Accession Number : ADA309908

Title :   Ultrasonic Inspection of Titan IV Stage I Baffles,

Corporate Author : AEROSPACE CORP EL SEGUNDO CA MECHANICS AND MATERIALS TECHNOLOGY CENTER

Personal Author(s) : Nokes, J. P.

PDF Url : ADA309908

Report Date : 01 MAR 1996

Pagination or Media Count : 14

Abstract : The first-stage Titan Iv engine employs a set of seven CRES 347 stainless-steel baffles mounted to the injector for protection against combustion instabilities. Recent baffle design changes resulted in the failure of several baffles during engine acceptance testing. These failures generated concerns about the structural integrity of the new baffle design, which was employed in the construction of a number of engines, including those of the Titan Iv K-23 vehicle, which was on a Cape Canaveral Air Force Station (CCAFS) launch pad. A Finite Element Model (FEM) was used to evaluate the baffle structure under extremes in both thermal and pressure loading. The FEM analysis indicated that poor-quality baffles would begin to debond at the braze joints during engine acceptance testing. Baffle failure during flight could result in significant performance degradation, leading to mission failure. To identify marginal baffles, a NonDestructive Evaluation (NDE) technique sensitive to small (<0.1-in.) debonds in the baffle braze joints was needed that could be applied to post-fired baffles in installed engines. Such a technique was developed at The Aerospace Corporation. Laboratory tests revealed that ultrasonic techniques could provide the necessary flaw resolution while being suitable for a field inspection of the engines. Additional effort was then applied toward determining the detection limits for the ultrasonic inspection of the baffle assembly, as well as providing baseline test procedures and tooling. This was followed by additional tooling development and modification performed in cooperation with engineers at Aerojet Corporation. Prior to the K-23 inspection, the procedures were verified on production hardware at the Aerojet facility in Sacramento, CA. The baffles on the K-23 vehicle engines (S/N 1030 & 1031) were inspected on March 1-2, 1995.

Descriptors :   *NONDESTRUCTIVE TESTING, *STAINLESS STEEL, *ULTRASONIC TESTS, *BAFFLES, THERMAL PROPERTIES, MATHEMATICAL MODELS, ACCEPTANCE TESTS, LABORATORY TESTS, DETECTION, DEGRADATION, TOOLS, FINITE ELEMENT ANALYSIS, RESOLUTION, FAILURE, TEST METHODS, COMBUSTION, DEFECTS(MATERIALS), QUALITY, BASE LINES, LIMITATIONS, MISSIONS, INSPECTION, PRESSURE, ENGINES, AIR FORCE FACILITIES, ASSEMBLY, INSTABILITY, FIELD CONDITIONS, BRAZING, JOINTS, STRUCTURAL INTEGRITY.

Subject Categories : Test Facilities, Equipment and Methods
      Guided Missiles

Distribution Statement : APPROVED FOR PUBLIC RELEASE