Planar truss span grammar problem

A discrete topology grammar for adding and removing joints and members in a planar truss.

See Grammar Problem Catalog for the grammar family index.

Quick Facts

Field	Value
Problem ID	`planar_truss_span`
Problem Family	grammar
Implementation	`design_research_problems.problems.grammar._planar_truss:PlanarTrussSpanProblem`
Capabilities	`discrete-actions`, `external-adapter`, `optional-evaluator`, `serializable-state`, `statement-markdown`
Study Suitability	none
Tags	`grammar`, `truss`, `discrete`, `topology`

Taxonomy

Formulation: discrete_grammar
Convexity: not_applicable
Design Variable Type: discrete
Is Dynamic: no
Orientation: engineering_practical
Feasibility Ratio Hint: 0.25
Objective Mode: single
Constraint Nature: hard
Bounds Summary: planar topology over a fixed span and height envelope
Tags: grammar, truss, discrete, topology

Statement

Create a stable, lightweight planar truss spanning a fixed distance between a left pinned support and a right roller support. The grammar begins with the supports and one loaded free joint. Designers can add interior joints, add members, and remove members.

States are evaluated by translating the library-owned grammar state into a fresh trussme.Truss, applying the load, and attempting a structural analysis. Singular or unstable states are treated as infeasible results.

Problem Shape

Field	Value
State Type	PlanarTrussState
Initial Transition Count	6
Initial Rule Names	`add_joint`, `add_member`

Manifest Parameters

Key	Value
load_magnitude	1000
max_height	5
span	10

Initial Transition Summary

Rule Name	Transition Count
add_joint	3
add_member	3

Library Interface

initial_state()
enumerate_transitions(state)
enumerate_next_states(state)
evaluate(state)