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Viewing 1 to 30 of 237
2017-03-28
Technical Paper
2017-01-1538
Jiaye Gan, Longxian Li, Gecheng Zha, Craig Czlapinski
Abstract This paper conducts numerical simulation and wind tunnel testing to demonstrate the passive flow control jet boat tail (JBT) drag reduction technique for a heavy duty truck rear view mirror. The JBT passive flow control technique is to introduce a flow jet by opening an inlet in the front of a bluff body, accelerate the jet via a converging duct and eject the jet at an angle toward the center of the base surface. The high speed jet flow entrains the free stream flow to energize the base flow, increase the base pressure, reduces the wake size, and thus reduce the drag. A baseline heavy duty truck rear view mirror is used as reference. The mirror is then redesigned to include the JBT feature without violating any of the variable mirror position geometric constraints and internal control system volume requirement. The wind tunnel testing was conducted at various flow speed and yaw angles.
2017-03-28
Technical Paper
2017-01-1531
Keiichi Taniguchi, Akiyoshi Shibata, Mikako Murakami, Munehiko Oshima
Abstract This paper describes a study of drag reduction devices for production pick-up trucks with a body-on-frame structure using full-scale wind tunnel testing and Computational Fluid Dynamics (CFD) simulations. First, the flow structure around a pick-up truck was investigated and studied, focusing in particular on the flow structure between the cabin and tailgate. It was found that the flow structure around the tailgate was closely related to aerodynamic drag. A low drag flow structure was found by flow analysis, and the separation angle at the roof end was identified as being important to achieve the flow structure. While proceeding with the development of a new production model, a technical issue of the flow structure involving sensitivity to the vehicle velocity was identified in connection with optimization of the roof end shape. (1)A tailgate spoiler was examined for solving this issue.
2017-03-28
Journal Article
2017-01-1416
B. Nicholas Ault, Daniel E. Toomey
Abstract Reconstruction of passenger vehicle accidents involving side impacts with narrow objects has traditionally been approached using side stiffness coefficients derived from moveable deformable barrier tests or regression analysis using the maximum crush in available lateral pole impact testing while accounting for vehicle test weight. Current Lateral Impact New Car Assessment Program (LINCAP) testing includes 20 mph oblique lateral pole impacts. This test program often incorporates an instrumented pole so the force between the vehicle and pole at several elevations along the vehicle - pole interface is measured. Force-Displacement (F-D) characteristics of vehicle structures were determined using the measured impact force and calculated vehicle displacement from on-board vehicle instrumentation. The absorbed vehicle energy was calculated from the F-D curves and related to the closing speed between the vehicle and the pole by the vehicle weight.
2017-03-28
Technical Paper
2017-01-1417
Enrique Bonugli, Richard Watson, Mark Freund, Jeffrey Wirth
Abstract This paper reports on seventy additional tests conducted using a mechanical device described by Bonugli et al. [4]. The method utilized quasi-static loading of bumper systems and other vehicle components to measure their force-deflection properties. Corridors on the force-deflection plots, for various vehicle combinations, were determined in order to define the system stiffness of the combined vehicle components. Loading path and peak force measurements can then be used to evaluate the impact severity for low speed collisions in terms of delta-v and acceleration. The additional tests refine the stiffness corridors, previously published, which cover a wide range of vehicle types and impact configurations. The compression phase of a low speed collision can be modeled as a spring that is defined by the force-deflection corridors. This is followed by a linear rebound phase based on published restitution values [1,5].
2017-03-28
Journal Article
2017-01-1415
John D. Struble, Donald E. Struble
Abstract Crash tests of vehicles by striking deformable barriers are specified by Government programs such as FMVSS 214, FMVSS 301 and the Side Impact New Car Assessment Program (SINCAP). Such tests result in both crash partners absorbing crush energy and moving after separation. Compared with studying fixed rigid barrier crash tests, the analysis of the energy-absorbing behavior of the vehicle side (or rear) structure is much more involved. Described in this paper is a methodology by which analysts can use such crash tests to determine the side structure stiffness characteristics for the specific struck vehicle. Such vehicle-specific information allows the calculation of the crush energy for the particular side-struck vehicle during an actual collision – a key step in the reconstruction of that crash.
