TITLE: Stages of Nondestructive test that will effect the inspectability of final assemblies and establishing traceable records for in process defects in advanced composite assemblies.

Abstract:
The inspection of detail parts has a direct effect on the inspectability of final assemblies. This paper will address the importance of controlling discontinuities in parts that require repetitive nondestructive testing and will also cover the need for traceability of defects found in early stages of part manufacture. Some of the tractors that effect the inspectability of assembled advanced composite structures are the number of discontinuites in detail parts, even though the discontinuities are within acceptable limits.

The vary nature of these accepted discontinuites may hinder the inspection of' the part at an assembled stage. An example of this scenario is a bonded assembly consisting of a laminate (with a large amount of porositiy) and a core section to be adhesively bonded. When the laminate is bonded to the core section, a subsequent test would have to be performed to ensure the bond integrity. In the case of an ultrasonic inspection where sound would be transmitted through the laminate and the amplitude of the bondline signal is monitored, the porosity in the laminate would have an adverse effect on the lest results, due to the loss of sensitivity, thus hindering the bondline inspection and possibly giving erroneous r esults.

Establishing traceable records for in-process inspection is an important part of quality control, not only for necessitating storage requirements but also for future reference in identifying accepted defects or repaired areas. Due to the nature of composite materials with detail parts going into assemblies and repairs not readily noticeable on the inspection surface, there needs to be a sufficient defect tracking system. The identification of defects is important, so that defects already dispositioned or repaired al curlier stages of' manufacture are not re-evaluated at final assembly, resulting in added inspection tune and reporting efforts.

Source: Proceedings of the 'NDE applied to Process Control of Composite Fabrication' - Conference, 4-5 Oct 1994 St. Louis, Missouri. Publisher and Organizer: Nondestructive Testing Information Analysis Center (NTIAC) Texas Research Institute Austin, Inc. Austin, Texas [http://www.ntiac.com] [Buying the Proceedings]