter-weight passenger car disc pads would exhibit wear behaviors similar to pickup truck pads and commercial heavy truck drum linings in terms of the permanent volume expansion of the friction material contact surface region. 2 high-copper NonAsbestos Organic formulations and 3 copper-free LowMet formulations were tested according to the SAE J2522 test procedure. In all cases, the measured pad thickness loss was found to be less than the thickness loss calculated from the weight loss, indicating pad volume expansion in the pad surface region, in full agreement with the results from the pickup truck and heavy trucks. The heataffected swollen/expanded layer ranges from 0.27 to 0.61 mm in thickness depending on the formula and test conditions. Due to the expansion, pad durability projections made from test results based on high temperature city traffic tests can result in underestimating the actual durability.
Technical Paper

Predictive Maintenance of Commercial Vehicle Brakes using Acoustic Monitoring

2021-10-11
2021-01-1280
This study evaluated the performance of a new approach for detecting problems with commercial vehicle brakes based on the analysis of sounds emitted during braking. Commercial vehicle brakes emit ultrasonic energy inaudible to humans as part of the friction process, and the spectral distribution of these sounds is highly dependent on the mechanical condition of the brakes. Data collected from a commercial vehicle fleet found that the acoustic signature changes as friction linings wear. This conforms with the acoustic theory that the resonant frequency of an object increases with its decrease in mass. The use of this information to inform maintenance operations is promising in that the scheduling of visual brake inspections could be based on acoustic wear patterns rather than arbitrary time intervals and the observation of anomalous signals that might indicate more immediate concerns.
Technical Paper

Intelligent Control System of Magnetic-Impulse Parts Processing in Ship Repair Production

2021-10-04
2021-01-5096
Humanity has been interested in magnetism for over 300 years. Many authors have studied the use of applied magnetism to change the properties of products and expand the use of magnetic processing in ship repair production [1, 2]. Experience shows that magnetic pulse processing (MPP) is a simple and economical way to increase the durability of metal-cutting tools, increase the resource of the most worn parts of machines and mechanisms, and increase the durability of friction units, assembly units, and structures during their repair and manufacture. MPP has a number of advantages: simplicity of electromagnetic energy concentration on the product, its rapid accumulation by the material of the working elements of the part, and the efficiency of improving the operational characteristics (processing time is 0.3 ... 2.0 s with insignificant energy consumption).
Technical Paper

Design and Development of Lightweight Pivot Arm Using Austempered Ductile Iron (ADI) for Heavy Commercial Vehicles

2021-09-22
2021-26-0255
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.
Technical Paper

Strength Evaluation and Validation of Structural Joints

2021-09-22
2021-26-0315
Many methods have been developed to evaluate the fatigue life of structures when the joints are as per ideal case. But if the joints are loosening, it leads to increase in loading on the other members which causes failures. Most commonly in commercial vehicle segment welding joint & bolting joints are most popular ones. It is very easy to find out bolts strength & loosening effect in static conditions. But when vehicle is moving (i.e. dynamic condition), same method cannot be used. For this we have developed methodology to predict the bolts loosening in dynamic condition using vibration data. Similarly, loading may differ on the structural members if the welds are failing in dynamic conditions. To overcome this problem, in our organization we have a solution. Of course to simulate welding failures fatigue analysis is mandatory. We are using notch-stress approach for evaluating the welding strength of the joint.
Technical Paper

Virtually Evaluated Welds for Powertrain Installation Bracketry and Physically Correlated for First Time Right Designs

2021-09-22
2021-26-0420
Virtual validation of automobile components poses a huge challenge and needs continuous process improvements. One of such challenge in FE modelling of welds and understanding its behavior with respect to physical behavior. With the ongoing development of BSVI line of products in commercial vehicle industry, the virtual validation needs to be accurate and close to the physical behavior of the components. The learning and challenges faced during the previous development is implemented in the current study for weld simulation and correlation activity. The brackets welded to the power train components is taken as a challenge in the present work. Initially weld model was depicted in the CAD and was analyzed in CAE by providing proper FE connection. This practice had lot of flaws, approximations due to perpendicularity and flatness concerns in the models leading to consuming a lot of time in model preparation.
Technical Paper

Bogie Wear Pad - A Comparative Study

2021-09-22
2021-26-0442
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.
Technical Paper

Multi Axis Fatigue Test of Lift Axle Assembly through Real Time Simulation Abstract

2021-09-22
2021-26-0486
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.
Technical Paper

Improvement in Drum-Brake Squeal Noise Prediction by Including the Effect of Brake-Liner Wear

