Chapter 3 Real-Time State Detection in Highly Dynamic Systems Ryan A. Kettle, Andrew J. Dick, Jacob C. Dodson, Jason R. Foley, and Steven R. Anton Abstract This article investigates the feasibility of real-time state detection on a microsecond timescale for use in highly dynamic systems and presents an experimental setup of a high-rate dynamic system coupled with real-time measurement architecture with the goal of detecting changes in the interfacial state of the system. The feasibility of microsecond state detection is assessed through a preliminary timing study. The experimental setup consists of two colliding aluminum bars and includes the option of changing the bar’s boundary conditions and the interface material between the bars. A piezoelectric transducer will be used for detecting changes in dynamic interfacial state by employing electromechanical impedance monitoring and the measurement data from this will be acquired and processed at high speeds using deterministic realtime tools and methodology. Damage detection algorithms from the structural health monitoring community will be used for rapid detection of changes in state. The eventual goal of this work is to adapt currently used methods or to develop entirely new high speed state detection algorithms to be implemented on the real-time system for state detection. This technology has the potential to be used in many applications, including the aerospace, civil, and energy industries among others. Keywords Real-time • Structural health monitoring (SHM) • Electromechanical impedance (EMI) method • State detection • Dynamic systems 3.1 Introduction The overall goal of this research is to create a system that enables rapid, microsecond detection in changes of state in highly dynamic environments. In this case state change is defined as any change to the physical properties of a material and can include changes in stiffness, boundary conditions, and mass. Detection of changes in state will be accomplished through high-speed sensing of a system’s mechanical impedance, which is made possible by adapting the structural health monitoring (SHM) community’s electromechanical impedance (EMI) method for damage detection. A potential benefit of this technology is the possibility to pair it with a control system that could work on the same microsecond time scale as the monitoring. This pairing would enable systems to react nearly instantaneously to changes in state as they occur in realtime. Possible applications for this technology are far reaching because it could be implemented in any situation where microsecond monitoring, decision making based on such monitoring, or rapid automated reaction via a control system is required or advantageous. One potential use of this technology is on the drill strings used in the mining industry. As a drill bit digs down deeper into the ground they will often dig into different layers of rock with different material properties, thus causing a change in the boundary conditions. With this technology immediate adjustments in torque, speed, etc. can be made. Additionally, a multitude of problems can occur due to different parts of the drill string making contact with the side of the wellbore and this could potentially be properly identified in real-time. Another potential use is to enable real-time monitoring of fluid flow around a hypersonic aircraft. This information could then be used to make rapid adjustments in the aircraft’s control surfaces allowing for enhanced flight handling characteristics. A final application of this technology to be considered is deployment in buildings. Building conditions could be monitored in real-time during an earthquake. If the system detects R.A. Kettle ( ) • S.R. Anton Department of Mechanical Engineering, Tennessee Technological University, Cookeville, TN 38505, USA e-mail: rakettle42@students.tntech.edu A.J. Dick Department of Mechanical Engineering, Rice University, Houston, TX 77005, USA J.C. Dodson • J.R. Foley Air Force Research Laboratory (AFRL/RWMF), Eglin AFB, FL 32542-5430, USA © The Society for Experimental Mechanics, Inc. 2016 J. De Clerck, D.S. Epp (eds.), Rotating Machinery, Hybrid Test Methods, Vibro-Acoustics & Laser Vibrometry, Volume 8, Conference Proceedings of the Society for Experimental Mechanics Series, DOI 10.1007/978-3-319-30084-9_3 27
RkJQdWJsaXNoZXIy MTMzNzEzMQ==