Research On The Lightweight And Miniaturization Of Pod Structure

With the deepening of pod application,pod platform performance has been improved. Structurally, lightweightand miniaturization is an important trend in th e development of pod, so the research on pod is very necessary. As known,pod work in complex environment including vibrati on and windward, so it is strict to the requirement of structure stif fness and dynamic performance. How to ensure the dynamic and static characteristics of st ructure with reaching lightweight and miniaturization becomes a difficult problem. Based on this, the paper provides the method to solve this issue.Firstly, the paper introduced the ba ckground, the purpose and significance, the current research of pod and lightweight technology development at present.Then, the paper analyzed the m ain framework of pod platform, and selects two axis two fram e as the structu re of miniaturization design; analyzed the general aerodynamic shape of pod, and selects cylindr ical shape; analyzed the layout and structure of pod generally cons titute, and built th e three-dimensional model of pod;Analyzed the working condition of pod, calculated the force of the pod under certain conditions;set up the finite elem ent model of pod, with statics and m odal analysis results obtained, and proposed the pod main framestructure andcover as the basis of lightweight design. And then analyzed the modal and static mechanics.Next, studied the topology method which can realize the lightweight design; By introducing the stif fness optimization function, frequency optim ization function, established amulti-objectivetopology optimization function as the objective function,And each of t hree functions of main frame topology optimization results are analyzed and com pared, showed the effectiveness of mu lti-objective topology optimization; Based on the Hypermesh/Optis truct software platform for pod m ain frame structure optim ization design, the results were analyzed and comparedandestablished a new m odel of m ain frame, verified the feasibility of lightweight design with t opology optimization method and the correctness of the multi-objective function.Based on topology optim ization function condition of stiffness, topology optim ization was carried out on the cover, while ensuring its static and dynamic characteristics at the same time, made its quality decreased from 1.8 Kg to 0.88 Kg, lightweight rate of 51.38%;Finally using 3D printing, nylon as material, successfully to print the cover structure, made quality decreased from 1.81 Kg to 0.38 Kg, lightweight rate of 79%, and successfully applied to a pod platform.Then introduced the composition of composite materials, and selected the T700 carbon fiber unidirection as design m aterial; studied Composite materials mechanics theory, and through theoretical analysis, get the way of layer design modeling;Based on the analysis of the topology optim ization results, the shell of the m ain frame model wasextracted, an d built the finite element model of carbon fiber based on layers;the static and m odal analysis was carried out on the m ain frame model, the results showed that the structure of initial designmeet requirements.Finally,The general optimization design method of composites was introduced; through size optimization, free size optimization, shuffle optimization, achieved the lightweight design of the m ain structure;By comparing the optim ized structure whose characteristics implementation with initial model, showed that the str ucture lightweight design achievedthe purpose. Finally the main frame structure meet the stiffness and the vibration characteristics, the quality from the original 6 Kg to 3.735 Kg, lightweight rate was 37.35%, achieved the purpose of lightweight design.