Refine Your Search

Topic

Author

Affiliation

Search Results

Technical Paper

Analysis of Road Traffic Accidents on NH 45 (Kanchipuram District)

2009-12-13
2009-28-0056
With the support and cooperation of the Kanchipuram district police and Tamil Nadu police, researchers conducted detailed investigations of accidents occurring on the National Highway 45 over a 60 km stretch. The primary objective was to collect and analyze India-based traffic crash data to begin to create a sound basis for decision making for improving safety on India's roadways. A secondary objective was to establish a standardized methodology using economical tools for collecting and analyzing crash data, specific to Indian roads. For the 45 day study period, an accident intimation network was established between researchers and all police stations/highway patrols in the study area. On occurrence of an accident, police called a 24-hour contact number and researchers responded to the scene. On site, researchers used standardized reporting forms, methodologies, and equipment to perform accident scene examinations, accident vehicle examination, and AIS injury coding.
Technical Paper

Research and Development on the Modular Dummy Model

2009-01-21
2009-26-0056
The modular dummy model is a new concept to represent a crash dummy in computer simulation. The modular dummy model could be a solution with combination of acceptable responses and quick run times. The approach of the modular dummy model is to take an existing standard model and create rigid modules of all major dummy components (Head, Thorax, Pelvis, Femurs, Tibias, Feet, etc.), which are fully interchangeable between deformable and rigid modules. The special run time efficient component models for the neck and lumbar spine are also developed for the modular dummy. Mass and inertial properties of each rigid module are derived from the corresponding deformable part. The joint and connection definitions are shared between the rigid and deformable modules. The users only need to decide and select which modules should be used in order to achieve the best compromise between CPU time and accuracy for the specific application.
Technical Paper

Material Model Development of an Energy Absorbing Foam for Occupant Safety

2009-01-21
2009-26-0088
Different Original Equipment Manufacturers (OEMs) use different Finite Element (FE) codes to perform crash analyses. Primary explicit codes widely used are LS-DYNA, PAM-CRASH and RADIOSS. These codes help rapid evaluation of vehicle design in the preliminary phase, eliminating the need for cumbersome design changes post-physical validation trials. This is more so critical for crash and safety aspects of design. A variety of Energy Absorbing (EA) foams are offered to OEMs to meet the EA performance requirements. Also the FE codes offer a variety of standard material models to the analyst to choose from. The choice of material model is governed by factors such as type of foam under consideration, simplicity of modeling, available material test data, performance objectives, etc. The development of a validated material model is hence a complex task. This paper deals with development and validation of material models of IMPAXX for the FE codes RADIOSS and PAM-CRASH.
Technical Paper

Accident Data Collection Methodology for Building a Traffic Accident Database for Tamil Nadu (India)

2009-01-21
2009-26-0008
India is facing the challenge of reducing road accident fatalities, which claim close to 100,000 lives every year. Road infrastructure is slowly improving, but the number of vehicles on the road is rising fast and so is the number of road accidents, which continue to increase year after year. The data collected by law enforcement agencies is not detailed enough to identify causes and develop solutions. Traffic accidents need to be investigated in detail to include specifics concerning crash location, vehicle damage and injuries sustained by road users. The development of such a detailed database requires the co-operation of a number of government and private organizations associated with road traffic collisions. The foundation for data collection activities is a road traffic accident notification network that enables access to accident details, crashed vehicles, and injury reports in a timely manner.
Journal Article

Pressure Based Sensing Approach for Front Impacts

2011-04-12
2011-01-1443
This study demonstrates the use of pressure sensing technology to predict the crash severity of frontal impacts. It presents an investigation of the pressure change in the front structural elements (bumper, crush cans, rails) during crash events. A series of subsystem tests were conducted in the laboratory that represent a typical frontal crash development series and provided empirical data to support the analysis of the concept. The pressure signal energy at different sensor mounting locations was studied and design concepts were developed for amplifying the pressure signal. In addition, a pressure signal processing methodology was developed that relies on the analysis of the air flow behavior by normalizing and integrating the pressure changes. The processed signal from the pressure sensor is combined with the restraint control module (RCM) signals to define the crash severity, discriminate between the frontal crash modes and deploy the required restraint devices.
Journal Article

