Structural Joint System
Bolted and Welded Structural Joint Assemblies
Structural joint assemblies connect structural frame members using friction stir welds, bolted interfaces, and titanium gusset plates to distribute loads across multi-member intersections under NASA-STD-5020. In the lunar vacuum, silver-plated anti-galling coatings are required on A286 stainless bolts to preserve predictable preload behavior and allow maintenance disassembly. These mechanical joints must maintain their clamp force over 100 years of thermal cycling while accommodating robotic inspection without teardown. For permanent connections, friction stir welded joints provide superior structural strength compared to bolted alternatives.
Joint assemblies connecting structural frame members with provisions for assembly and inspection
Purpose
Joint assemblies connecting structural frame members with provisions for assembly and inspection
Context
Child of L2-STR-FRAME
Principles
- ▸Bolted joints enable disassembly for maintenance with predictable preload behavior
- ▸Friction stir welded joints provide higher strength than bolted for permanent connections
- ▸Gusset plates distribute load at multi-member intersection points
- ▸Joint design follows NASA-STD-5020 for fatigue and fracture requirements
Typical implementations
- ▸ISS module-to-module joint connections
- ▸NASA-STD-5020 structural joint design requirements
- ▸Friction stir welding for spacecraft structures (Orion, SLS)
Lunar considerations
- ▸Joint preload must be maintained over 100 years of thermal cycling
- ▸Robotic joint inspection must be possible without disassembly
- ▸Anti-galling coatings essential for titanium/stainless fasteners in vacuum
Specifications
Functional
| primary function | Joint assemblies connecting structural frame members with provisions for assembly and inspection |
Physical
| materials | Titanium gussets, A286 stainless bolts, Silver-plated anti-galling coating |
Interfaces
Provides
- Frame member connections
Requires
- Fasteners for joint assembly
Cite this entry
Lunar Ark Codex. "Structural Joint System" (L3-STR-FRAME-JOIN). Retrieved 10 September 2026, from https://lunarark.com/entry/L3-STR-FRAME-JOIN
Licensed CC-BY-SA 4.0. You may reuse and adapt this entry with attribution, under the same licence.