Acoustic emission linear pulse holography
First Claim
Patent Images
1. A method for monitoring growing defects in an inspection zone within a structure, comprising the following steps:
- mounting a plurality of discrete sensors, including a reference sensor, at fixed locations in a preselected array along a surface of the structure adjacent to the inspection zone;
detecting the acoustic waves emitted from a growing defect in the inspection zone as output pulses generated at each sensor;
determining the phase components of the output pulse generated at each sensor at a selected time as a function of the pulse transmission time between the sensor and the reference sensor and as a function of a synthetic frequency selected from the pulse bandwidth; and
combining the resulting cumulative phase information into a synthetic hologram of the defect.
1 Assignment
0 Petitions
Accused Products
Abstract
Defects in a structure are imaged as they propagate, using their emitted acoustic energy as a monitored source. Short bursts of acoustic energy propagate through the structure to a discrete element receiver array. A reference timing transducer located between the array and the inspection zone initiates a series of time-of-flight measurements. A resulting series of time-of-flight measurements are then treated as aperture data and are transferred to a computer for reconstruction of a synthetic linear holographic image. The images can be displayed and stored as a record of defect growth.
-
Citations
5 Claims
-
1. A method for monitoring growing defects in an inspection zone within a structure, comprising the following steps:
-
mounting a plurality of discrete sensors, including a reference sensor, at fixed locations in a preselected array along a surface of the structure adjacent to the inspection zone; detecting the acoustic waves emitted from a growing defect in the inspection zone as output pulses generated at each sensor; determining the phase components of the output pulse generated at each sensor at a selected time as a function of the pulse transmission time between the sensor and the reference sensor and as a function of a synthetic frequency selected from the pulse bandwidth; and combining the resulting cumulative phase information into a synthetic hologram of the defect. - View Dependent Claims (2, 3, 4)
-
-
5. An apparatus for monitoring growing defects in an inspection zone within a structure, comprising:
-
a plurality of discrete sensors, including a reference sensor, mounted at fixed locations in a preselected array along a surface of the structure adjacent to the inspection zone, each sensor having the capability of detecting acoustic waves emitted from a growing defect within the structure as an output pulse; means for determining the phase components of the output pulses generated at each sensor at a selected time as a function of the pulse transmission time between the sensor and the reference sensor and as a function of a synthetic frequency selected from the pulse bandwidth; and means for combining the resulting cumulative phase information into a synthetic hologram of the defect.
-
Specification