2017-03-28
Technical Paper
2017-01-1341
Alok Kumar, Sandeep Sharma
Abstract Public conveyance such as a bus is a major contributor to socio - economic development of any geography. The international market for passenger bus needed to be made viable in terms of passenger comfort, minimum operational costs of the fleet by reduced fuel consumption through light weighting and yet robust enough to meet stringent safety requirements. Optimized design of bus body superstructure plays vital role in overall performance and safety, which necessitates to evaluate bus structure accurately during initial phase of design. This paper presents a robust methodology in numerical simulation for enhancing the structural characteristics of a bus body with simultaneous reduction in the weight by multi-material optimization while supplemented with sensitivity and robustness analysis. This approach ensures significant reduction in vehicle curb weight with promising design stiffness.
2017-01-10
Technical Paper
2017-26-0257
Mandar Bhatkhande, Rahul Mahajan, Amol Joshi
Abstract Front windscreen wiping test is legal requirement for all motor vehicles as per standards like IS15802:2008 [1], IS15804:2008 [2] in India. This test requires windscreen mock-up/actual vehicle to be tested along with all wiping mechanisms such that minimum percentage areas to be wiped should meet the requirements specified in the IS standard. From manufacturer’s perspective this involves investment of lot of time and cost to arrive at the final design solution in order to meet the wiping requirements. The work scope in this paper is limited to bus category of vehicles. The methodology presented in this paper would enable quick design solutions for bus body builders or manufacturers to meet the wiping requirements specified in IS standard. The methodology presented in this paper was developed to carry out windscreen wiping test through commercially available simulation software.
2017-01-10
Technical Paper
2017-26-0304
P M Aneeth, Rajeev Dave, Manoj Yadav, Shinoy Kattakayam
Abstract The entire commercial vehicle industry is moving towards weight reduction to leverage on the latest materials available to benefit in payload & fuel efficiency. General practice of weight reduction using high strength steel with reduced thickness in reference to Roark’s formula does not consider the stiffness & dent performance. While this helps to meet the targeted weight reduction keeping the stress levels within the acceptable limit, but with a penalty on stiffness & dent performance. The parameters of stiffener like thickness, section & pitching are very important while considering the Stiffness, bucking & dent performance of a dumper body. The Finite Element Model of subject dumper body has been studied in general particularly on impact of dent performance and is correlated with road load data to provide unique solution to the product. The impact of payload during loading of dumper is the major load case.
2016-09-27
Technical Paper
2016-01-8050
Chihua Lu, Wenxin Yang, Hao Zheng, Jingqiang Liang, Guang Fu
Abstract In this paper, we propose a method of dynamics simulation and analysis based on superelement modeling to increase the efficiency of dynamics simulation for vehicle body structure. Using this method, a certain multi-purpose vehicle (MPV) body structure was divided into several subsystems, and the modal parameters and frequency response functions of which were obtained through superelement condensation, residual structure solution, and superelement data restoration. The study shows that compared to the traditional modeling method, the computational time for vehicle body modal analysis can be reduced by 6.9% without reducing accuracy; for the purpose of structural optimization, the computational time can be reduced by 87.7% for frequency response analyses of optimizations; consistency between simulation and testing can be achieved on peak frequency points and general trends for the vibration frequency responses of interior front row floors under accelerating conditions.
2016-09-27
Technical Paper
2016-01-8138
Pranav Shinde, K Ravi, Nandhini Nehru, Sushant Pawar, Balaji Balakrishnan, Vinit Nair
Abstract Body in white (BIW) forms a major structure in any automobile. It is responsible for safety and structural rigidity of the vehicle. Also, this frame supports the power plant, auxiliary equipments and all body parts of the vehicle. When it comes to judging the performance of the vehicle, BIW is analyzed not only for its strength and shape but also the weight. Light weight BIW structures have grown rapidly in order to fulfill the requirements of the best vehicle performance in dynamic conditions. Since then lot of efforts have been put into computer-aided engineering (CAE), materials research, advanced manufacturing processes and joining methods. Each of them play a critical role in BIW functionality. Constructional designing, development of light materials with improved strength and special manufacturing practices for BIW are few research areas with scope of improvement. This paper attempts to review various factors studied for BIW weight reduction.
