Abstract: The static strength and durability/damage tolerance of fuselage panels under various forms of loads such as tension,compression, shear, and air pressure are important topics in aircraft strength research. The previous test technology can only simulate the uniform stress/strain field of fuselage panels under the above loads alone or combined. However, the complex stress distribution of aircraft fuselage around large openings such as hatches or portholes makes it difficult to accurately simulate the complex stress field by a single load or the superposition of a few loads. To realize accurate simulation of the stress distribution around the large opening structure of the fuselage panel, the complex stress field test technology of large fuselage panels was studied, and a set of multi-load joint application test facility was developed to independently or jointly apply axial (tension/compression), bending, in-plane shear, end shear, floor beam (axial force and bending) and air pressure loads. Each load application system is decoupled from each other without interference. The stress/strain distribution in the test area can be consistent with the finite element solution of the complete aircraft by optimizing the proportion of various loads and applying them together according to the proportion. The static and fatigue tests show that the test technology and facility can accurately simulate the complex stress/strain state of fuselage panels.

Key words: complex stress field, fuselage panel, large opening, combined loads, test technology