NTRS - NASA Technical Reports Server

Back to Results
Ability of Impedance-Based Health Monitoring To Detect Structural Damage of Propulsion System Components AssessedImpedance-based structural-health-monitoring uses piezoelectric (PZT) patches that are bonded onto or embedded in a structure. Each individual patch behaves as both an actuator of the surrounding structural area as well as a sensor of the structural response. The size of the excited area varies with the geometry and material composition of the structure, and an active patch is driven by a sinusoidal voltage sweep. When a PZT patch is subjected to an electric field, it produces a mechanical strain; and when it is stressed, it produces an electric charge. Since the patch is bonded to the structure, driving a patch deforms and vibrates the structure. The structure then produces a localized dynamic response. This structural system response is transferred back to the PZT patch, which in turn produces an electrical response. The electromechanical impedance method is based on the principle of electromechanical coupling between the active sensor and the structure, which allows researchers to assess local structural dynamics directly by interrogating a distributed sensor array. Because of mechanical coupling between the sensor and the host structure, this mechanical effect is picked up by the sensor and, through electromechanical coupling inside the active element, is reflected in electrical impedance measured at the sensor s terminals.
Document ID
Document Type
Martin, Richard E.
(Cleveland State Univ. Cleveland, OH, United States)
Gyekenyesi, Andrew L.
(Ohio Aerospace Inst. Brook Park, OH, United States)
Sawicki, Jerzy T.
(Cleveland State Univ. Cleveland, OH, United States)
Baaklini, George Y.
(NASA Glenn Research Center Cleveland, OH, United States)
Date Acquired
September 7, 2013
Publication Date
June 1, 2005
Publication Information
Publication: Research and Technology 2004
Subject Category
Quality Assurance And Reliability
Distribution Limits
Work of the US Gov. Public Use Permitted.
No Preview Available