SAWE Aircraft - Commercial https://www.sawe.org Society of Allied Weight Engineers, Inc. Sat, 04 Jul 2026 18:52:43 +0000 en-US hourly 1 https://wordpress.org/?v=7.0.4 231197347 3855 Double-Shell and Sandwich Fuselages for Future Aircraft https://www.sawe.org/product/3855-double-shell-and-sandwich-fuselages-for-future-aircraft/ Fri, 29 May 2026 16:30:32 +0000 https://www.sawe.org/?post_type=product&p=11470 Paper
Hans-Peter Dahm: 3855. Double-Shell and Sandwich Fuselages for Future Aircraft. 2026.
 

Abstract

There are several fuselage concepts which show alternatives in comparison to the classical cylindrical fuselage concept. Double-shell fuselages include classic double-bubble cabins, double-D variants, and multi-shell arrangements in which one or more near-cylindrical pressure lobes are enclosed by an outer aerodynamic shell. This paper restructures the topic and describes basic structural-mechanical behavior of double-shell sandwich fuselages. The objective is to determine when shell duplication in a sandwich creates a real mass benefit and when it redistributes mass among pressure skins, outer shells, webs, floors, and reinforcement details. A literature review is combined with a mechanics-based preliminary sizing method and a worked A220-like derived sample calculation. The paper then develops a separate aircraft-level estimate for a concentric circular double-shell sandwich concept manufactured as pre-equipped major shell modules. The approach combines a bottom-up structural mass build-up for the circular double-shell fuselage concept with a top-down aircraft-level fuselage-group allocation for the broader savings assessment. These two approaches serve different purposes and therefore produce different mass values. A future aircraft must integrate cryogenic hydrogen tanks, insulation, battery systems, cable runs, thermal management hardware, and larger secondary systems volumes than conventional kerosene aircraft. The architecture-only estimate yields a net installed mass saving of about 1.28 t. When a conservative transition from a public A220-like mixed-material fuselage baseline to a full thermoplastic-resin CFRP fuselage is added, with overlap correction to avoid double counting, the holistic aircraft-level rises to about 2.01 t. On a 39.0 t class level operating-empty-weight baseline this corresponds to about 5.16% of OEW, while remaining a concept-level result rather than a validated OEM design value. Public thermoplastic fuselage demonstrator results are treated conservatively as weight-positive but recurring-cost neutral relative to a metallic barrel, so the recurring production benefit remains dominated by modular preinstallation and reduced detail count at about €0.30 million per aircraft.]]> Paper
Hans-Peter Dahm: 3855. Double-Shell and Sandwich Fuselages for Future Aircraft. 2026.
 

Abstract

There are several fuselage concepts which show alternatives in comparison to the classical cylindrical fuselage concept. Double-shell fuselages include classic double-bubble cabins, double-D variants, and multi-shell arrangements in which one or more near-cylindrical pressure lobes are enclosed by an outer aerodynamic shell. This paper restructures the topic and describes basic structural-mechanical behavior of double-shell sandwich fuselages. The objective is to determine when shell duplication in a sandwich creates a real mass benefit and when it redistributes mass among pressure skins, outer shells, webs, floors, and reinforcement details. A literature review is combined with a mechanics-based preliminary sizing method and a worked A220-like derived sample calculation. The paper then develops a separate aircraft-level estimate for a concentric circular double-shell sandwich concept manufactured as pre-equipped major shell modules. The approach combines a bottom-up structural mass build-up for the circular double-shell fuselage concept with a top-down aircraft-level fuselage-group allocation for the broader savings assessment. These two approaches serve different purposes and therefore produce different mass values. A future aircraft must integrate cryogenic hydrogen tanks, insulation, battery systems, cable runs, thermal management hardware, and larger secondary systems volumes than conventional kerosene aircraft. The architecture-only estimate yields a net installed mass saving of about 1.28 t. When a conservative transition from a public A220-like mixed-material fuselage baseline to a full thermoplastic-resin CFRP fuselage is added, with overlap correction to avoid double counting, the holistic aircraft-level rises to about 2.01 t. On a 39.0 t class level operating-empty-weight baseline this corresponds to about 5.16% of OEW, while remaining a concept-level result rather than a validated OEM design value. Public thermoplastic fuselage demonstrator results are treated conservatively as weight-positive but recurring-cost neutral relative to a metallic barrel, so the recurring production benefit remains dominated by modular preinstallation and reduced detail count at about €0.30 million per aircraft.]]> 11470