Since 2016

Topology finding tackles the exploration of the topological properties of a structure, by analogy and in complement to form finding.

Shell-like structures allow to elegantly and efficiently span large areas. Quad meshes are natural patterns to represent these surface objects, which can also serve for mapping other patterns. Patterns for these shells, vaults, gridshells or nets can represent the materialised structure, the force equilibrium or the surface map. The topology of these patterns constrains their qualitative and quantitative modelling freedom for geometrical exploration. Unless topological exploration is enabled.
Parametric design supporting exploration and optimisation of the geometry of structures is spreading across the community of designers and builders. Unfortunately, topological design is lagging, despite some optimisation-oriented strategies for specific design objectives. Strategies, algorithms and tools for topological exploration are necessary to tackle the multiple objectives in architecture, engineering and construction for the design of structures at the architectural scale.
The task of structural design is rich and complex, calling for interactive algorithms oriented towards co-design between the human and the machine. Such an approach is complementary and empowered with existing methods for geometrical exploration and topology optimisation.
The present work introduces topology finding for efficient search across the topological design space.
This thesis builds on three strategies for topology finding of singularities in quad-mesh patterns, presented from the most high-level to the most low-level approach.
  • Geometry-coded exploration relies on a skeleton-based quad decomposition of a surface including point and curve features. These geometrical parameters can stem from design heuristics to integrate into the design, related to the statics system or the curvature of the shell, for instance.
  • Graph-coded exploration relies on the topological strips in quad meshes. A grammar of rules allows exploration of this strip structure to search the design space. A similarity-informed search algorithm finds design with different degrees of topological similarity. Designs optimised for single objectives can inform this generation process to obtain designs offering different trade-offs between multiple objectives. A two-colour search algorithm finds designs that fulfil a two-colouring requirement of two-colouring. This topological property allows a partition of the pattern elements that many structural systems necessitate.
  • String-coded exploration relies on the translation of the grammar rules into alphabetical operations, shifting encoding from a phenotype mesh to a genotype string. Modifications, or mutations, of the string transform the genotype and change the phenotype of the design. String or vector encoding opens for the use of search and optimisation algorithms, like linear programming, genetic algorithms or machine learning.

This research is implemented in compas_pattern, a package of COMPAS.

This research is a joint effort with the Block Research Group, Institute of Technology in Architecture, ETH Zürich.

People

Collaborators

Institutions

  • Laboratoire Navier, École des Ponts ParisTech
  • Block Research Group, ETH Zürich

  • All
  • Architectural Geometry

 Feature-based Topology Finding of Patterns for Shell Structures – R. Oval et al. (2019)

Authors

R. Oval, M. Rippmann, R. Mesnil, T. Van Mele, O. Baverel, P. Block

Abstract

This paper introduces topology finding of patterns such as beam grids for gridshells or voussoir tessellations for masonry vaults, among others. The authors refer to topology finding, by analogy and in complement to form finding, as the design of the connectivity of patterns in order to follow architectural, structural and construction requirements. This paper presents an automated generation and a rule-based exploration for coarse quad meshes that encode the data about the singularities and their relationships in the pattern. The automated generation relies on the medial axis of an input shape, and the rule-based exploration on a quad mesh grammar. These coarse quad meshes are further computed for the design of structured patterns integrating the boundary and features of the input shape. This design framework is an aid for topological exploration of patterns for shell-like structures by architects and engineers.

Status

Accepted

Journal

Automation in Construction

Links

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 Topology Finding of Structural Patterns – R. Oval et al. (2018)

Authors

R. Oval, M. Rippmann, R. Mesnil, T. Van Mele, O. Baverel, P. Block

Abstract

This paper presents a strategy for the exploration of the topology of structural patterns, such as beam grids for gridshells or voussoir tessellations for masonry vaults. The authors define topology finding, by analogy and in complement to form finding, as the design of the connectivity of patterns in relation to architectural and structural requirements. The method focuses on the design of the singularities in the pattern through the automatic generation and subsequent rule-based editing of a coarse quad mesh that encodes the properties of the singularities and their relationships before mesh densification, pattern mapping, geometrical exploration and performance assessment.

 

Date

Sept. 2018

Conference

Advances in Architectural Geometry 2018

Links

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 Patterns for Masonry Vault Design – R. Oval et al. (2017)

Authors

R. Oval, M. Rippmann, T. Van Mele, O. Baverel, P. Block

Abstract

This paper presents a methodology to generate structural patterns for masonry vault design. First, a quad- dominant block decomposition is proposed based on a medial axis pruning/rebranching method from an input that comprises outer and inner boundaries as well as point and curve features, representing a point load or a crease in the structure, for instance. The meshing and smoothing of the resulting set of patches is straightforward and the mesh densities can be controlled globally and locally. The resulting meshes can be processed for form finding and further optimisation. Second, fabrication-and construction-aware rules to convert these form-found patterns into a tessellation are proposed.

Date

Sept. 2017

Conference

IASS 2017

Links

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