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O-EA tubing is a composite structure, made of aluminum and paper, that is being used for energy absorption and crash injury mitigation in automotive head impact, side impact and knee bolster applications. This paper describes the component testing, material/geometry characterization and the evolution of a finite element model of the O-EA tubing through a 3-Stage methodology. In the first part of the paper, a description of the O-EA tubing construction and the manufacturing process is provided. Next, the material and geometry characterization of the constituent aluminum and paper layers, using static component tests and a finite element model, is described. A layered composite material model in conjunction with a shell element discretization of the geometry is identified to be the most suitable modeling approach.

Rigid, polyurethane foam filling is currently being used for NVH (Noise, Vibration and Harshness) improvement in many automobiles The improvement is typically achieved by the injection of the rigid polyurethane foam into the thin-walled, hollow sections of the body members such as the pillars and rocker panels The foam seals the cavities thereby blocking the transmission and amplification of wind, engine and road noises Also by increasing the stiffness of the members and the joints, the body natural frequencies are increased thereby reducing the vibration Another potential application of the rigid polyurethane foam is strength improvement of the body structures Thin-walled, hollow sections are inherently susceptible to buckling due to section collapse When filled with the rigid polyurethane foam, the section collapse can be significantly reduced thereby increasing the strength of such structures, in addition to the demonstrated NVH improvement Bending tests (4-point) of foam-filled steel sections were performed to show the effectiveness of various densities of foam in improving the strength in the flexural mode These tests were replicated in nonlinear finite element simulations to establish the appropriate material characteristics including fracture properties Additionally, these tests served to identify the appropriate density range for roof-crush strength improvement Subsequently, nonlinear finite element analyses were performed to simulate the roof crush test per FMVSS 216 (Federal Motor Vehicle Safety Standards) at the A-pillar roof joint The study shows that the strength can be improved substantially by using rigid polyurethane foam By using foam, it is possible to reduce the pillar sections, reduce the thicknesses or eliminate reinforcements inside the pillars and thereby offset the mass increase due to the foam filling Also, a possible design concept utilizing the foam filling in a B-pillar that could meet the interior head impact requirements (per the FMVSS 201 Head Impact Protection upgrade) is presented

Light metal alloys based on magnesium and aluminum are increasingly being pursued for various vehicle interior applications because of distinct advantages such as weight savings and potential parts consolidation. One such application of light metal alloys is the steering wheel, which is an important component of a safety system that is comprised of the driver-side airbag, steering wheel, the steering column and its attachment bracketry to the instrument panel and the vehicle body structure. For the airbag to function effectively as a restraint during a frontal crash, the steering wheel has to provide adequate support. In addition to the steering column which is designed to absorb energy, the wheel can also function as an energy absorber if so designed. One way of achieving this energy absorption is through plastic deformation of the wheel. Adverse material characteristics, however, make the energy absorbing steering wheel design, using light metal alloys, a sizeable challenge.

Automotive vehicle crash safety requirements have steadily become more stringent over the last decade. Automobiles of tomorrow have to comply with a host of requirements in various crash modes in order to be considered roadworthy. In the first section of the paper, the current major requirements, some important requirements that are imminent, and desirable requirements in the near future are briefly discussed. Until recently, crash requirements have been focused mostly on the vehicle structure rather than the occupant protection, with the exception of frontal crash. Scarcity of in-depth interpretation of accident data, lack of biofidelic injury assessment devices (“crash dummies”) and the necessity for test repeatability had kept the testing procedures simple. Often, crash testing involved statically loading the vehicle to measure the structural strength, without consideration of the dynamic behavior of the structure or the structure/occupant interaction.

As passenger-side airbags are introduced into the vehicle fleet, consideration must be given to the possible interaction of the airbag with children and child restraint systems. Specifically, a rear-facing infant seat may represent an out-of-position occupanVrestraint system in relation to the deploying airbag due to the limited distance between the infant seat and the instrument panel. Current safety standards for child restraints do not address this issue and the potential for serious injury mandates further analysis. Simulation studies can assist in understanding the behavior of such interaction and help to reduce the number of tests to evaluate infant seat performance. New developments in simulation technology offer state-of-the-art tools to simulate a deploying airbag using a finite element model while the occupant, infant seat and vehicle interior are simulated with linked rigid body systems.