Advanced Laser Technology for Composite Bond Evaluation

To reduce weight and improve fuel efficiency, composites are being using 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 innovative aspect of the proposed SBIR Phase II program is to fabricate a factory-hardened process head (or heads) to be mated to the compact laser device under development. The process head would include the best features of the Phase I process head approaches, as well as those of the process head approaches developed under the CAI program. This advancement is essential for rapid insertion of the LBI process into aircraft manufacturing plants operations and aircraft maintenance depots.