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Technical Paper

You're Not Out There Alone: High-Tech and Other Aids for Your Career Planning and Management

Career development planning is critical to getting the most out of one's working years. It should start when one starts a career, but even if you start in mid-career, it's not too late. For those who haven't done it, career planning may seem difficult and confusing. Increasingly, your community library and state employment service agency provides valuable help in the form of computerized and manual aids to career planning and job-getting. This article follows Dave Brown, a mid-career engineer, through the career-planning process, introduces library and government resources to you and provides a list of computer programs relating to career planning and job getting.
Technical Paper

Winterization Of Construction Equipment - Report of CIMTC Subcommittee XV—Winterization

SINCE 1954 the CIMTC Subcommittee has been engaged in a program to meet military requirements through industry's production of construction equipment which can give satisfactory cold weather performance down to temperatures of −65 F. Individual contracts for three crawler tractors and one motor grader were negotiated by ERDL for these projects, and their performance is discussed. Industry participation was subsequently expanded to include engineering tests in the cold weather conditions of the Mesabi Iron Range. This joint report of the Winterization Sub-committee of the CIMTC and ERDL Winterization Section consists of separate papers by various members and consultants of this Sub-committee and ERDL personnel.
Technical Paper

Wind-Averaged Drag Determination for Heavy-Duty Vehicles Using On-Road Constant-Speed Torque Tests

To investigate the feasibility of various test procedures to determine aerodynamic performance for the Phase 2 Greenhouse Gas (GHG) Regulations for Heavy-Duty Vehicles in the United States, the US Environmental Protection Agency commissioned, through Southwest Research Institute, constant-speed torque tests of several heavy-duty tractors matched to a conventional 53-foot dry-van trailer. Torque was measured at the transmission output shaft and, for most tests, also on each of the drive wheels. Air speed was measured onboard the vehicle, and wind conditions were measured using a weather station placed along the road side. Tests were performed on a rural road in Texas. Measuring wind-averaged drag from on-road tests has historically been a challenge. By collecting data in various wind conditions at multiple speeds over multiple days, a regression-based method was developed to estimate wind-averaged drag with a low precision error for multiple tractor-trailer combinations.
Journal Article

Wind Tunnel and Track Tests of Class 8 Tractors Pulling Single and Tandem Trailers Fitted with Side Skirts and Boat-tails

A 1:10-scale wind tunnel development program was undertaken by the National Research Council of Canada and Airshield Inc. in 1994 to develop trailer side skirts that would reduce the aerodynamic drag of single and tandem trailers. Additionally, a second wind tunnel program was performed by the NRC to evaluate the fuel-saving performance of boat-tail panels when used in conjunction with the skirt-equipped single and tandem trailers. Side skirts on tandem, 8.2-m-long trailers (all model dimensions converted to full scale) were found to reduce the wind-averaged drag coefficient at 105 km/h (65 mi/h) by 0.0758. The front pair of skirts alone produced 75% of the total drag reduction from both sets of skirts and the rear pair alone produced 40% of that from both pairs. The sum of the drag reductions from front and rear skirts separately was 115% of that when both sets were fitted, suggesting an interaction between both.
Technical Paper

Wind Tunnel Test of Cab Extender Incidence on Heavy Truck Aerodynamics

A wind tunnel experiment has been conducted to determine the changes in drag and side force due to the presence and position of cab extenders on a model of a commercial tractor-trailer truck. The geometric variables investigated are the cab extenders angle of incidence, the tractor-trailer spacing and the yaw angle of the vehicle. Three cab extender angles were tested-0°, 15° (out) and -15° (in) with respect to the side of the tractor. The cab and trailer models have the same width and height. The minimum drag coefficient was found for the tractor and trailer combination when the cab extenders were set to 0° angle of incidence with respect to the headwind. This result holds for all yaw angles with moderate gap spacing between the tractor and trailer. This study suggests that commercial tractor-trailer trucks can benefit from adjustable cab extender settings; 0° when using a trailer and -15° when no trailer is used.
Technical Paper

Wind Tunnel Evaluation of Potential Aerodynamic Drag Reductions from Trailer Aerodynamic Component Combinations

The use of devices to reduce aerodynamic drag on large trailers and save fuel in long-haul, over-the-road freight operations has spurred innovation and prompted some trucking fleets to use them in combinations to achieve even greater gains in fuel-efficiency. This paper examines aerodynamic performance and potential drag reduction benefits of using trailer aerodynamic components in combinations based upon wind tunnel test data. Representations of SmartWay-verified trailer aerodynamic components were tested on a one-eighth scale model of a class 8 sleeper tractor and a fifty three foot, van trailer model. The open-jet wind tunnel employed a rolling floor to reduce floor boundary layer interference. The drag impacts of aerodynamic packages are evaluated for both van and refrigerated trailers. Additionally, the interactions between individual aerodynamic devices is investigated.
Technical Paper

