Search Results

General Motors Powertrain Division has developed the next generation big block V8 engine for introduction in the 1996 model year. In addition to meeting tighter emission and on-board diagnostic legislation, this engine evolved to meet both customer requirements and competitive challenges. Starting with the proven dependability of the time tested big block V8, goals were set to substantially increase the power, torque, fuel economy and overall pleaseability of GM's large load capacity gasoline engine. The need for this new engine to meet packaging requirements in many vehicle platforms, both truck and OEM, as well as a requirement for minimal additional heat rejection over the engine being replaced, placed additional constraints on the design.

Engineers need to have a basic understanding of intellectual property: patents, trademarks, copyrights and trade secrets. This article is designed to serve as an introduction to patents as well as a guide for the technical professional who may or may not have the assistance of corporate legal counsel. Practical approaches to the three common issues that engineers are likely to get involved in: patent searching a product; avoiding patent infringement and protecting a new product idea are covered. Many facts about patents and intellectual property are introduced and a few myths are exposed.

Sudden tire deflation, or blow-out, is sometimes cited as the cause of a crash. Safety researchers have previously attempted to study the loss of vehicle control resulting from a blow-out with some success using computer simulation. However, the simplified models used in these studies did little to expose the true transient nature of the handling problem created by a blown tire. New developments in vehicle simulation technology have made possible the detailed analysis of transient vehicle behavior during and after a blow-out. This paper presents the results of an experimental blow-out study with a comparison to computer simulations. In the experiments, a vehicle was driven under steady state conditions and a blow-out was induced at the right rear tire. Various driver steering and braking inputs were attempted, and the vehicle response was recorded. These events were then simulated using EDVSM. A comparison between experimental and simulated results is presented.

According to accident analysis, submarining is responsible for most of the frontal car crash AIS 3+ abdominal injuries sustained by restrained occupants. Submarining is characterized by an initial position of the lap belt on the iliac spine. During the crash, the pelvis slips under the lap belt which loads the abdomen. The order of magnitude of the abdominal deflection rate was reported by Uriot to be approximately 4 m/s. In addition, the use of active restraint devices such as pretensioners in recent cars lead to the need for the investigation of Out-Of-Position injuries. OOP is defined by an initial position of the lap belt on the abdomen instead of the pelvis resulting in a direct loading of the abdomen during pretensioning and the crash. In that case, the penetration speed of the belt into the abdomen was reported by Trosseille to be approximately 8 to 12 m/s. The aim of this study was to characterize the response of the human abdomen in submarining and OOP.

This paper describes the risk of injury to the rider in a crash using a statistical model based on real-world accident data. We analyzed the road traffic accidents data in Los Angeles and Hanover. Logistic regression modeling technique was used to clarify the relationship among probabilities of minor, serious, fatal injury risk to the rider, and the influence of risk factors in accidents involving opposing vehicle contact point, motorcycle contact point, opposing vehicle speed, motorcycle speed, relative heading angle of impact, and helmet use. The odds ratio, which was adjusted for risk factors simultaneously, was estimated by using the developed technique, and was compared with the effects of risk factors individually. The results showed that there was a statistically significant relationship between minor and serious injuries and opposing vehicle speed, motorcycle speed and opposing vehicle contact point.

The injury-reducing functions of crash padding are discussed as they relate to head impact. The bony structure of the cranial vault (above eyebrows) is strong under localized impact compared with the face. Padding used to protect the cranial vault from impact has the primary function of absorbing energy to reduce the possibility of brain damage. On the other hand, padding for facial protection has the primary function of providing uniform load distribution on the face. The pad understructure then supplies the needed energy absorbing capacity. Test procedures to measure both energy absorption and load distribution are described, and evaluation criteria are shown. Other factors that affect padding, such as temperature and cover stock material, are discussed.

Biomechanical data on the response of the face to localized and distributed loads are analyzed to provide performance goals for a biomechanically realistic face. Previously proposed facial injury assessment techniques and dummy modifications are reviewed with emphasis on their biomechanical realism. A modification to the Hybrid III dummy, called the GM Hybrid III Deformable Face, is described. The modification produces biomechanically realistic frontal impact response for both localized and distributed facial loads and provides for contact force determination using conventional Hybrid III instrumentation. The modification retains the anthropometric and inertial properties and the forehead impact response of the standard Hybrid III head.

