As a typical double-skin stiffened structure, the rudder structure of high-speed aircraft demands multiple performance requirements, such as lightweight, high stiffness and high flutter boundary. A ‘stiffener-skin-damper’ multi-component concurrent topology optimization method is proposed. Considering vibrational energy, modal characteristic, and mechanical perspectives, the method innovatively reformulates the flutter-oriented structural optimization problem into a specific static-dynamic optimization within frequency band between critical modes. The proposed method enables flutter suppression while achieving structural weight reduction and enhanced load-bearing capacity. To ensure effective coordination among multiple components during the optimization process, a novel dual nodal finite element model is developed alongside an interpolation system that separately handles static and dynamic objectives. The stiffener layout is optimized using the Adaptive Growth Method (AGM), the skin thickness is determined through Geometry Optimization (GO), and the damper placement is obtained via the Solid Isotropic Material with Penalization (SIMP) method. Here, the damper adopted is Embedded Powder Particle Damper (EPPD), a novel type of damper fabricated by intentionally retaining unmelted metal powder during the additive manufacturing process. In order to integrates the EPPD into the optimization framework, the equivalent mechanical property of the EPPD is estimated through the homogenization approach. The proposed method is applied to a rudder structure, resulting in tree-like stiffeners, crown-like skins, and fruit-like dampers. Comparative analysis confirms that the optimized structure exhibits a 14.85% weight reduction, an 11.68% increase in static stiffness, up to a 43.71% reduction in critical mode amplitude, and a marked 10.31% increase in flutter boundary. The proposed method holds substantial engineering value and provides a novel approach for the optimization of double-skin stiffened structures.
Wang et al. (Wed,) studied this question.