Wind Tunnel Concepts for Testing Heavy Trucks

The trucking industry is being encouraged by environmental and cost factors to improve fuel efficiency. One factor that affects fuel efficiency is the aerodynamic design of the vehicles; that is, the vehicles with lower aerodynamic drag will get better mileage, reducing carbon emissions and reducing costs through lower fuel usage. A significant tool towards developing vehicles with lower drag is the wind tunnel. The automobile industry has made great improvements in fuel efficiency by using wind tunnels to determine the best designs to achieve lower drag. Those wind tunnels are not optimum for testing the larger, longer heavy trucks since the wind tunnels are smaller than needed. The estimated costs for a heavy truck wind tunnel based on automotive wind tunnel technology are quite high. A potential nozzle concept to reduce wind tunnel cost and several other new possible approaches to lower wind tunnel costs are presented.
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Wiley SAE MOBILUS® eBook Package

Committed to being the primary source for aerospace and ground vehicle engineering resources, SAE International has added the full compilation of our Wiley eBook collections to the SAE MOBILUS® technical resource platform. Purchasable as an annual subscription and containing the titles from the Wiley Aerospace Collection, the Wiley Automotive Collection, the Wiley Computer Systems Collection, and the Wiley Cyber Security Collection.
Technical Paper

Why You Should Use Web Based Learning for CAD Training in Your Organization

Since 1992, Caterpillar has invested millions of dollars to purchase CAD software, and spends nearly $2M per year keeping its engineers up-to-date, via instructor lead training (ILT), as new enhancements are introduced. Periodic upgrades to the software also require huge resource (people, costs) commitments for the planning and execution of the training requirements required for a large global workforce. This paper will examine gaps uncovered in the efficiency and effectiveness of the current training process, and the cultural change required as a result of switching from an instructor led environment to a completely web-based solution, which, once deployed, had promised to change the way Caterpillar approached training for the future. The proposed change promised to improve human resource capability by utilizing new technological capabilities, and resulted in improvements in organizational capabilities as well.

Why Attend COMVEC?

Industry professionals talk about the importance of attending COMVEC, and the value for young professionals.
Technical Paper

What is Wrong with Continuing Education?

Continuing education is important; in fact, it is absolutely necessary for the person or corporation that expects to be successful. Yet a lot of continuing education programs seem to be of little or no use as measured by the changes they effect in both people and companies. This study shows why so little success occurs, and makes suggestions to correct that shortfall. Good programs must be supported with time and resources provided by the employer. However, a truly successful continuing education program must be managed and driven by the individual. Otherwise, it will not pay off. The smart employer provides time and financial support, but expects the individual to direct his own career program.
Technical Paper

What Does It Take To Retire?

Financial planners are always anxious to assist engineers and scientists in making retirement decisions. Many engineers, especially Industrial Engineers (IE), have had courses that provide the knowledge to make these retirement financial plans themselves. This paper will provide a method of estimating retirement needs utilizing Excel software and IE college coursework.
Technical Paper

Water-flow Simulation on Vehicle Panels by Taking into Account the Calculated Aerodynamic Field

A numerical methodology using 3D computational fluid dynamics (CFD) was developed to simulate the water flows on vehicles in order to check the specifications under rain (visibility of door mirror by the driver, sealing…), or to evaluate washing efficiency (washing headlight, washing windshield …). The CFD method is constituted by a three step procedure. In the first step, the aerodynamic field around the vehicle is calculated with Powerflow software in a large domain. It uses a Lattice Boltzmann approach to solve airflow. The existing process of Powerflow computation developed by aerodynamic and aeroacoustic teams of Renault SAS was adapted to refine results in high gradients of velocity zones. In the second step, the field of air velocity vectors calculated with Powerflow is mapped towards a small domain where the water flow will be solved.
Technical Paper

Virtual Testing: Fatigue Life (S-N Curves) Simulations for Commercial Vehicle Axle Components

