Post-limit stiffness and ductility of end-plate beam-to-column steel joints

Abstract

A procedure for the evaluation of ductility in steel joints is presented. Using the component method as background, a non-linear analysis for a number of end-plate beam-to-column joints is performed that is capable of identifying the ''yield'' sequence of the various components and the failure of the joint. Each component is characterised using a bilinear approximation for the force-displacement relation. Comparing these results with the corresponding experimental results leads to a proposal of the post-limit stiffness of the various components. A component ductility index is proposed for each component as a means of classification with respect to ductility, using the three ductility classes currently proposed in the literature. A joint ductility index is also proposed, which can be used to verify available rotation against the structure required rotation. Ó

Experimental assessment of the ductility of extended end plate connections

“…This property can be quantified by means of an index, w j that relates the maximum rotation of the joint, / max to the rotation value corresponding to the joint plastic resistance, / M Rd [18,30,31]:…”

“…Also, two different values for / max are considered: / Cd and / M max . Similar ductility index can also be defined for a single component, w i , by replacing the rotation values with the axial deformation values [30,31].…”

Parametric study and analytical characterization of the bolt–column (BC) joint for single-layer reticulated structures

“…High-strength bolts exhibit a brittle response up to failure, and the resistance of each bolt is given by F u ¼ 0:9f u Á A s [18]. By applying the principles of Hooke's law, the elastic stiffness of the bolt k b can be expressed as…”

Reliability assessment of the post-limit stiffness and ductility of steel joints

“…In order to assess the influence of component characterization on the global response of joints, a probabilistic description for each variable is adopted. While fairly accurate estimates already exist in the literature for the quantification of k e and F Y for the various components [3], little or no guidance at all is available on the characterization of k p and D f [7]. Accordingly, two alternative possibilities are considered:…”