2016-09-27
Technical Paper
2016-01-8123
Lei Peng, Zhuo Wang, Jiantao Gu
Abstract Body structure design needs to meet multi-attributes requirements such as global bend stiffness/modal, torsion stiffness/modal, Noise and velocity transfer functions (NTF/VTF), and others. Computer-aided engineering (CAE) is a significant way to enhance the accuracy of design results. However, it also brings computation burden for optimization. In order to improve the performance and reduce the weight of automobile body structure, this paper presents a novel process of body CAE multi-attributes optimization. Four significant phases are described: 1) Sensitivity analysis for each body CAE performance, 2) MDO process, 3) Non-sensitive gauges reducing, and 4) Slightly optimization. Considering the mixed variables in the MDO process including continuous geometry shapes and discrete gauges, the developed continuous relaxation method was employed to deal with such situation.
2016-09-27
Technical Paper
2016-01-8155
Devaraj Dasarathan, Jonathan Jilesen, David Croteau, Ray Ayala
Abstract Side window clarity and its effect on side mirror visibility plays a major role in driver comfort. Driving in inclement weather conditions such as rain can be stressful, and having optimal visibility under these conditions is ideal. However, extreme conditions can overwhelm exterior water management devices, resulting in rivulets of water flowing over the a-pillar and onto the vehicle’s side glass. Once on the side glass, these rivulets and the pooling of water they feed, can significantly impair the driver’s ability to see the side mirror and to see outwardly when in situations such as changing lanes. Designing exterior water management features of a vehicle is a challenging exercise, as traditionally, physical testing methods first require a full-scale vehicle for evaluations to be possible. Additionally, common water management devices such as grooves and channels often have undesirable aesthetic, drag, and wind noise implications.
2016-09-27
Technical Paper
2016-01-8053
Adime Kofi Bonsi, Marius-Dorin Surcel
Abstract The objective of this project was to provide pertinent information on the performance of refrigeration and heating transportation units to help fleets make decisions that will improve efficiency and increase productivity. To achieve this objective, tests were designed to measure the performance of selected refrigeration and heating units, mounted on refrigerated and heated van semitrailers. Cooling and freezing tests were carried out in summer conditions while heating tests were carried out in winter conditions, for various temperature settings. Two fundamental approaches were considered: the design of the refrigerated or heated trailer and the temperature setting of the refrigeration or heating unit. For cooling and freezing tests, the fuel consumption comparison between similar trailer models of different ages showed that newer units performed better than older ones.
2016-09-27
Technical Paper
2016-01-8141
Brian R. McAuliffe
Abstract With increasing use of boat-tails on Canadian roads, a concern had been raised regarding the possibility for ice and snow to accumulate and shed from the cavity of a boat-tail affixed to a dry-van trailer, posing a hazard for other road users. This paper describes a preliminary evaluation of the potential for ice and snow accumulation in the cavity of a boat-tail-equipped heavy-duty vehicle. A transient CFD approach was used and combined with a quasi-static particle-tracking simulation to evaluate, firstly, the tendency of various representative ice or snow particles to be entrained in the vehicle wake, and secondly, the potential of such particles to accumulate on the aft end of a dry-van trailer with and without various boat-tail configurations. Results of the particle tracking analyses showed that the greatest numbers of particles impinge on the base of the trailer for the no-boat-tail case, concentrated on the upper surface of the back face of the trailer.
2016-09-27
Journal Article
2016-01-8015
Brian R. McAuliffe, Alanna S. Wall
Abstract This paper describes an investigation of the performance potential of conventional flat-panel boat-tail concepts applied to tractor-trailer combinations. The study makes use of data from two wind-tunnel investigations, using model scales of 10% and 30%. Variations in boat-tail geometry were evaluated including the influence of length, side-panel angle and shape, top-panel angle and vertical position, and the presence of a lower panel. In addition, the beneficial interaction of the aerodynamic influence of boat-tails and side-skirts that provides a larger drag reduction than the sum of the individual-component drag reductions, identified in recent years through wind-tunnel tests in different facilities, has been further confirmed. This confirmation was accomplished using combinations of various boat-tails and side-skirts, with additional variations in the configuration of the tractor-trailer configuration.
