Intrusion Factors and Their Effects on Steering Column Movements During Vehicle's Frontal Impact Testing

Significant dashpanel intrusion is seen in some cars after severe frontal crashes at high speeds or after offset impact with rigid barrier or both. This intrusion may also result in severe steering column displacements and rotation. Knowledge of both responses is critical for designing an efficient vehicle front end that will respond well in crash. The intrusion has an effect on deciding the car front end length, while the column movements have an effect on the driver dummy's response. For reasons of developing efficiency and safety in vehicles and due to lack of published research, studies were conducted to understand the nature of the intrusion phenomenon as well as the mechanics of the steering column movement in the presence of intrusion.

This paper describes an experimental investigation on intrusion and steering column movements. The different factors causing intrusion modes are identified, and the contributions of these factors to the movement of the steering column are determined. A front part of a midsize front-wheel drive vehicle was used as the design for test structures. A crusher testing approach was used in accordance with a comprehensive test matrix that included eight different tests. In each test the dashpanel of the test structure was crushed at single or multiple points to generate a different intrusion mode, thus simulating the sources of motion that occurs in frontal barrier tests. Intrusion as well as movements of the steering column were among the significant data collected during these tests. The paper presents the results as well as comprehensive implications of the findings on evaluating the capacity of the vehicle structure and steering column support for resisting intrusion.