Papers · Open source

Research we publish in the open.

Our published papers, from reciprocal frames to tall buildings in the wind, and the theory behind structural design proved in the Lean theorem prover.

The lean-mechanics library: eight areas of continuum mechanics, and a published paper formalised on top of them
The lean-mechanics library: eight areas of continuum mechanics, and a published paper formalised on top of them

Engineering software rests on theory that is usually trusted rather than checked: tensor identities, energy principles, closed-form solutions, homogenized stiffnesses. We formalise that theory in Lean 4 on top of Mathlib, so every statement is verified by a proof checker, down to the axioms.

The work is public on GitHub. It started from our own research on reciprocal frames, published at IASS 2013, and grew into a general library of continuum mechanics and structural theories.

Each of our papers has its own page below: structural homogenization, computational architecture, gridshell layout, machine learning for steel design, and full-scale wind monitoring of a London tower.

In this area

7 projects.

Open any project for the full write-up, capabilities and links.

Two theorems from the paper’s formalisation: the bending moment in the members is never below 2√2 − 2 of its reference value, and reaches that bound at a/l = 1 − √2/2

Open source · Lean 4 + Mathlib

lean-mechanics

Open-source Lean 4 library: tensors, kinematics, stress, constitutive laws, elastostatics, beams and plates, plus a formalised 2013 paper. No sorry, no axioms.

  • Lean 4
  • Mathlib
  • Formal verification
  • Continuum mechanics
  • Beams & plates
  • Homogenization
A nexorade surface: short bars that rest on one another in loops. Figure from the paper’s presentation

Paper · IASS 2013, Wrocław

Elastic behaviour of reciprocal systems by homogenization

Greco, Lebée and Douthe (IASS 2013): the square nexorade homogenized as a plate, with closed-form stiffness and an optimal cell geometry. Every result is now a Lean theorem.

  • Reciprocal frames
  • Nexorades
  • Homogenization
  • Plates
  • Lean 4
The roof over the Scuola Normale courtyard, shown in section through the surrounding buildings. Render: Claudio Campanile

Poster · AAG 2014

A free-form roof for the Scuola Normale Superiore

Greco, Bevilacqua and Croce (AAG 2014): a funnel-shaped glass and steel roof for the Scuola Normale Superiore courtyard, from form finding to panel moulds and sized beams.

  • Computational architecture
  • Free-form roofs
  • Glass panelization
  • Structural optimisation
  • Grasshopper
  • ABAQUS
The final quad gridshell, generated from a global smooth parameterization of the surface

Paper · IASS 2018, MIT

Optimized quad gridshells from stress and curvature fields

Greco (IASS 2018): quad-only gridshells whose edges follow principal stresses and principal curvatures at once, built on CGAL and libigl in the Capybara plugin.

  • Gridshells
  • Quad remeshing
  • Stress fields
  • Curvature
  • CGAL
  • libigl
  • Grasshopper
A steel end-plate connection, the element the models learn to design

Paper · IASS 2018, MIT

Machine learning and optimization for steel connections

Greco (IASS 2018): machine-learning models trained on Eurocode 3 designs that predict steel end-plate connections, tested on a real London project.

  • Machine learning
  • Optimization
  • Steel connections
  • Eurocode 3
  • scikit-learn
The ultrasonic anemometer on the roof of the tower, above the London skyline

Paper · UK Wind Engineering 2018

Wind-induced response of a slender tall building in London

Margnelli, Greco, Gkoktsi et al. (2018): nine months of full-scale monitoring on a slender 47-storey tower in London, with damping and response identified from the data.

  • Wind engineering
  • Tall buildings
  • Structural monitoring
  • System identification
  • Signal processing

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