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Structure enhancement based on data monitored in a traditional side impact evaluation is primarily a trial and error exercise resulting in a large number of computer runs. This is because how the structure gets loaded and the degree of contribution of local structural components to resist the impact while absorbing energy during a side collision is not completely known. Developing real time complete load profiles on a body side during the time span of an impact is not an easy task and these loads cannot be calculated from that calculated at the barrier mounting plate. This paper highlights the load distribution, calculated by a procedure using computer aided engineering (CAE) tools, on a typical 2-door vehicle body side when struck by moving deformable barriers used in the insurance institute for highway safety (IIHS), EuroNCAP and LINCAP side impact evaluations.

The dynamics of vehicle front end crash are studied using the ADAMS dynamic simulation code. The analysis is carried out in three dimensions and can capture the behavior associated with an asymmetrical structure or impact mode. Subroutines which allow the modeling of structural crush and plastic hinge formation, contact forces and friction forces are discussed. The method is relatively inexpensive, but does require a good understanding of the problem on the part of the analyst. A discussion of the techniques that are used to model the structural system is given. The results of the analysis are compared with experimental data and the correlation is very encouraging.

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 will provide an overview of the work progress of the advanced offset frontal crash protection group of IHRA. It resumes, including tables, the strategy of the group to cope with the assigned task. This is the commitment to achieve an harmonized frontal crash protection procedure taking into account the different world wide views in this field.

Today’s automotive world has moved towards an age where safety of a vehicle is given the topmost priority. Many stringent crash norms and testing methodology has been defined in order to evaluate the safety of a vehicle prior to its launch in a particular market. If the vehicle fails to meet any of these criteria then it is debarred from that particular market. With such stringent norms and regulations in place it becomes quite important on the engineer’s part to define the structural requirements and protect the space to meet the same. If the concept level platform definition is done properly it becomes very easy to achieve the crash targets with less cost and weight impact.

This paper describes the development of a new sled system that can address many safety-related issues pertaining to the racing industry. The system was designed to re-create acceleration and velocity levels similar to levels evident in race car crashes. The sled utilizes equipment typically used in passenger car crash research with the primary change to a specially designed lightweight carriage. This paper will overview the system and the types of crash events that can be simulated. Readers of this paper will gain a much broader understanding of accelerator sled testing and the issues related to the simulation of high speed crashes using physical testing.

This paper presents a 2D model for frontal vehicle-to-vehicle crashes that can be used for fleet modeling. It presents the derivational details and a preliminary assessment of the model. The model is based on rigid-body collision principles, enhanced adequately to represent energy dissipation and lateral engagement that plays a significant role in oblique frontal vehicle-to-vehicle crashes. The model employs the restitution and the apparent friction in order to represent dissipation and engagement respectively. It employs the impulse ellipse to identify the physical character of the crash, based on the principal directions of impulse. The enhancement of the rigid body collision model with restitution and apparent friction is based on collision simulations that use very simple finite element vehicle representations. The dependence of the restitution and the apparent friction on the incidence angle, the frontal offset, and the mass ratio, as predicted by the 2D model, has been presented.

A 50th percentile male pelvis finite element model was designed for impact simulation. Shell elements represented the pelvic bone, which geometry was taken into account. Non linear viscous springs accounted for soft tissues connecting skin to bone structure, and body segments inertia around the pelvis were represented using rigid bodies. Geometric and mechanical characteristics were taken either from litterature or by identification to in house experimental results. Three dimensional movements were reproduced by the model for static lateral loading and dynamic lateral impact simulation at two different velocities, 3.5 and 6.5 m/s, with a good agreement with experimental results. This model takes into account pelvic bone geometry, allowing an appreciation of its deformation and therefore injury risk.

A test fixture for use on the Hyge Sled was fabricated to NHTSA specifications, matching the fixture used at Heidelberg University to measure forces on cadavers in side impact configurations. Tests were conducted at 16, 22, 24, and 32 km/h to simulate both the APR cadaver drop tests and Heidelberg sled tests. Comparisons to the cadaver data were made with the Ford Side Impact Body Block and the APR and SID dummies. Test results are shown and discussed.

