Abstract: In order to reveal more information on initial stiffness of T-stubs, a brief introduction on calculative methods for predicting mechanical behaviors of T-stubs was firstly presented . Though comparing these methods, the continuous beam model which bending stiffness of bolts are considered was determined to calculate initial stiffness of T-stubs. Comparisons between theoretical and numerical results on initial bending stiffness of a series of T-stubs are presented and good agreements exist. Further, parametric analysis was conducted mainly on flange thicknesses and locations of bolts of T-stubs. The parametric analysis results show that with increase of flange thicknesses the distance between axis of bolts and edges of flange decreases, the influence of bending stiffness on initial stiffness of T-stubs increases. For mild steel T-stubs, when bending stiffness of bolts is considered, initial stiffness improve less than 5%. But for high strength steel (HSS) T-stubs, initial stiffness improves even more than 30%. Thus for HSS T-stubs, bending stiffness of bolts cannot be neglected when calculated initial stiffness of T-stubs.

Key words: T-stub, initial stiffness, bending stiffness of bolts, continuous beam model, high strength steel (HSS)