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Event
2015-06-22
The focus of the Structural Analysis session is to share experiences on analyzing, testing, and developing solutions to structural noise and vibration problems from powertrain sources. Analytical modeling, experimental testing and predictive correlation are just a few of the tools used in this endeavor.
Event
2015-06-22
This session covers static and dynamic issues in the body and chassis that contribute to noise and vibration problems in vehicles. Included in this session are modal studies, measurement and analysis methods, transfer path analysis, design guidelines, and recommended practices for noise and vibration control of the body and chassis.
Event
2015-06-22
This session focuses on the development and application of analytical methods for characterizing the dynamic behavior of structural systems. Analysis methods for all structural components, subsystems and complete systems found in automotive vehicles will be considered, except for powertrain and driveline which are covered in Powertrain Structural Analysis session. Examples include (but are not limited to) body structure, chassis structure, seats and interior structures.
Technical Paper
2014-09-30
Zhigang Wei, Shengbin Lin, Limin Luo, Litang Gao
Road vibrations cause fatigue failures in vehicle components and systems. Therefore, reliable and accurate damage and life assessment is crucial to the durability and reliability performances of vehicles, especially at early design stages. However, durability and reliability assessment is difficult not only because of the unknown underlying damage mechanisms, such as crack initiation and crack growth, but also due to the large uncertainties introduced by many factors during operation. How to effectively and accurately assess the damage status and quantitatively measure the uncertainties in a damage evolution process is an important but still unsolved task in engineering probabilistic analysis. In this paper, a new procedure is developed to assess the durability and reliability performance, and characterize the uncertainties of damage evolution of components under constant amplitude loadings. The linear and two nonlinear probabilistic damage accumulation models are briefly described first.
Technical Paper
2014-09-30
Iman Hazrati Ashtiani, Mehrnoosh Abedi
Abstract Road train vehicles have been applied as one of the common and efficient ways for transportation of goods, specifically hazardous liquid cargos, in different nations. These vehicles have a wide variety of lengths and towing systems such as the fifth wheel or the dolly draw-bar. Based upon specific regulations, they could be authorized to move on specific roads. In order to avoid hazard and danger in case of accidents, safety performance of a B-train vehicle as a specific type of road train vehicles is investigated in this paper. A Multi-Body Dynamic (MBD) model, which consists of a prime mover and two trailers coupled by fifth wheels, are simulated in the initial phase of the study. The developed dynamic model is capable of simulating required tests as well as the SAE lane change, along with a constant radius turn for the purpose of roll and yaw stability analysis and safety evaluation. The effects of variation of the fluid fill level are considered in this research. The trammel pendulum concept is adopted for simulation of fluid movements, known as sloshing, in two articulated tankers of the model.
Technical Paper
2014-09-30
John Anderson
Abstract This paper describes the development and testing of a Dynamic Vibration Absorber to reduce frame beaming vibration in a highway tractor. Frame beaming occurs when the first vertical bending mode of the frame is excited by road or wheel-end inputs. It is primarily a problem for driver comfort. Up until now, few options were available to resolve this problem. The paper will review the phenomenon, design factors affecting a vehicle's sensitivity to frame beaming, and the principles of Dynamic Vibration Absorbers (AKA Tuned Mass Dampers). Finally, the paper will describe simulation and testing that led to the development of an effective vibration absorber as a field fix.
Technical Paper
2014-09-30
Marc Ratzel, Warren Dias
Abstract This paper discusses the behavior of a flexible flap at the rear end of a generic car model under aerodynamic loads. A strong bidirectional coupling between the flap's deflection and the flow field exists which requires this system to be simulated in a coupled fluid-structure manner. A coupled transient aerodynamic and structural simulation is performed for a generic car model with a flexible/deformable flap at the rear end. An automatic workflow is established which generates new flap designs, derived from an initial flap design by applying a mesh deformation technology, and performs the coupled fluid-structure interaction analysis. For each shape variation, the flap's maximum displacement is monitored and used to classify the individual flap designs. This process allows for design of experiment (DOE) studies in an automated manner. Several shape variations of the flap and their impacts on the maximum deflection are investigated. Design changes causing a reduction in the maximum deflection are identified and used in an optimization loop to determine a flap design with minimum displacement.
Technical Paper
2014-09-30
Marc Auger, Larry Plourde, Melissa Trumbore, Terry Manuel
Abstract Design of body structures for commercial vehicles differs significantly from automotive due to government, design and usage requirements. Specifically, heavy truck doors are not required to meet side impact requirements due to their height off the ground as compared to automobiles. However, heavy truck doors are subjected to higher loads, longer life, and cannot experience permanent deformation from overload events. Aluminum has been used intensively in commercial vehicle doors and cab structures for over 50 years by several different manufacturers in North America. It has been only in the last few years that aluminum has appeared in automotive door structures other than in high-end luxury vehicles. Commercial vehicle customers are expecting the same features found in premium automobiles resulting in opportunities to learn from each other's designs. In order to optimize the strength and weight of a commercial vehicle door, a new aluminum intensive structure was developed. The new structure featured a unique architecture that was the first in the industry to use a multi-cavity aluminum extrusion joined to stamped sheet reinforcements in order to provide a direct load path between the hinges and the latch.
