Accession Number : AD0670487

Title :   EXHAUSTION OF DUCTILITY IN COMPRESSED BARS WITH HOLES.

Descriptive Note : Progress rept. no. 6,

Corporate Author : BROWN UNIV PROVIDENCE R I

Personal Author(s) : Kobayashi,S. ; Mylonas,C.

Report Date : JUN 1968

Pagination or Media Count : 30

Abstract : The brittleness of mild steel subjected to tension after prior compressive prestraining has been in part attributed to the collapse of microscopic flaws or voids and to the resulting severe straining, work hardening, and sharpening of the flaw edges. A similar mechanism of embrittlement should operate also with artificial macroscopic flaws such as holes. This was checked with tests of axially compressed bars of ABS-B and of E-steel with transverse pre- or post-drilled single or double holes. The overall nominal compressive prestrain (exhaustion limit) causing brittleness in subsequent tension in bars with pre-drilled holes was about 1/4 the corresponding prestrain for solid bars of E-steel and about 1/2 for ABS-B steel. The possible causes of this difference and the modes of fracture initiation and propagation are discussed. The strong differentiation of steel quality achieved with these tests is very promising for the development of a related acceptance test. (Author)

Descriptors :   (*STEEL, DUCTILITY), RODS, COMPRESSIVE PROPERTIES, STRAIN(MECHANICS), DEFORMATION, STRESSES, MICROSTRUCTURE, FRACTURE(MECHANICS), METAL PLATES, BRITTLENESS

Subject Categories : Properties of Metals and Alloys
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE