Design and Evaluation of a Guided Dynamic Rollover Test Device 2014-01-0540
Many dynamic test systems currently exist to assess rollover. This paper introduces a new test device that combines features from a multitude of different tests. It also covers the concept development, a scaled prototype design and test results from both physical and virtual tests.
The Guided Rollover Test (GRT) device subjects vehicles to repeatable initial conditions by having a cart follow a guided maneuver similar to a forward J-turn with an increasing curvature sufficient to roll most vehicles. A test vehicle is carried on the cart at constant longitudinal velocity until it rolls. The cart is fitted with a tripping edge to eliminate slipping and remove the influence of tire properties and road-surface friction. Vehicles are subjected to a rollover based on their own performance characteristics which define the dynamics and consequently the roof to ground contact. Vehicle mechanical systems (suspension), passive safety systems (roof) and occupant containment systems (airbags, seat-belts, etc.) would be assessed under dynamic rollover loading. The GRT also allows for use of a crash test dummy to asses injury protection and ejection mitigation.
Firstly, Vehicle Dynamics Analysis (VDA) was used to evaluate variations in rollover initiation among different vehicles to verify the concept. A scaled prototype was then designed and later constructed to perform and validate the tests. To ensure the repeatability of rollover initial conditions, the scaled GRT device was tested several times using a scaled test vehicle. The sensitivity of the GRT was then observed by varying the Center of Gravity (CG) height on the test vehicle. High speed video was used in the assessment.
The study results indicate that the test device offers a good level of repeatability and an expected response to changes in vehicle CG height.