CAUSES OF CLEAVAGE FRACTURE IN SHIP PLATE, TESTS OF RESTRAINED WELDED SPECIMENS AND HATCH CORNER SPECIMENS OF MILD STEEL

This report summarizes the results of a series of tests conducted as a supplementary program to the research investigation that was carried out on the behavior of high yield strength structural steels under the U. S. Navy Research Contract NObs-31222. The main objective of this auxiliary program was to provide a basis for comparison of results from the high yield strength structural steels and the extensive results that were obtained in the numerous investigations conducted on the ship quality mild steels. The temperatures at which the mode of fracture changed from shear to cleavage type were determined for two of the mild steels by means of tests on several types of specimens. Several widely different types of specimens were used in this investigation. The first type of specimen was made in two different sizes but with the same thickness of steel plate. They were made to provide restraint to plastic flow at a corner produced by welding together steel plates set along three mutually perpendicular planes. Other speciments were in the form of simple notched plates of different sizes. Also, tensile tests were made on 3/4-inch thick flat plate specimens. Some of these contained welds only along their longitudinal axes while others had both transverse and longitudinal welds. The results of the tests on the two sizes of large restrained welded specimens indicated that the width and height of this type of specimen apparently had little or no effect on the transition temperature. The results of the tests performed on notched plate specimens showed that the transition temperatures determined by tests of the two sizes of this type of specimen were in good agreement with each other, but that the transition temperatures as determined by notched plate tests were considerably lower than those obtained with large restrained welded specimen tests. Tension tests of simple welded flat plate specimens indicated that the transition temperatures of the steels were not materially affected by the introduction of a single longitudinal weld along the loading axis or by the presence of two intersecting welds at the center of the unnotched plate specimen.

• Corporate Authors:

  University of California, Berkeley

  Berkeley, CA  United States  94720

  Ship Structure Committee

  National Academy of Science, 2101 Constitution Avenue, NW
  Washington, DC  United States  20418
• Authors:
  • Boodberg, A
  • Parker, E R
• Publication Date: 1949-8-19

Media Info

• Features: References;
• Pagination: 33 p.

Subject/Index Terms

• TRT Terms: Cleavage fracture; Fracture mechanics; Hatch covers; High strength steel; Plate bearing test; Tension tests; Transition point
• Identifier Terms: Ship Structure Committee
• Old TRIS Terms: Hatch corners; Hatch stress; Tensile test
• Subject Areas: Marine Transportation; Materials;

Filing Info

• Accession Number: 00330982
• Record Type: Publication
• Source Agency: Ship Structure Committee
• Report/Paper Numbers: SSC- 27 Prog Rpt.
• Contract Numbers: NObs-31222, NObs-34232
• Files: TRIS
• Created Date: May 21 1981 12:00AM