Stiffness Modeling of Bolted T-Stub Connection Components

The results of 48 T-stub component tests and eight full-scale T-stub connection tests are used to develop and calibrate a comprehensive T-stub connection stiffness model. The model, based on basic component spring theory, incorporates deformations from tension bolt elongation, bending of the T-stub flange, elongation of the T-stem, slip of the T-stub relative to the beam flange, bearing deformation of the T-stem, and bearing deformation of the beam flange. Nonlinear material models, for both the tension bolts and the T-stub base material, are included. A sophisticated slip/bearing routine accounts for the misalignment of shear bolt holes and variable slip conditions. Comparisons of multilinear model predictions with experimental data show that the model accurately predicts connection stiffness response and deformation at failure.