2016-09-27
Journal Article
2016-01-8030
Dai Quoc Vo, Hormoz Marzbani, Mohammad Fard, Reza N. Jazar
Abstract As long as a tire steers about a titled kingpin pivot, the point coming in contact with the road moves along its perimeter. This movement affects the determination of kingpin moments caused by the tire forces, especially for large steering angles. The movement, however, has been neglected in the literature on the steerable-tire-kinematics-related topics. In this investigation, the homogeneous transformation is employed to develop a kinematic model of a steering tire in which the instantaneous ground-contact point on the tire is considered. The moments about the kingpin axis caused by tire forces are then computed based on the kinematics. A four-wheel-car model is constructed for determining the kingpin moment of steering system during the low-speed cornering maneuver. The result shows that the displacement of the ground-contact point along the tire perimeter is significant for large steering angles.
2016-09-27
Technical Paper
2016-01-8049
Keith Friedman, Khanh Bui, John Hutchinson, Matthew Stephens, Francisco Gonzalez
Abstract Frame rail design advances for the heavy truck industry provide numerous opportunities for enhanced protection of fuel storage systems. One aspect of the advanced frame technology now available is the ability to vary the frame rail separation along the length of the truck, as well as the depth of the frame. In this study, the effect of incorporating the fuel storage system within advanced technology tapered frame rails was evaluated using virtual testing under impact conditions. The impact performance was evaluated under a range of horizontal impacts conditions. The performance observed was quantified and then compared with previous testing of baseline diesel tank systems. Fuel storage system impact performance metrics over the range of crash conditions considered were quantified using virtual testing methods. The results obtained from the application of the impact performance evaluation methodology were then described.
2016-04-05
Technical Paper
2016-01-0217
Somnath Sen, Mayur Selokar, Diwakar Nisad, Kamal Kishore
Abstract Adequate visibility through the vehicle windshield over the entire driving period is of paramount practical significance. Thin water film (fog) that forms on the windshield mainly during the winter season would reduce and disturb the driver’s visibility. This water film originates from condensing water vapor on inside surface of the windshield due to low outside temperatures. Primary source of this vapor is the passenger’s breath, which condenses on the windshield. Hot and dry air which impinges at certain velocity and angle relative to the windshield helps to remove the thin water film (defogging) and hence improves driver’s visibility. Hence a well-designed demisting device will help to eliminate this fog layer within very short span of time and brings an accepted level of visibility. An attempt is made here to design and develop a demisting device for a commercial vehicle with the help of numerical and analytical approach and later on validated with experimental results.
2016-04-05
Technical Paper
2016-01-1329
Fulin Wei, Yanhua Shen, Tao Xu
Abstract Off-road dump truck body is exposed to abrasive wear during handling of granular materials. The wear rate of body of dump truck has direct influence on maintenance and replacement during its service process. In this paper the discrete element method (DEM) is used to simulate the granular materials of dump truck. The wear of body floor during one dumping process can be achieved by cosimulation of FEM-DEM. The wear depth variation of body has the stochastic characteristic which can be modeled by Geometric Brownian Motion (GBM). The two parameters in the stochastic differential equation, drift coefficient and diffusion coefficient, can be estimated by the wear depth measuring data. It is possible to quantitatively predict the wear evolution of every grid point of the body floor by solving this stochastic differential equation. The simulation result of the wear model is helpful to optimize design of off-road dump truck body.
