masoud pourhasan shahri

In the steel plate shear wall, the thin steel plate is connected to the boundary elements, Therefore, forces transfer from the panel to the columns and increase the required cross sectional area of the columns. Separating the steel panel from the columns, reduces the seismic demands on the columns and prevent from the premature failure of the columns and the collapse of the entire structure. However, this technic decreases the lateral resistance of the system, therefore in such a case, using high yield steel (HYS) for the panel or utilizing a thicker steel plate may be required. In this paper, the seismic behavior of the steel plate shear walls connected to frame beams only (SSW-BO) is studied through nonlinear finite element analysis by ABAQUS software. After validating the numerical model against available experimental results, the effect of the edge stiffeners on the behavior of SSW-BO is explored. Based on the results, changing the edge stiffener cross section does not influence the seismic behavior, the stiffness, the lateral resistance and the dissipated energy of SSW-BO if the stiffeners are not connected to the top and bottom beams. However, connecting the stiffeners to the beams, drastically improve the seismic behavior and hysteretic characteristics of SSW-BO. It should be noted that, in such a case, greater forces may apply to the beams which should be considered in the seismic design of these members.

In the conventional steel plate shear walls (SPSWs), the steel plate is connected to all boundary elements, but in the steel plate shear walls connected to frame beams only (SSW-BOs) the plate is not connected to columns. The separation of the plate from the columns decreases the flexural demands of the columns and prevents the premature failure of the columns. In this paper, the effect of opening properties on the seismic behavior of SSW-BOs is studied through nonlinear finite element modeling and analysis. Based on the obtained results, initial stiffness, lateral strength and dissipated energy were higher in the specimen containing square opening compared to the one with circular opening. Moreover, increasing the opening dimension altered the tension field path from a line along the diagonal of the panel to the corners of the opening and degraded the seismic performance of SSW-BO. The most critical opening location is the central one since it disturbs the lateral load path in the panel more than any other locations. Finally, the results of numerical simulations are used to propose a simple method for estimation of the lateral stiffness and strength of SSW-BOs with openings based on the stiffness and strength reduction factors and the corresponding values of the solid SSW-BOs.

The purpose of this study was to investigate the effect of transformational leadership on the motivation of public services. The statistical population of the research is all employees of district 4 of Mashhad municipality. Using a Morgan table, 127 students were selected as the statistical sample. The questionnaire was randomly distributed among them. In this research, the Transformation Leadership Questionnaire (AWF) and Alois (2000) and Perry and Wise Public Service Motivation Questionnaire (1997) were used. This research was a descriptive-correlational study. The reliability of the questionnaires was obtained using Cronbach's alpha coefficient greater than 0.7, which can be said that the instrument has an appropriate reliability. In this research, descriptive and inferential statistics were used to analyze the data. In the test section, the hypothesis of the research was utilized by using the smart PLS software using partial least squares method. The results showed that transformational leadership positively affects the motivation of public services.

The purpose of this study was to investigate the effect of transformational leadership on the motivation of public services. The statistical population of the research is all employees of district 4 of Mashhad municipality. Using a Morgan table, 127 students were selected as the statistical sample. The questionnaire was randomly distributed among them. In this research, the Transformation Leadership Questionnaire (AWF) and Alois (2000) and Perry and Wise Public Service Motivation Questionnaire (1997) were used. This research was a descriptive-correlational study. The reliability of the questionnaires was obtained using Cronbach's alpha coefficient greater than 0.7, which can be said that the instrument has an appropriate reliability. In this research, descriptive and inferential statistics were used to analyze the data. In the test section, the hypothesis of the research was utilized by using the smart PLS software using partial least squares method. The results showed that transformational leadership positively affects the motivation of public services.