Vehicle Finite Element Model Research Articles

Robust control design of active suspensions using modal descriptions of vehicle finite element models

The objective in this paper is to combine the finite element method with the robust control design method. The finite element method results in a high-complexity model with a large number of degrees-of-freedom, which is the basis of the control design. The superposition method is applied as a modal reduction in order to reduce the large-scale finite element model into an acceptable reduced-complexity model. This method guarantees the effective selection of all the significant frequencies in the control design sense. In the design of a robust control, both the performance specification and the model uncertainties are taken into consideration. To demonstrate the effectiveness of the proposed procedure a finite element structure of a bus model with 3444 degrees-of-freedom is applied. The active suspension system designed is tested with the original non-linear finite element model.

Crashworthiness Evaluation Using Integrated Vehicle and Occupant Finite Element Models

Recent development in computer hardware technology and software advancement has made it possible to develop large and detailed finite element models, which include vehicle structures, interior, seats, airbags, and hybrid-III dummies, for crashworthiness evaluation. This paper presents some recent effort of developing an approach for crashworthiness using integrated vehicle structural, interior, occupant, and airbag finite element models. A case study using integrated finite element models of vehicle structure and interior, airbag, seats, and hybrid-III dummy is discussed to demonstrate the potential benefit of the integrated simulation and analysis approach. This new integrated approach will further improve the engineering practice with cost saving in engineering resources and producing more accurate and consistent analysis results.

The frontal impact response of a spaceframe chassis sportscar

The frontal impact behaviour of a low volume, niche market sportscar with a spaceframe chassis has been investigated using the non-linear finite element code Oasys LS-DYNA3D. In considering the options for crashworthiness improvements, it was first essential to understand and have confidence in the overall structural response that was being predicted. An experimental test programme has supported the finite element predictions and has included the impact testing of typical brazed tubular structures and an automotive wheel and tyre. Results from a 23 000 finite element vehicle model correlate well with the digitized results of a crash test video.

Development of a Detailed Vehicle Finite Element Model Part I: Methodology

on September 29, 1993, President Clinton and the Chief Executive Officers of the major domestic automakers (Chrysler Corporation, Ford Motor Company, and General Motors Corporation) announced the formation of the Partnership for a New Generation of Vehicles (PNGV). The long-term goal of PNGV is to develop vehicles that will deliver up to three times today's fuel efficiency (80 miles per gallon or BTU equivalent) and cost no more to own and operate than today's comparable vehicles. At the same time, this new generation of vehicles should maintain the size, utility and performance standards of today's vehicles (i.e., the 1994 Chrysler Concorde, Ford Taurus, and Chevrolet Lumina) and meet all mandated safety and emission requirements [1,2]. As part of the PNGV program, The National Highway Traffic Safety Administration (NHTSA) intends on developing a vehicle finite element model representing each vehicle class and size. These FE models will be used in compatibility studies to ensure that PNGV vehicles meet safety standards and that crashworthiness and crash avoidance attributes are not compromised by their lightweight and use of advanced materials. A detailed finite element model of a 1996 Plymouth Neon was developed at the FHWA/NHTSA National Crash Analysis Center as part of the PNGV program. The Neon represents the sub-compact vehicle class. The three dimensional geometric data of each component was obtained by using a passive digitising arm. The geometric data was imported into a preprocessor for mesh generation, parts connection, and material properties. Tensile testing was conducted on specimen to obtain the material properties of the various sheet metal components. Sheet metal thickness was obtained by using an ultrasonic thickness measurement gauge. The non-linear explicit finite element code LS-DYNA, was used to perform the various simulations. This paper will conclude on the following issues; describing and efficient methodology for reverse engineering vehicles; importance of maintaining geometric accuracy; issues concerning material characterization; significance and necessity of component wise testing.

Development of a Detailed Vehicle Finite Element Model Part II: Material Characterization and Component Testing

A detailed multi-purpose finite element model of a 1996 Plymouth Neon was developed at the FHWA/NHTSA National Crash Analysis Center. The model was developed to address vehicle safety issues, including front, side and rear performances. In part I of this paper, the methodology used in the development of the Neon model was presented. Issues concerning material characterization and the necessity of component wise testing were discussed. This paper will focus on material and component testing and validation. Conclusions will be made on the effect of material characterization to the overall model behaviour. Results of the component tests will be presented. Simulations, using LS-DYNA, of the body-in-white model will be performed. Visual validation of the body-in-white frontal impact will be conducted to evaluate the accuracy and validity of the model.

A Finite Element Tire Model and Vibration Analysis: A New Approach

Abstract A complete finite element tire model was developed for the purposes of vehicle dynamics analyses and full vehicle finite element model real time proving ground simulations. The tire model was validated through simulations of some of the very important global, static and dynamic mechanical properties such as the tire radial and lateral stiffnesses, free-drop test, and low-speed rolling cornering stiffness. The three-dimensional free vibration and harmonic/randomly forced vibrations with ground contact of the tire model were studied here. One of the main purposes for the present study is to provide a new approach toward tire and vehicle NVH studies. All the analyses were nonconventional in the sense that, instead of NASTRAN-type modal analysis, the explicit nonlinear dynamic finite element code LS/DYNA3D was used to conduct all the analyses in the time domain, and the vibration modes were decomposed via fast fourier transformation.