2016-04-05
Technical Paper
2016-01-1398
Ahmet Turan
Abstract Optimization of a structure which is subjected to simultaneous multiple load cases starts with the investigation of worst possible load case combination. This is called conventional optimization approach, which can be considered impractical due to the excessive CPU times in the application of multiple load cases. This computational difficulty can be overcome by deploying singular value decomposition (SVD) to find the worst possible load case against which the structure should be optimized. To this end, the SVD based optimization approach to optimization of a structure subject to simultaneous multiple load cases is presented. Conventional Multiobjective optimization and SVD based Multi-objective optimization approaches are applied to a sample Commercial Truck Chassis Frame structure for durability vs. weight objectives. This will enable designer to select the optimum design parameters out of the calculated Pareto sets.
2016-02-01
Technical Paper
2016-28-0242
Ashwin Vaidyanathan, Aono Noriaki
Abstract This paper reinforces the importance of correlation between CAE Analysis of CAB Bridge and Vehicle test data. CAB Bridge is a structural assembly, bolted to the Frame of a Truck. The initial objective of the study was to evaluate the influence of particular design modification on CAB Bridge. To perform CAE calculations, two different iterations of Boundary & loading conditions, were established and executed using CATIA V5. During Post processing of CAE results, detailed data analysis and interpretation were performed. The results of CAE Analysis and Vehicle test data were compared, to identify the iteration that correlated better with Vehicle test data. The data analysis and interpretation guided in finding key observations and concluding that the Torsion case as the most important loading condition.
2015-09-29
Technical Paper
2015-01-2837
Subramanian Premananth, Hareesh Krishnan, Riyaz Mohammed, Dharmar Ganesh
Abstract Overall in-vehicle visibility is considered as a key safety parameter essentially mandated due to the increasing traffic scenario as seen in developing countries. Driver side bottom corner visibility is one such parameter primarily defined by A-pillar bottom and outside rear-view mirror (OSRVM). While defining the OSRVM package requirements such as size, position and regulatory aspects, it is also vital to consider other influencing parameters such as position of pillars, waist-line height, and Instrument panel which affect the in-vehicle visibility. This study explains the various package considerations, methods to optimize OSRVM position, shape and housing design in order to maximize the in-vehicle visibility considering the road and traffic conditions. A detailed study on in-vehicle visibility impacted by OSRVM packaging explained and had been verified for the results.
2015-09-29
Technical Paper
2015-01-2867
Sanket Pawar
Abstract Work lights with high power rating consume high current. Since the battery voltage is fixed, high currents are needed to generate the necessary power (wattage). This makes it difficult to manage the load on the Electronic Control Unit (ECU) responsible for controlling the work lights and also on the entire electrical system of the vehicle. It is possible to prevent the system from getting over loaded by employing effective means of work light control techniques. These techniques differ based on the type of work lights connected on the vehicle. There are three types of work lights available in the market. Halogen work lights, High Intensity Discharge (HID) work lights and Light Emitting Diode (LED) work lights. HIDs are not preferred by most customers due to their high warm up times & cost/unit. The other two types of lights, i.e. LED & Halogen, are comparatively less expensive. They also need negligible warm up times which are not objectionable to the vehicle operators.
2015-09-29
Technical Paper
2015-01-2903
Miguel Hurtado, Amine Taleb-Bendiab
Abstract Similar to Passenger Vehicles (PV), Commercial Vehicles and Trucks (ComVecT) use standard rearview mirrors to improve the visibility of the surrounding environment and facilitate a safer maneuvering of large vehicles. Standard rearview mirrors used in ComVecT are large and flat to cover outside areas as specified in theFMVSS 111 standard, or other requirements like ECE-R46. In addition, ComVecT are also equipped with optional mirrors with different Field of View (FoV), such as wide angle, look-down cross proximity, and front mirrors. These optional mirrors cover wider or specific areas around the vehicle which might not be possible otherwise with standard mirrors only. While these mirrors tend to enhance the visibility around the truck, they create undesirable blind zones to the driver. These blind zones can be gaps between the direct vision through the windows and indirect vision provided by the mirror.
