Accession Number : ADA953351

Title :   An Engineering Evaluation of Residual Stress Effects (OSRD Reports 3348, 3580, 4396)

Descriptive Note : Special literature evaluation rept.

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE METALS PROCESSING LAB

Personal Author(s) : Palme, Richard ; Udin, Harry ; Wulff, John

PDF Url : ADA953351

Report Date : 20 Sep 1954

Pagination or Media Count : 43

Abstract : This report consists of an engineering evaluation of OSRD Reports 3348, 3580, and 4396. An introduction containing an orienting discussion of the general problem of residual stresses and their effects on the mechanical behavior of weldments is followed by detailed summaries of the above three reports. The results and conclusions contained in the reports are discussed and evaluated in the light of the present literature. The following conclusions are reached in this evaluation: (1) Concerning the effects of residual stress on ballistic performance, the most significant point in this (and other) reports is that appreciable plastic deformation of a weldment obliterates any locked-in stress system. Fracture of ballistically loaded welded armor in the field is nearly always accompanied by extensive plastic deformation. Therefore, if it can be shown by field tests that deformation precedes fracture, the question of effect of locked-in stress becomes relatively unimportant. (2) The subject reports do not give clear-cut answers as to the effect of residual stress on performance; nor will these answers be found in the literature. The reason is straightforward. To investigate the effect of a parameter (residual stress in this instance) means must be found to vary this parameter while holding everything else of unknown effect constant. (3) The metallurgical effects of post-weld thermal treatments appear to outweight the effect of these treatments on residual stress levels. (4) If research on the effect of residual stress on ballistic performance is to be continued, it is strongly recommended that specimen geometry, test temperature, and loading rates be devised such that failure involving no plastic deformation are induced. (5) From the practical standpoint of building armored equipment, consideration should be given to changing process schedules so that facilities now devoted to or intended for stress-relieving the final weldment can be used for intermediate stress...

Descriptors :   *RESIDUAL STRESS, *WELDMENTS, FRACTURE(MECHANICS), MECHANICAL PROPERTIES, PLASTIC DEFORMATION, STEEL, TERMINAL BALLISTICS

Subject Categories : Couplers, Fasteners, and Joints
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE