Date of this Version
Schlueter, B.D., Predicting Vehicle Dynamics for Roadside Safety Using Multibody Systems Simulations. MS Thesis, University of Nebraska-Lincoln. 2012.
Accurate means for predicting vehicle dynamics is required in the design and testing of roadside safety hardware. Past research has used finite element (FE) modeling to this end, but multibody systems (MBS) modeling may provide a more efficient way to solve these problems. MBS modeling using Adams/Car was investigated by first compiling an introduction to the program, then performing basic vehicle dynamics simulations using a supplied model. Next, a model of a 2270 kg pickup was created and validated against physical test data involving impact with a speed bump. Finally, pickup trajectories in 4H:1V and 6H:1V V-ditches were predicted for widths of 24, 30, 38, and 46 ft.
A poor tire model and the inability to account for bumper contact led to inaccuracies in the results, and guidelines are established for scaling damper rates to compensate. For small obstacles and low impact scenarios, scaling damper rates by two produces good results. As large tire deformations and bumper contact become important, scale factors of 30 are required. Unfortunately, even high damper rates cannot fully compensate for all factors. MBS modeling may prove useful in vehicle dynamics simulations relating to roadside safety, but only for low impact events at least until a better tire model can be acquired and bumper contact definitions can be included.
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