FMVSS 214 Dynamic NPRM - An Overview of the New Procedure, Component-Level Development Tests, and Vehicle Design Changes

2005 ◽  
Author(s):  
David Winkelbauer ◽  
P. Michael Miller ◽  
Helen A. Kaleto ◽  
Jessica Gall ◽  
Shefalika Naik ◽  
...  
Keyword(s):  
Vehicle Design ◽  
Component Level ◽  
Design Changes

A Method of Utilizing Digital Manikins to Assist Passenger Vehicle Design

2017 ◽  
Author(s):  
Jian Wan ◽  
Nanxin Wang ◽  
Ksenia Kozak ◽  
Gianna Gomez-levi ◽  
Linas Mikulionis
Keyword(s):  
Human Body ◽  
Human Subjects ◽  
Video Gaming ◽  
Vehicle Design ◽  
Future Design ◽  
Design Changes ◽  
Swept Volumes ◽  
Numerical Rating ◽  
Space Limit ◽  
Swept Volume

Most occupant accommodation assessments of a new vehicle design currently still utilize human appraisal. That is, human subjects experience the new design physically and provide feedback including a numerical rating or verbatim description. There are two drawbacks with this type of assessment: 1) the outcome is subjective. They are likely affected by other factors such as the vehicle’s appearance or brand and the individual’s own bias; 2) the outcome may not be able to reveal where the issues are nor how to resolve them. The digital manikin technology has been widely used in different areas: starting from movie and video gaming industries, and getting more and more involved in the product life circle of manufacture industries. Human motions are captured, and the digital manikin is utilized to present these motions virtually. This paper introduces a method that uses digital manikins to assist the process of vehicle design. Subjects’ motions interacting with a vehicle, which are related to a new design change, are captured. These motions are used to drive digital manikins that represent their respective subjects in size and body shape. A software system that animates the digital manikin according to the motions and creates swept volumes of selected body segments was created. The collection of the swept volumes of all subjects represents the space that is occupied by the human body during the motion. This space can be used to assess the design changes by indicating the minimum clearance between the swept volume and vehicle components or the interference between the human body with the components. In addition, the space described by the swept volumes provides a guideline or space limit for any future design changes. This method is objective. It not only pin-points the locations that cause discomfort or inconvenience by the new design, but also provides quantitative suggestions on how much improvement is needed for a better design.

Review: CFD Applications in the Automotive Industry

1996 ◽  
Vol 118 (4) ◽  
pp. 647-653 ◽  
Author(s):  
M. N. Dhaubhadel
Keyword(s):  
Automotive Industry ◽  
Cycle Time ◽  
Computer Hardware ◽  
System Level ◽  
Design Environment ◽  
Component Level ◽  
Automotive Design ◽  
Design Changes ◽  
Wide Range ◽  
Cfd Applications

A general review of Computational Fluid Dynamics (CFD) applications in the automotive industry is presented. CFD has come a long way in influencing the design of automotive components due to continuing advances in computer hardware and software as well as advances in the numerical techniques to solve the equations of fluid flow. The automotive industry’s interest in CFD applications stems from its ability to improve automotive design and to reduce product cost and cycle time. We are able to utilize CFD more and more in day-to-day automotive design, and we can expect better conditions for CFD applications in the coming years. CFD applications in the automotive industry are as numerous as are the codes available for the purpose. Applications range from system level (e.g., exterior aerodynamics) to component level (e.g., disk brake cooling). The physics involved cover a wide range of flow regimes (i.e., incompressible, compressible, laminar, turbulent, unsteady, steady, subsonic and transonic flows). Most of the applications fall in the incompressible range and most are turbulent flows. Although most of the flows encountered are unsteady in nature, a majority of them can be approximated as steady cases. The challenge today is to be able to simulate accurately some very complex thermo-fluids phenomena, and to be able to get CFD results fast, in order to effectively apply them in the “dynamic” design environment of frequent design changes. The key is to utilize CFD in the early design phases so that design changes and fix-ups later are minimized. Proper use of CFD early, helps to significantly reduce prototyping needs and consequently, reduce cost and cycle time.

An Example Performance Trade-Off Evaluation Using the Integration Framework for Architecture Development (IFAD) for Conceptual Vehicle Design

2005 ◽  
Author(s):  
Xiaoyu Gu ◽  
Peter A. Fenyes
Keyword(s):  
Genetic Algorithm ◽  
Vehicle Design ◽  
Vehicle Performance ◽  
Integration Framework ◽  
Trade Offs ◽  
Design Variables ◽  
Design Changes ◽  
High Level ◽  
Architecture Development ◽  
Geometrical Dimensions

The Integration Framework for Architecture Development (IFAD) is an integrated framework that provides fast and consistent discipline analysis results and identifies discipline consequences corresponding to vehicle design changes. This information is valuable for balancing and integration in the early design phase. In this paper, the IFAD framework is utilized to conduct an example multi-objective multi-disciplinary optimization to evaluate vehicle performance trade-offs for a hypothetical vehicle. We consider design changes on high-level geometrical dimensions including front overhang, rear overhang and vehicle width at rocker. We also study vehicle configurations including choice of materials and tires and choice of powertrains. A commonly used multi-objective genetic algorithm (MOGA) technique, Non-dominated Sorting Genetic Algorithm (NSGAII [1]) is chosen because of the mixed types of design variables involved (i.e., continuous design variables representing high-level geometrical dimensions and discrete design variables representing vehicle configurations such as powertrain selection and material choice). Vehicle performance analyses in a range of disciplines such as geometry, aerodynamics and energy are carried out automatically through IFAD. The use of response surface modeling (RSM) is desired due to the large number of evaluations typical for a MOGA application. A comparison of the engineering performance trade-offs based on two different sets of performance objectives is presented.