The Coast Guard has a primary duty to administer laws and promulgate and enforce regulations for the promotion of safety of life and property on the high seas and on waters subject to the jurisdiction of the United States. The rapid expansion of undersea activity indicates a need for government regulation without waiting for a disaster to provide the impetus. The expected Coast Guard relationship to civil submersible safety is discussed from the standpoint of legislation; preparation, promulgation and enformcement of regulations; duplication of efforts by other organizations; and avoidance of unnecessary interference with use of new developments and technical advancement.

Over the past 30 years, the computer-aided engineering (CAE) tools have been applied extensively in the automotive industry. In order to accelerate time-to-market while coping with legal limits that have become increasingly restrictive over the last decades, CAE has become an indispensable tool covering all major fields in a modern automotive product design process. However, when tackling complex real-life engineering problems, the computational models might become rather involved and thus less efficient. Therefore, the overall trend in the automotive industry is currently heading towards combined approaches, which allow the best of the both worlds, namely the experimental measurement and numerical simulation, to be merged into one integrated scheme. In this paper, the so-called patch transfer function (PTF) approach is adopted to solve coupled vibro-acoustic problems. In the PTF scheme, the interfaces between fluid and structure are discretised in terms of patches.

The objective of this study is to compare the risk of injury to pedestrians involved in vehicle-pedestrian impacts as predicted by two different types of risk assessment tools: the pedestrian subsystem impactors recommended by the European Enhanced Vehicle-Safety Committee (EEVC) and post-mortem human surrogates (PMHS). Seven replicate full-scale vehicle-pedestrian impact tests were performed with PMHS and a mid-sized sedan travelling at 40 km/h. The PMHS were instrumented with six-degree-of-freedom sensor cubes and sensor data were transformed and translated to predict impact kinematics at the head center of gravity, proximal tibiae, and knee joints. Single EEVC WG 17/EuroNCAP adult headform, upper legform and lower legform impactor tests of the same vehicle were selected for comparison based on the proximity of their impact locations to that of the PMHS.

Studies show that the pedestrian population at high risk of injury consists of both young children and adults. The goal of this study is to gain understanding in the mechanisms that lead to injuries for children and adults. Multi-body pedestrian human models of two specific anthropometries, a 6year-old child and a 50th percentile adult male, are applied. A vehicle model is developed that consists of a detailed rigid finite element mesh, validated stiffness regions, stiff structures underlying the hood and a suspension model. Simulations are performed in a test matrix where anthropometry, impact speed and impact location are variables. Bumper impact occurs with the tibia of the 50th percentile adult male and with the thigh of the 6-year-old child. The head of a 50th percentile male impacts the lower windshield, while the 6-year-old child's head impacts the front part of the hood.

A total of 200 detailed pedestrian accident cases of several areas in China were collected and analysed during last three years, the important information mainly include accident conditions, pedestrian information, human injury, vehicle injury sources, impact velocity, wrap around distance, and so on. The front shape of 37 passenger cars with high occupancy in domestic market involved in the accident cases were investigated and categorized into three groups: Sedan, SUV (Sport Utility Vehicle) and 1-Box (One Box Vehicle), so that the effect of vehicle front shapes on the pedestrian impact dynamics response and body injuries were studied. Then, the mathematical models for simulation of vehicle-pedestrian impact were developed using multi-body dynamics codes MADYMO to study response of pedestrian in vehicle-pedestrian impact.

A variety of energy absorbing foams were evaluated to address the Federal Motor Vehicle Safety Standard (FMVSS) 201 extended rule requirements for automotive interior head impact protection. The methodology used for the comparative study was the “Fast Path System” developed in part by Chrysler Corporation to provide a quick and reliable procedure to compare different materials and designs for energy management. Polyurethane, expanded polypropylene and expanded polystyrene energy absorbing foams were evaluated in this study.

This paper describes the results of 13 tests simulating a frontal impact against a fixed barrier at 50 km/h and 25 g. The results showed a marked increase in the severity of injuries with increasing age and more frequent chest injuries than head and spinal injuries. The tests were made with two types of restraint systems, both of which seemed equal in occupant protection.

