Viewing 1 to 30 of 387
Technical Paper
Michael Fasse
The use of acoustic cavity fillers to prevent the propagation of air borne and structure borne noise, water and dust into the interior spaces of vehicle structures has been in practice for many years. Various technologies are available to OEMs to provide sealing that will prevent water and dust penetration, maximize performance of vehicle HVAC systems, and minimize the propagation of noise into a vehicle under operating conditions. The current state of the application of these technologies in the automotive, medium duty and heavy duty truck markets will be reviewed. Comparisons will be drawn between two categories of cavity fillers: pre-formed heat reactive expandable parts; and bulk applied chemically reacting polyurethane foam. Typical OEM material requirements will be discussed for these technologies. The pros and cons of these competing technologies, as well as their acoustic performance applied to a full vehicle will be considered.
Technical Paper
Manimaran Krishnamoorthy, Mathew Sam Paul Albert
In this work, durability of the bus structure is evaluated with a Virtual Test Model (VTM).Full vehicle Multi Body Dynamics (MBD) model of the bus is built, with inclusion of flexibility of the bus structure to capture structural modes. Component mode synthesis method is used for creation of flexible model for use in MBD. Load extraction is done by performing MBD analysis with measured wheel inputs. Modal Superposition Method (MSM) is employed in FE along with these extracted loads for calculation of modal transient dynamic stress response of the structure. e-N based fatigue life is estimated. The estimated fatigue life from the modal superposition method show good correlation with the physical test results done in 6-poster test rig.
Technical Paper
Harish Harinarayanan
Commercial vehicle payload depends on the client for which the vehicle fleet owner is operating. Load carriers like flatbed trailer offer the flexibility to be loaded with a large number of light payloads or a few numbers of massive payloads. Such load carriers have to be evaluated for various possibilities of loading patterns that could happen in the market. The objective of this work is to evaluate flatbed trailer for its structural strength for different customer application cases, using computer simulation. Structural load cases due to payloads like containers, steel coils and cement bags are arrived at. Static structural analysis using MSC Nastran is performed to evaluate for the worst customer loading pattern from structural stress point of view. This paper also describes a simplified method for simulating the effect of trailer suspension, tractor suspension and the fifth-wheel coupling in the analysis whose detailed modeling is not possible at the concept level.
Technical Paper
Ivan Lima, Geraldo Minoru Kato, Juan Carlos Parrilla
The growing competition of the automotive market makes more and more necessary the reduction of development time and consequently, the increase of the capacity to quickly respond to the launching of the competitors. One of the most costly phases on the vehicle development process is the field durability test, both in function of the number of prototypes employed and the time needed to its execution. More and more diffused, the fatigue life prediction methods have played an important part in the durability analysis via CAE. Nevertheless, in order they can be reliable and really being able to reduce the development time and cost, they need to be provided with load cases that can accurately represent the field durability tests. This work presents a CAE approach used for light trucks in order to get a reasonable understanding of component durability behavior due to payload increase. In general, road load data is not available for a new payload condition.
Technical Paper
Ashok Patidar, Umashanker Gupta, Nitin Marathe
Assessment of cooling performance in the design stage of vehicle allows a reduction in the number of needed prototypes and reduces the overall design cycle time. Frontend cooling and thermal management play an essential role in the early stages of commercial vehicle design. Sufficient airflow needs to be available for adequate cooling of the under-hood components. The amount of air mass flow depends on the under-hood geometry details, positioning and size of the grilles, fan operation and the positioning of the other components. Thermal performance depends on the selection of heat exchanger. This paper describes the effects of several design actions on engine cooling performance of a commercial vehicle with the help of Computational Fluid Dynamics (CFD) simulation tool Fluent™. Front of vehicle design is captured in detailed FE model, considering front bumper, grille, cabin, cargo and surrounding under-hood and underbody components.
Technical Paper
Sylla Benedicto Abibe Aranha, Edgard Fernandes de Andrade, Eliana Mitiko Katayose, Kaísa Couto Machado, Marcelo Gonçalves
The truck body on chassis for dry freight applies to several types of goods, including packagings, broken or unitized cargoes. In Brazil, this equipment is traditionally made of wood and recently of steel. Moreover, in overseas countries the manufacturing of aluminium bodies is quite common (mainly in Europe and the United States), for economic, operational and environmental reasons, such as: weight reduction and resulting increase in payload capacity of the vehicle; easy manufacturing and repair; recyclability of the material used. This paper presents the main features and technical requirements from the Design of a Aluminium Truck Body mounted on a 3-axle truck, with 23 tons of deadweight (Gross Weight) and 5.4m of distance between axes.
