The 8 papers in this technical paper collection focus on occupant protection. Topics covered include headform impact tests, simulated injury monitors (SIMon), injury factors in vehicles in small-overlap frontal crashes, and more. The 7 papers in this technical paper collection focus on occupant protection. Topics covered include headform impact tests, simulated injury monitors (SIMon), injury factors in vehicles in small-overlap frontal crashes, and more.
Alyson Lyon, Executive Leadership Coach, explains what stress is, and how to handle personally and professionally. SAE Members can view the full version by logging into the Member Connection. Not a Member? Join us today at sae.org/join.
Modern trends in noise control engineering have subjected the automobile to the “drained swamp” syndrome. Squeaks and rattles (S&R) have surfaced as major concerns. Customers increasingly perceive S&R as direct indicators of vehicle build quality and durability. The high profile nature of S&R has led manufacturers to formulate numerous specifications for assemblies and components. Even so, a large majority of buzz, squeak and rattle (BSR) issues are identified very late in the production cycle, some often after the vehicle is launched. Traditionally, the “find-and-fix” approach is widely adopted, leading to extensive BSR warranty bills. The “design-right-the-first-time” approach must replace the “find-and-fix” approach. Due to the vast breadth and depth of S&R issues, a comprehensive summary of the present state of the art is essential. This paper includes a literature survey of the current state of the art of S&R, and discusses the methods available to further advance it.
Age-related declines in sensory-motor and musculoskeletal systems may interfere with the use of computer pointing devices by older adults. This experiment compared older and younger adults’ ability to select onscreen targets using a mouse and two trackball designs (finger-ball vs. thumb-ball). Analysis of throughput values indicated that the mouse was superior to either trackball design, which supported equivalent levels of performance. For older computer users, the thumb-ball was associated with higher levels of perceived exertion. The results suggest the mouse may be a better input device but the finger-ball may represent a viable alternative for elderly with a reduced range of motion of the wrist.
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.
President Clinton announced in February 1997 a national goal to reduce the fatal accident rate for aviation by 80% within ten years. Weather continues to be identified as a causal factor in about 30% of all aviation accidents. An Aviation Weather Information Distribution and Presentation project has been established within the National Aeronautics and Space Administration’s Aviation Safety Program to develop technologies that will provide accurate, timely and intuitive information to pilots, dispatchers, and air traffic controllers to enable the detection and avoidance of atmospheric hazards. This project, described herein, addresses the weather information needs of general, corporate, regional, and transport aircraft operators.
Although the total number of car occupants involved in accidents in Germany has not significantly reduced during the past 10 years, the number of fatalities has steadily decreased. Most of the severe accidents result from a loss of control of the car. The problem of the driver losing control of his car will be explained. This problem is then used to formulate the goal for the vehicle dynamics control system ESP (Electronic Stability Program, also known as VDC). The approach chosen to reach this goal will then be shown. It will be shown that the vehicle slip angle is a crucial indicator for the maneuverability of the automobile. Since the complete vehicle state is not readily available, estimation algorithms are used to supply the control algorithms with sufficient information. With the automatic control of the slip angle the required yaw moment can be generated by individual wheel slip control.
Vehicle structural resonance modes are classified generally into rigid and flexible (non–rigid) body modes. During motorcycle testing and development for design validation, it is often useful to understand these modes of vibration. Understanding rigid and flexible body modes helps to improve the ride and handling performance. Understanding the flexible body modes helps to isolate noise, vibration, and harshness (NVH) problems. It can also help to find the root causes of structural durability failures. Flexible body modes can also be annoying or unsafe to the operator. For example, handlebar vibrations may cause numbness in the hands or arms. Flexible body modes also can contribute to motorcycle dynamic instability modes such as the weave instability. Similarly, the rider's ability to see approaching traffic from the rear may be reduced if mirrors are vibrating due to a flexible body mode in the handlebars, frame, or front fork.
When a motorcycle runs with hands free riding, the change of the handle deflection angle is interlocked with the vehicle body (frame) bank angle, which is operated by the rider lean angle and caused by the disturbance of road surface. In this report, the motion of the rider who maintains the upright stability of a motorcycle in hands free and hold grips running at low speeds was studied from the experiment with measuring the vehicle frame bank angle, the rider's lean angle and the handle deflection angle, and the rider's feeling evaluation concerning the stability.
