Ryan Kettle successfully defended his Masters of Science degree in Mechanical Engineering entitled “Electromechanical Impedance Based Microsecond State Detection” on March 14, 2018. Congratulations Ryan!
Abstract:
This thesis concerns the development of various technologies necessary to increase the speed of electromechanical impedance based state detection to the microsecond timescale. The eventual end goal of this research is the creation of a microsecond state detection system for structures operating in highly dynamic environments capable of monitoring the structure during dynamic events in real-time. Measurements are made using the electromechanical impedance method, which utilizes a piezoelectric transducer bonded to the surface of the structure as both an actuator and sensor. State detection is the process of continuously monitoring a structure with the goal of detecting and identifying any physical change that effects the structure and so is related to the field of structural health monitoring. Conventionally though, structural health monitoring is applied to large civil structures which undergo slow structural changes, such as crack propagation and creep; therefore both the measurements and time between measurements of the structure take place over large time scales. By decreasing the measurement time sufficiently physical changes occurring in a structure during dynamic events can be detected. This drastic decrease in measurement time will be achieved through the use of: a novel multi-tonal excitation signal, field-programmable gate arrays, and high-frequency MHz excitation signals. This work applies these methodologies to static structure and lays the foundations for further work to be done on dynamic testing.