Analysis And Design Of Functionally Graded Material Structures

Functionally graded material (FGM) is a type of composite, consisting of two or morephases, which can be designed its composition varies in some spatial direction. It has attracteda significant amount of interest from researchers. For its potential application in aeronauticand astronautic field, it attracts attention from the department of designing plane. It is veryimportant to reduce weight in plane structures' designs. Currently, the materials of the loopframe in the airframe are metal, but designers wish to use FGM instead of Titanium alloy inorder to reduce weight and improve the performance. The works in this paper focus on thestructure design of beams. The basic analysis method has been developed using a beam theorywhich considers warping deformation of the cross-section. Topology and size optimizationmethods are used to design the distribution of the materials so as to optimize this distributionand the graded variety rule of the material property in the transition region. The main worksof the dissertation are as follows:1. Based on the majority of current literature, the current research and the futureapplications of FGM are summarized, and the significance on the study of FGM ispointed out. (In chapter 1 )2. The beam theory which considers warping and the common topology methods are brieflyintroduced. The suitable model for the topology design of the beam's section materials isobtained. Topology optimization for FGM is done using an in-house developed program,which is based on the program made by research group. The optimum distribution ofmaterials in the FGM beam in different case of loads and meshes is found byoptimization method. (In chapter 2)3. The optimal distribution of graded cores in the laminate structure is studied. For thelaminate structure made of different materials, the position of graded cores affects thethickness of each layer. Therefore, the carrying capacity and dosage of the materials canbe designed by controlling the position. A methodology for the design of graded coreoptimum position is proposed to maximize carrying efficiency of the structure. Theoptimum capability of the beam is obtained by designing the position of the graded cores.(In chapter 3)4. The one typical frame in the airframe is analyzed. The parameter model of the originallymodel is established, and then the parameter is optimized. Based on the optimized result,the distribution of the materials is designed and the method of design for FGM at the beginning of thesis is tried to use to practice project. A valuable result is obtained. (Inchapter 4)...