Portable real-time high-resolution digital phase-stepping shearography with integrated excitation mechanisms

A method of nondestructive testing, comprising:

• a) stepping a shearography camera through a plurality of video frames, each frame comprising an image of a test object, and storing each video frame,
• b) repeating step (a) while the test object is deformed, and
• c) generating an interference pattern representative of phase differences caused by deformation of the object,
• wherein the camera is stepped between successive video frames.

A portable real-time high-resolution digital phase-stepped shearography apparatus comprising:

• a) a shearography head including at least one movable mirror and a piezoceramic disk connected to the mirror,
• b) a programmed computer connected to said shearography head, and
• c) a display, connected to the computer,
• wherein the computer is programmed to issue signals to the piezoceramic disk so as to control movements of the mirror, and wherein the computer is programmed to store images of a test object captured by the shearography head, and to analyze said images so as to produce an interference pattern viewable on the display.

A portable real-time high-resolution digital phase-stepped shearography apparatus comprising:

• a) a shearography head including a high-resolution video camera and a Michelson interferometer including at least one movable mirror and a piezoceramic disk connected to the mirror,
• b) the shearography head being connected to a housing, wherein the housing supports at least one excitation mechanism,
• c) a programmed computer connected to said shearography head, and
• d) a display, connected to the computer,
• wherein the computer is programmed to issue signals to the piezoceramic disk so as to control movements of the mirror, and wherein the computer is programmed to store images of a test object captured by the shearography head, and to analyze said images so as to produce an interference pattern viewable on the display.

A portable real-time high-resolution digital phase-stepped shearography apparatus comprising:

• a) a shearography head including a high-resolution video camera and a Michelson interferometer including at least one movable mirror and a piezoceramic disk connected to the mirror,
• b) the shearography head being mounted on an exterior surface of a housing, wherein the housing includes at least two distinct excitation mechanisms, the excitation mechanisms being adapted to cause deformation of a test object,
• c) a programmed computer connected to said shearography head, and
• d) a display, connected to the computer,
• wherein the computer is programmed to issue signals to the piezoceramic disk so as to control movements of the mirror, and wherein the computer is programmed to store images of a test object captured by the shearography head, and to analyze said images so as to produce an interference pattern viewable on the display.

A method of nondestructive testing of an object, comprising:

• a) aiming a portable shearography unit at a test object, the shearography unit including a shearography head, and at least one excitation mechanism, the shearography unit being connected to a computer and a display,
• b) activating the shearography head to acquire images of the test object while the object is in an undeformed state,
• c) actuating the excitation mechanism so as to deform the object,
• d) activating the shearography head to acquire images of the test object while the object is in a deformed state,
• e) processing the images acquired in steps (b) and (d) in the computer so as to generate an interference pattern on the display.