LEPL1110 - Finite Element Project: Bridge vs. Tank

The Saga of Yevgeny's Bridge Problem...

Yevgeny has a T-80 battle tank and a penchant for energetic infrastructure testing. While using a certain beam bridge over a tributary of the Dnieper for target practice, his expert marksmanship pierces one of the beams right in the middle. Boom.

To his surprise, the bridge, though damaged, remains standing. Before Yevgeny can deliver a coup de grâce, his lieutenant radios in: "Yevgeny, you need to cross that river and attack the next village!"

Oops. The critical question arises: Can this damaged bridge handle the weight of Yevgeny's T-80? That's what this project aims to find out (through the magic of finite element analysis, of course!).

Table of Contents

• The Saga of Yevgeny's Bridge Problem...
• Project Overview
• Code Structure: Organized Chaos
• Dependencies: The Necessary Evils
• Getting it Running: Compilation Rituals
• How to (Try to) Cross the Bridge: Usage
• Future Dreams & Known Quirks

Project Overview

This repository contains our code for the LEPL1110 Finite Element Method project. We simulate the structural integrity of a damaged bridge under the load of a tank. It's built primarily in C, featuring a custom FEA solver and OpenGL for visualization.

Code Structure

We've structured the code into two main parts:

• The Main Project (Root Directory): Handles mesh generation (using gmsh), rendering the bridge and tank (via glfw, glad, and our own lightweight graphics code found in src/gui), loading assets (stb_image.h), and logging useful (or cryptic) messages (log.c). It depends on the solver library below.

• The Standalone Solver (solver/ directory): Heart of the FEA simulation. It's an independent library, containing our finite-element method implementation. No dependencies here!

Dependencies

We tried to keep things contained:

• Vendored: Most minor dependencies (glfw, glad, log.c, stb_image.h) are included directly in the repository for your convenience.
• gmsh: The one major external dependency. CMake should automagically download the SDK for you.
  • Murphy's Law Clause: If https://gmsh.info happens to be down (like it is right now while I'm writing those lines at 2 AM on April 4th), don't worry. It's OK. You can manually download the SDK and extract it to gmsh/gmsh-4.13.1-Linux64-sdk at the project root. CMake should then detect it and let the build proceed. (Fun fact ! You can download the SDK from the Wayback Machine !)

Getting it Running

To build and run the full bridge simulation project:

mkdir build
cmake -B build
make -C build
./build/bridge

⚠️ WARNING: You MUST run the bridge executable from the root directory of the project (the one containing this README). It needs to find shaders and assets via relative paths. Running it from the build directory will likely result in sadness, crashes, or summoning unintended demons. (If it does work from the build directory... well, you're a wizard, Harry.)

To build only the standalone solver library:

cd solver
mkdir build
cmake -B build
make -C build
./build/solver-bin

This will also create a static library solver/build/libsolver.a if you wish to link against it elsewhere.

How to (Try to) Cross the Bridge: Usage

Once the simulation is running:

• Tank Movement: Use the Arrow Keys to carefully drive Yevgeny's tank across the bridge. Pray the bridge holds up!
• Target Practice: Use your Mouse to aim and click to simulate firing the cannon. See the stress distributions change in real-time !

Shortcuts:

• Toogle visibility of deformation: Press T to toogle the deformation visibility
• Get Tank Position: Press E to get the tank position in stdout