Magazine
2014-09-16
All the right connections With 2013 sales of $6.8 billion, Dana is a leading tier one supplier. Ian Adcock catches up with its chief technical and quality officer George Constand. Jaguar's lightweight challenger Ian Adcock uncovers the secrets that make the XE saloon, Jaguar's most important car yet. Boxing clever How composite crashboxes save weight and cost
Standard
2014-08-21
Scope is unavailable.
Standard
2014-08-21
Scope is uanvailable.
Standard
2014-08-21
Scope is unavailable.
Standard
2014-08-20
Scope is unavailable.
Magazine
2014-07-01
Global Viewpoints The latest strategies are investigated for vehicle development by automakers and major suppliers. Sports cars embrace array of green technology IMSA Tudor United SportsCar Championship promotes a variety of green technologies to link racing to the road. More gears, more challenges Many strategies, as well as key software and hardware aspects related to controllers, networks, sensors, and actuators, must be considered to keep automatic transmissions shifting smoothly as more gears are added to improve fuel economy. Advancing structural composites Industry experts address the opportunities and challenges involved with moving toward composite-intensive vehicles, including Nissan's effort to produce a high-volume, fully recyclable composite liftgate with low metal content.
Technical Paper
2014-06-30
Rainer Stelzer, Theophane Courtois, Ki-Sang Chae, Daewon SEO, Seok-Gil Hong
Abstract The assessment of the Transmission Loss (TL) of vehicle components at Low-Mid Frequencies generally raises difficulties associated to the physical mechanisms of the noise transmission through the automotive panel. As far as testing is concerned, it is common in the automotive industry to perform double room TL measurements of component baffled cut-outs, while numerical methods are rather applied when prototype or hardware variants are not available. Indeed, in the context of recent efforts for reduction of vehicle prototypes, the use of simulation is constantly challenged to deliver reliable means of decision during virtual design phase. While the Transfer matrix method is commonly and conveniently used at Mid-High frequencies for the calculation of a trimmed panel, the simulation of energy transfer at low frequencies must take into account modal interactions between the vehicle component and the acoustic environment. After providing a brief review of the established approaches for TL simulation at LF, the article will present a new FE methodology for TL simulation and introduce the advantages of “in-situ” TL simulations by means of fluid-structure FE calculation.
Technical Paper
2014-06-30
Gregor Tanner, David J. Chappell, Dominik Löchel, Niels Søndergaard
Abstract Modelling the vibro-acoustic properties of mechanical built-up structures is a challenging task, especially in the mid to high frequency regime, even with the computational resources available today. Standard modelling tools for complex vehicle parts include finite and boundary element methods (FEM and BEM), as well as Multi-Body Simulations (MBS). These methods are, however, robust only in the low frequency regime. In particular, FEM is not scalable to higher frequencies due to the prohibitive increase in model size. We have recently developed a new method called Discrete Flow Mapping (DFM), which extends existing high frequency methods, such as Statistical Energy Analysis or the so-called Dynamical Energy Analysis (DEA), to work on meshed structures. It provides for the first time detailed spatial information about the vibrational energy of a whole built-up structure of arbitrary complexity in this frequency range. The response of small-scale features and coupling coefficients between sub-components are obtained through local FEM models integrated in the global DFM treatment.
Standard
2014-06-26
This SAE Recommended Practice defines, for vehicle manufacturers and collision information and equipment providers, the types of vehicle dimensional data needed by the collision repair industry and aftermarket equipment modifiers to properly perform high-quality repairs to damaged vehicles. Both bodyframe and unitized vehicles, including passenger cars and light trucks, are addressed.
WIP Standard
2014-06-17
1.1 Purpose The three parts of SAE J1453 cover material, dimensional, and performance requirements of steel O-ring face seal (ORFS) connectors for tubing and the O-ring face seal interface and nut portion of hose stem assemblies for nominal tube diameters of 6 mm through 38 mm and for nominal hose diameters 6.3 mm through 38 mm. SAE J1453-2 covers the requirements for “metric based” O-ring face seal connectors to metric stud ends along with the associated adapters, bulkhead and union connectors. Metric hex wrenching flats are used throughout this standard. 1.2 Field of Application These connectors are intended for general application and hydraulic systems on industrial equipment and commercial products, where elastomeric seals are acceptable to overcome leakage and variations in assembly procedures. These connectors are capable of providing leak proof full flow connections in hydraulic systems operating from 95 kPa vacuum to the working pressures shown in Table 3. Since many factors influence the pressure at which a hydraulic system does or does not perform satisfactorily, these values should not be construed as guaranteed minimums.
