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Technical Paper

Compliance Criteria for Side Facing Aircraft Seats

1999-04-20
1999-01-1598
A series of side facing seat impact sled tests were conducted using the SID, EuroSID-1 and BioSID side impact Anthropomorphic Test Dummies (ATDs) at the FAA Civil Aeromedical Institute (CAMI). The tests were performed on a side facing sofa fixture with a rigid bulkhead adjacent to the forward end of the seat. The purpose of the research project was to examine the methods utilized by the automobile industry to assess thoracic injuries due to side impact accidents, and to investigate the potential applicability of these methods for side facing seats and sofas in civil aircraft. Tests were conducted with single and double occupants. The test conditions complied with the 16g 44 f/s horizontal impact specified in 14 CFR 25.562. Various side impact injury criteria were evaluated in the tests, including the Thoracic Trauma Index (TTI), Viscous Criteria (VC), rib deflection and pelvis acceleration.
Technical Paper

Analysis of Vehicle Response Data Measured During Severe Maneuvers

2000-05-15
2000-01-1644
During the past few years, the National Highway Traffic Safety Administration's (NHTSA) Vehicle Research and Test Center has generated a plethora of reliable vehicle test data during their efforts to study vehicle rollover propensity. This paper provides further analyses of a small selection of some of the data. The analyses provided here derive in part from the previous work, trying to answer some of the questions spawned by earlier analyses. The purpose of this paper is to introduce several new concepts to the study of vehicle roll stability and provide case studies using the results available from the NHTSA testing. Results from several severe maneuvers are studied in detail to gain understanding of vehicle response in these cases.
Technical Paper

Friction Induced Rollover from Lift-Off to Launch

2000-05-01
2000-01-1649
A friction induced rollover event generally comprises successive stages of control loss, lift-off, transition from lift-off to launch, and roll to rest. This transition is, of course, not instantaneous due to vehicle inertia. It is analyzed by numerical integration of the equations of motion to determine roll angle and time to launch, plus roll velocity at launch, as well as intermediate values of roll angle, roll velocity and surface force versus time. Representative curves and launch values are presented. The time to launch, which is several times greater than typical vehicle collision contact time, is seen to be dependent on the magnitude of surface friction; while roll angle from over-center at launch and roll velocity at launch do not vary substantially with changes in vehicle and surface conditions. It is also seen that the surface force initially rises above static weight, producing lateral force greater than the friction coefficient times vehicle weight as rotation progresses.
Technical Paper

A Study in Rollover Prevention Using Anti-Rollover Braking

2000-05-01
2000-01-1642
A single vehicle on-road rollover accident of a small van is used to examine the effectiveness of the Anti-Rollover Braking System (ARB). The circumstances of the accident are reviewed, and how the accident was modeled using ADAMS. ARB is then added to the vehicle model to examine what would happen if ARB had been on the vehicle. Two cases are examined. One case uses the same steering as in the accident, and one case uses the same path as the accident. In both of these cases, ARB would have prevented the vehicle from rolling over.
Technical Paper

Review of Parameters Affecting Stability of Partially Filled Heavy-Duty Tankers

1999-11-15
1999-01-3709
Partially filled tanker trucks are susceptible to rollover instabilities due to fluid sloshing. Due to the catastrophic nature of accidents involving the rollover of tanker trucks, several investigations have been conducted on the parameters affecting stability of partially filled heavy-duty tankers. Since stability of heavy-duty tankers undergoing on-road maneuvers such as braking, and/or lane changing has been an issue that concerned many researchers for a long time, a literature review has been conducted which underlines the most important contributions in this field. This review covers work done in the field of fluid-structure interaction, yaw and roll stability of heavy-vehicles, and fluid-vehicle dynamic interaction. In addition, vehicle stability issues are addressed such as jack-knifing, side slipping, vehicle geometry and container geometry among others.
Technical Paper

Optimal Tank Geometry to Enhance Static Roll Stability of Partially Filled Tank Vehicles

1999-11-15
1999-01-3730
A generic tank cross-section is formulated to describe the geometry of currently used tanks in transportation of fuel oils and bulk liquids, and to explore optimal tank geometry for enhancement of roll stability limit of tank vehicle combinations. The tank periphery, composed of 8 circular arcs symmetric about the vertical axis, allows more design flexibility in view of the roll stability limits than the conventional tank shapes. A shape optimization problem is formulated to minimize the overturning moment imposed on the vehicle due to c.g. height of the liquid load, and the lateral and vertical movement of the liquid bulk within the partly filled tank. Different optimal tank cross-sections are proposed corresponding to varying fill conditions, while the total cross-sectional area, overall height and overall width are constrained to specified values.
Technical Paper

Proposal for a New Frontal Crash Test Procedure to Meet Self Protection and Compatibility Needs

2000-03-06
2000-01-1373
Compatibility between cars is a major issue worldwide. In Europe several groups are dealing with it: BRITE EURAM, which involves the majority of European manufacturers, and EEVC WG15, involving several European test laboratories and institutes, are the most active in Europe at the moment. In the past also ADAC developed a similar study in Germany. In US NHTSA is conducting studies, mainly related to the particular American market, where pick-ups represent the most important cause of incompatibility. Several approaches and test procedures are proposed to assess compatibility which consider tests against fixed obstacles, like offset deformable barriers and full width barrier (to measure energy absorption and stiffness of the front end and its distribution) and overload tests (to measure resistance capability of the compartment).
Technical Paper

