THE THEORETICAL MODEL AND MEASURING CALCULATION METHOD OF THE BEAM-TO-COLUMN JOINT ROTATION IN STEEL FRAMES

The beam-to-column joint rotation influences the internal force and deformation of steel frames, thus influences the design of the beam and column members. Because of the differences in research conditions and research methods, many researchers use their own definitions and methods for the calculation of beam-to-column joint rotation in steel frames, which results in some unknown errors due to the introduction of the beam and column deformation, as a result, some achieved research results can not be referred. This paper compares and analyzes some definitions and measuring calculation methods for beam-to-column joint rotation in steel frames currently used in China and other countries, proposes the improved measuring calculation method for welded joint rotation and welded-flange-bolted-web joint rotation, and verifies its accuracy and feasibility; then combines the measuring calculation method of joint rotation and uses the suitable joint simplified theoretical model to carry out the global analysis, and discusses its accuracy. The results of the finite element analysis show that the three proposed measuring calculation methods of joint rotation have high precision, and the simplified model of the global frame, which incorporates the panel zone diagonal spring, not only considers the influence of joint rotation, but also has high accuracy.