Buckling and postbuckling of curvilinearly grid-stiffened variable-stiffness composite fuselage panels

曲线网格加固变刚度复合材料机身面板的屈曲和后屈曲

• 批准号: 509719919
• 负责人: Professor Dr.-Ing. Christian Mittelstedt
• 金额: --
• 依托单位: Fachgebiet Konstruktiver Leichtbau und Bauweisen
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/509719919?language=en
• 关键词: Buckling; postbuckling; curvilinearly; grid; stiffened

Due to their benefits and high structural performance in terms of strength, stability and damage tol-erance, grid-stiffened structures are used on a large scale in aerospace structures. Manufacturing of an integrated structure consisting of a tow-placed variable-stiffness composite skin and curvilinear stiffeners is possible using advanced techniques such as automated fibre placement and additive manufacturing (known also as 3D printing). In this proposed project, the buckling and postbuckling performance of curvilinearly grid-stiffened composite structures will be addressed. The variable-stiffness (V-S) concept based on the tow-placed steered fibres will be adopted to develop innovative tailored composite designs that are able to improve the buckling and postbuckling performance of aircraft structures. The primary objective of this research is to concurrently determine the optimal fibre paths of the skin and the optimal trajectories of the stiffeners for maximum buckling capacity taking into account the manufacturing constraints. In order to achieve this objective, as a first step, accurate yet fast semi-analytical solutions using energy-based approaches will be developed for ob-taining the buckling response of curvilinearly stiffened V-S composite plates and shells applicable to aircraft structures. Then, an optimization framework that includes different design tailoring scenari-os will be developed to investigate the effects of different parameters on the buckling performance of panels. The buckling performance of the designs obtained in each scenario will be compared with that for the traditionally stiffened straight design baselines. Additionally, the postbuckling behav-iour of the designs obtained in the previous scenarios will be addressed using the finite element method to assess the residual stiffness of the panels optimized for maximum buckling resistance.

由于它们的优势和高度性能在强度，稳定性和损害耐受性方面，因此在航空航天结构中大规模使用了网格延伸的结构。使用高级技术（例如自动化的纤维放置和添加剂制造）（也称为3D打印），可以使用由拖放位置的可变状态复合皮肤和曲线加强剂组成的集成结构的制造。在这个拟议的项目中，将解决曲线固定的复合结构的屈曲和弯曲后表现。将采用基于拖放式转向纤维的可变状态（V-S）概念来开发创新的量身定制的复合设计，以改善飞机结构的屈曲和弯曲性能。这项研究的主要目的是同时确定皮肤的最佳纤维路径和加强剂的最佳轨迹，以考虑到制造限制的最大屈曲能力。为了实现这一目标，将开发出使用基于能量的方法的准确但快速的半分析解决方案，以遵守适用于飞机结构的曲线僵硬的V-S复合板和壳的屈曲响应。然后，将开发一个包括不同设计剪裁方案的优化框架，以研究不同参数对面板屈曲性能的影响。在每种情况下获得的设计的屈曲性能将与传统上僵硬的直线设计基线相提并论。此外，将使用有限元方法来解决以前方案中获得的设计后行为 - 评估优化面板的残留刚度，以获得最大的屈曲电阻。