Increasing the accuracy of definition torsional geometric properties for rolled and welded beams

Abstract

Abstract The features of determining the torsional geometric properties of the cross-section of a steel beam, rolled or composed of three sheets of arbitrary thickness, are considered. When calculating warping properties, it is suggested to take into account the degree of torsional stiffness of the attached structures, that more accurately reflects the actual operation of the fixed beam in the composition of the decking. The differentiated account of rounding at the flange adjacent to the web leads in the rolled profiles to a significant structured increase in the value of the torsional constant. These factors characterize the special conditions of operation of the steel element with complex resistance, that allows determining more precisely the value of internal forces, namely the design bending moments in two planes and the bimoment, which are proportional to the distribution function of the angle of rotation of the rod along its length. It is noted that in fact the bimoment is not only determined by on the load, the elastic bending-torsional constant of the cross-section and the span of the beam, an eccentricity, as well as on the stiffness of the structure that attached to the beam.