CORRELATION OF LABORATORY TESTS WITH FULL SCALE SHIP PLATE FRACTURE TESTS
Initially, standard Charpy impact tests were made on all of the steels and the results compared with those for the 72 inch wide plate tests. The comparisons showed that no direct correlation existed between these two widely differing types of notched specimen tests. One of the striking inadequacies of the impact test was the failure to show a difference between steels A and C, a difference which was most pronounced in the 72 inch wide plate tests. Separation of steels A and C to some extent, and in the right direction, was achieved by the use of prestrained Charpy keyhole-notch test bars, but the overall results did not warrant the further use of this test, as the temperatures of tough to brittle transition were too low to use direct correlation procedures. Because of this, a program was initiated in which the effects of specimen size, geometry, and testing velocity on the temperature of transition from tough to brittle behavior were investigated. The results of slow bend testing (at 1 inch per minute) of standard V-notch Charpy impact bars did not separate Steels A and C. The transition temperatures for these two steels were appreciably lowered however, as compared to those obtained from the impact test, and fell in the range of temperatures observed for the large plate test results. An increase in the specimen size to 0.788 inches high x .394 inches wide gave transition temperatures for most of the steels tested which were 10 deg to 20 deg F below those for the 72 inch wide plate tests. Finally, specimens were prepared which were full plate thickness in width and 0.788 inches in height. The tough to brittle transition, as measured by energy absorption values, occurred for these specimens at temperatures which agreed fairly well with the transition ranges for the 72 inch wide plates. Specimens of this type, when tested across a 40 millimeter span, had the disadvantage of not breaking completely. By drilling the compression zone from the specimen and using a hardened steel pin on which to apply the load, as described by Schnadt, it was possible to circumvent this difficulty. The present report is confined to the outline of experiments with this "Schnadt type" specimen and the results pertaining to those experiments.
Pennsylvania State University, University ParkSchool of Mineral Industries, Experiment Station
University Park, PA USA 16802
Ship Structure CommitteeNational Academy of Science, 2101 Constitution Avenue, NW
Washington, DC USA 20418
- WAGNER, C
- Klier, E P
- Publication Date: 1948-5-12
- Features: References;
- Pagination: 43 p.
- TRT Terms: Fracture tests; Plate bearing test; Steel plates; Transition point
- Identifier Terms: Ship Structure Committee
- Old TRIS Terms: Charpy tests; Ship plates
- Subject Areas: Marine Transportation; Materials;
- Accession Number: 00330978
- Record Type: Publication
- Source Agency: Ship Structure Committee
- Report/Paper Numbers: SSC- 18 Prog Rpt.
- Contract Numbers: NObs-31217, NObs-34231
- Files: TRIS
- Created Date: May 21 1981 12:00AM