Study on Characteristics of Event Data Recorders in Japan; Analysis of J-NCAP and Thirteen Crash Tests

2011-04-12
2011-01-0810
Event Data Recorder (EDR) is a device to record vehicle and occupant information for a brief period of time before, during and after a crash event. EDR is one of the promising devices for accident reconstruction by recording important information e.g. vehicle speed, engine speed, brake switch, throttle and delta-V. However, in order to use EDR for an accident investigation, reliability and accuracy of those EDR data must be examined firstly. The aim of this study is to evaluate the characteristics of EDR and to understand the performance of EDR for the improvement of accident reconstruction with more reliable and accurate information on an accident in Japan. The analysis is based on J-NCAP crash tests from 2006 to 2009 with corresponding EDR datasets. Full-overlap frontal collision test and offset frontal collision test of fourteen car models were analyzed.
Technical Paper

Appling CAE to Understand the Causality of Dummy Neck Injury Readings

2011-04-12
2011-01-1069
The progress of computer technology and CAE methodology makes it possible to simulate dummy injury readings in vehicle crash simulations. Dummy neck injuries are generally more difficult to simulate than injuries to other regions such as the head or chest. Accordingly, improving the accuracy of dummy neck injury data is a major concern in frontal occupant safety simulations. This paper describes the use of an advanced airbag modeling methodology to improve the accuracy of dummy neck injury readings. First, the following items incorporated in the advanced airbag model are explained. (1) The Finite Point Method (FPM) is used to simulate the flow of gas. (2) A folding model is applied to simulate the folded condition. (3) The fabric material properties used in the simulation take into account anisotropy in the fiber directions and the nonlinear, hysteresis characteristics of stiffness.
Journal Article

Evaluating Impact Attenuator Performance for a Formula SAE Vehicle

2011-04-12
2011-01-1106
Formula SAE® is one of several student design competitions organized by SAE International. In the Formula SAE events undergraduate and graduate students are required to conceive, design, fabricate and compete with a small, formula-style, race car. Formula SAE safety rules dictate a 7 m/s (or approximately 15.65 mph) frontal crash test for nose-mounted impact attenuators. These rules are outlined in section B3.21 of the Formula SAE rule book. Development and testing methods of these energy-absorbing devices have varied widely among teams. This paper uses real-world crash sled results to research methods for predicting the performance of aluminum honeycomb impact attenuators that will comply with the Formula SAE standards. However, the resulting models used to predict attenuator performance may also have a variety of useful applications outside of Formula SAE. In this paper, various energy absorbers were mounted to a free rolling trolley sitting on top of a crash sled.
Technical Paper

Rollover Crash Test Results: Steer-Induced Rollovers

2011-04-12
2011-01-1114
A series of rollover tests was conducted in a real-world environment in which a vehicle was driven or towed to highway speed then steered to induce a rollover. This research presents analysis of the rollover phase of five tests. In each test, the steering maneuver was initiated on-pavement, and the rollover was caused by tire-to-ground interaction. Tests included vehicles that tripped both on-pavement and on soil. Four tests ended with the vehicle at rest off-road, and one ended with the vehicle remaining on the pavement. A programmable remote control radio was used to steer the vehicles through a double-step steer maneuver to result in a rollover. The test vehicles were instrumented and data was collected during each test, including steering, suspension motion, rotational rates, and accelerations. A Global Positioning System (GPS) speed sensor (VBOX III manufactured by Racelogic) was used to monitor the vehicle speed. Data from all tests is presented in the Appendix .
Technical Paper

Comprehensive Computational Rollover Sensitivity Study Part 2: Influence of Vehicle, Crash, and Occupant Parameters on Head, Neck, and Thorax Response

2011-04-12
2011-01-1115
Fatalities resulting from vehicle rollover events account for over one-third of all U.S. motor vehicle occupant fatalities. While a great deal of research has been directed towards the rollover problem, few studies have attempted to determine the sensitivity of occupant injury risk to variations in the vehicle (roof strength), crash (kinematic conditions at roof-to-ground contact), and occupant (anthropometry, position and posture) parameters that define the conditions of the crash. A two-part computational study was developed to examine the sensitivity of injury risk to changes in these parameters. The first part of this study, the Crash Parameter Sensitivity Study (CPSS), demonstrated the influence of parameters describing the vehicle and the crash on vehicle response using LS-DYNA finite element (FE) simulations.
Journal Article

