A methodology to design multi-axis test rigs for vibration and durability testing using frequency response functions

The multi-axis simulators are designed for experimental verification of the safe functioning of large components and subsystems under real world customer usage in vibration and durability testing. Transformation of the full vehicle conditions to mast rig testing with correct system dynamics and vibration characteristics and boundary conditions is a key challenge in the development of the experimental set-up. In this paper, a systematic methodology is formalized how to design the experimental set-up on MAST rig to replicate the vehicle dynamics and vibration characteristics in vehicle conditions. System modes and frequency response functions are chosen as key performance metrics to compare the dynamics of the system to be tested for both full vehicle and rig design. Criteria on the metrics are defined to make decision if the test rig design is sufficiently replicating the in-vehicle conditions. The methodology is illustrated on a side skirt attached to a heavy duty truck chassis that demonstrates the application of the methodology in practice.