Topology Optimization Based Method For Layout Design Optimization Of Lightening Hole And Multi-pocket And Topological Design Of Typical Structures

Lightweight has always been an important indicator in the structural design of components in aerospace and automotive industries.In structural design,slotting and perforating are the most common methods for the structural lightweight.Usually,the designers usually determine the lightening hole and multi-pocket initial layout based on the design requirements,check and modify the size characteristics repeatedly until the desired design result is obtained.The traditional design method of inheriting and improving,which is mainly dependent on the experience of the designers or refer to the other similar structures,has been unable to meet the higher design requirements.Topology optimization is to obtain the optimal layout of the material in the design domain under the premise of guaranteeing the structure performance.Topology optimization is a very promising engineering structure optimization design method,and can significantly improve the utilization rate of the material.Developing the design method of the lightening hole and multi-pocket based on topology optimization has important theoretical significance and practical application value.In this paper,the structural lightweight design of components based on slotting and perforating is studied with topology optimization,and propose a design method for the structural lightweight design problems based on slotting and perforating.The structural design of the torque arm of the aircraft landing gear and gear mechanism are completed based on topology optimization.The main studied contents and results summarized as follows:(1)Topology optimization based method for layout design optimization of lightening hole and multi-pocket.In structural design,slotting and perforating are the most common methods for the structural lightweight.However,designers determine the location of slots and holes based on their experience.In order to overcome the dependence of design problems on the designer's experience,it's necessary to develop a design method of the lightening hole layout and multi-pocket layout.This paper proposes a design method of the lightening hole layout and multi-pocket based on topology optimization.First of all,convert the layout design problem of the lightening hole layout and multi-pocket into the plane problem with different stiffness materials designs.It can be solved by establishing topology optimization model.And then,the material layout with three kinds of thickness,representing the slotted area,the hole area and the solid area,is realized by mapping.Finally,the layout configuration of the lightening hole layout and multi-pocket is got from the material layout.This work is not only the foundation of the follow-up work,but also provides an effective design method for the structural lightweight design problems based on slotting and perforating.(2)The topological configuration design of torque arm in landing gear.The torque arm of aircraft landing gear as design subject,the innovative configuration design of torque arm is carried out with the aid of structural optimization software ——OptiStruct,and the mechanical properties of the design results are checked and analyzed.First of all,the basic theory of structural optimization design and the mathematical expression of several manufacturing constraints are summarized and analyzed.Then,the optimal design of the torque arm is completed based on the topology optimization with manufacturing process constraints.The design of the torque arm is completed by the multi-pocket and lightening hole layout method proposed in part one.It is completed multi-level optimization design considering the reduced area of the slot filled with the same volume of micro-structure lattice.Finally,the mechanical properties of several kinds of torque arm configurations are analyzed.(3)The finite element modeling and topology optimization of gear mechanism.The gear transmission is the most commonly used driving style in modern complex mechanical system.The reasonable and accurate finite element modeling of the gear transmission is related to the efficiency and accuracy of the whole mechanical system structure analysis.The structural lightweight design of gear structure is great significant to save materials,reduce the moment of inertia of gear system to decrease the useless power and improve the performance of gear system.Therefore,first of all,several basic assembly techniques used to connect different parts are introduced and the finite element modeling method of gear mechanism is emphatically analyzed.Then,the gear structure in an airborne antenna pedestal is used as the research object.Under the premise of meeting the requirements,the structure of the gear is designed with the topology optimization method.Finally,the static simulation analysis of the optimized gear mechanism is carried out.