Hybrid Wing Body Pressurized Fuselage and Bulkhead Design and Optimization

Abstract

The structural weight reduction of a pressurized Hybrid Wing-Body (HWB) fuselage is a serious challenge. Hence, research and development are presently being continued at NASA under the Environmentally Responsible Aviation (ERA) and Subsonic Fixed Wing (SFW) projects in collaboration with the Boeing Company, Huntington Beach and Air Force Research Laboratory (AFRL). In this paper, a structural analysis of the HWB fuselage and bulkhead panels is presented, with the objectives of design improvement and structural weight reduction. First, orthotropic plate theories for sizing, and equivalent plate analysis with appropriate simplification are considered. Then parametric finite-element analysis of a fuselage section and bulkhead are conducted using advanced stitched composite structural concepts, which are presently being developed at Boeing for pressurized HWB flight vehicles. With this advanced stiffened-shell design, structural weights are computed and compared to the thick sandwich, vaulted-ribbed-shell, and multibubble stiffened-shell structural concepts that had been studied previously. The analytical and numerical results are discussed to assess the overall weight/strength advantages.

Hybrid-Wing-Body Vehicle Composite Fuselage Analysis and Case Study

“…The equivalent thicknesses were selected to provide same order of deflection on both bulkheads (stiffened thin shell and uniform shell). This mixed model is 6 inches shorter on both ends than the multi-bay analyzed previously 11 . The three crown panel frames are at 24 inches spacing and have 2 stacks wrap (Table 2a).…”

“…Together, the frame and the skin segment between adjacent frames have running bending rigidity D x of approximately 5.98×10 6 lbs.-in. This configuration was used in the previous preliminary analysis 11 . By adding a 0.4 in 2 area frame cap, shown in Table 2b, D x is increased to 6.49x10 6 lb-in.…”

“…Preliminary FEM model development, analysis and weight estimation of a conceptual fuselage section and bulkhead configurations were presented in Ref. 11. At the vehicle level, structural systems studies for the 100, 200, 300, and 400-passenger versions were presented by Gern [12][13] , to estimate the full vehicle structural weight at critical load conditions.…”

Composite Structure Modeling and Analysis of Advanced Aircraft Fuselage Concepts

“…The most recent structural analysis of the HWB multi-bay fuselage section test article was presented by Przekop 16 . An integrated multi-bay fuselage and bulkhead finite element models (FEM) with flat PRSEUS panels were developed and analyzed for an independent case study and weight estimation 13,17 . In this paper, the PRSEUS modeling and analyses are applied to a representative cylindrical pressurized fuselage section and a multi-bubble section fuselage for comparison with the HWB concept.…”

“…Many novel structural concepts such as the ribbeddouble-shell, multi-bubble stiffened shell, thick composite sandwich shell, and recently the Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) construction have been studied under the NASA Environmentally Responsible Aviation (ERA) research project [6][7][8][9][10][11][12][13][14][15][16][17] in collaboration with the Boeing Company. Figure 1 shows a schematic diagram of the PRSEUS technology development, starting with test coupons, flat and curved PRSEUS panels and progressing towards a HWB fuselage section construction at the Boeing Company and follow-up testing under way at NASA Langley Research Center.…”