Current trends in vehicle development, including both automotive and commercial vehicles, are characterized by short model life cycles, reduced development time, concurrent design and manufacturing development, reduced design changes, and reduced total cost. All of these are driven by customer demand of higher load capacity, reduced weight, extended durability and warranty requirement, better NVH performance and reduced cost. These trends have resulted in increased usage of computational simulation tools in design, manufacturing, and testing, i.e. virtual testing or virtual prototyping. This paper summarizes our work in virtual testing, i.e. fatigue life simulations using computational fracture mechanics for commercial vehicle axle gearing development. First, fatigue life simulation results by using computational fracture mechanics CRACKS software were verified by comparing with gear teeth bending fatigue test data and three point bending fatigue test data.
Technical Paper

Virtual Simulation Research on Vehicle Ride Comfort

In this paper, a computer model of a multi-purpose vehicle (MPV) is built to study vehicle ride comfort by multi-body system dynamic theory. Virtual test rigs are developed to perform natural body frequency tests and random road input tests on the complete vehicle multi-body dynamic model. By comparing simulation results with field test results, the accuracy of the model is validated and the feasibility of virtual test rigs is established.
Technical Paper

Vibroacoustic Optimisation of Tractor Cabin and Correlation with Experimental Data

Tractor operators prefer to drive more comfortable tractors in the recent years. The high noise and vibration levels, to which drivers of agricultural tractor are often exposed for long periods of time, have a significant part in the driver’s fatigue and may lead to substantial hearing impairment and health problems. Therefore, it is essential for an optimal cabin design to have time and cost effective analysis tools for the assessment of the noise and vibration characteristics of various design alternatives at both the early design stages and the prototype testing phase. Airborne excitation and Structure Borne excitation are two types of dynamic cabin excitations mainly cause the interior noise in a driver’s cabin. Structure-borne excitation is studied in this paper and it consists of dynamic forces, which are directly transmitted to the cabin through the cabin suspension. These transmitted forces introduce cabin vibrations, which in turn generate interior noise.
Journal Article

Vehicle System Simulator: Development and Validation

A graphical user interface (GUI) toolbox called Vehicle System Simulator (VSS) is developed in MATLAB to ease the use of this vehicle model and hopefully encourage its widespread application in the future. This toolbox uses the inherent MATLAB discrete-time solvers and is mainly based on Level-2 s-function design. This paper describes its built-in vehicle dynamics model based on multibody dynamics approach and nonlinear tire models, and traction/braking control systems including Cruise Control and Differential Braking systems. The built-in dynamics model is validated against CarSim 8 and the simulation results prove its accuracy. This paper illustrates the application of this new MATLAB toolbox called Vehicle System Simulator and discusses its development process, limitations, and future improvements.
Technical Paper

Vehicle Stability and Control Research for U.S. Comprehensive Truck Size and Weight (TS&W) Study

The U.S. Department of Transportation's Comprehensive TS&W Study addressed the safety impacts of potential changes to TS&W limits from two perspectives: (1) the assessment of crash information and exposure data (vehicle miles traveled), and (2) the evaluation of stability and control performance of several truck configurations in terms of static roll stability, rearward amplification, and load transfer ratio. This paper addresses the analytical approach used to evaluate safety impacts from the latter perspective. The vehicle performance measures were estimated using simulation models. Several vehicle parameters were varied in a large parametric analysis for use in the study.
Technical Paper

Vehicle Stability Control for Trucks and Buses

Vehicle and traffic safety improvement is one of the most important targets in the vehicle industry. The introduction of ABS for commercial vehicles, meanwhile standard in various countries, was one of the major safety improvements. This system, based on electronics, sensors and actuators shows what is achievable by controlling brakes of such heavy vehicles at the physical limits under various road conditions. With EBS (brake-by-wire) further safety features are integrated including active access of each wheel brake that allows, independent from the driver to apply the brakes to keep the vehicle stable. Electronic stability control as the overall vehicle control system integrated into EBS leads to a new generation of driver assistance concepts. The concept of Electronic Stability Control (ESC) integrated into EBS, simulation studies of vehicle behavior in critical situations, the control strategies and discussion of test results are the main content of this paper.
Journal Article

Vehicle Simulation for the Development of an Active Suspension System for an Agricultural Tractor

The design of suspension systems for heavy-duty vehicles covers a specific field of automotive industry. The proposed work focuses on the design development of a front controllable suspension for an agricultural tractor capable to satisfy the system requirements under different operating conditions. The design of the control algorithms is based on the developed multibody model of the actual tractor, including the pitch motion of the sprung mass, the anti-dive effects during braking and forward-reverse maneuvers and the non-linear dynamics of the actuation system. For an advanced analysis, a novel thermo-hydraulic model of the hydraulic system has been implemented. Several semi-active damping controls are analyzed for the specific case study.