Accession Number : AD0013809

Title :   AN EXPERIMENTAL INVESTIGATION AND LIMIT ANALYSIS OF NET AREA IN TENSION

Corporate Author : BROWN UNIV PROVIDENCE RI DIV OF APPLIED MATHEMATICS

Personal Author(s) : BRADY, W.G. ; DRUCKER, D.C.

Report Date : MAY 1953

Pagination or Media Count : 1

Abstract : The weakening effect of holes in tension members was re-examine d with respect to plastic action. By using the maximum shearing-stress yield criterion and the Mises criterion, upper and lower bounds for the limit load were computed for thin sheets with 6 configurations of staggered rows of holes. The limit load was defined as the force required for unrestricted plastic flow across the entire member; the hole patterns were chosen to give the same least net area for 2 or more rows of holes as for one row by using the rule, s to the power of 2/4g, where s equals the pitch of any 2 successive holes in the chain and g equals the gage of the same holes. Current design specifications were compared with the results from tests of hot-rolled steel and 61S-T6 Al-alloy sheets cut from 1/16-in. stock and having the long dimension in the direction of rolling. The test pieces were pulled to a total extension in a 10-in.-gage length, sufficiently large to ensure flow across the specimen. Both the analysis and tests indicated that the configuration of holes is important in a sheet under tension and must be taken into account for an accurate analysis. The s to the power of 2/4g rule does not properly take this effect into account. A 0.75 stress ratio is given for all configurations tested. This value is appreciably above many of the test results which range from 0.63 to 0.92, depending on the number of rows of holes and the uniformity of the test specimen.

Descriptors :   , ACCURACY, CONFIGURATIONS, HOLES(OPENINGS), HOT PRESSING, PLASTIC FLOW, PLASTICS, ROLL, ROLLING(METALLURGY), SHEETS, SIZES(DIMENSIONS), SPECIFICATIONS, STEEL, TEST AND EVALUATION, THINNESS.

Distribution Statement : APPROVED FOR PUBLIC RELEASE