Design of frames with partially restrained connections.

The load and resistance factor design (AISC-LRFD) specification allows the designer to consider the partial restraint (PR) in a steel connection. The success of efforts to include connection effects in the design will depend greatly on the development of reliable and practical analytical methods for the prediction of connection behavior. The moment-rotation relationships for 31 semirigid steel beam-to-column connection are developed based on seven generalized analytical connection models (web connection, top and seat, top and seat with web, web connection with seat, composite with web, composite with web and seat, and composite with web and top and seat connection model). As a result of this development, a more effective method for type PR construction can be devised. Moment-rotation curves for framed steel connections are derived from force-deformation data obtained from laboratory tension and compression tests for different types of connection segments. The laboratory force-deformation test results are analytically described by the Richard four parameter function. These parameters are dependent upon the connection geometry, stiffness and strength. A generalized analytical connection model comprising a rigid bar and nonlinear springs which simulate the connection segments is then used to generate the moment-rotation curve