Thermographic nondestructive testing (TNDT) of honeycomb composite structural parts of Atlas space launch vehicles
- General Dynamics Space Systems Division, San Diego, CA (United States)
Thermography is a means of recording the patterns of heat emission from a surface. Thermographic nondestructive testing (TNDT) uses this technology to detect sub-surface defects. Generally, a heat pulse is applied to a surface that is thermographically monitored. If a sub-surface defect exists that locally reduces or improves the thermal properties of the material, the surface thermal pattern will be perturbed over the defect. TNDT has been used successfully on a wide variety of composite laminates, filament-wound structures, sandwich structures, and foam-insulated cryogenic tanks. Both real structures with real delamination and impact damage, as well as test panels with simulated delaminations, face sheet disbonds, and interply implants have been tested. For some of these applications, TNDT is the best technique. The thrust structure at the aft end of the Atlas space launch vehicle is a composite sandwich comprised of aluminum honeycomb core with fiberglass/phenolic face sheets. The surface area of this structure is approximately 600 ft{sup 2}. In 1992, General Dynamics Space Systems Division (GDSS) began using TNDT for quality verification of these complex composite parts. TNDT has been used on these parts during manufacture and assembly, and on the launch pad at Cape Canaveral. The NDT technique previously used on these parts, since their design in 1957, was ``coin tap.`` Compared to this method, TNDT provides a greatly improved inspection in less time and at a lower cost. A heat gun with a diffuser attachment is used to heat the inspection area while the area is monitored thermographically. TNDT is a rapid, remote, non-contact, highly portable, real-time scanning technique that can provide a well-documented video record of subsurface structural details including facesheet disbonds and skin delaminations. A specification and test procedure has been written, equipment has been procured, and personnel have been trained and certified.
- OSTI ID:
- 220707
- Report Number(s):
- CONF-940449-; ISBN 0-8194-1549-9; TRN: IM9620%%101
- Resource Relation:
- Conference: Society of Photo-Optical Instrumentation Engineers conference on intelligent information systems, Orlando, FL (United States), 4-8 Apr 1994; Other Information: PBD: 1994; Related Information: Is Part Of Thermosense 16: An international conference on thermal sensing and imaging diagnostic applications; Snell, J.R. Jr. [ed.]; PB: 330 p.; Proceedings/SPIE, Volume 2245
- Country of Publication:
- United States
- Language:
- English
Similar Records
Damage tolerance assessment of bonded composite doubler repairs for commercial aircraft applications
Thermographic NDT based on transient temperature field under Joule effect heating