Vehicle traffic accidents have been extensively studied in various countries, but any differences in traffic accidents the studied areas have not yet been adequately investigated. This paper aims to make a comparison study of head injury risks and kinematics of adult pedestrian accidents in Changsha, China, and Hannover, Germany, as well as correlate calculated physical parameters with injuries observed in real-world accidents of the two cities. A total of 20 passenger cars versus adult pedestrian accidents were collected from the two areas of study, including 10 cases from Changsha and 10 cases from Hannover. Virtual accident reconstructions using PC-Crash and MADYMO software were performed. The in-depth study focused on head injury risks while kinematics were conducted using statistical approaches. The results of the analysis of the Chinese data were compared with those of the German data.

Frontal crashes and near-side crashes were compared and found to be significantly different events. In a frontal crash, the energy to be dissipated from the occupant is constant for a given speed. In a side crash, the energy transferred to a struck-side occupant depends highly on his interaction with the door. That difference has important implications on the choice of countermeasures, injury criteria, and subsystem tests. In a frontal crash, chest and abdominal injuries occur in the “second” impact when the occupant, acting like a free-flight mass, strikes the interior. Padding can absorb some of the free-flight energy, reduce the impact force, and provide earlier and longer contact of the occupant with the interior. The earlier contact decreases the differential velocity of the occupant to the interior, and the longer contact allows more time and greater distance to dissipate the kinetic energy.

The WorldSID dummy can be equipped with both a pubic and a sacroiliac joint (S-I joint) loadcell. Although a pubic force criterion and the associated injury risk curve are currently available and used in regulation (ECE95, FMVSS214), as of today injury mechanisms, injury criteria, and injury assessment reference values are not available for the sacroiliac joint itself. The aim of this study was to investigate the sacroiliac joint injury mechanism. Three configurations were identified from full-scale car crashes conducted with the WorldSID 50th percentile male where the force passing through the pubis in all three tests was approximately 1500 N while the sacroiliac Fy / Mx peak values were 4500 N / 50 Nm, 2400 N / 130 Nm, and 5300 N / 150 Nm, respectively. These tests were reproduced using a 150 kg guided probe impacting Post Mortem Human Subjects (PMHS) at 8 m/s, 5.4 m/s and 7.5 m/s.

This study focuses on the behaviour of child dummies, namely a 3-year-old Hybrid III and a TNO P3, in terms of head and neck injury potential in forward and rearward facing child safety seats in frontal vehicle crash. Numerical simulations were conducted using a moderate acceleration pulse acquired from the National Transportation Biomechanics Research Center database with a closing speed of 41 km/h. A finite element model incorporating a three-year-old Hybrid III dummy, in a five-point convertible child safety seat was developed and the prescribed acceleration pulse was simulated using LS-DYNA. A multi-body dynamic simulation, utilizing the identical acceleration pulse, was completed for the three-year-old P3 dummy in a four-point convertible child safety seat using MADYMO. Similarities and differences were noted in the numerical observations for both the P3 and Hybrid III dummies which are presented within the paper.

The THUMS (Total HUman Model for Safety) 3-year-old child finite element (FE) model was developed by Toyota Central R&D Labs (TCRDL) by model-based scaling from the AM50 (50 percentile male) human FE model. The objective of this paper is to present a comparison between the kinematics of a child FE model developed from the adult THUMS model and a HYRID III 3-year-old child dummy using observations from numerical simulations of a CMVSS 208 frontal crash. Both the child models were positioned in a forward facing, five point child restraint systems (CRS). An acceleration pulse acquired from a vehicle crash test in accordance with Canadian Motor Vehicle Safety Standards (CMVSS) 208 was applied to the seat buck supporting the CRS. Numerical simulations with both the child model and the Hybrid III child dummy were conducted using LS-DYNA version 970.

This paper presents a review on pedestrian impact reconstruction methodology and offers a comprehensive review of the literature. Several types of analyses are discussed which can be used to reconstruct the accident scenario using the facts collected from the scene. Inclusive in this review is the utilization of skid mark analysis, debris analysis, injury/damage match-up, trajectory analysis, nighttime visibility, and alcohol effects. The pedestrian impact reconstruction methodology is illustrated with a real world case example to point out different observations which can provide insight into the pedestrian/vehicle collision reconstruction approach. The literature review provides a broad foundation of information on pedestrian impact reconstruction and can be used to supplement the techniques presented in this paper in areas related to pedestrian impact. Research advances in the area of pedestrian impact reconstruction are also discussed in this paper.