Systems Approach in Development of Adaptive Energy Absorbing Steering Columns by Virtual Engineering

In this paper, the design and development of an adaptive Energy Absorbing (EA) steering column using systems and virtual engineering approach is presented. An adaptive EA column adapts to the load characteristics based on crash severity, the occupant mass, the seat position and seat belt usage. The EA device provides the intended load profile during column loading. The design of this device used in steering column is achieved by virtual prototyping using LS-DYNA3D finite element (FE) code in analysis and synthesis based on component and subsystem models. The load-carrying member in the EA device is a metallic strap and the load carrying capacity of this strap is determined for various design parameters such as the strap geometry, thickness, material and the friction between the strap and the housing. Correlation of the analysis with limited dynamic pull test of the strap is shown. Further, the results of a subsystem FE mini-sled model using a Blak tuffy are presented. A MADYMO sled model was used to evaluate the occupant performance at system level for vehicle pulses at 25,30 and 35mph based on the results obtained from component analyses. Four column load levels were chosen for this study. The influences of the column load levels on occupant performance for both belted and unbelted dummies are presented for given vehicle pulses.