Computational modeling and constructal design method applied to the geometric evaluation of stiffened thin steel plates considering symmetry boundary condition

The present article presents a geometric evaluation of stiffened plates employing the symmetry boundary condition. The computational models were developed in the software ANSYS, based on the Finite Element Method, using the SHELL281 finite element. As expected, the numerical simulations considering the symmetry demonstrated a gain in computational processing because of the possibility of developing the models in a quarter of a plate rather than simulating the entire plate, without accuracy loss. The geometric configurations are obtained through the application of Constructal Design. For this, some geometric parameters are varied (degrees of freedom) and others are kept fixed (restrictions). After that, these plates with different geometries are numerically simulated and their mechanical behaviors (deflection and stress) are compared to each other through the Exhaustive Search Technique. Then, it is possible to define the stiffened plate that has the best mechanical behavior. For this, a reference plate without stiffeners was used. In this plate part of its volume of material was transformed into stiffeners by reducing the thickness of the same, thus maintaining the value of the length and the value of the width as constants. The objective here is to determine the geometric configurations that minimize the maximum deflection and the maximum von Mises stress of the stiffened plates. The obtained results showed that, by transforming part of the volume of the reference plate into stiffeners, structural stiffness gains can be achieved in the stiffened plates when compared with the values of deflection and stress reached by the reference plate.