Cyclic Yield Reversal in Steel Building Connections

Abstract

Inelastic design of steel structures to withstand seismic forces requires a knowledge of the behavior of connections when subjected to cyclically reversed loading. This paper contains a description of the design and quasi-static testing of selected steel beam-to-column connection specimens. The motivations for the choice of connection types and over-all geometry of the specimens are described, relating them to full-size prototypes used in actual building frames. The characteristics of the test installation are described, including means of loading, type of lateral support provided, etc. The programs of cycling of most of the tests are presented in terms of the deflection of the tip of the cantilever beam. Typical hysteresis diagrams and failure photographs are also included. The outstanding features of the behavior of several specimens during testing are described and compared, and possible explanations given for particular aspects. It is shown that steel connections are remarkably resistant to failure due to cyclically induced damage. The results of all of the tests are summarized, and an attempt made to draw comparisons and conclusions of some-what broader applicability.