In the mid-20th century, aircraft manufacturing companies such as Pratt & Whitney began implementing composite materials into their designs. Since that time composite pieces have become an integral part of airplanes because of their superior mechanical properties and relatively light weights.
A composite is a material that consists of two or more materials with different physical properties. When combined together, the joint piece has better physical characteristics than the individual parts. In fact, there are multiple aircraft today which consist of over 50% composite material—which has dramatically increased plane fuel efficiency.
One issue with composite pieces though, is their ability to lose structural integrity while keeping the same appearance on the surface. Currently there is no process used to detect defects that is defined and accepted across the industry, which is the motivation behind this project.
We designed a validation protocol to inspect composite pieces and improve customer safety and business efficiency. In order to validate that a given composite piece does not contain defects, we use Non-Destructive Evaluation (NDE). NDE is the process of inspecting, testing or evaluating materials, components or assemblies for discontinuities in characteristics without destroying the serviceability of the part.
For this project, our team is using an ultrasonic C-Scan machine. This machine emits ultrasonic waves throughout a material and gathers feedback which allows for detection of defects beneath the surface of the piece. The benefits of the C-Scan are dimensional accuracy, detailed resulting images, and its accessibility at the FAMU-FSU College of Engineering. At the conclusion of this project, our team provides a case study on the characteristics and process steps involved with testing composite materials for defects using a C-Scan machine.