Structural optimization strategies for simple and integrally stiffened plates and shells

Abstract

Purpose-Shells are widely used structural systems in engineering practice. These structures have been used in the civil, automobile and aerospace industries. Many shells are designed using the finite element analysis through the conventional and costly trial and error scheme. As a more efficient alternative, optimization procedures can be used to design economic and safe structures. Design/methodology/approach-This paper presents developments, integration and applications of reliable and efficient computational tools for the structural optimization of variable thickness plates and free-form shells. Topology, sizing and shape optimization procedures are considered here. They are applied first as isolated subjects. Then these tools are combined to form a robust and reliable fully integrated design optimization tool to obtain optimum designs. The unique feature is the application of a flexible integrally stiffened plate and shell formulation to the design of stiffened plates and shells. Findings-This work showed the use of different optimization strategies to obtain an optimal design for plates and shells. Both topology optimization (TO) and structural shape optimization procedures were considered. These two optimization applications, as separate procedures produce new designs with a great improvement when compared to the initial designs. However, the combination of stiffening TO and sizing optimization using integrally stiffened shells appears as a more attractive tool to be used. This was illustrated with several examples. Originality/value-This work represents a novel approach to the design of optimally stiffened shells and overcomes the drawbacks of both topology optimization and structural shape optimization procedures when applied individually. Furthermore, the unique use of integrally stiffened shell elements for optimization, unlike conventional shell-stiffening optimization techniques, provided a general and extremely flexible tool.

Strengthening effects of stiffeners on arbitrarily stiffened plates and regularly stiffened plates subject to biaxial stress

“…Afonso and coworkers presented developments, integration and applications of reliable and efficient computational tools for structural optimization of the stiffened plates. In their work, different optimization strategies were used to obtain an optimum design of the stiffened plate [5]. Paik et al presented a series of ALPS/ULSAP (analysis of large plated structures/ ultimate limit state assessment program) methods to determine the ultimate strength of stiffened plates.…”

H-DGTP—a Heaviside-function based directional growth topology parameterization for design optimization of stiffener layout and height of thin-walled structures

“…Because of their high rigidity-toweight ratio, stiffened plates or shells have been widely used as primary or secondary load bearing components in automotive, aerospace and civil engineering structures (Inoue et al 2002;Afonso et al 2005;Chen et al 2007). Topology optimization has been regarded as the most general type of optimization problems and has been used to improve an initial design by variation of its geometrical and material properties with regards to a set of prescribed objectives and constraints (Sigmund and Maute 2013).…”

Stiffener Layout Optimization of Inlet Structure for Electrostatic Precipitator by Improved Adaptive Growth Method

“…Thus it can be used to solve the stiffener layout of the inlet structure. In these decades, many scholars have proposed a variety of structural topology optimization techniques to deal with the problems of the stiffener layout of plate and shell structures, such as homogenization method and density method [3][4][5][6]. However, most research efforts to date have focused on transforming the problem of stiffener layout pattern design into a search for an optimal distribution of material.…”