2021-09-22
2021-26-0287
Drum brake squeal noise has been under investigation by automotive companies for decades due to consistent customer complaints and high warranty costs. Unstable natural frequencies of a brake system are closely linked with brake squeal noise. Complex eigenvalues are widely used to predict unstable frequencies of brake systems. Unstable frequencies are very sensitive to various system parameters such as vehicle speed, coefficient of friction, contact pressure distribution at the liner-drum interface, brake pressure, etc. In this paper, the author has focused on the brake pad wear effects on pressure distribution and eventually on the squeal noise propensity of a commercial vehicle drum-brake system. Wear at brake pads interface is simulated using simplified wear rate formula followed by complex eigenvalue analysis. Predicted unstable frequencies considering the effect of pad wear are found closer to the frequencies of measured noise in physical testing.
Journal Article

Nonlinear Structural Analysis by Finite Element Method with Experimental Validation in a Rotatory Column for Loader Crane

2021-09-14
Abstract The main objective is to evaluate the level of stresses and strains in the component structure responsible for supporting the entire movable upper part of a loader crane and to indicate possible design adjustments in order to improve the product and predict possible structural problems using the experimental analysis to calibrate the numerical model that also serves as a procedure to validate the total structure and futures new similar cases. For this purpose, a nonlinear static structural analysis will be performed using the finite element method, where the system will be adjusted to a virtual environment in order to better represent the reality of the efforts and supports involved, taking into account the contacts between bushings, the mechanical properties of the materials, and also the geometric nonlinearity of the components. Validation was performed by means of an experimental analysis carried out in a test field on the final product.
Technical Paper

Monitoring Brake Wear with Acoustics

2021-08-31
2021-01-1053
A new approach for detecting problems with vehicle brakes by analyzing sounds emitted during braking events is proposed. Vehicle brakes emit acoustic energy as part of the braking process; the spectra of these sounds are highly dependent on the mechanical condition of the brake and can be used to detect problems. Acoustic theory indicates that as brake linings wear thinner the resonant frequency of the shoe or pad increases, potentially enabling the monitoring of lining wear through passive acoustic sensors. To test this approach, passive acoustic sensors were placed roadside at the exit of a transit bus facility for 9 months. The sensors collected almost 10,000 recordings of a fleet of 160 vehicles braking over a variety of conditions. Spectra of vehicles that had brake work performed during this period were analyzed to compare differences between new and worn friction linings.
Journal Article

Thermal Energy Performance Evaluation and Architecture Selection for Off-Highway Equipment

2021-08-31
Abstract Off-highway equipment are subjected to diverse environmental conditions, severe duty cycles, and multiple simultaneous operations. Due to its continuous, high-power adverse operating conditions, equipment are exposed to high thermal loads, which result in the deterioration of its performance and efficiency. This article describes a model-based system simulation approach for thermal performance evaluation of a self-propelled off-highway vehicle. The objective of developing the simulation model including thermal fidelity is to quantify the impact of thermal loads on vehicular system/subsystems performance. This article also describes the use of simulation models for driving architectural design decisions and virtual test replication in all stages of product development.
Journal Article

Cavitation Erosion Prediction at Vibrating Walls by Coupling Computational Fluid Dynamics and Multi-body-Dynamic Solutions

2021-08-24
Abstract Cavitation erosion caused by high-frequency vibrating walls can appear in the cooling circuit of internal combustion engines along the liners. The vibrations caused by the mechanical forces acting on the crank drive can lead to temporary regions of low pressure in the coolant with local vapor formation, and vapor collapse close to the liner walls leads to erosion damage, which can strongly reduce the lifetime of the entire engine. The experimental investigation of this phenomenon is so time consuming and expensive, which it is usually not feasible during the design phase. Therefore, numerical tools for erosion damage prediction should be preferred. This study presents a numerical workflow for the prediction of cavitation erosion damages by coupling a three-dimensional (3D) Multi-Body-Dynamic (MBD) simulation tool with a 3D Computational Fluid Dynamics (CFD) solver.
Journal Article

TOC

2021-06-07
Abstract TOC
Standard

Fatigue Test Procedures: Hubs and Wheels for Demountable Rims

2021-05-06
CURRENT
J1095_202105
This SAE Recommended Practice provides uniform laboratory procedures for fatigue testing of wheels for demountable rims and hubs intended for normal highway use on trucks, buses, truck trailers, and multipurpose passenger vehicles. The hubs included have bolt circle diameters ranging from 165.1 to 335.0 mm (6.500 to 13.189 inches). It is up to each hub and/or wheel for demountable rims manufacturer to determine the appropriate test method, accelerated load factor and cycle life requirements applicable to obtain satisfactory service life for a given application. When deviations from the procedures recommended herein are made, it is the responsibility of the hub and/or wheel for demountable rims developer to modify other parameters as necessary to ensure satisfactory service life for the intended application. It should be noted that this test procedure focuses on fatigue resulting from vehicle loading and cornering forces.
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