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Recently there has been a greater awareness of the increased risk of certain injuries associated with air bag deployment, especially the risks to small occupants, often women. These injuries include serious eye and upper extremity injuries and even fatalities. This study investigates the interaction of a deploying air bag with cadaveric upper extremities in a typical driving posture; testing concentrates on female occupants. The goals of this investigation are to determine the risk of upper extremity injury caused by primary contact with a deploying air bag and to elucidate the mechanisms of these upper extremity injuries. Five air bags were used that are representative of a wide range of air bag ‘aggressivities’ in the current automobile fleet. This air bag ‘aggressivity’ was quantified using the response of a dummy forearm under air bag deployment.

To address the growing need for detailed chemistry in engine simulations, new software tools and validated data sets are being developed under an industry-funded consortium involving members from the automotive and fuels industry. The results described here include systematic comparison and validation of detailed chemistry models using a wide range of fundamental experimental data, and the development of software tools that support the use of detailed mechanisms in engineering simulations. Such tools include the automated reduction of reaction mechanisms for targeted simulation conditions. Selected results are presented and discussed.

A series of eight sled tests was conducted using Hybrid III dummies and cadavers in order to examine the influence of foot placement on the brake pedal in frontal collisions. The brake pedal in the sled runs was fixed in a fully depressed position and the occupants' muscles were not tensed. The cadaver limbs and the Hybrid III lower extremities with 45° ankle and soft joint-stop were extensively instrumented to determine response during the crash event. Brake pedal reaction forces were measured using a six-axis load cell and high speed film was used for kinematic analysis of the crashes. Four right foot positions were identified from previous simulation studies as those orientations most likely to induce injury. In each test, the left foot was positioned on a simulated footrest, acting as a control variable that produced repeatable results in all dummy tests. Each of the different right foot orientations resulted in different loads and motions of the right leg and foot.

A simulation model of the Hybrid III lower extremities with the 30 degree dorsiflexion ankle was developed using the CVS/ATB program. The femur and tibia were modeled as a sequence of rigid beams with a hinge and slider at the knee. Special, locked joints were placed in the femur and tibia at the same locations as the load cells in the actual dummy. Constraint forces and moments at these joints can be compared directly to load cell data. The complex geometry of the foot was divided into five segments representing the heel, toe, forefoot, midfoot, and ankle regions. Two foot models were constructed: one barefoot and one with a Lehigh safety shoe. Good agreement was obtained for most parameters when single-leg pendulum tests, and full-body sled tests, were simulated using the new model.

An Articulated Total Body frontal crash simulation was created with the dummy's right foot placed on the brake pedal. This study examined how interaction of the driver's foot with the brake pedal influenced the behavior of the lower extremities in frontal collisions. Braking parameters considered in the study included foot position on the pedal, whether or not the occupant's muscles were tensed and if the brake pedal was rigid or was allowed to depress. Two basic foot positions were identified as most likely to induce injury of the lower limb. One represented a foot that was pivoted about the heel from the gas pedal to the brake pedal. The other position replicated a foot that was lifted from the gas pedal to the brake pedal, resulting in an initial gap between the heel and floor. Both positions resulted in different loads and behavior of the foot, indicating that driver pre-impact position is a contributing factor to one's injury risk.

Experimental testing was performed to provide input data for a new, multi-body computer model of the Hybrid III lower extremity, with the 30 degree dorsiflexion ankle. The leg was disassembled into its components to mass, geometric, and inertial properties for each segment. Stiffness and damping coefficients were measured for the hip, leg, foot, and ankle. Joint rotational and translational properties were measured for the knee and ankle. To characterize interactions of the foot with the footwell, flexion and compression tests of the foot were conducted. The lower extremity was segmented at the joint and load cell locations, to permit rigid body dynamics codes to compute the forces at these locations for comparison to test data and for calculation of injury criteria.

Tailor welded steel blanks have long been applied in stamping of automotive parts such as door inner, b-pillar, rail, sill inner and liftgate inner, etc. However, there are few known tailor welded aluminum blanks in production. Traditional laser welding equipment simply does not have the capability to weld aluminum since aluminum has much higher reflectivity than steel. Welding quality is another issue since aluminum is highly susceptible to pin holes and undercut which leads to deterioration in formability. In addition, high amount of springback for aluminum panels can result in dimension control problem during assembly. A tailor-welded aluminum blank can help reducing dimension variability by reducing the need for assembly. In this paper, application of friction stir and plasma arc welded blanks on a liftgate inner will be discussed.