Modeling of Occupant Impacts During Rollover Collisions

2000-03-06
2000-01-0854
This paper describes a modeling method whereby the occupant impacts during rollover collisions may be predicted with sufficient accuracy to predict their injury level. By using MADYMO to reconstruct the vehicle motions during a rollover collision and the subsequent vehicle accelerations, the model may also be used to calculate occupant impact accelerations if reasonable estimates of interior surface stiffnesses are used.
Technical Paper

Accident Reconstruction of Rollovers - A Methodology

2000-03-06
2000-01-0853
There is little debate that reconstructing a rollover crash presents complex multi-dimensional challenges to the reconstructionist. Real world rollovers often cover large amounts of various terrains and typically involve multiple ground impacts. The possible vehicle orientations throughout the roll are almost unlimited. It is also clear that the complexities of these events have placed practical limitations on the abilities for both analytical and experimental models to accurately recreate specific real world rollover collisions. The fundamentals of accident reconstruction do still apply, however, and much valuable and insightful test data is available. This paper will describe a practical methodology and protocol to assist reconstructionists in reconstructing both on-road and off-road rollover accidents.
Technical Paper

Driver Fatalities in Frontal Crashes of Airbag-Equipped Vehicles: A Review of 1989-96 NASS Cases

2000-03-06
2000-01-1003
Using data from the National Automotive Sampling System/Crashworthiness Data System (NASS/CDS) for1995-96, this study updates previous analyses of driver fatalities in airbag-equipped vehicles in the NASS/CDS database for 1989-93 and 1989-94. A total of 59 cases of frontal crashes of airbag-equipped vehicles with driver fatalities were identified in these 8 years of NASS/CDS data, but in 9 cases the fatalities were not related to the impacts (e.g., fire, medical condition). Vehicle intrusion was the cause of the fatal injuries in 27 cases, and 7drivers died from injuries sustained when they were either partially or totally ejected from their vehicles. There was one case in which the airbag did not deploy, although the crash conditions indicated it should have. One driver died from contact with a nonintruding vehicle surface, and the causes of the fatal injuries in 5 cases were unknown.
Technical Paper

Comparison of Vehicle Structural Integrity and Occupant Injury Potential in Full-frontal and Offset-frontal Crash Tests

2000-03-06
2000-01-0879
The frontal crash standard in the USA specifies that the full front of a vehicle impact a rigid barrier. Subsequently, the European Union developed a frontal crash standard that requires 40 percent of the front of a vehicle to impact a deformable barrier. The present study conducted paired crashes of vehicles using the full-frontal barrier procedure and the 40 percent offset deformable barrier procedure. In part, the study was to examine the feasibility of adding an offset test procedure to the frontal crash standard in the USA. Frontal-offset and full-frontal testing was conducted using both the mid-size (50th percentile male Hybrid III) and the small stature (5th percentile female Hybrid III) dummies. Five vehicle models were used in the testing: Dodge Neon, Toyota Camry, Ford Taurus, Chevrolet Venture and Ford Contour. In the crash tests, all dummies were restrained with the available safety belt systems and frontal air bags.
Technical Paper

Head Injury in Fork Lift Upsets

2000-09-11
2000-01-2547
Phase I, Phase II, Caterpillar, Allis-Chalmers, Clark, Hyster, Toyota, and Entwistle fork lift upset studies have been conducted with Hybrid II dummies, Side Impact Dummies, and stunt men. The investigations concluded that the dummy lacks the ability to brace itself, hold on, and does not have adequate biofidelity to represent the human in a fork lift upset. Crushing injuries and death typically occur when the operator is thrown or jumps from the overturning forklift and is pinned by the overhead guard or canopy. The dummy studies demonstrated a wide range of Head Injury Criteria (HIC) values that were not reproducible. Furthermore, other injury producing variables such as angular acceleration, angular velocity or induced brain stress were not investigated. The injury level of 1000 for the HIC for the mid-sized male, small female, and 6 year-old has been recommended by the National Highway Transportation Safety Administration (NHTSA).
Technical Paper

Anthropometry for WorldSID A World-Harmonized Midsize Male Side Impact Crash Dummy

2000-06-19
2000-01-2202
The WorldSID project is a global effort to design a new generation side impact crash test dummy under the direction of the International Organization for Standardization (ISO). The first WorldSID crash dummy will represent a world-harmonized mid-size adult male. This paper discusses the research and rationale undertaken to define the anthropometry of a world standard midsize male in the typical automotive seated posture. Various anthropometry databases are compared region by region and in terms of the key dimensions needed for crash dummy design. The Anthropometry for Motor Vehicle Occupants (AMVO) dataset, as established by the University of Michigan Transportation Research Institute (UMTRI), is selected as the basis for the WorldSID mid-size male, updated to include revisions to the pelvis bone location. The proposed mass of the dummy is 77.3kg with full arms. The rationale for the selected mass is discussed. The joint location and surface landmark database is appended to this paper.
Technical Paper

