EASi Engineering and Plymouth, MI-based Johnson Controls are developing computer-aided engineering (CAE) methods to assist in occupant protection in front, rear, and side impacts and rollover crashes. The model was used to evaluate various concepts incorporated into an Advanced Integrated Structural Seat (AISS) design including one intended to increase resistance to passenger compartment intrusion in accident situations.
The two companies are working on the project under the direction of the U.S. National Highway Transportation Safety Administration (NHTSA). A cooperative effort between the government and industry, the project began in 1994 to bring together experts in the fields of impact biomechanics, CAE, and seat-systems engineering and manufacturing.
A key purpose of the collaborative effort is to validate CAE methods for evaluating seat features in future cars and trucks. The team assembled by EASi evaluated an AISS property that included a feature to deform the seat back in a controlled manner during rear-end collisions. The AISS also had a load limiter feature on the seat belt. Finally, it included features designed to react structurally to an intruding door for side impacts and to an intruding roof during a rollover.
The project is intended to provide tools that assist in the evaluation of the current Federal Motor Vehicle Safety Standards (FMVSS) that apply to vehicle seating systems. EASi's work has included project management and development of a computer model using coupled DYNA3D and MADYMO rigid body code that was validated by front-impact sled tests. The model is configured for a generic vehicle environment with an existing Integrated Structural
Seat design.
"We are striving to help NHTSA improve the overall protection provided by vehicle seats and to ensure that seat systems are lightweight, comfortable and user-friendly," said Prakash Krishnaswamy, President of EASi Engineering. "We believe that automakers and consumers will experience significant benefits as a result of the methods developed in this project."
Johnson Controls has provided design, advanced engineering support, and project coordination for the future vehicle seat concept. Engineering and design personnel at the company's facilities have fabricated specialized seating components, assembled metal structures, and conducted dynamic crash tests.
"We're involved in the partnership to learn, to add value to our interior products, and to apply continuous improvement techniques to advanced seat system designs," said Lou Kincaid, Group Vice President of Product and Business Development for
Johnson Controls.
Jean L. Broge
AEI September 2000
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