Newer automobiles have complex dynamic and stability controls due to regulations, competition, and safety concerns. More systems require testing at the subcomponent level to ensure proper operation in the final vehicle assembly. Many of the stability and navigation features originally designed for aircraft components are now being incorporated into automobiles. Certain types of motion test simulators were originally designed for testing aircraft sensors as: gyroscopes, inertial navigation systems (INS), inertial measurement units (IMU), and attitude heading and reference systems (AHARS) This same type of equipment is now used for automotive testing as: airbag fuse sensors, anti-skid sensors, rollover sensors, vehicle stabilization systems, active suspension sensors, and navigation systems.

Various means for measuring a vehicle's roll stability performance are considered in terms of the pertinence of their test conditions to the rollover crash record, the practicality and quality of the measurement, and their ability to span the performance range of the population of light-duty vehicles. Classical static measures as well as the so-called “maneuver-type” tests that have been under extensive study by the U.S. Dept. of Transportation are specifically addressed. In light of limitations facing the existing methods, the concept of a centrifuge test device is introduced and discussed. The apparatus is comprised of a relatively large machine that mounts a full-sized vehicle tangent to the rotation of a radial arm which revolves at a controlled angular rate. The minimum steady speed of rotation that induces a rollover response in the mounted vehicle corresponds to the static rollover threshold, in units of lateral (or centripetal) acceleration.

Accelerator-type sled systems have been very useful to the automotive industry for many years. These systems have allowed engineers to effectively evaluate a safety component in a frontal crash environment without having to conduct a full-scale crash test. While accelerator-type sleds are an excellent tool for frontal crashworthiness development, the energy required to simulate a side impact or lateral pole impact test is just a small fraction of the total capacity of the system. In light of this, a project was undertaken to develop a system which incorporated many features of the current accelerator-type sled system, but was designed to simulate non-frontal crash test cases. This paper describes the development and test applications for the new sled system. The operating theory and general design is similar to current accelerator-type sled systems, although the new system has been scaled down significantly.

This study investigates occupant containment characteristics of tempered and laminated automotive moveable side glass in rollover collisions. FMVSS 216 test protocols were used to induce roof damage or sheet metal damage around the window opening in Lincoln Navigators equipped with tempered and laminated side glass. Dummy-drop tests were then performed to investigate relative containment. The results demonstrate that, for rollovers in which the window structure is compromised, tempered side glass and laminated side glass perform comparably relative to occupant containment. Also discussed are the general strength characteristics of different types of glass construction, the availability of laminated side glass in recent model U.S. vehicles, and anecdotal data supporting the conclusions of testing.

The analysis presented here updates and expands previous research in which rollover critical events were classified based on a detailed review of about 500 police-reported single-vehicle rollover crashes of ESC-equipped vehicles. In order to compare the rollover performance of vehicles with and without ESC for the present study, an additional sample of 150 police reports on non-ESC passenger cars and 196 police reports on light vehicles with ESC in single-vehicle rollovers were obtained, and detailed coding of rollover scenarios was performed. The coding effort was undertaken by an engineering team and focused on critical events leading to rollovers (departure from road, loss of directional control, impact with an object, and departure from road with possible driver's input); driver factors (alcohol/drug involvement, speeding, inattention, distraction, fatigue, and overcorrection); and environmental factors.

Hundreds of millions of micromachined, piezoresistive Manifold Absolute Pressure (MAP) sensors have been produced to reduce pollution and improve fuel efficiency in engine control systems. Other vehicle applications for micromachined pressure sensors include monitoring turbo pressure, barometric pressure, fuel tank leakage, fuel rail pressure and tire pressure. Exhaust gas recirculation and even door compression for side impact detection are employing micromachined silicon pressure sensors. Piezoresistive pressure sensors have dominated the automotive market to date. Practical micromachined capacitive pressure sensors have recently been developed and could replace the piezoresistive sensor in many applications. This paper will examine the advantages of both pressure sensing technologies, and discuss applications that an inexpensive capacitive pressure sensor will open up.

