INVESTIGATION OF THE BEHAVIOR FACTOR IN DUAL SYSTEMS WITH SIDE PLATE CONNECTION

After the 1994 Northridge and 1995 Kobe earthquakes and the extensive damage in moment resisting connections side plate connection was introduced. This connection is able to hold plastic hinge far from the beam-column connection and has sufficient strength and ductility so plastic hinges can form in beams. The structure is expected to withstand large deformations resulting from lateral loads, this property of structures is defined as ductility. In order to include ductility in structure analysis and also to use entire capacity of the structure, the conception of R-factor is used in linear analysis. To evaluate the ductility and R-factor of a structure, use of nonlinear analysis is inevitable. In the present study models of dual systems with side plate connections, various types of bracing, different braced spans and lateral load distribution patterns has been nonlinearly analyzed using PERFORM-3D at different heights (4, 8 and 12 stories). Then using Uang method ductility, extra resistance and behavior factor of the models were obtained and compared. On the basis of this study, the side plate connection increases R-factor and as the number of bracing increases, R-factor increases as well. Studying chevron, diagonal and X bracing indicates that R-factor is the greatest for diagonal bracing and smallest for chevron bracing. Comparison of uniform, triangular and modal lateral loading patterns indicates that R-factor reaches its highest value for triangular lateral load distribution and the lowest value is obtained through triangular loading pattern.