Conceptual Design of Diagrids and Hexagrids by Distribution of Lattice Structures

Matteo Bruggi

doi:10.3389/fbuil.2020.00080

Abstract

The conceptual design of grid systems in tall buildings is addressed combining optimization and multiscale analysis of lattice structures. Macroscopic properties of lattices with given cross-section are available in the literature for different cell topologies. A multi-material optimization problem is formulated to find the distribution of a prescribed discrete set of candidate cross-sections and shapes such that the structural weight of the grid is minimized under constraints on the lateral displacements of the building. Preliminary numerical simulations are shown addressing the design of tall buildings that employ diagrids and hexagrids.

Highlights

Diagrids and hexagrids are special tubular structures that adopt inclined members instead of conventional vertical columns to carry both vertical and lateral loads
Hexagrids take full advantage of rigid diaphragms (RDs) to reduce their deformability, whereas diagrids are less affected by such a stiffening
The analyses address the grids represented in Figure 3: (a) a diagrid having reference length L = 8 m, made of tubes with circular hollow cross-section, diameter√φ = 558 mm and thickness th = 16 mm, slenderness L/ I/A = 42; (b) a hexagrid having reference length L = 4 m, made of tubes with square hollow cross-section, √side l = 650 mm and thickness th = 40 mm, slenderness L/ I/A = 17

Summary

Introduction

Diagrids and hexagrids are special tubular structures that adopt inclined members instead of conventional vertical columns to carry both vertical and lateral loads (see e.g., Mele et al, 2014; Montuori et al, 2015). It is well-known that perimeter grids are an efficient solution to cope with horizontal forces in high-rise buildings. Investigations on the optimal layout of the members of a diagrid can be found e.g., in Moon (2010), Montuori et al (2014), and Angelucci and Mollaioli (2017)

Methods

Results

Conclusion