Accession Number : ADA301293

Title :   Pocketing Mechanics of SRM Nozzle Liner.

Descriptive Note : Technical paper,

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION HUNTSVILLE AL GEORGE C MARSHALL SPACE FLIGHT CENTER

Personal Author(s) : Verderaime, Vincent S.

PDF Url : ADA301293

Report Date : MAR 1986

Pagination or Media Count : 28

Abstract : A systems approach was adopted to study the pocketing phenomena on a solid rocket nozzle liner. The classical thermoelastic analysis was used to identify marginally strained regions on the composite liner erosion surface and at a depth coincident with the peak value of the across ply coefficient of thermal expansion. A failure criterion was introduced which included a thermal term and permitted failure assessment over the charred liner. The method was verified by satisfactory application to a reported related experiment. Liner pocketing mechanism was attributed to very localized material degradation caused during manufacturing process either by reduction of fiber strength and/or by concentration of resin volume fraction. Pocketing scenario over the degraded material was constructed with supporting formulation to predict size of fissures with respect to degraded material size and location in the liner and with burn time. Sensitivities of liner material parameters were determined to influence test programs designed to update mechanical data base of carbon cloth phenolic over the char temperature range.

Descriptors :   *THERMAL PROPERTIES, *COMPOSITE MATERIALS, *LININGS, *FAILURE(MECHANICS), *SOLID PROPELLANT ROCKET ENGINES, *ROCKET NOZZLES, TEST AND EVALUATION, DATA BASES, PEAK VALUES, TEMPERATURE, MECHANICAL PROPERTIES, MANUFACTURING, DEGRADATION, SIZES(DIMENSIONS), PARAMETERS, POLYMERS, FORMULATIONS, COMPOSITE STRUCTURES, FRACTURE(MECHANICS), REDUCTION, EROSION, THERMAL EXPANSION, STRENGTH(GENERAL), SPACE SHUTTLES, RANGE(EXTREMES), BURNING RATE, CARBON PHENOLIC MATERIALS, THERMOELASTICITY, CHARRING.

Subject Categories : Laminates and Composite Materials
      Thermodynamics
      Solid Propellant Rocket Engines

Distribution Statement : APPROVED FOR PUBLIC RELEASE