A modular impact-based experimental setup for evaluation of EMI based structural health monitoring in highly dynamic environments

Abstract

This poster investigates the application of the electromechanical impedance (EMI) method for detecting changes in the dynamic state of engineering structures. A low-cost, modular, instrumented, impact-based experimental setup is proposed, which creates a collision between a pneumatically actuated moving striker bar, and a static instrumented incident bar at different impact velocities. The setup is made user-configurable with options for configuring the boundary condition of the incident bar and the dimension and material of the incident and striker bars. The velocity of the striker bar is controlled by varying the driving gas pressure, and the impact velocity is measured by a photoelectric sensor-based measurement system. A piezoelectric transducer attached to the incident bar is utilized for detecting the changes in dynamic state at the interface between the two bars by utilizing the EMI method. Impedance data is continuously acquired and processed during impact using a custom-made measurement and analysis suite. The measurement results are used to examine the capability of the developed system to generate customized, repeatable impact events and also monitor the impedance response of the piezoelectric sensor. The long-term goal of this research is the use of the impact-based experimental setup for examining damage detection in structures operating in highly dynamic environments. This will be done by coupling the setup with a measurement system capable of microsecond data acquisition and signal processing.