When it comes to engineering, high performance is always a desired goal. In this context, regarding stiffened plates, the search for better geometric configurations able to minimize the out-of-plane displacements become interesting. So, this study aimed to analyze several stiffened plates defined by the Constructal Design Method (CDM) and solved through the Finite Element Method (FEM) using the ANSYS® software. After that, these plates are compared among each other through the Exhaustive Search (ES) technique. To do so, a non-stiffened rectangular plate was adopted as reference. Then, a portion of its steel volume was converted into stiffeners through the ϕ parameter, which represents the ratio between the volume of the stiffeners and the total volume of the reference plate. Taking into consideration the value of ϕ = 0.3, 75 different stiffened plates arrangements were proposed: 25 with rectangular stiffeners oriented at 0°; 25 with rectangular stiffeners oriented at 45° and 25 with trapezoidal stiffeners oriented at 0°. Maintaining the total volume of material constant, it was investigated the geometry influence on the maximum deflection of these stiffened plates. The results have shown trapezoidal stiffeners oriented at 0° are more effective to reduce the maximum deflections than rectangular stiffeners also oriented at 0°. It was also observed that rectangular stiffeners oriented at 45° presented the smallest maximum deflections for the majority of the analyzed cases, when compared to the trapezoidal and rectangular stiffeners oriented at 0°.

This study applied the Constructal Design Method (CDM) associated with the Finite Element Method (FEM) through computational models to perform a geometric analysis on rectangular stiffened plates of steel subjected to a uniform transverse loading, in order to minimize its maximum and central out-of-plane deflections. Considering a non-stiffened plate as reference and maintaining the total volume of steel constant, a portion of material volume deducted from its thickness was transformed into stiffeners through the ϕ parameter, which represents the ratio between the material volume of the stiffeners and the reference plate. Adopting ϕ = 0.30, 27 geometric arrangements of stiffened plates were established, being 9 arrangements for each 3 different stiffeners' thicknesses adopted: t_s = 6.35 mm, t_s = 12.70 mm and t_s = 25.40 mm. For each ts value, the number of longitudinal (N_ls) and transverse (N_ts) stiffeners were varied from 2 to 4. Thus, in each plate arrangement configured, the influence of the ratio between the height of the transverse and longitudinal stiffeners (h_ts/h_ls) was analyzed, taking into account the values 0.50; 0.75; 1.00; 1.25; 1.50; 1.75 and 2.00, regarding to the maximum and central deflections. The results have shown that transforming a portion of steel from a non-stiffened reference plate into stiffeners can reduce the maximum and central deflections by more than 90%. Moreover, it was observed that to reduce the deflections it is more effective consider h_ts > h_ls, once the ratio hts/h_ls = 2.00 was the one that led to the better mechanical behavior among the analyzed cases.