This paper describes control system and psychological concepts enabling the development of a simulation model suitable for use in emulating driver performance in situations involving the longitudinal control of the distance and headway-time to a preceding vehicle. The developed model has mathematical expressions and relationships pertaining to the driver's skill in operating the brake and accelerator (“inverse dynamics”) and the driver's perceptual and decision-making capabilities (“desired dynamics”). Simulation results for driving situations involving braking and accelerating are presented to aid in understanding the research work.
To achieve a mass goal and minimize the bell mouthing phenomenon of Passenger Air Bag Housing which takes place when the air bag is in explosive action and detrimental to the safety of passenger side because excessive canister bell mouthing may distort and crash the top surface of instrument panel, a study on the replacing process of a PAB housing to a different material and process was performed. The explosive action of current steel PAB housing was firstly analized to evaluate the reaction forces transferred through the PAB and find out the adaptable material for replacing process. Due to the properties among the die casting alloys, the AM60B alloy was chosen for our new material for PAB housing. Then, stress analysis by the finite element method was performed for a design modification of magnesium one piece housing.
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).
Despite extensive media coverage to the contrary, mismatches among cars, utility vehicles, and pickups in crashes is not a big problem from a societal perspective. On the other hand, if you are riding in a small car that is about to be hit by a big utility vehicle, then the problem looms large. Crash compatibility has attracted a lot of attention lately because utility vehicles have become so popular. The concern is that their designs pose a threat to people riding in smaller cars. But the fact is, two-vehicle collisions between cars (including passenger vans) and utility vehicles or pickups account for only about 15 percent of all car occupant deaths. As a result, countermeasures that focus on making utility vehicles and pickups more crash compatible, however appropriate, can have only small effects on crash injuries and fatalities. On the other hand, improvements in crashworthiness not only reduce crash incompatibilities but also protect across a wider spectrum of crashes.
Crash testing injury calculations have historically been based on measurements of forces and accelerations on cadavers subjected to crashes. For example, the Head Injury Criteria (HIC) was developed by bolting accelerometers to the skulls of cadavers and comparing the actual damage to the head and brain to the measured acceleration. These calculations are currently being improved by evaluating the injuries sustained by race car drivers involved in crashes during races. Biomechanics researchers have installed accelerometers to measure the race car accelerations during a crash. To further improve the injury assessment capabilities, the researchers would like to measure the actual acceleration of the driver’s head. Unfortunately race drivers, unlike cadavers, object to having accelerometers bolted to their skulls. Mounting accelerometers on the racing helmets gives some data, but the drivers head can move within the helmet during a crash.
The Shadow Moiré fringe patterns are level lines of equal depth generated by interference between a master grid and its shadow projected in the surface. By a simple approach, the minimum error is of the order of the master grid pitch, that is, always larger than 0,1 mm resulting in a experimental technique of low precision. The introduction of a phase shift increases the accuracy of the Shadow Moiré technique. The current work uses the method of phase sifting to determine the three-dimensional shape of surfaces using isothamic fringe patterns and digital image processing. The current study presents the method and applies it to images obtained by simulation for error evaluation, as well as to a buckled plate obtaining excellent results. The method hands itself particularly useful to decrease the errors due to the interpretation of the Moiré fringes that can adversely affect the calculations of displacements in pieces containing many concave and convex regions in relatively small areas.
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.
Piston designers are limited in their ability to design precisely what they want because the machinery to accomplish their ideal designs has not been available. What they need is equipment that can accurately reproduce, in large quantities, their desired shapes at speeds that keep the manufacturing cost at an acceptable level. A new CNC shape-turning system has demonstrated a solution that's ideally suited for turning piston skirts and other non-round parts. At its heart is a high-speed solid-state actuator originally developed for military applications. The actuator rod is made of a “smart” material, so called because it has the ability to change its physical shape when subjected to an external stimulus. Called Pulse-Turn™, the camless system turns complicated shapes with high accuracy at speeds substantially higher than those possible with current technology. It's a self-contained package that mounts on suitable, standard CNC lathes.
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.
Engine and vehicle development is a multi-step process: from component design, to system integration, to system control. There is a multitude of tools that are currently being used in the industry for these purposes. They include detailed simulations for component design on one hand, and simplified models for system and control applications on the other hand. This introduces one basic problem: these tools are almost totally disconnected, with attendant loss of accuracy and productivity. An integrated simulation tool has been developed, which is applicable to all of the design issues enumerated above. A key feature introduced for the first time by this new tool is that it is truly a single code, with identical handling of engine and powertrain elements. Further, it contains multiple levels of engine and powertrain models, so that the user can select the appropriate level for the project at hand (e.g. depending on the time scale of the problem).