A hybrid topology optimization algorithm for static and vibrating shell structures

AbstractArchitects and engineers have been always attracted by concrete shell structures due to their high efficiency and plastic shapes. In this paper the possibility to use concrete shells to support footbridges is explored. Starting from Musmeci’s fundamental research and work in shell bridge design, the use of numerical form-finding methods is analysed. The form-finding of a shell-supported footbridge shaped following Musmeci’s work is first introduced. Coupling Musmeci’s and Nervi’s experiences, an easy construction method using a stay-in-place ferrocement formwork is proposed. Moreover, the advantage of inserting holes in the shell through topology optimization to remove less exploited concrete has been considered. Curved shell-supported footbridges have been also studied, and the possibility of supporting the deck with the shell top edge, that is along a single curve only, has been investigated. The form-finding of curved shell-supported footbridges has been performed using a Particle-Spring System and Thrust Network Analysis. Finally, the form-finding of curved shell-supported footbridges subjected to both vertical and horizontal forces (i.e. earthquake action) has been implemented.

Download Full-text

Adaptive topology optimization of shell structures

10.2514/6.1996-4114 ◽

1996 ◽

Cited By ~ 1

Author(s):

Kurt Maute ◽

Ekkerhard Ramm

Keyword(s):

Topology Optimization ◽

Shell Structures ◽

Adaptive Topology

Download Full-text

A topology optimization algorithm based on topological derivative and level-set function for designing phononic crystals

Engineering Computations ◽

10.1108/ec-06-2021-0352 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Rolando Yera ◽

Luisina Forzani ◽

Carlos Gustavo Méndez ◽

Alfredo E. Huespe

Keyword(s):

Topology Optimization ◽

Level Set ◽

Optimization Algorithm ◽

Phononic Crystal ◽

Phononic Crystals ◽

Lagrangian Function ◽

Topological Derivative ◽

Content Type ◽

Level Set Function ◽

Set Function

PurposeThis work presents a topology optimization methodology for designing microarchitectures of phononic crystals. The objective is to get microstructures having, as a consequence of wave propagation phenomena in these media, bandgaps between two specified bands. An additional target is to enlarge the range of frequencies of these bandgaps.Design/methodology/approachThe resulting optimization problem is solved employing an augmented Lagrangian technique based on the proximal point methods. The main primal variable of the Lagrangian function is the characteristic function determining the spatial geometrical arrangement of different phases within the unit cell of the phononic crystal. This characteristic function is defined in terms of a level-set function. Descent directions of the Lagrangian function are evaluated by using the topological derivatives of the eigenvalues obtained through the dispersion relation of the phononic crystal.FindingsThe description of the optimization algorithm is emphasized, and its intrinsic properties to attain adequate phononic crystal topologies are discussed. Particular attention is addressed to validate the analytical expressions of the topological derivative. Application examples for several cases are presented, and the numerical performance of the optimization algorithm for attaining the corresponding solutions is discussed.Originality/valueThe original contribution results in the description and numerical assessment of a topology optimization algorithm using the joint concepts of the level-set function and topological derivative to design phononic crystals.

Download Full-text