Space truss span structural optimization (mass minimization)

A fixed-joint binary optimization problem that selects candidate 3D truss members to minimize mass subject to factor-of-safety and deflection thresholds.

See Optimization Problem Catalog for the optimization family index.

Quick Facts

Field	Value
Problem ID	space_truss_span_mass_min
Problem Family	optimization
Implementation	design_research_problems.problems.optimization._truss_topology:SpaceTrussEngineeringOptimizationProblem
Capabilities	baseline-solver, bounded-variables, external-adapter, optional-evaluator, statement-markdown
Study Suitability	none
Tags	optimization, truss, 3d, structural, mass

Taxonomy

Formulation

binary_optimization

Convexity

nonconvex

Design Variable Type

discrete

Is Dynamic

no

Orientation

engineering_practical

Feasibility Ratio Hint

0.02

Objective Mode

single

Constraint Nature

hard

Bounds Summary

one binary variable per candidate member over a fixed 3D space-truss joint set

Tags

optimization, truss, 3d, structural, mass

Statement

Choose a 3D space-truss topology over a fixed bridge-like scaffold. Each binary design variable decides whether one candidate member is present. The optimizer builds a concrete SpaceTrussState, runs the real trussme structural analysis, and minimizes structural mass.

Feasible candidates must satisfy a minimum factor of safety and a maximum deflection threshold. The built-in baseline uses deterministic binary enumeration with cheap graph prechecks plus hard structural thresholds.

Problem Shape

Field	Value
Design Variable Count	36
Bound Summary	one binary variable per candidate member over a fixed 3D space-truss joint set
Total Constraint Count	4
Equality Constraint Count	0
Inequality Constraint Count	4

Variable Bounds

Variable	Lower Bound	Upper Bound
x[0]	0	1
x[1]	0	1
x[2]	0	1
x[3]	0	1
x[4]	0	1
x[5]	0	1
x[6]	0	1
x[7]	0	1
x[8]	0	1
x[9]	0	1
x[10]	0	1
x[11]	0	1
x[12]	0	1
x[13]	0	1
x[14]	0	1
x[15]	0	1
x[16]	0	1
x[17]	0	1
x[18]	0	1
x[19]	0	1
x[20]	0	1
x[21]	0	1
x[22]	0	1
x[23]	0	1
x[24]	0	1
x[25]	0	1
x[26]	0	1
x[27]	0	1
x[28]	0	1
x[29]	0	1
x[30]	0	1
x[31]	0	1
x[32]	0	1
x[33]	0	1
x[34]	0	1
x[35]	0	1

Manifest Parameters

Key	Value
candidate_point_fractions_3d	[[0.25, -1.0, 0.5], [0.25, 1.0, 0.5], [0.75, -1.0, 0.5], [0.75, 1.0, 0.5]]
load_magnitude	1000
max_height	5
maximum_deflection	0.2
minimum_fos	1
objective_metric	mass-min
span	10
width	4

Library Interface

• generate_initial_solution(seed=None)

• objective(x)

• evaluate(x)

• solve(initial_solution=None, seed=None, maxiter=200)