Planar roof truss grammar (depth = 1/6 span)

A symmetric three-point roof-truss grammar constrained to the 1/6-span depth variant reported in the structural essay study.

See Grammar Problem Catalog for the grammar family index.

Quick Facts

Field	Value
Problem ID	`planar_roof_truss_three_point_symmetric_depth_sixth`
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`, `roof`, `discrete`, `topology`, `symmetric`, `depth-limited`

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: symmetric planar roof-truss topology with a 1/6-span roof rise
Tags: grammar, truss, roof, discrete, topology, symmetric, depth-limited

Statement

This catalog entry approximates the third planar roof-truss formulation from the structural essay study: the symmetric three-point loading case with the depth limit relaxed to approximately one-sixth of the span.

Relative to the 1/8-span variant, the load joints and candidate interior joints are placed in a taller envelope to reflect the larger allowable truss depth.

Problem Shape

Field	Value
State Type	PlanarTrussState
Initial Transition Count	9
Initial Rule Names	`add_joint`, `add_joint_pair`, `add_member`

Manifest Parameters

Key	Value
candidate_point_fractions	[[0.2, 0.2], [0.35, 0.34], [0.5, 0.22]]
enforce_symmetry	yes
load_magnitude	1000
max_height	1.66667
roof_load_x_fractions	[0.25, 0.5, 0.75]
span	10

Initial Transition Summary

Rule Name	Transition Count
add_joint	1
add_joint_pair	2
add_member	6

Library Interface

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