A SYSTEMS MODELING METHODOLOGY FOR ESTIMATION OF HARM IN THE AUTOMOTIVE CRASH ENVIRONMENT

2001-06-04
2001-06-0238
A systems modeling approach is presented for assessment of harm in the automotive crash environment. The recent surge in light truck sales has highlighted the need to evaluate these vehicles’ aggressivity in two-vehicle crashes while also considering potential self protection benefits in single-vehicle crashes. The methodology consists of parametric simulation of several controlled accident variables, with case results weighted by the relative frequency of each specific event. A hierarchy of models is proposed, consisting of a statistical model to define the crash environment and assign weighting factors for each crash situation case, and vehicle models for parametric simulation of crash events. Approximating functions are utilized to estimate occupant harm metrics based on vehicle crash response. Head and chest injury results for each case are converted to harm vectors, in terms of probabilistic Abbreviated Injury Scale (AIS) distributions.
Technical Paper

STUDY ON CAR-TO-CAR SIDE IMPACT

2001-06-04
2001-06-0236
This paper studies the factors which affect the occupant injuries in Car-to-Car side impacts using CAE simulation. The parameters of CAE simulation were derived from US-SINCAP(Side Impact New Car Assessment Program) test conditions and the field accident statistical data of NASS(National Automobile Sampling System). The parameters varied in the CAE simulation were as follows: 1) Striking vehicle curb weight 2) Collision speed 3) Ground clearance 4) Front profile 5) Vehicle width And the comparing factors are Thorax injury severity (Thorax Trauma Index, TTI)and Pelvis injury severity (PELVIC G) as occupant protection of driver or passenger in the front seat position. These studies make it possible to analyze directions for compatibility studies on side impacts including SUV (Sports Utility Vehicles), and these results are introduced herein.
Technical Paper

A tibial mid-shaft injury mechanism in frontal automotive crashes

2001-06-04
2001-06-0241
Lower extremity injuries in frontal automotive crashes usually occur with footwell intrusion where both the knee and foot are constrained. In order to identify factors associated with tibial shaft injury, a series of numerical simulations were conducted using a finite element model of the whole human body. These simulations demonstrated that tibial mid-shaft injuries in frontal crashes could be caused by an abrupt change in velocity and a high rate of footwell intrusion.
Technical Paper

VEHICLE DEFORMATION IN REAL-WORLD SIDE IMPACT CRASHES AND REGULATORY CRASH TESTS

2001-06-04
2001-06-0248
Side impact crashes with fatal or serious injuries were selected from the National Automotive Sampling System/Crashworthiness Data System files. Deformation patterns for the sample of crashes were compared with the damage seen in regulatory tests. In particular, the rate of involvement of the sill and pillar structures was considered. The study suggests these structures are less involved in real crashes than in the current regulatory Federal Motor Vehicle Safety Standard 214 test. Suggestions for altering the test conditions are made.
Technical Paper

VEHICLE COMPATIBILITY IN CAR -TO-CAR FRONTAL OFFSET CRASH

2001-06-04
2001-06-0247
A series of full-scaled car-to-car frontal offset crash tests within passenger car category were conducted to research the current incompatible situations using Hyundai Autonomous Crash Vehicle System. The first test using two midsize cars with 50% overlap and 50km/h each was conducted to compare the injury levels and deformations with the offset regulation case, and check the test results within two same vehicles for test repeatability. The second test using midsize and minisize car with mass ratio of 1.58 :1 was done. The last test with MPV and small car at closing speeds of 120kph was followed. Mass, stiffness and geometry effects are investigated. Simulation results of car-to-car frontal offset and side impacts in case of MPV-to-small and small-to-MPV are included for better understanding. Finally a few design recommendations are also suggested.
Technical Paper

Virtual testing driven development process for side impact safety

2001-06-04
2001-06-0251
A new simulation tool was established and approved by TRW as part of the continuous improvement of the development process. This tool allows the OEM and the system supplier to keep high quality even with further reduced development times. The introduction of the tool in a side air-bag development program makes it possible to ensure high development confidence with a reduced number of vehicle crash tests and late availability of interior component parts.
Technical Paper

Full Vehicle Frontal Crash and Rollover Simulation Using Ls-Dyna3D and Experimental Validation

2001-01-10
2001-26-0033
Knowing the human suffering and financial burden on the society due to vehicle accidents and legal requirements, it becomes necessary to study the crashworthiness of the vehicle. The experimental methods used for the crashworthiness analysis are very expensive and time consuming, also these methods are not feasible to study the different design alternatives at the developmental phase of the vehicle structure. In this aspect explicit finite element method plays an important role in the non-linear analysis of crashworthiness of vehicle. The present paper describes the frontal barrier impact of a full vehicle finite element model using a nonlinear finite element code LS-DYNA3D. These FE results were compared with the experimental results and comparable patterns of deformations were observed. An approximate finite element model is used to simulate a vehicle rollover. The main purpose of this simulation is to develop a methodology for rollover simulation.
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