Accession Number : AD0709451

Title :   DESIGN OF LATERALLY UNSUPPORTED COLUMNS. THE STRENGTH AND BEHAVIOR OF LATERALLY UNSUPPORTED COLUMNS.

Descriptive Note : Progress rept.,

Corporate Author : LEHIGH UNIV BETHLEHEM PA FRITZ ENGINEERING LAB

Personal Author(s) : Lim,Lee C. ; Lu,Le-Wu

Report Date : JUN 1970

Pagination or Media Count : 240

Abstract : The report is a study of the behavior of laterally unsupported as-rolled steel beam-columns under constant axial load and monotonically increasing strong-axis end moments. The first part presents the theoretical solutions for the occurrence of inelastic lateral-torsional buckling of beam-columns with restraints provided at the ends to resist weak-axis bending and warping of the section. The solutions are based on either the tangent modulus concept or the reduced modulus concept of unloading of the yielded portions. The different degrees of restraints are studied and their beneficial effects are compared with the solutions for pinned-end beam-columns, free to warp and bend about the weak-axis. The theoretical solutions are then compared with the available test results and the CRC interaction formula. In the second part, the same method is extended to solve the buckling problems in continuous beam-columns with warping and weak-axis bending restraints at the joints. Sample numerical results are obtained for three-span continuous beam-columns. They are used to check the accuracy of the method currently recommended by the AISI and the AISC for predicting the buckling strength of an assembly of beams and beam-columns. (Author)

Descriptors :   (*BEAMS(STRUCTURAL), LOADS(FORCES)), SUPPORTS, METAL JOINTS, BUCKLING, SHEAR STRESSES, DEFLECTION, PREDICTIONS, DIFFERENTIAL EQUATIONS

Subject Categories : Structural Engineering and Building Technology

Distribution Statement : APPROVED FOR PUBLIC RELEASE