Laser bond inspection (LBI) in conjunction with bond process control is an enabling technology to transition primary bonded composite structures. Composite structures, when joined using adhesive bonding rather than traditional rivets or fasteners, require a new inspection process to verify the strength and safety of the composite bonds. LBI is a stress test to ensure that adhesively fastened structures are joined correctly using a bond’s response to a high-energy pulsed laser generated stress wave to detect structurally substandard bonds. LBI is the only reliable and mature method capable of assessing the integrity of adhesive bonds in composite structures and detecting kissing bonds, a bond line defect where two surfaces are in intimate contact but are not properly bonded. Future work in this technology area includes analyzing data for bond integrity in the field. Tests also need to be done to define a wider gamut of materials, thicknesses, and joint designs so the technology can be expanded to other platforms. Additionally, hardware improvements must be made to the laser bond inspection unit for usability in a manufacturing environment. This technology is a significant step in enabling bonded aircraft structures use in the field.