Technical Paper
N Suresh, John G. Argeropoulos, Craig Patterson, Del Schroeder
The automobile industry is seeing an increased need for the application of plastics and their derivatives in various forms such as fiber reinforced plastics, in the design and manufacture of various automotive structural components, to reduce weight, cost and improve fuel efficiency. A lot of effort is being directed at the development of structural plastics, to meet specific automotive requirements such as stiffness, safety, strength, durability and environmental standards and recyclability. This paper presents the concept of reinforcing large injection molded fiber reinforced body panels with structural uni-directional fibers (carbon, graphite, kevlar or fiber glass) wound in tension around the body panels by filament winding technique. Structural uni-directional fibers in tension wound around the fiber reinforced plastic inner body panels would place these body panels under compression.
Technical Paper
L. C. Ferraro, M. A. Fogaça, M. Ururahy, M. A. Argentino, A. Costa Neto, T. Adelmann, O.T. Perseguim
1 ABSTRACT The present work describes the modeling and analysis processes of a medium sized truck manufactured in Brazil with regard to comfort behavior. The vehicle model includes Hotchkiss suspensions front and rear with shackle and with a double stage with bump stops at the rear. It is also included frame flexibility in ADAMS, the frame characteristics were imported from a Finite Element Analysis model. Nonlinear shock absorber curves are also represented for the vehicle and cab suspensions. Viscoelastic bushings for cab and powertrain suspension are also included. Random track profile is generated as input and vehicle comfort is described in terms of the ISO 2631-85 Standard. The effect on vehicle comfort of changing a design parameter can be predicted in the model and verified experimentally.
Technical Paper
Pooja Dwivedi, Adwait Kulkarni, Sujit Chalipat, Mahesh Pardeshi
During the frontal pendulum impact on commercial vehicles as per AIS029, flat front end vehicles usually show severe cabin deformations. In most of these cases the impact load directly acts on the cabin structure resulting in severe loading of front part of the cabin. This is likely to result in failure of cab mounts causing cabin separation, undesirable cab movement and high intrusion inside the cabin structure. This unpredictable cabin behavior exposes cabin occupants to high risk of injuries. The possible way of reducing occupant injuries in pendulum impact test is to limit the undesirable displacement of the cabin structure during the test and maintain its structural integrity. This can be achieved by having multiple load paths to transfer loads from firewall structure to cabin underbody structure, chassis frame structure and controlling cabin displacement in case of cab mount failure preventing excessive rotation of cabin structure.
Technical Paper
Gaetano Coraggio, Gianfranco Rizzo, Cecilia Pisanti, Adolfo Senatore
The integration of photovoltaic (PV) panels on electric and hybrid vehicles is gaining interest, thanks to the increasing fleet electrification, the improvement in solar panel efficiency and the reduction in their costs. In order to maximize the solar contribution, the adoption of self-orienting solar roof when the vehicle is parked can be considered. In the paper, the authors present a study on the energy management of a moving solar roof, as a 3 d.o.f. parallel robot, in a solar assisted vehicle. A model based control is developed, based on combined use of measured solar power, image processing form a digital camera and data provided by a GPS module, and implemented over a small scale prototype. An optimal tracking strategy, considering the effects of different insolation and of mechanical losses, is also presented.
Technical Paper
Michael Karge
By the fatigue assessment of large welded steel structures such as construction machines structures, the calculation engineer is confronted with a difficulty: the local stress approaches with fictitious notch radius that are very accurate cannot be used on the global structure because of the current computer limitations. Only a nominal stress can be estimated on the whole structure. The accuracy of the current commercial code methods that are using the nominal stress approach is not satisfying for most of the cases. The major problems are the following: only one SN-Curve (FAT-class) can be chosen for a weld the stress used for the calculation is based on the critical plane concept, not taking into account the direction of the weld (anisotropy of notch effects) and the geometrical weld parameters (e.g. weld throat thickness and penetration) choice of the FAT-class when the structural detail is not available in the IIW guideline.
