Structural Developments Improve High-Frequency Vibration Testing on a CUBE Multi-Axis System

摘要

The frequency response of a multiple-input, multiple-output (MIMO) vibration test system is typically limited by the dynamic response of the table structure between the vibration exciters and the test payload. The primary design goal in developing this structure is to minimize the moving mass and maximize the stiffness to give the highest possible first vibration mode, while realizing all other structural requirements. Many Department of Defense random vibration test profiles have a 500 Hz bandwidth, and depending on the system and test article, often the first mode of the loaded table structure must be outside of the test bandwidth to adequately control the test. This is a challenging requirement when the vibration system is multi-axis and the test spectra are excited simultaneously on all axes. Team Corporation addressed these issues with a special version of the Cube six degree-of-freedom (6-DOF) vibration test system. The challenges of the design requirements and the development of a structure with a frequency response that exceeds 500 Hz are discussed. Additionally, test results from the MIL-STD-S10G Common Carrier random vibration profiles are presented for the final design and for two of these Cubes operated simultaneously with a bridging test article.