Coding Architecture II: FS26

Week 10 – Structural Analysis

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Interfacing with structural analysis tools to evaluate and optimize the performance of our designs.

Table of Contents

Introduction

This week introduces structural analysis as a critical layer in the design-to-fabrication pipeline. Geometry alone is no longer sufficient — we now evaluate whether our systems actually perform.

We begin with a guest lecture by Patrick Studer, focusing on the fundamentals of structural engineering, followed by a hands-on session using Karamba3D to simulate and assess the performance of your timber structures.

The goal is to understand how forces flow through your system and how design decisions affect structural behavior.

Structural Design Fundamentals

Structural engineering translates design intent into load-bearing systems.

Key objectives:

Typical workflow:

  1. Concept / draft
  2. Modelling and calculation
  3. Dimensioning and verification
  4. Detailed design

Structural thinking must be integrated early. The system, not the shape, defines performance.

Loads, Combinations & Supports

Structures are governed by the loads they carry. These include permanent loads (self-weight), variable loads (wind, snow, occupancy), and exceptional loads (e.g. earthquakes). Their magnitude depends on site conditions and geometry, and they are applied as line or surface loads within the model.

Since loads act simultaneously, they are combined using safety factors. Two limit states define the design space: ULS for structural safety and SLS for usability (deflection, vibration). Variable loads are reduced using combination factors (ψ) to represent realistic scenarios.

Structural behaviour is equally defined by boundary conditions. Supports such as roller, pinned, or fixed constraints directly influence force distribution and deformation. Identical geometry can behave entirely differently depending on how it is supported.

Structural Verification

A structure must satisfy both safety (ULS) and usability (SLS) criteria. This involves checking internal forces such as normal force (tension/compression), bending, and shear against material capacity, while also ensuring acceptable deflection and vibration. Only when both conditions are met is a design considered valid.

Finite Element Method (FEM)

FEM is the core computational method for structural analysis.

Concept

Workflow

  1. Define geometry (lines → structural members)
  2. Assign material and cross-section
  3. Define supports (boundary conditions)
  4. Apply loads
  5. Solve system
  6. Interpret results

FEM transforms geometry into a calculable mechanical system.

Reciprocal Frames: Structural Logic

Your design system is evaluated structurally.

Key Properties

Structural Implications

For analysis, joints are often abstracted into simplified connections.

Karamba3D Workflow

We translate our timber models into structural simulations using the provided analysis template.

karamba3d

Resources

The Grasshopper file includes a JSON exporter for your timber model. Use the provided example model as a reference and replace it with your own design.

The workflow is designed to be plug-and-play. For your information, here is the underlying logic:

Pipeline

  1. Convert geometry into line elements and generate virtual connector elements
  2. Assign cross-sections and material properties
  3. Define supports
  4. Apply loads (self-weight, wind, etc.)
  5. Run analysis
  6. Evaluate results

Outputs

This allows iterative refinement of your design based on performance.

Slides

Slides

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