Technical Paper
Claudio Crivellaro, Eduardo Reyna
Looking for fuel efficiency and improvement of the load capacity, new truck designs are targeting chassis weight reduction. As a consequence, the frame can become less stiff, and its higher flexibility can affect the vehicle handling and NVH performance. This paper presents a study of the effects of the frame compliance in regard to the vehicle dynamic behavior.
Technical Paper
Sittikorn Lapapong, Narong Pitaksapsin, Sedthawatt Sucharitpwatkul, Tanakorn Tantanawat, Rattanasuda Naewngerndee, Anek Phuchamnong
The strength of the superstructure of a bus is very critical to the safety of passengers, both in normal operation and in the event of accident. During the normal operation, the structure of the bus is subjected to several loads, which may be induced by its inertia during vehicle maneuvering (i.e. braking and cornering) or by external loads from the road (i.e. crossing over a speed bump). Moreover, there is a substantial possibility that these loads may lead to a structural failure. Hence, it is necessary to determine stresses occurred in the bus's superstructure to ensure its integrity under these driving scenarios. This paper presents techniques implemented to analyze stresses on the superstructure of a newly designed 15-meter long bus subjected to loads previously mentioned using Finite Element Method (FEM). The stress analysis technique used in each scenario is selected based upon the frequency intensity of load excitations and the dynamic responses of the structure.
Technical Paper
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.
Technical Paper
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.
Technical Paper
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.
Technical Paper
The author quotes statistics relating to the proportion of closed to open bodies and outlines the changes that have taken place in body construction in recent years. He sketches the advances that have been made and states that the question to be answered now relates to what all this improvement in manufacturing methods has accomplished toward reducing the price of a closed-car body to the consumer. He compares the percentage of public benefit in 1922 with that of 1914, excluding the period of inflated prices immediately following the war, and states that it is 10 to 15 per cent, but says also that this is an unfair comparison because of the excessive increases in the cost of labor, lumber, sheet steel and trimming cloth. An unconventional type of body, covered entirely with fabric over a foundation of wire-mesh and buckram fastened to the conventional wood-framing, is illustrated and described in detail, together with a statement of its advantages.
Technical Paper
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.
Technical Paper
S Mithun, Suresh Gaikwad, Jobin Chowattukunnel, D Prasadkumar
Abstract A Door Control System is being used for controlling doors in buses running in urban/suburban areas as a part of safety requirement and to protect the passengers. The opening and closing of the doors will be in logical sequence depending upon the driver input, vehicle speed and the emergency conditions. To achieve this logic the door control system consists of an ECU, pneumatic valves, pressure sensors and switches. To predict the performance of this system under various operating conditions, the entire system is being modeled in one of the commercially available multi-domain physical modeling software employing bond graph technique and lumped system and the performance is predicted. This paper deals with the modeling and simulation of entire Door Control System.
Technical Paper
Torbjörn Narström
Abstract The use of modern quenched and tempered steels in dumper bodies to reduce weight to increase the payload and reduce the fuel consumption is briefly discussed. Modern quenched and tempered steels in combination with adopted design concept will further increase weight savings of the dumper body. Use of these materials may lead to 4 times longer wear life than ordinary steels. One of the main load cases for a dumper body is impact of an object, i.e. boulders and rocks, into the body. A well-proven test setup is used to develop a model to predict failure and depth of the dent after the impact. A material model with damage mechanic was utilized to predict fracture. The developed model was used to study the effect of the geometry of the impacting object, thickness of the plate and unconstrained plate field. The model was also implemented in larger model and compared with a full scale test of dumper body.
Technical Paper
Timo Björk, Ilkka Valkonen, Jukka Kömi, Hannu Indren
Abstract The development of weldable high-strength and wear-resistant steels have made modern structures such as booms and mobile equipment possible. These sorts of novel and effective designs could not be constructed with traditional mild steel. Unfortunately, the use of these novel steels requires proper design, and there is no practical design code for these novel steels. This paper addresses stability issues, which are important considerations for designs with high-strength steels, and the properties of the heat-affected zone, which may require special attention. Fatigue design is also discussed in this paper, and the importance of the weld quality is highlighted, along with discussions on which details in the weld are the most important. By comparing the test results with the classical load limit solution, it is determined that full plastic capacity is reached and that the samples display good strain properties.
Technical Paper
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.
Technical Paper
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.
Technical Paper
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.
Technical Paper
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.
Technical Paper
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.
Technical Paper
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.
Technical Paper
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.
Technical Paper
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.
Technical Paper
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.
Viewing 1 to 30 of 387


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