Method and system for determining and verifying ply orientation of a composite laminate

A method for determining and verifying ply orientation of a composite laminate of an aircraft composite structure, the method comprising the steps of:

• preparing an edge of the composite laminate to obtain a prepared edge;
• performing with a scanning device having at least one off-axis inclined light source a first scan of the prepared edge using the at least one off-axis inclined light source to direct light at a first acute angle to a first area on the prepared edge to produce a first scanned image;
• rotating 180 degrees an orientation of the at least one off-axis inclined light source relative to the prepared edge, such that the off-axis inclined light source directs light at a second acute angle symmetrically opposite the first acute angle;
• performing with the scanning device a second scan of the prepared edge using the at least one off-axis inclined light source to direct light at the symmetrically opposite second acute angle to the first area on the prepared edge to produce a second scanned image;
• transferring the first scanned image and the second scanned image from the scanning device to a processing device for processing;
• comparing the first scanned image and the second scanned image to determine a ply orientation of each ply of the composite laminate, wherein the ply orientation is determined based on light source reflections of the at least one off-axis inclined light source;
• preparing a baseline matrix comprising a baseline ply orientation of a baseline composite laminate of the aircraft composite structure;
• and,
• verifying the ply orientation of the composite laminate against the baseline ply orientation of the baseline matrix.

A system for determining and verifying ply orientation of a composite laminate, the system comprising:

• a composite laminate that is cured and comprises at least one prepared edge and a plurality of plies, each ply having a ply orientation;
• and
• a scanning assembly comprising:
• a scanning device having at least one off-axis inclined light source configured to direct light at a first acute angle to a first area on the prepared edge of the composite laminate to illuminate and capture a first scanned image, and further configured to reorient the direction of the off-axis light source to a second acute angle symmetrically opposite the first acute angle, to direct light at a symmetrically opposite second acute angle to the first area on the prepared edge to illuminate and capture a second scanned image;
• a processing device coupled to the scanning device, the processing device configured to receive and process the first scanned image and the second scanned image from the scanning device;
• and
• a baseline matrix comprising a baseline ply orientation of a baseline composite laminate,
• wherein the system provides a ply orientation determination of each ply of the composite laminate based on light source reflections of the at least one off-axis inclined light source and a comparison of the first scanned image and the second scanned image, and further wherein the system provides a ply orientation verification of the composite laminate using the baseline matrix.