典型飞机壁板结构的抗屈曲优化设计与试验验证

Buckling⁃resisting optimization design of typical aircraft panel and test validation

加筋壁板是飞机机身和机翼中常见的典型承力结构,其在轴压和机身弯矩载荷作用下极易发生屈曲失效,严重制约飞行器安全性能与服役周期。飞机结构静强度校核时多采用经验公式进行工程计算,其中加筋壁板结构承载能力的工程计算与机身框结构端部支持系数的选取密切相关。现有飞机型号研制中端部支持系数的选取通常较为保守,结构安全裕度大、质量冗余,阻碍了飞行器轻量化水平的进一步提升。为此,首先基于欧拉长柱失稳理论,建立了基于切缝法的典型飞机壁板结构端部支持系数仿真计算模型;同时深入分析了端部支持系数与加筋壁板结构和支撑框段的耦合作用关系;进一步地,分析了框、长桁等结构特征参数对端部支持系数的影响规律,并分别开展了框、长桁-蒙皮以及框-长桁-蒙皮协同优化的飞机壁板结构抗屈曲设计;最后,基于增材制造缩比样件和轴压屈曲试验,验证了典型壁板结构抗屈曲优化设计方法的有效性。所建立的仿真分析模型和优化设计方法实现了飞机壁板结构抗屈曲性能的有效提升,对进一步提升飞机性能指标具有重要意义。

Stiffened panels are common load-bearing structures in aircraft fuselage and wings.Under axial compres⁃sion and fuselage bending loads,they are susceptible to buckling failure,which limits the structural safety and aircraft service life.Empirical formula is often used for engineering calculations in aircraft structural static strength assessment.The engineering calculation of load-carrying capacity for stiffened panels is closely related to the selection of end sup⁃port coefficients for fuselage frame structures.In the development of existing aircraft models,typically conservative end support coefficients are chosen,resulting in excessive structural safety margins and weight redundancies,hinder⁃ing further advancements in aircraft lightweight design.To address the problem,this study first establishes a simula⁃tion calculation model for end support coefficients of typical aircraft panel structures based on slitting method,using Euler’s buckling theory.Subsequently,the coupled relationship between end support coefficients and the interaction between stiffened panel structures and supporting frame segments is analyzed in depth.Furthermore,the influence structural characteristic parameters such as frames and longitudinal stiffeners on end support coefficients is analyzed,and integrated buckling-resisting optimization designs of aircraft panel structure are conducted for frames,longitudinal stiffeners-skin,and frame-skin-longitudinal stiffener configurations.Finally,the effectiveness of buckling-resisting opti⁃mization designs for typical panel structure is validated through additive manufacturing of scaled-down specimens and axial compression tests.The established simulation and optimization methods in this study effectively enhance the buckling resistance of aircraft panel structures,offering significant opportunities for improving aircraft performances.