Design of a Dynamic Rollover Test System

2011-04-12
2011-01-1116
A dynamic rollover test system (DRoTS) capable of simulating rollover crashes in a laboratory was designed for research use at the University of Virginia. The goal of the current study is to describe the system's capabilities and specifications as well as to explore the limitations of the system's ability to simulate rollover crashes. The test apparatus was designed to permit simulation of a single roof-to-ground interaction of a rollover crash with the potential to be modified for evaluation of pre-roof contact occupant motion. Special considerations were made to permit testing of both dummies and post-mortem human surrogates in both production vehicles and a parametric test buck. DRoTS permits vertical translation, pitch, and roll of the test vehicle while constraining longitudinal and lateral translations and yaw. The study details the ranges of test parameters capable with the DRoTS and evaluates the limitations of the system relative to rollover crash conditions.
Technical Paper

Safety Belt and Occupant Factors Influencing Thoracic & Upper Abdominal Injuries in Frontal Crashes

2011-04-12
2011-01-1129
This paper reports on a study that examines the effect of shoulder belt load limiters and pretensioners as well as crash and occupant factors that influence upper torso harm in real-world frontal crashes. Cases from the University of Michigan International Center for Automotive Medicine (ICAM) database were analyzed. Additional information was used from other databases including the National Highway Traffic Safety Administration (NHTSA) New Car Assessment Program (NCAP), the Insurance Institute for Highway Safety (IIHS), the National Automotive Sampling System - Crashworthiness Data System (NASS-CDS), and patient data available from the University of Michigan Trauma Center. The ICAM database is comprised of information from real-world crashes in which occupants were seriously injured and required treatment at a Level 1 Trauma Center.
Technical Paper

Development and Validation of an Occupant Lower Limb Finite Element Model

2011-04-12
2011-01-1128
More than half of occupant lower extremity (LEX) injuries due to automotive frontal crashes are in the knee-thigh-hip (KTH) complex. To design the injury countermeasures for the occupant LEX, first the biomechanical and injury responses of the occupant LEX components during automotive frontal crashes should be known. The objective of this study is to develop a detailed biofidelic occupant LEX Finite Element (FE) model based on the component surfaces reconstructed from the medical image data of a 50th percentile male volunteer in a sitting posture. Both volumetric (unstructured) and structural mesh methods were used to generate the solid elements (mostly hexahedral type) to enhance the model simulation accuracy. The FE model includes the femur, tibia, fibula, patella, cartilage, ligaments, menisci, patella tendon, flesh, muscle, and skin. The constitutive material models and their corresponding parameters were defined based on literature data.
Technical Paper

Three-Dimensional Shape Optimization Through Design of Experiments and Meta Models in Crash Analysis of Automobiles

2013-01-09
2013-26-0032
Crash analysis is an important step in modern day design of vehicles to satisfy the standards laid down by various agencies. In order to satisfy the standards, the designs should adopt energy absorbing members that are efficient and thus optimization becomes important. Modern design practices now provide procedures for this optimization involving shapes. Because each crash analysis takes considerable computer time, Design of Experiments (DOE) methods are used to generate the response surface on which the optimum is searched using approximate or meta models that consume less computational time. This paper describes methods to achieve shape optimization of the identified members which absorb the energy to a maximum possible value.
Technical Paper

Representativeness and Weighting Methods of Real Time Accident Data in India

2013-01-09
2013-26-0022
The 2011 Report of Ministry of Road Transport and Highways, Government of India states that the total accidents with injuries is estimated about 497, 686 out of which the injuries are 511, 394 and fatalities are 142, 485, an average of one fatality per 3.5 [1]. Social losses on account of these crashes are estimated at over Rupees 100 000 Crores annually or 3% of our Gross Domestic Product (GDP) [2]. The irony is that these causalities are rising at 5.9 % annually. India accounts for 10% of the global road crash fatalities. Therefore traffic safety became very important in India. In order to understand the root causes of accidents data is needed in more detail which could be analyzed and points out the major issues to find solutions to stop this trend. Besides vehicle safety, infrastructure related issues and education skills can be derived out of accident data. Official statistics regarding accidents in India are available in national and state wise reports.
Journal Article

