Accession Number : ADA294278

Title :   Finite Element Shock Analysis of a Cryogenic Refrigerator.

Descriptive Note : Interim rept. Jan-Aug 93,

Corporate Author : NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD SHIP SYSTEMS AND PROG RAMS DIRECTORATE

Personal Author(s) : Schroeder, Erwin A. ; Green, Geoffrey

PDF Url : ADA294278

Report Date : DEC 1994

Pagination or Media Count : 30

Abstract : Two-stage Gifford-McMahon refrigerators are candidates for use in cooling superconducting magnets for naval applications in mine countermeasures and electric-drive propulsion for ships. For these applications, the refrigerators can be expected to undergo shock and vibration due to the motion of the platform on which they are mounted and to explosions of nearby mines. If the refrigerator is to continue operating effectively, the cylinder walls must not be permanently deformed when subjected to shock loads, and therefore stresses in the walls must not approach the elastic limit of the wall material. The stress in the cylinder walls due to specified shocks was determined by an axisymetric finite element shock analyses of the two-stage cylinder and displacer assembly. For this analysis, it was assumed that the displacers were at the bottom of their stroke and each was resting on the bottom of its cylinder. Constant horizontal and vertical accelerations of 100 g and a time-dependent acceleration with maximum amplitude of 103 g were applied to the model The analysis for the vertical shock loading produced a maximum stress of 36.7 MPa, 5 percent of yield for the 304-type stainless steel used for the cylinder walls. (MM)

Descriptors :   *SHIPS, *REFRIGERATION SYSTEMS, VIBRATION, STRESS ANALYSIS, SUPERCONDUCTORS, FINITE ELEMENT ANALYSIS, DEFORMATION, MINE COUNTERMEASURES, DISPLACEMENT, SHIP MOTION, SHOCK(MECHANICS), STAINLESS STEEL, COOLING, EXPLOSION EFFECTS, MILITARY APPLICATIONS, NAVAL OPERATIONS, YIELD STRENGTH, MAGNETS, CRYOGENICS, ELECTRIC PROPULSION.

Subject Categories : Air Condition, Heating, Lighting & Ventilating
      Marine Engineering

Distribution Statement : APPROVED FOR PUBLIC RELEASE