Despite the general similarity of U.S. and European heavy trucks, there are differences in design properties that affect braking and turning performance. A European tractor-semitrailer was studied for the purpose of comparing its properties to those of U.S. vehicles and assessing the comparative performance. Mass, suspension, and braking system properties of the European tractor and semitrailer were measured in the laboratory and on the proving ground. Turning and braking performance qualities were evaluated by computer simulation and by experimental tests. In turning performance the European combination had a 9 percent advantage in rollover threshold, compared to a generic U.S. vehicle with properties that were in the midrange of U.S. design practice. Higher suspension roll stiffness and higher chassis weight on the European tractor and semitrailer accounted for the higher threshold.

This research compares vehicle dynamic simulations in PC-Crash 8.2 to data recorded during instrumented handling tests conducted by Mechanical Systems Analysis Incorporated (MSAI). The handling tests, which were used to examine rollover stability in a 1998 and a 1999 Ford Explorer, involve rapid steering inputs at speeds between 30 mph [48.3 kph] and 60 mph 96.6 [kph]. Vehicle weight, center of gravity (c.g) position, suspension stiffness parameters, tire parameters, steering angle, and vehicle speed data provided by MSAI were used as input for the PC-Crash model. Lateral acceleration, roll angle, roll rate, and yaw rate vehicle response from PC-Crash were compared to the MSAI sensor data. The authors modeled 26 handling tests. PC-Crash appeared to be a reasonable tool for modeling gross vehicle response. In addition, PC-Crash correctly predicted whether or not the test vehicle would experience rollover instability in a majority of the cases.

Evaluation of vehicle impacts may involve the use of computer simulations. While simulation programs with two-dimensional impact models have been used for decades, more recent three-dimensional impact models have been developed. This research compares DyMESH, the three-dimensional vehicle impact model in HVE-SIMON, with full-scale vehicle crash tests involving low-speed rear impacts. Exponent Failure Analysis Associates (Phoenix, Arizona) conducted rear impact research involving two virtually identical 1983 Nissan Pulsar NX 2-door vehicles. One vehicle was stationary, while the second vehicle impacted the rear of the first vehicle in an aligned configuration. Tests were run at impact speeds ranging from 5 to 20 MPH. Tri-axial accelerometers were positioned in both vehicles and vehicle acceleration and velocity responses were recorded. SIMON-DyMESH was used to simulate these impact tests. DyMESH utilizes a mesh shell determined by the three-dimensional geometry of the vehicle.

This paper presents the results of a test program comparing the performance of the CAUSFIX (originally known as CANFIX) and the Uniform Child Restraint Anchorage (UCRA) systems to the conventional Australian anchorage system of adult belt and top tether. Each anchorage configuration was subjected to both 45 and 90 degree simulated side impacts. The performance of the attachment systems was assessed using the TNO P3/4 dummy in both a rearward facing restraint and a forward facing restraint. Assessment was based on peak head acceleration and displacement. The results indicate that both the CAUSFIX and the UCRA system can provide improved protection for children in side impacts. The CAUSFIX system was found to offer the greatest potential for improvement. The results of this work are significant to the current debate concerning the proposed draft international standard for universal anchorage systems.

Martinez and Schlueter [6] described a three-phase model for reconstructing tripped rollover crashes, where the vehicle's path is divided into pre-trip, trip, and post-trip phases. Brach and Brach [9] also described this model and noted that the trajectory segmentation method for the pre-trip phase needed further validation. When a vehicle leaves a measurable yaw mark at the start of its pre-trip phase it might be possible to compare estimates from the three-phase model to those obtained using the critical speed method, and this paper describes Bayesian reconstruction of two such cases. For the first, the 95 percent confidence interval for the case vehicle's initial speed, estimated using the critical speed method, was (64 mph, 81 mph) while the 95 percent confidence interval via the three-phase model was (66 mph, 79 mph).