Dr. Trey Gordon has 20 years experience in x-ray source/detector design, x-ray imaging physics, ultrafast laser design and NDE. Currently at Boeing Research & Technology, at the Boeing Company, he has been studying new methods for Material State Awareness in aerospace structures using non-linear UT, laser UT material property measurements and x-ray diffraction for residual stress measurements in metals. His Ph.D was in Applied Physics from Stanford University and entitled “Time-gated medical x-ray imaging with an ultrashort pulse, laser-produced-plasma x-ray source.” Prior to coming to Boeing in 2007, he had been at GE for 12years as a Non-destructive Evaluation Scientist at GE Global Research (digital x-ray detector array design and performance) and Image Systems Scientist at GE Medical Systems leading design efforts for both digital x-ray and CT products

Abstract

Material State Awareness and NDE in CFRP Aerospace Structures

New aerospace structural designs are beginning to include Carbon Fiber Reinforced Plastic (CFRP) laminate composites that are tailored to provide stiffness in particular directions to optimize performance. As a result, new approaches are being investigated at The Boeing Company to evaluate and characterize the material state of these structures as a part of the design and part qualification processes.

Currently, the standard ultrasonic inspection process uses a cross ply measurement of acoustic attenuation to assess the consolidation quality of the CFRP. While this is useful for porosity, delamination or inclusion detection, it does not address a primary interest in the use of CFRP. A more appropriate measure of the quality of the laminate (material state) would be the determination of the in-plane characteristics to evaluate the desired directional stiffness of the product.

The new in-plane acoustic velocity measurements are performed using insertion and receiving sensors spaced known distances apart on the surface of the CFRP structure and in a desired directional orientation for evaluation. The time and distance of the transmission of the head wave from the insertion to the sensing allows a velocity calculation. This method is demonstrated using laser generated ultrasound and a pin transducer receiver. Measurement of the in-plane acoustic head wave velocity has been found to correlate to the CFRP material modulus from mechanical tests.

This presentation will cover the material state awareness vision, a new in-plane ultrasonic velocity measurement approach to measure modulus, and also provide an overview of non-destructive evaluation and testing activities at The Boeing Company.