Topology Optimization Based Structural Configuration Design Of Typical Connectors

Various connectors are used to connect different parts of the aircraft. The role of connectors is transferring the force from one component to another component, Transiting and distributing of force between different components. As a transition structure between the components, owing to the form of connection and the configurations, connectors are working in very complex stress status, often the hot points where strength or fatigue failure first occurs, and should be designed carefully. In this paper, some typical connectors of helicopter rotor without bear and landing gear of a certain aircraft were chosen for research. The structure’s configurations of these aviation connectors were redesigned according to different problems. The main contents and results are given in the following paragraphs.(1) Topology optimization based design of cross-section of a flexible beam used in hingeless rotor hub of helicopter. The connector between the helicopters’hub and blade was chosen for research. According to special requirements of stiffness characteristics of the typical cross-section, the configuration of cross-section was designed, basing on the theory for beam cross-section properties considering the warping effects of cross section developed by Giavotto, taking advantage of topology optimization method, stiffness characteristics of typical cross-section were chosen as the objection and constraints, the model of topology optimization was established using material distribution as design parameter, and methods of sensitivity analysis were given. Aiming at improving the design of a typical flexible beam.At first, deduced material parameters for topology optimization based on cross-section of existing flexible beam, and two schemes of solution were made to get reasonable configuration of typical cross-section of the flexible beam by topology optimization. The size optimization was also untaken, at last got better configuration of cross-section than the existing one.(2) Topology optimization based design of typical connectors between landing gear and the airplane. Connectors between landing gear and the airplane are the most easily damaged parts of aircraft structures, so they are the key points in design. For the complexity of the stress state, besides the shape and size, the connectors’performance depend more on their configurations, thus the configurations should be well designed. In this paper, some typical connectors of a certain aircraft landing gear were chosen for research. According to their force status, and based on topology optimization technology, the method of structure’s configuration design was established and the structure configurations of these aviation connectors were redesigned. Using FEM simulation technology, according to the stress status around these connectors, a reasonable mechanical model of the connection parts between the connectors and surrounding structures were established, and the boundary conditions were obtained for topology optimization. Aimed at minimizing structures’compliance, the topology optimization model was established using material distribution as design parameter. At the same time, the simplified design of structures’configuration was established based on topology optimization, and the elaborate design of structures’shape and size was also undertaken. Several typical connector configurations were given, and their synthesized performance were analyzed.(3) Topology optimization based structural design for reduction of concentrated force. It is the common problem that designing the configuration of connector to make sure the concentrated forces transmit through connector to the principal load-bearing structure reasonably. If the connector is poorly designed, the phenomenon of very serious stress concentration will occur and result in the structural’s damage. In this chapter, chosen the beam as the basic structure, established a simple model, the objective is to find common connector configuration, make sure the concentrated force transmit through the connector to the principal load-bearing structure reasonably. Aiming at avoiding the local stress in the connector is too large; using the two steps optimization method, at first, designed the loads distribution on the nodes of the beam, and the obtained distributed loads were used as the boundary conditions for topology optimization. Aimed at minimizing structures’compliance, the topology optimization model was established using material distribution as design parameter. In this chapter, two programs were designed to get reasonable configurations of the connectors.