Management of Sampling Uncertainty Using Conservative Estimate of Probability in Bayesian Network

2017 ◽  
Author(s):  
Sangjune Bae ◽  
Nam H. Kim ◽  
Seung-gyo Jang
Keyword(s):  
Sensitivity Analysis ◽  
Bayesian Network ◽  
Global Sensitivity Analysis ◽  
Epistemic Uncertainty ◽  
Probability Of Failure ◽  
System Level ◽  
Conservative Estimate ◽  
Component Level ◽  
Global Sensitivity ◽  
Design Changes

Since the safety of a system is often assessed by the probability of failure, it is crucial to calculate the probability accurately in order to achieve the target safety. Despite such importance, calculating the precise probability is not a trivial task due to the inherent aleatory variability and epistemic uncertainty. Therefore the safety is assessed by a conservative estimate of the probability rather than using a single value of the probability. In general, there are two ways to achieve the target probability: Shifting the probability or reducing the uncertainty. In this paper, among various sources of epistemic uncertainty, the uncertainty quantification error from sampling is considered to calculate the conservative estimate of a system probability of failure. To quantify and shape the epistemic uncertainty, Bayesian network is utilized for constituting the relationship between the system probability and component probabilities, while global sensitivity analysis is employed to connect the variance in the probabilities in system level with that in the component level. Based on this, local sensitivity of the conservative estimate with respect to a design change in a component is derived and approximated for a simple numerical calculation using Bayesian network and global sensitivity analysis. This is to show how a design can meet the probabilistic criteria considering propagated uncertainty when the design changes.

Evaluation of Risk Reduction From Tank Car Design and Operations Improvements: An Extended Study

2016 ◽  
Author(s):  
Francisco Gonzalez ◽  
Anand Prabhakaran ◽  
Graydon F. Booth ◽  
Florentina M. Gantoi
Keyword(s):  
Crude Oil ◽  
Mitigation Strategies ◽  
Impact Loads ◽  
Probabilistic Framework ◽  
Operating Environment ◽  
Component Level ◽  
Extended Study ◽  
Train Derailment ◽  
Design Changes ◽  
Objective Methodology

Critical derailment incidents associated with crude oil and ethanol transport have led to a renewed focus on improving the performance of tank cars against the potential for puncture under derailment conditions. Proposed strategies for improving puncture performance have included design changes to tank cars as well as operational considerations, such as reduced speeds and upgraded brake systems. In a prior paper on this topic, the authors conceptualized a novel and objective methodology for quantifying and characterizing the reductions in risk that result from changes to tank car design or to the tank car operating environment. This paper describes an extension of that effort to include additional derailment cases, additional operating speeds, considerations for alternate train configurations, such as Distributed Power (DP) and Electrically Controlled Pneumatic (ECP) brakes, as well as options for component level studies. In essence, the developed methodology considers key elements that are relevant to tank car derailment performance and combines these elements into a consistent probabilistic framework to estimate the relative merit of proposed mitigation strategies. The relevant elements considered include variations in the derailment scenarios, chaotic derailment dynamics, the distribution of impact loads and impactor sizes, various operating speeds, brake system differences, and variations in tank car design. The paper also provides an overview of the validation efforts which suggest that the gross dynamics of a tank car train derailment, and the resulting puncture performance of the tank cars, are captured well by this methodology.

Parallel Computing for Tire Simulations

2011 ◽  
Vol 39 (3) ◽  
pp. 193-209 ◽  
Author(s):  
H. Surendranath ◽  
M. Dunbar
Keyword(s):  
High Performance ◽  
Effective Means ◽  
Cost Effective ◽  
Turnaround Time ◽  
Careful Consideration ◽  
Rolling Contact ◽  
Element Analysis ◽  
Parallel Solvers ◽  
Design Changes ◽  
Highly Nonlinear

Abstract Over the last few decades, finite element analysis has become an integral part of the overall tire design process. Engineers need to perform a number of different simulations to evaluate new designs and study the effect of proposed design changes. However, tires pose formidable simulation challenges due to the presence of highly nonlinear rubber compounds, embedded reinforcements, complex tread geometries, rolling contact, and large deformations. Accurate simulation requires careful consideration of these factors, resulting in the extensive turnaround time, often times prolonging the design cycle. Therefore, it is extremely critical to explore means to reduce the turnaround time while producing reliable results. Compute clusters have recently become a cost effective means to perform high performance computing (HPC). Distributed memory parallel solvers designed to take advantage of compute clusters have become increasingly popular. In this paper, we examine the use of HPC for various tire simulations and demonstrate how it can significantly reduce simulation turnaround time. Abaqus/Standard is used for routine tire simulations like footprint and steady state rolling. Abaqus/Explicit is used for transient rolling and hydroplaning simulations. The run times and scaling data corresponding to models of various sizes and complexity are presented.

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