Spatial Phase-Shift Digital Shearography for Out-of-Plane Deformation Measurement

2014-04-01
2014-01-0824
Measuring deformation under dynamic loading is still a key problem in the automobile industry. The first spatial phase-shift shearography system for relative deformation measurement is reported. Traditional temporal phase-shift technique-based shearography systems are capable of measuring relative deformation by using a reference object. However, due to its low acquisition rate, the existing temporal phase-shift shearography system can be only used under static loading situations. This paper introduces a digital shearography system which utilizes the spatial phase-shift technique to obtain an extremely high acquisition rate. The newly developed spatial phase-shift shearography system uses a Michelson-Interferometer as the shearing device. A high power laser at 532nm wavelength is used as the light source. A one mega pixels high speed CCD camera is used to record the speckle pattern interference.
Technical Paper

Benefit of Structural Adhesives in Full Car Crash Applications

2014-04-01
2014-01-0811
Abstract Structural adhesives are widely used across the automotive industry for several reasons like scale-up of structural performance and enabling multi-material and lightweight designs. Development engineers know in general about the effects of adding adhesive to a spot-welded structure, but they want to quantify the benefit of adding adhesives on weight reduction or structural performance. A very efficient way is to do that by applying analytical tools. But, in most of the relevant non-linear load cases the classical lightweight theory can only help to get a basic understanding of the mechanics. For more complex load cases like full car crash simulations, the Finite Element Method (FEM) with explicit time integration is being applied to the vehicle development process. In order to understand the benefit of adding adhesives to a body structure upfront, new FEM simulation tools need to be established, which must be predictive and efficient.
Technical Paper

Scalable Multi-Purpose Virtual Human Model for Future Safety Assessment

2014-04-01
2014-01-0534
Abstract The paper concerns the development of a new scalable virtual human body model. The model has been developed to assess safety risk during various complex crash scenarios including impacts from different directions. The novel approach described couples the basic multi-body structure with deformable segments, resulting in short calculation time. Each multi-body structure segment carries the particular surface parts that are linked to the segment with non-linear springs representing the behavior of related soft tissues. The response of particular body segments (head, thorax, pelvis, lower extremities) is validated in known impact scenarios and the response of the model is tuned to the experimental corridors obtained from literature. The tuning process involved the adjustment of both model material and numerical parameters in order to get the correct response for all the tests.
Journal Article

Influences on the Risk of Injury of Bicyclists' Heads and Benefits of Bicycle Helmets in Terms of Injury Avoidance and Reduction of Injury Severity

2014-04-01
2014-01-0517
This study deals with the risk of injury to the bicyclist's head and the benefits of wearing a bicycle helmet in terms of reduction of injury severity or even injury avoidance. The accident data of 4,245 injured bicyclists as a randomized sample, collected by a scientific research team within the GIDAS project (German In-Depth Accident Study) were analyzed. Given that head injuries result in approximately 40% of bicycle-related crashes, helmet usage provides a sensible first-level approach for improving incidence and severity of head injuries. The effectiveness of the bicycle helmet was examined using descriptive and multivariate analysis for 433 bicyclists with a helmet and 3,812 bicyclists without a helmet. Skull fractures, severe brain injuries and skull base fractures were up to 80% less frequent for bicyclists wearing a helmet.
Technical Paper

An Improved Methodology for Calculation of the Inertial Resistance of Automotive Latching Systems

2014-04-01
2014-01-0544
Abstract This paper outlines an improved methodology to perform calculations to verify the compliance of automotive door latch systems to minimum legal requirements as well as to perform additional due diligence calculations necessary to comprehend special cases such as roll over crashes and locally high inertial loadings. This methodology builds on the calculation method recommended by SAE J839 and provides a robust and clear approach for application of this method to cable release systems, which were not prevalent at the time J839 was originally drafted. This method is useful in and of itself but its utility is further increased by the application of the method to a Computer Aided Design (CAD) template (in this case for Catia V5), that allows some automation of the calculation process for a given latch type. This will result in a savings of time, fewer errors and allows for an iterative concurrent analysis during the design process.
X