Design of Experiment Issues in Material Component Damage Detection Including Sensor Mass and Footprint Studies
In structural health monitoring, the reliability of measured data for use in damage detection is greatly influenced by the sensor characteristics. Specific issues related to design of experiments in structural health monitoring are analyzed including sensor attachment, mass, frequency range, and footprint. A circular plate instrumented with various sensors and attachment methods (adhesive, stud) is used to study the effects of sensor bond on dynamic measurements. Attachment types are shown to have different amounts of measurement variability using an ANalysis Of VAriance technique. Differences in the amount of measurement variability lead to different damage detection thresholds. A validated sandwich metallic honeycomb panel finite element model is also used to conduct a numerical sensitivity analysis. Sensor mass is shown to reduce the sensitivity of damage detection for realistic sensor masses. The sensor footprint is shown to become an issue, by an acceleration field analysis, when the wavelength of the frequency of excitation is on the order of the sensor diameter.