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.

由于网格加筋结构在强度、稳定性和抗损伤能力等方面的优点和优良的结构性能，在航空航天结构中得到了广泛的应用。使用自动化纤维放置和增材制造（也称为3D打印）等先进技术，可以制造由拖放可变刚度复合材料蒙皮和曲线加强筋组成的集成结构。在本项目中，将讨论曲线网格加筋复合材料结构的屈曲和后屈曲性能。基于拖曳导向纤维的变刚度（V-S）概念将被用于开发创新的定制复合材料设计，能够改善飞机结构的屈曲和后屈曲性能。本研究的主要目标是同时确定皮肤的最佳纤维路径和增强筋的最佳轨迹，以获得最大的屈曲能力，同时考虑到制造限制。为了实现这一目标，作为第一步，将采用基于能量的方法开发准确而快速的半解析解，以获得适用于飞机结构的曲线加强V-S复合材料板和壳的屈曲响应。然后，开发了包含不同设计裁剪场景的优化框架，以研究不同参数对板屈曲性能的影响。将在每种情况下获得的设计的屈曲性能与传统的加筋直线设计基线进行比较。此外，将使用有限元方法来评估为最大抗屈曲优化的面板的剩余刚度，从而解决在上述情况下获得的设计的后屈曲行为。