Low-Power System Design for Impedance-Based Structural Health Monitoring

Simple item page
dc.contributor.authorKim, Jinaen
dc.contributor.committeechairHa, Dong Samen
dc.contributor.committeememberReed, Jeffrey H.en
dc.contributor.committeememberMartin, Thomas L.en
dc.contributor.committeememberArmstrong, James R.en
dc.contributor.committeememberTront, Joseph G.en
dc.contributor.departmentElectrical and Computer Engineeringen
dc.date.accessioned2014-03-14T21:23:20Zen
dc.date.adate2008-01-09en
dc.date.available2014-03-14T21:23:20Zen
dc.date.issued2007-12-04en
dc.date.rdate2008-01-09en
dc.date.sdate2007-12-10en
dc.description.abstractMaintenance of the structural integrity and damage detection are critical for all massive and complicated new and aging structures. A structural health monitoring (SHM) system intends to identify damage on the structure under monitoring, so that necessary action can be taken in advance to avoid catastrophic results. Impedance-based SHM utilizes a piezoelectric ceramic as a collocated actuator and sensor, which measures the electrical impedance of the piezoelectric ceramic over a certain frequency range. The impedance profile of a structure under monitoring is compared against a reference profile obtained from the healthy structure. An existing approach called the sinc method adopts a sinc wave excitation and performs traditional discrete Fourier transform (DFT) based structural condition assessment. The sinc method requires rather intensive computing and a digital-to-analog converter (DAC) to generate a sinc excitation signal. It also needs an analog-to-digital converter (ADC) to measure the response voltage, from which impedance profile is obtained through a DFT. This dissertation investigates system design approaches for impedance-based structural health monitoring (SHM), in which a primary goal is low power dissipation. First, we investigated behaviors of piezoelectric ceramics and proposed an electrical model in order to enable us to conduct system level analysis and evaluation of an SHM system. Unloaded and loaded piezoelectric ceramics were electrically modeled with lumped linear circuit components, which allowed us to perform system level simulations for various environmental conditions. Next, we explored a signaling method called the wideband method, which uses a pseudorandom noise (PN) sequence for excitation of the structure rather than a signal with a particular waveform. The wideband method simplifies generation of the excitation signal and eliminates a digital-to-analog converter (DAC). The system form factor and power dissipation is decreased compared to the previously existing system based on a sinc signal. A prototype system was implemented on a digital signal processor (DSP) board to validate its approach. Third, we studied another low-power design approach which employs binary signals for structural excitation and structural response measurement was proposed. The binary method measures only the polarity of a response signal to acquire the admittance phase, and compares the measured phase against that of a healthy structure. The binary method eliminates the need for a DAC and an ADC. Two prototypes were developed: one with a DSP board and the other with a microcontroller board. Both prototypes demonstrated reduction of power dissipation compared with those for the sinc method and for the wideband method. The microcontroller based prototype achieved an on-board SHM system. Finally, we proposed an analytical method to assess the quality of the damage detection for the binary method. Using our method, one can obtain the confidence level of a damage detection for a given damage distance.en
dc.description.degreePh. D.en
dc.identifier.otheretd-12102007-160159en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-12102007-160159/en
dc.identifier.urihttp://hdl.handle.net/10919/40400en
dc.publisherVirginia Techen
dc.relation.haspartDissertation_Kim_V2.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectDamage Detection Performanceen
dc.subjectBinary Methoden
dc.subjectWideband Methoden
dc.subjectStructural Health Monitoringen
dc.subjectPiezoelectric Ceramic Electrical Modelen
dc.titleLow-Power System Design for Impedance-Based Structural Health Monitoringen
dc.typeDissertationen
thesis.degree.disciplineElectrical and Computer Engineeringen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.leveldoctoralen
thesis.degree.namePh. D.en

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Dissertation_Kim_V2.pdf
Size:
1.79 MB
Format:
Adobe Portable Document Format
Download

Collections

Doctoral Dissertations