The objective of this paper is to investigate the effect of stamping process on oil canning and dent resistance performances of an automotive roof panel. Finite element analysis of stamping processes was carried out using LS-Dyna to obtain thickness and plastic strain distributions under various forming conditions. The forming results were mapped onto the roof model by an in-house developed mapping code. A displacement control approach using an implicit FEM code ABAQUS/Standard was employed for oil canning and denting analysis. An Auto/Steel Partnership Standardized Test Procedure for Dent Resistance was employed to establish the analysis model and to determine the dent and oil canning loads. The results indicate that stamping has a positive effect on dent resistance and a negative effect on oil canning performance. As forming strains increase, dent resistance increases while the oil canning load decreases.

The control of trace contaminants on the International Space Station (ISS) is carried out by a combination of activated carbon absorption and catalytic oxidation. The carbon bed absorbs most hydrocarbons, chloro and chlorofluorocarbons (CHCs and CFCs) while the catalytic oxidizer removes compounds such as methane, ethylene, ethane, and carbon monoxide that cannot be absorbed by the charcoal bed. Unfortunately, the Space Station catalyst of 0.5% palladium on alumina does not effectively oxidize CHCs and CFCs, and in fact is powerfully poisoned by them (Wright et al. 1996). Thus, even though the charcoal bed has little affinity for CFCs and CHCs, it must be sized to completely remove these compounds in order to protect the crew and prevent poisoning of the catalytic oxidizer. TDA Research Inc. (TDA), under contract to NASA-JSC, has designed, built, and tested an all-catalytic trace contaminant control system (TCCS) to be used in Phase III of the Early Human Testing Program.

The two main motivations for Wayne State University (WSU) and Henry Ford Hospital (HFH) researchers to develop numerical human surrogates are advanced computing technology and a high-speed x-ray imaging device not available just a decade ago. This paper summarizes the capabilities and limitations of detailed component models of the human body, from head to foot, developed at WSU over the last decade (Zhang et al. 2001, Yang et al. 1998, Shah et al. 2001, Iwamoto et al. 2000, Lee et al. 2001 and Beillas et al. 2001). All of these models were validated against global response data obtained from relevant high-speed cadaveric tests. Additionally, some models were also validated against local kinematics of bones or soft tissues obtained using the high-speed x-ray system. All of these models have been scaled to conform to the key dimensions of a 50th percentile male.

Advanced material modeling was conducted to describe the thermal-mechanical behavior of Boron Steel during hot stamping, a process in which blanks at 900 °C are formed and quenched between cold dies. Plastic deformation, thermal dilatation and phase transformation were incorporated in the constitutive model and a user-defined subroutine was developed to interface with LS-DYNA. Simulation was conducted on the hot stamping process of a door intrusion beam to gain insight into the physics of the process. Results showed significant influence of the thermal cycle on final product. It was also demonstrated that the program developed can be used as an early feasibility tool to determine baseline processing parameters and to detect potential defects in products without physical prototyping.

Mechanical properties of as-rolled steels used in a vehicle vary with many parameters including gages, steel suppliers and manufacturing processes. The residual forming and strain rate effects of automotive components have been generally neglected in full vehicle crashworthiness analyses. Not having the above information has been considered as one of the reasons for the discrepancy between the results from computer simulation models and actual vehicle tests. The objective of this study is to choose the right material property for as-rolled steels for stamping and crash computer simulation, and investigate the effect of forming and strain rate on the results of full vehicle impact analyses. Major Body-in-White components which were in the crash load paths and whose material property would change in the forming process were selected in this study. The post-formed thickness and yield stress distributions on the components were estimated using One Step forming analyses.

Laminated steel sheets sandwiched with a polymer core are increasingly used for automotive applications due to their vibration and sound damping properties. However, it has become a major challenge in finite element modeling of laminated steel structures and forming processes due to the extremely large differences in mechanical properties and in the gauges of the polymer core and the steel skins. In this study, circular cup deep drawing and V-bending experiments using laminated steels were conducted in order to develop a modeling technique for laminate forming processes. The effectiveness of several finite element modeling techniques was investigated using the commercial FEM code LS-Dyna. Furthermore, two production parts were selected to verify the modeling techniques in real world applications.

