The consideration of sizing parameter contribution of stiffeners on the free vibrating stiffened plate elements

The objective of this study is the consideration of both stiffener and plate sizing parameter contributions to the natural frequency and establishing a relation between/among them in the stiffening process made for increasing the rigidity of a free vibrating plate element. The first period value (minimum period or maximum natural frequency), which is taken as the basis in the modeling of structural seismic behavior according to the Turkish Earthquake Regulation, is taken into consideration as an indicator in order to measure the increasing rigidity degree of the stiffened plate element (SPE) under free vibration. In this context; SPE geometry is defined with the sizing parameters called the plate element dimensions (Lx, Ly, Lz), the plate thickness (tp), the stiffened plate thickness (tw) and the stiffener number (OfsetNum). The sizing parameters of SPE is limited to their certain minimum-maximum values. 6 (six) different sizing parameters used in this thesis are combined in the MATLAB software in the matrix format as 6 (six) different combinations. For the analysis and modeling of the proposed SPE problem thereby created according to these combinations, the ANSYS finite elements program is utilized. Linear regression model is used to meaningfully correlate the related combinations with the natural frequency values. Relating the sizing parameters with each others thereby representing them with the full and/or double cases is made by using a linear regression model and described with graphical sketches. Furthermore, the strength and/or weakness of the obtained linear regression model are not solely evaluated depending on the statistical test (F Test) but also on the comparison between its reaction values and the true values of frequency obtained using the current sizing parameters.