Development of a Compact Laser for Damage Detection and the Laser Bond Inspection (LBI) Process

To reduce weight and improve fuel efficiency, composites are being used in aircraft construction at an accelerating rate. The presence of material defects in these composite structures can lead to disastrous failure under flight loads. Many classes of these defective regions are undetectable by conventional NDI techniques such as ultrasonic probing. A revolutionary new inspection technology invented at Boeing and under development at LSP Technologies, Inc., offers a practical solution to locating composite damage/defect regions in laminate and laminate-adhesive bonds in aircraft structures. This inspection technique, known as Laser Bond Inspection (LBI), is a proof-testing method that applies a well-controlled dynamic stress to the composite structure, and senses the failure of weak laminate or weak adhesive bonds in response to the stress. The LBI process has been developed using a research laser that is not optimized for the process. Now, as a result of the SBIR Phase I, LBI can be implemented by a new advanced laser device that will reduce both the size and cost of the presently used research laser. This advancement is essential for rapid insertion of the LBI process into aircraft manufacturing plants operations and aircraft maintenance depots.