This paper describes the performance improvement and cost savings achieved by the Stamping Technology Department at DaimlerChrysler Corporation (Chrysler group), in migrating from Unix workstations with RISC technology to Linux PCs with Intel Pentium technology. Performance comparisons of various engineering applications running on these two system configurations are analyzed. The major aspects such as hardware configuration, operating system, software availability, compatibility, reliability, accuracy and consistency of simulation results are discussed. The improvement in computing speed and deviations in simulation results between MPP LS-Dyna and SMP LS-Dyna are presented.

Elevated CO2 level in the closed space or room has much been concerned. Control of CO2 within certain range is one of the most important contents in the life support system. In this paper, a 10 liter membrane-photobioreactor operated with dead end mode was prepared to remove CO2 from air by using the photosynthetic alga, Chlorella vulgaris. The results showed that gas exchange efficiency was improved greatly when the membrane module was adopted. Compared to that in the ordinary photobioreactor, not only the retention time of the smaller and more uniform gas bubble is increased from 2 s to more than 20 s, but also the dissolved oxygen (DO) dropped by a factor of 30, resulting in that the CO2 fixation rate was enhanced 2 from 80 to 260 mg l-1 h-1.

Originally designed for measuring closed-loop contours such as those around a human thorax, the External Peripheral Instrument for Deformation Measurement (EPIDM), or chestband, was developed to improve the measurement of dummy and cadaver thoracic response during impact. In the closed-loop configuration, the chestband wraps around on itself forming a closed contour. This study investigates the use of the chestband for dynamic deformation measurements in an open-loop configuration. In the open-loop configuration, the chestband does not generally form a closed contour. This work includes enhanced procedures and algorithms for the calculation of chestband deformation contours including the determination of static and dynamic chestband contours under several boundary conditions.

This work studies the effect of padding on the force levels in impulsively loaded dummy lower extremities. Tests include the effect of padding incorporated into the soles of shoes and an examination of the potential of shoe padding for mitigating impact loading on the lower extremities. Three different shoes and three paddings were studied using a pendulum impactor; two different padding levels were studied in an impact sled test with simulated translational structural intrusion. The tests indicate a greater than 20% variation in peak axial force imparted to the lower tibia between shoes, and a greater than 50% variation in peak axial force across the paddings tested. From sled tests with simulated structural intruaion, we see a decrease of approximately 15% in peak axial load and a decrease of over 20% in peak anterior/posterior moment.

The University of Virginia is investigating the use of a magnetohydrodynamic (MHD) angular rate sensor to measure head angular acceleration in impact testing. Output from the sensor, which measures angular velocity, must be differentiated to produce angular acceleration. As a precursor to their use in actual testing, a torsional pendulum was developed to analyze an MHD sensor's effectiveness in operating under impact conditions. Differentiated and digitally filtered sensor data provided a good match with the vibratory response of the pendulum for various magnitudes of angular acceleration. Subsequent head drop tests verified that MHD sensors are suitable for measuring head angular acceleration in impact testing.

Three-dimensional simulation models of a driver's right upper extremity interacting with a deploying airbag have been set up and run with the Articulated Total Body program. The goal of this study is to examine the significance of various occupant and airbag parameters during deployment, such as grip strength, upper extremity position, shoulder compliance, flap position, flap aggressivity, and deployment speed. Given a range of 250 N to 650 N, the grip strength did not affect the resultant loads. Also, the contact force and torque at the e.g. of the forearm are not sensitive to shoulder joint compliance. The flap aggressivity and the position of the airbag module relative to the upper extremity are most important in affecting the interaction. This study is used to justify cadaveric experiments involving disarticulated upper extremities.

In this paper, a 3 L membrane-photobioreactor was first prepared to study the CO2 removal capability using Chlorella pyrenoidosa. The CO2 was efficiently removed from the airstream when the following operating conditions were set: the inlet airflow of 0.6 L/min, the aeration gas containing 1% CO2, light intensity of 3500 Lx, at 25~30°C and pH at 8.5~9.5. It showed that CO2 concentration in the discharged gas decreased 50% compared to that in the aeration gas, and the removal capacity of the experimental photobioreactor was 0.118 g CO2/(L-medium·h). The medium composition of C. pyrenoidosa for CO2 removal from air was also studied in a 10 L enclosed photobioreactor, in which the proper values of temperature, pH and dissolved oxygen (DO) were controlled on-line. In order to alleviate the influence of DO on the growth of microalgae, N2 was also used to form mixed aeration gas instead of condensed air.