Research On The Method Of Lightweight Design For Loaded Sandwich Structure Composite And Its Application

As an inevitable trend of industrial technology's development and a seeking goal of enterprises, lightweight technology of product is the single technology or integration technology of lightweight structural design, lightweight materials and lightweight manufacturing. Loaded sandwich structure composite is a kind of typical lightweight structural material which is composed of high strength faceskins and lightweight core and is increasingly applied to engineering due to its superior properties like lightweight, high strength, high stiffness and good stability and so on. Aiming at loaded sandwich structure composite, this dissertation has a systematic study on the loaded sandwich structure composite's lightweight design method. The lightweight design of loaded box-type components and parts is taken as an example to seek a best joint among the multiple objects of weight, performance and cost in order to eventually realize the box components and parts'lightweight. The main research contents of this dissertation are as follows.(1) On the basis of analysis about mechanical properties of loaded sandwich structure composite, the strength, stiffness and weight's formulas of loaded sandwich structure are deduced according to composite material mechanics and mechanics of materials theories and also according to engineering examples, corresponding calculation method is proposed.(2) Based on analysis of honeycomb sandwich structure's mechanical properties of loaded sandwich structure composite, the mechanical equivalent model of honeycomb sandwich structure is established, and the equivalent elastic constants' formulas of honeycomb sandwich structure are deduced. At the same time, based on the engineering cases, the simulation analysis method of honeycomb sandwich structure's mechanical properties is proposed.(3) In terms of structural lightweight design, sandwich structure's lightweight design requirements of loaded sandwich structure composite are analyzed. Aiming at the lightweight design of loaded sandwich structure under single-constraint conditions, the method of the lightweight design is proposed. (4) The multi-constraint conditions of loaded sandwich structure are analyzed, and optimal design theory of multi-constraint is used to build the multi-constraint optimization model of loaded sandwich structure; by means of multi-constraint optimal design theory, the lightweight design method of the loaded sandwich structure under multi-constraint condition is proposed and also is verified well according to an engineering example's analysis.(5) From the point of material lightweight design, lightweight loaded sandwich structure composite is designed and the model of its design process is built. In accordance with equivalent plate theory, the mechanical equivalent model of loaded sandwich structure is established and elastic constants'formulas of the equivalent model are deduced; According to a specific example, the lightweight design method of loaded sandwich structure composite is proposed.Finally, the box of a certain type of underground lifting compression garbage station is taken as an application example. The box's loads are analyzed and the distributed loads model of box is set up. Loaded sandwich structure composite is applied to the box instead of the original material, and the lightweight design of box is realized by means of the lightweight design method of loaded sandwich structure composite. Accordingly, lightweight box's finite element analysis and simulation are carried out to verify the correctness and feasibility of the lightweight design solution. The proposed methods in the dissertation can apply to engineering and have good effects according to engineering practice's results.