This work searched for the optimal geometrical configuration of simply supported stiffened plates subjected to a transverse and uniformly distributed load. From a non-stiffened reference plate, different geometrical configurations of stiffened plates, with the same volume as the reference plate, were defined through the constructal design method. Thus, applying the exhaustive search technique and using the ANSYS software, the mechanical behaviors of all the suggested stiffened plates were compared to each other to find the geometrical configuration that provided the minimum deflection in the plate’s center when subjected to this loading. The optimum geometrical configuration of stiffeners is presented at the end of this work, allowing a reduction of 98.57% for the central deflection of the stiffened plate if compared to the reference plate. Furthermore, power equations were adjusted to describe the deflections for each combination of longitudinal and transverse stiffeners as a function of the ratio between the height and the thickness of the stiffeners. Finally, a unique equation for determining the central deflections of the studied stiffened plates based only on the number of longitudinal stiffeners without significantly losing accuracy has been proposed.

Stiffened thin steel plates are structures widely employed in aeronautical, civil, naval, and offshore engineering. Considering a practical application where a transverse uniform load acts on a simply supported stiffened steel plate, an approach associating computational modeling, Constructal Design method, and Exhaustive Search technique was employed aiming to minimize the central deflections of these plates. To do so, a non-stiffened plate was adopted as reference from which all studied stiffened plate’s geometries were originated by the transformation of a certain amount of steel of its thickness into longitudinal and transverse stiffeners. Different values for the stiffeners volume fraction (φ) were analyzed, representing the ratio between the volume of the stiffeners’ material and the total volume of the reference plate. Besides, the number of longitudinal (Nls) and transverse (Nts) stiffeners and the aspect ratio of stiffeners shape (hs/ts, being hs and ts, respectively, the height and thickness of stiffeners) were considered as degrees of freedom. The optimized plates were determined for all studied φ values and showed a deflection reduction of over 90% in comparison with the reference plate. Lastly, the influence of the φ parameter regarding the optimized plates was evaluated defining a configuration with the best structural performance among all analyzed cases.

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Verificação de modelos computacionais para placas com enrijecedores submetidas a carregamento transversal uniforme Verification of computational models for stiffened plates under uniform transverse loading RESUMO Este artigo apresenta a verificação de modelos computacionais para a análise da deflexão em placas reforçadas com enrijecedores. No presente estudo, essas placas enrijecidas são analisadas quando submetidas a esforços transversais uniformemente distribuídos. A verificação é realizada por meio da comparação entre os resultados numéricos obtidos neste estudo com resultados encontrados em referências científicas publicadas por outros autores. Os modelos computacionais foram desenvolvidos no software ANSYS, que é baseado no Método dos Elementos Finitos (MEF), e utilizam dois tipos de elementos finitos diferentes: SHELL93 e SOLID95. São utilizadas duas variações na geometria de cada um desses dois tipos de elementos, totalizando, portanto, quatro modelos computacionais distintos entre si. Os testes de independência de malha evidenciam um comportamento convergente das simulações realizadas para os dois exemplos de placa retangular analisados: uma com apenas um enrijecedor central e outra com dois enrijecedores ortogonais em formato de cruz. Os resultados da verificação dos modelos mostram que os quatro tipos de elementos apresentam boa concordância entre si em todos os problemas avaliados. Além disso, os resultados gerados pelos modelos computacionais são compatíveis com as referências científicas utilizadas para comparação.

Slenderness is a remarkable geometrical characteristic of thin steel plates. When a slender plate is subjected to an axial compression loading, a mechanical behavior called buckling can occur, causing an out-of-plane displacement. This instability phenomenon can be divided into elastic buckling (linear) and elasto-plastic buckling (nonlinear), depending on dimensional, constructive, or operational aspects. Moreover, in several practical situations, it is necessary to provide holes on thin steel plates, causing stress redistribution and changes in its buckling behavior. The present work purposes a buckling study in square and rectangular plates, simply supported, with two different centered perforations types: longitudinal hexagonal and transverse hexagonal. Numerical simulation, using the ANSYS ® software, was employed to determine the critical buckling load and the ultimate buckling load of the plates. The constructal design method was applied, allowing evaluating the variation effect of the degree of freedom H 0 /L 0 (being H 0 the width and L 0 the length of the perforation) on the plate's mechanical buckling behavior. The hole volume fraction (ϕ) was another considered parameter, corresponding to cutouts of 10%, 15%, 20%, and 25% of the total plate volume. The results showed the direct influence of the H 0 /L 0 ratio on the buckling type, allowing the definition of a buckling stress limit curve for each cutout type and hole volume fraction. Besides, the constructal design method, associated with the exhaustive search technique, enabled to define the optimized geometric configuration for each hole type that conducted the plate to a maximized mechanical performance.

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