Influence of Restrained Torsion on the Bearing Capacity of I-Beam

Abstract

Torque has a significant impact on the carrying capacity of I-beams. In connection with this practical interest is the development of engineering methods of calculating beams under the action of torque. The paper investigated the bearing capacity of an I-beam loaded in the middle of the passage of concentrated force. Beam simply supported at both ends, the concentrated force is applied with an eccentricity relative to the longitudinal axis of the beam. Found that the stress-strain state of thin-walled open section beam depends on its passage, the height of the cross section, rigidity characteristics and the estimated resistance, as well as the eccentricity of application of concentrated force. To account for these parameters derived generalized indicator $\bar{e}$ the relative eccentricity. Maximum load capacity of I-beam cross section is defined on the basis of multivariate numerical calculations using finite element shells, the variation of the relative parameters and the location of load application, taking into account the geometrical and physical nonlinearity of the structure. Span and rigidity design parameters were varied so that the product of flexural-torsional characteristics of the beam on its passage kl was changed in the range from 0.8 to 7.The relative eccentricity varies from 0 to 9, the calculated resistance from 210 to 515 MPa. Propose a formula for testing the resistance of an I-beam under the action of torque. Given a table for determining ϕ _t - factor that determines the carrying capacity of the beam. For small eccentricities the loss of carrying capacity is manifested in the sharp increase in the angles of torsion and horizontal displacements at a load equal to the critical. At large eccentricities it determines the deformation of the beam.