Real-Time Hybrid Substructuring For System Level Vibration Testing Of Mechanical Equipment

Vibration of mechanical equipment in structures can result in fatigue, detection, and/or environmental concerns. Numerical simulation of these mechanical/structural systems to verify the system meets these performance requirements can be difficult and can require full system testing. During the design phase of a system, however, the mechanical portion of the system may be pre-existing and can be physically tested while the support structure is still existent as a computer aided design concept which can be numerically simulated. The challenge in verifying the full system meets performance requirements is to accurately combine the physical and numerical substructures. One forma of substructuring, where physical and numerical substructures are combined for dynamic testing in real-time as a feedback loop, is called real-time hybrid substructuring. This research proposes to extend and demonstrate RTHS for the system level vibration testing of mechanical equipment. The overall approach to extend RTHS for system level vibration testing of mechanical equipment involves the analysis of the dynamics of a notional multiple degree of freedom (MDOF) mechanical system to demonstrate the need and application of RTHS for mechanical equipment and the implementation of compensation techniques for a uni-directional MDOF servo-hydraulic shake table serving as the transfer system to interface between the physical and numerical substructures. These research efforts will specifically address the unique challenges encountered in the application of RTHS to mechanical equipment including nonlinearities of the transfer system actuator dynamics due to low amplitude high bandwidth demands and the application of RTHS to lightly damped substructures. Experimental results demonstrate that RTHS accurately captures the system-level response and allows for repeatable tests of various dynamic conditions and potential system improvements to be efficiently examined