Computational Modeling and Constructal Design Theory Applied to the Geometric Optimization of Thin Steel Plates with Stiffeners Subjected to Uniform Transverse Load

Abstract

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.

Analysis Through Constructal Design of the Influence of Spacing Between Stiffeners in the Deflection of Plates

“…To determine the appropriate size of the finite elements used in the discretization of the numerical models analyzed in this study, a mesh convergence test was previously performed, using the plate P(2,2) with Sl = 222.22 mm, St = 111.11 and hs/ts = 20.84. The size of the finite elements was reduced consecutively with reference to the plate width b = 1000 mm, according to the mesh definition criteria presented in Troina et al (2020). The result can be seen in Fig.…”

“…Following the criteria established in Troina et al (2020), the height of the stiffeners was limited to 300 mm to avoid excessive disproportion in relation to the dimensions of the plate. Likewise, ratios hs/ts less than 1 have been disregarded, avoiding stiffeners with thicknesses greater than heights.…”

“…Among them, one can highlight the investigations concerning the buckling of perforated plates (HELBIG et al, 2016;and DA SILVA et al, 2019); and stiffened plates (LIMA et al, 2018 andLIMA et al, 2020). Specifically, on stiffened plates under bending, it is possible to mention: De Queiroz et al 2019, Pinto et al (2019);and Troina et al (2020).…”

Advances in Design by Metallic Materials: Synthesis, Characterization, Simulation and Applications

“…The collection includes papers regarding the most multifaced aspects of metals as synthesis [1][2][3], treatments [2][3][4], experimental characterization [4][5][6][7], material models [7][8][9] and engineering applications [10][11][12] providing a clear cross-section of the wide variety of topics and research arguments under investigation in the scientific community now.…”

“…However, surface hardening and wear continues to represent a relevant aspect to take care on in the use of metals, as demonstrated in [6] where metal matrix composites are experimentally investigated or in [8] where numerical models are developed in a way that predicts the final effect of hardening treatments. Numerical models, sometimes powered by finite elements, are also present in other contributions with the scope to predict plasticity [9] or failures [10] or, even, to support design actions with the scope to optimize the use of metal structures [11]. Finally, the last paper in the list [12] is maybe able to provide a synthesis in the proposed concept, regarding the opportunity of metallic materials, often considered as belonging to a quite old past, in an epoch where a large assortment of new materials is emerging, as in the case of polymer composites.…”