Magnetic Actuators for Non-Destructive Evaluation (NDE) of Rotating Machinery for Health Diagnostics and Prognostics

Virginia Polytechnic Institute And State University, Blacksburg VA

Investigators

Abstract

Abstract A jet engine failure at 30,000 feet or a power plant shutdown during peak operational hours can be costly from a human as well as financial standpoint. Well-established procedures exist to monitor and diagnosis fairly severe problems with rotating machinery but little progress has been made in developing techniques to detect subtle changes in machine condition for both improved diagnostics, and to develop prognostic procedures for determining remaining service life. The proposed project uses a novel application of Active Magnetic Bearings (AMBs) as actuators for applying a variety of known force inputs to a spinning rotor in order to monitor and evaluate response signals resulting from these inputs on-line. The proposed procedure allows for multiple forms of force input signals to be applied to a rotating structure. An important aspect of this approach is that the AMB(s) will be used in mid-shaft locations in conjunction with conventional support bearings. In this manner, the diagnostic/prognostic procedures are developed here for use on any general rotating machine that can be designed or retrofitted with a single AMB actuator and still be supported in the original mechanical bearings. The ability to examine a variety of known inputs and resulting outputs for condition monitoring in rotating machinery is unprecedented and the proposed technique has broad implications for improving operational safety and reducing maintenance costs in rotor-bearing systems in the aerospace, power generation, and petrochemical industries. In addition, the very nature of the proposed procedure will ultimately facilitate machinery self-diagnostics and prognostics by allowing a method for self-testing.