Cing-Dao Kan

Crashworthiness Evaluation Using Integrated Vehicle and Occupant Finite Element Models

Abstract 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.

Development and validation of a vehicle suspension finite element model for use in crash simulations

Abstract Finite element models, based on a Chevrolet C2500 pickup truck vehicle, were developed at the FHWA/NHTSA National Crash Analysis Center (NCAC). These models have been used by several transportation safety researchers to analyze vehicle safety issues as well as to evaluate and improve roadside hardware. Over the past few years, modifications and more details have been incorporated in the models to add capabilities of these models to be used in different impact scenarios. In this study, a detailed suspension model has been added to the C2500 pickup truck model. Pendulum tests have been conducted at The Federal Highway (FHWA) Federal Outdoor Impact Laboratory (FOIL) and used in the validation of the suspension model. The focus in this study was on the rear suspension system of the vehicle. Simulations were conducted and the results are compared to the pendulum tests in terms of deformation, displacement and acceleration at various locations. To ensure the accuracy of the newly upgraded vehicle model, previously conducted full-scale crash tests were simulated and the results from these simulations were analyzed and compared to the tests.

EVALUATION OF CAR-TO-CAR FRONTAL OFFSET IMPACT FINITE ELEMENT MODELS USING FULL SCALE CRASH DATA

This paper describes the results of a study conducted to evaluate the performance and accuracy of a medium size sedan finite element model (FEM) for off-set car-to-car impacts. This model was originally developed for front impact. The model does not include side structure compliance. Two tests conducted by the National Highway Traffic Safety Administration (NHTSA) are used for evaluation of the simulations. The overall results indicate that the simulations appear to be consistent with the crash test data. Problems associated with the use of node constraints, lack of side structure model fidelity, and the different integration time marching are identified. Solutions for the problems are proposed. (A) For the covering abstract of the conference see IRRD 875833.

Determination of the Ballistic Performance of a Cold-Rolled, Deep-Drawing Sheet Metal

Cold-rolled deep drawing sheet metals are very widely used for building vehicles since they are easy to obtain from the market, can provide necessary strength with a reasonable weight/cost ratio and are also very easy to be manufactured. These materials also can provide enough protection against threat under ballistic speeds. In this study, the ballistic performances of deep drawing sheet metal specs that have a thickness of 1 mm are investigated. The sheet metal specs that are used as targets have a trade mark of 7132, which is known as H320 LA or DIN EN 10268 - 99 for cold forming. The bullets that are used during the ballistic experiments belong to 9x19 mm Parabellum cartridges and contain different amounts of gunpowder. For the perpendicularly impacting bullets, the speed of the impact and also, the speed of the bullets after penetration are measured by a digital bullet speed measurement device set-up, which is specially designed and manufactured for this particular study. While determining the deformation pattern of the targets, diameter of the front face deformation, crater depth and diameter of the hole for the penetration case are defined and depending on the impact speed of the bullet, changes in these quantities are investigated. A finite element model of the ballistic impact scenarios for different impact speeds are also modeled and simulated by using a non-linear explicit finite element code (LS- DYNA). The numerical results are also in good agreement with the experimental values.