WIP Standard
2014-06-16
This recommended practice is a source of information for body and trim engineers and represents existing technology in the field of on-highway vehicle seating systems. It provides a more uniform system of nomenclature, definitions of functional requirements, and testing methods of various material components of motor vehicle seating systems.
Video
2014-05-19
This video summarizes Chapter 10 of the book, “Theory and Applications of Aerodynamics for Ground Vehicles”, by Dr. T. Yomi Obidi, published by SAE International. Concepts demonstrated include the effects of the control surfaces on vehicle performance and drag in sunroofs and convertibles.
Video
2014-05-16
This video summarizes Chapter 6 of the book, “Theory and Applications of Aerodynamics for Ground Vehicles”, by Dr. T. Yomi Obidi, published by SAE International. Concepts demonstrated include aerodynamic considerations in building each of the three vehicle sections, drag reduction methods at section interface, and aerodynamic benefits of composite build.
Technical Paper
2014-05-07
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. It was found that the most sensitive parameter is the geometry of the falling object.
Technical Paper
2014-05-07
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. Additionally, the reliability of the classical formulas is shown by comparing them to a recently proposed, novel formula.
Technical Paper
2014-04-01
Mehdi Safaei, Shahram Azadi, Arash Keshavarz, Meghdad Zahedi
Abstract The main end of this research is the optimization of engine sub-frame parameters in a passenger car to reduce the transmitted vibration to vehicle cabin through DOE method. First, the full vehicle model of passenger car including all its sub-systems such as engine, suspension and steering system is modeled in ADAMS/CAR and its accuracy is validated by exerting swept sine and step input. After that, the schematic geometry of sub-frame is modeled in CAD software and transferred to ADAMS/CAR. Hence, the efficiency of the sub-frame in terms of reducing the induced vibration to vehicle cabin is examined through the various road inputs e.g. swept sine, step and random road input type (B). The results will illustrate that the sub-frame has significant effect in reduction of transmitted vibration to occupants. In order to optimize the sub-frame parameters, the sensitivity analysis is performed to derive effective parameters of sub-frame using DOE method. In this regard, the parameters which have dominant effect on transmitted vibration (the stiffness of sub-frame bushing in vertical direction) are optimized via RSM (Response Surface Method) method.
Technical Paper
2014-04-01
Gaurav Gupta, Rituraj Gautam, Chetan Prakash Jain
Abstract Interior sound quality is one of the significant factors contributing to the comfort level of the occupants of a passenger car. One of the major reasons for the deterioration of interior sound quality is the booming noise. Booming noise is a low frequency (20Hz∼300Hz) structure borne noise which occurs mainly due to the powertrain excitations or road excitations. Several methods have been developed over time to identify and troubleshoot the causes of booming noise [1]. In this paper an attempt has been made to understand the booming noise by analyzing structural (panels) and acoustic (cavity) modes. Both the structural modes and the acoustic modes of the vehicle cabin were measured experimentally on a B-segment hatchback vehicle using a novel approach and the coupled modes were identified. Panels contributing to booming noise were identified and countermeasures were taken to modify these panels to achieve decoupling of structural and cavity modes which results in the reduction of cabin noise levels.
Technical Paper
2014-04-01
Hyungtae Kim, Sehwun Oh, Ki-Chang Kim, Ju Young Lee, Jungseok Cheong, Junmoo Her
Abstract It is common knowledge that body structure is an important factor of road noise performance. Thus, a high stiffness of body system is required, and determining their optimized stiffness and structure is necessary. Therefore, a method for improving body stiffness and validating the relationship between stiffness and road noise through CAE and experimental trials was tested. Furthermore, a guideline for optimizing body structure for road noise performance was suggested.
Technical Paper
2014-04-01
Anthony Barkman, Kelvin Tan, Arin McIntosh, Peter Hylton, Wendy Otoupal-Hylton
This paper discusses a project intended as a design study for a team of college students preparing for careers in motorsports. The project's objective was to conduct a design study on the possible redesign of the suspension for a dirt-track sprint car. The car examined was typical of those which race on one-quarter to one-half mile dirt oval tracks across the United States. The mission of this concept study was to develop a different configuration from the traditional torsion bar spring system, for the front end. The design included moving the dampers inboard with the addition of a rocker to relate the movement through the front suspension system. For the rear end, components were designed to allow the radius rod to be adjustable from the cockpit, thus providing the driver with adjustability to changing track conditions. The project goal was to design functional front end and rear end changes that could provide a positive impact on handling as well as keeping the system easy to replace in a short period of time.
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