| --- |
| language: |
| - en |
| tags: |
| - structural-engineering |
| - truss-optimization |
| - reinforcement-learning |
| - reasoning |
| - design-benchmark |
| license: mit |
| --- |
| |
| # DesignBench-Truss |
|
|
| ## Overview |
|
|
| DesignBench-Truss is the benchmark split (problems 090–099) of DesignBench, a |
| dataset for teaching and evaluating large language models on iterative |
| structural engineering design via Tree-of-Thought reasoning. |
|
|
| Each problem requires minimising the mass of a 2-D pin-jointed truss structure |
| while satisfying structural safety constraints (factor of safety ≥ 1.5 for both |
| buckling and yielding failure modes). A finite-element analysis oracle |
| (trussme) provides deterministic feedback after every design modification. |
|
|
| ## Task Description |
|
|
| Given an initial truss design with known joint positions, member cross-sections, |
| material properties, and loading conditions, a model must produce a sequence of |
| discrete grammar actions that transform the design into a feasible, |
| mass-minimised structure. |
|
|
| ### Grammar Actions |
|
|
| | Action | Signature | Description | |
| |--------|-----------|-------------| |
| | SCALE_PARAM | `SCALE_PARAM(member_id_or_all, param, factor)` | Scale one parameter of one (or all) members | |
| | SCALE_MULTI_PARAM | `SCALE_MULTI_PARAM([member_ids], [param:factor, ...])` | Scale multiple parameters simultaneously | |
| | ADD_MEMBER | `ADD_MEMBER(joint1, joint2, material, shape_type, r, t)` | Add a new pipe member between two joints | |
| |
| ## Data Format |
| |
| ### `benchmark.json` |
| |
| Flat list of examples — one per gold trace — with the following fields: |
| |
| ```json |
| { |
| "problem_id": "auto_problem_090", |
| "trace_id": "auto_problem_090_trace_0", |
| "problem_text": "PROBLEM: Truss optimization ...", |
| "initial_state": { |
| "mass": 142.5, |
| "fos_buckling": 0.31, |
| "fos_yielding": 1.09, |
| "deflection": 0.038, |
| "is_feasible": false |
| }, |
| "gold_action_sequence": [ |
| "ADD_MEMBER(5, 6, 6061_T6_Aluminum, Pipe, 0.0497, 0.0056)", |
| "SCALE_PARAM(all_members, thickness, 1.28)" |
| ], |
| "reaches_solution": true, |
| "trace_quality": 0.98 |
| } |
| ``` |
| |
| ### `problems/` |
|
|
| Raw problem JSON files containing joint positions, member topology, loads, and |
| design constraints. |
|
|
| ### `trees/` |
|
|
| Full modification trees as JSON. Each tree contains all explored design states |
| (nodes) and the grammar actions connecting them (edges). |
|
|
| ### `traces/` |
|
|
| Serialized gold traces — lists of node-sequences extracted from each tree. |
|
|
| ## Metrics |
|
|
| | Metric | Description | |
| |--------|-------------| |
| | feasibility_rate | Fraction of episodes reaching `is_feasible=True` | |
| | mass_reduction | `(initial_mass - final_mass) / initial_mass` | |
| | grammar_validity_rate | Fraction of steps with parseable grammar actions | |
| | avg_steps_to_feasibility | Mean episode length when a feasible design is found | |
| | overall_score | Weighted composite: design_correctness (0.5) + structural_validity (0.25) + reasoning_quality (0.15) + grammar_compliance (0.10) | |
|
|
| ## Example Usage |
|
|
| ```python |
| import json |
| |
| with open("benchmark.json") as f: |
| examples = json.load(f) |
| |
| print(f"Loaded {len(examples)} benchmark examples") |
| |
| for ex in examples[:3]: |
| print(ex["problem_id"], "->", ex["reaches_solution"], |
| "actions:", len(ex["gold_action_sequence"])) |
| ``` |
|
|
| ## Citation |
|
|
| ```bibtex |
| @misc{designbench2025, |
| title = {DesignBench: A Benchmark for Iterative Structural Engineering Design}, |
| author = {DesignBench Authors}, |
| year = {2025}, |
| note = {https://huggingface.co/datasets/DesignBench-Truss} |
| } |
| ``` |
|
|