2015-09-29
Journal Article
2015-01-2894
Marius-Dorin Surcel, Mithun Shetty
Abstract The performance of several aerodynamic technologies and approaches, such as trailer skirts, trailer boat tails, gap reduction, was evaluated using track testing, model wind tunnel testing, and CFD simulation, in order to assess the influence of the design, position and combination of various aerodynamic devices. The track test procedure followed the SAE J1321 SAE Fuel Consumption Test Procedure - Type II. Scale model wind tunnel tests were conducted to have direct performance comparisons among several possible configurations. The wind tunnel tests were conducted on a 1/8 scale model of a tractor in combination with a 53-foot semi-trailer. Among others, the wind tunnel tests and CFD simulations confirmed the influences of trailer skirts' length observed during the track tests and that the wider skirt closer to the ground offer better results.
2015-09-29
Technical Paper
2015-01-2892
Carlos A. Pereira, Max Morton, Claire Martin, Geert-Jan Schellekens
Abstract The current trend towards energy efficient commercial vehicles requires a substantial improvement in their aerodynamic performance. This paper describes the design methodology for a new roof fairing design with integrated ducts and the predicted effects of the final design on downstream flow. It also provides a baseline comparison with the fairing of a commercial platform and highlights the advantages of using rapid prototyping technologies to test aerodynamic improvements on commercial vehicles. By integrating into the design of a thermoplastic roof fairing ducts that divert and speed-up air flow it is possible to obtain reduction of drag in the trailer gap and alter the trailer wake favorably. The resulting decrease in yaw-averaged overall drag coefficient is of 5.8%. This translates into an improvement in fuel efficiency of 2.9% when compared to the baseline.
2015-04-14
Technical Paper
2015-01-1700
John D. Bullough
Abstract Warning lights and beacons on service vehicles such as maintenance trucks, tow trucks, utility service vehicles and delivery vehicles are an important line of defense for the workers who operate them. These flashing lights can also contribute to visual chaos making it difficult to navigate through a work zone location. Research on the flashing configuration and spatial and temporal coordination of warning lights that could adapt to ambient conditions and situations is described, leading to recommendations for preliminary performance specifications
2015-03-30
Technical Paper
2015-01-0090
Cherdsak Chuaymung, Chi-na Benyajati, Sutee Olarnrithinun
Abstract A vehicle of interest in this paper was a light agriculture truck. In order to obtain reliable predictions of stress generated in the frame under loads, a combination of experimental tests and computer simulations was arranged. Since the focused deformations were bending and torsion modes, the truck driven up one-wheel ramp and two-wheel ramp was investigated. Strains results obtained from both tests and simulations were compared. The discussions and conclusions were made regarding the accuracy and further improvements of the simulations.
2015-03-10
Technical Paper
2015-01-0014
Yadong Deng, Yulian Chen, Long Xie, Meng Xu
Abstract A key problem of designing a light off-road vehicle with separate frame construction is to improve its torsional characteristic, which has a significant influence on the performance of the vehicle. Inevitably, a certain distortion of the body would be produced by the vibration and impact passing from the road. In present research, an analysis model of light off-road vehicle is established based on the theories and methods of finite element (FEM). The static stiffness of the body is simulated and the deformation of openings on the body, mainly the windows and the doors of the vehicle is studied. On the working conditions of torsion and braking combination, torsion and cornering combination, diagonal dangling, ultimate torsion of unilateral wheels and diagonal wheels, the static strength of separate frame construction is studied as well. The stress concentration regions are obtained according to the results of simulation.
2015-03-10
Technical Paper
2015-01-0022
James Keogh, Tracie Barber, Sammy Diasinos, Graham Doig
Abstract When a vehicle travels through a corner it can experience a significant change in aerodynamic performance due to the curved path of its motion. The yaw angle of the flow will vary along its length and the relative velocity of the flow will increase with distance from the central axis of its rotation. Aerodynamic analysis of vehicles in the cornering condition is an important design parameter, particularly in motorsport. Most racing-cars are designed to produce downforce that will compromise straight-line speed to allow large gains to be made in the corners. Despite the cornering condition being important, aerodynamicists are restricted in their ability to replicate the condition experimentally. Whirling arms, rotary rigs, curved test sections and bent wind tunnel models are experimental techniques capable of replicating some aspects of the cornering condition, but are all compromised solutions.
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