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An extensive experimental and theoretical investigation was carried out at Lehigh University with the purpose of determining the static carrying capacity of welded plate girders. This paper constitutes a report on the experimental work. It is, presented in four parts:Part 1 "The Test Girder."
Part 2 "Tests on Plate Girders Subjected to Bending."
Part 3 "Tests on Plate Girders Subjected to Shear."
Part 4 "Tests on Plate Girders Subjected to Combined Bending and Shear."The objective of the Investigation was to determine the postbuckling strength of thin web plate girders. Presently, the design of transversely stiffened plate girders is limited to girders whose web depth to web thickness ratios do not exceed the value of 170, a limit derived from the linear buckling theory. In discussing the application of the theoretical buckling formulas, Timoshenko (Ref 253, p. 415) suggests using a factor of safety of only 1.5 against web buckling, since its occurrence does not cause immediate failure of the girder. Similar considerations are advanced by many foreign specifications to justify their factors of safety against web buckling. For instance, the German specifications require 1.35 or 1.25 as factors of safety for principal loading and for combined principal and secondary loading, respectively. The corresponding Swiss specifications recommend values of 1.3, 1.5 arid 1.8 for plate girders used in buildings, highway bridges and railroad bridges, respectively. In Belgium, a factor of safety of 1.35 against buckling due to shear and 1.15 against buckling due to bending has been suggested (Ref. 162, p. 81). Thus, the safety factors differ considerably and seem to depend on loading conditions and other factors. In order to clarify these uncertainties, to obtain information of the actual carrying capacity and to develop design recommendations, this Plate Girder Project was initiated.Sponsored jointly by the American Institute of Steel Construction, The U. S. Department of Commerce -Bureau of Public Roads, the Pennsylvania Department of Highways, and the Welding Research Council, the research project at Lehigh University was guided by the "Welded Plate Girder Project Committee" of the Welding Research Council.