Development of Large Diameter High Chamber Pressure Throat Insert Materials. Volume II.
Abstract
Volume II describes the nondestructive testing of the PG coated throat inserts, the design analysis of the 7 inch PG coated throat, and the design analysis of the 7 inch nozzle, nozzle fabrication, and the post-firing analysis of the ablative components. In the nondestructive testing, microscopy, radiography, alcohol wipe, holographic interferometry, acoustic emission, and spectral audiosonic prints were studied and evaluated. Microscopy and holography appeared to be the most useful. Extensive analytical studies were conducted on the large PG coated throat inserts using an anisotropic axisymmetric, finite element computer program. The effects on the stress state of size, coating thickness, coating thickness distribution, end face grooves, substrate thickness, backside substrate restraint, and variations in properties of the coating and substrate material were calculated. It was concluded that PG coated insert is in a high-stress condition, both as-fabricated and during firing. More accurate characterization of the properties of these materials is required. Also, several effects, such as plastic deformation and graphitization of the PG coating which can occur during the thermal history, need to be better understood to arrive at a more accurate determination of the stress state. It was concluded, and later confirmed by tests, that the 7 inch nozzle was structurally adequate. Several moderate cost ablative materials were found to be satisfactory for the service conditions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1972
- Accession Number
- AD0907192
Entities
People
- Eugene L. Olcott
- James Murray
- Wendell A. Stephens