In-situ structural health monitoring, diagnostics and prognostics system utilizing thin piezoelectric sensors
AssigneeUniversity of South Carolina
InventorVictor Giurgiutiu
Life of this patent
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Abstract
A method of detecting a damaged feature within a structure includes embedding a plurality of thin piezoelectric ceramic sensors on the structure. A first sensor is excited so that the first sensor produces a responsive signal in the structure. The responsive signal is received at a second sensor. The presence or absence in the received responsive signal of at least one predetermined signal characteristic is determined, where the predetermined signal characteristic is related to existence of the damage feature.
Claims22
A system operative to detect a damage feature in a thin wall structure, said system comprising:
- an array of piezoelectric wafer sensors embedded on said structure in a predetermined pattern;
- a generator operative to excite at least one of said sensors to produce tuned ultrasonic guided waves having a frequency of at least about 200 KHz in said structure;
- and
- a signal processor operative to process received signals reflected from said damage feature at said at least one sensor so as to detect said damage feature via a pulse-echo technique.
A system operative to detect a damage feature in a thin wall structure, said system comprising:
- an array of piezoelectric wafer sensors embedded on said structure in a predetermined pattern;
- a generator operative to excite at least one of said sensors to produce ultrasonic waves having a frequency of at least about 200 KHz in said structure, said generator being operative to excite each of said sensors in said array in round-robin fashion;
- and
- a signal processor operative to process received signals at least two of said sensors so as to detect said damage feature.
A system operative to detect a damage feature in a structure, said system comprising:
- an array of piezoelectric wafer active sensors embedded on said structure in a predetermined pattern, said wafer sensors having a planar surface area no greater than approximately 169 mm2 and a thickness no greater than approximately 0.49 mm;
- a generator operative to excite each of sensors in said array in round-robin fashion to produce ultrasonic waves in said structure;
- and
- a signal processor operative to process received signals at least two of said sensors so as to detect said damage feature.
A method of detecting a damage feature present within a predetermined sensing zone in a thin wall structure, said method comprising steps of:
- (a) providing at least one piezoelectric wafer sensor embedded on said structure;
- (b) exciting said sensor with a first electrical signal spanning a predetermined frequency range;
- (c) deriving first data characteristic of a drive-point impedance of said wafer sensor as embedded on said structure;
- (d) exciting said sensor with a second electrical signal spanning said predetermined frequency range;
- (e) deriving second data characteristic of said drive-point impedance of said wafer sensor;
- and
- (f) comparing said first data and said second data.
Dependencies are inferred from the claim text.