چكيده به لاتين
Functionally graded materials (FGM) are non-homogeneous materials which main characteristic of them is that their component could be selected with different properties, so that the properties varying continuously according to the volume fraction. Due to unique features of these materials in one volume of material, various industries, especially aerospace, turbomachinery, coating systems, storing electrical energy systems, automotive and related industries, etc. used them widely. The microstructure and chemical composition of FGM has a variable distribution in the volume of material, which leads to multiple properties of the material. One of the structures used in industries, especially in automotive applications, is thick-walled cylinders. Stress analyzing is so important for acceptable design of these structures.
In this study, Optimal design of rotating functionally graded material (FGM) cylindrical shell for minimizing the maximum von Mises stress and total mass of the FGM is investigated. Functionally graded shells consist of two constituent ceramic and metal that graded through the radial direction according to a specific distribution. Material properties like young’s modulus are specific function of radius. Elastic analysis for cylindrical shell is carried out to find radial stress, radial displacement, circumferential stress and von Mises stress along the radial direction for three arbitrary boundary conditions. Validation of elastic analysis is shown by comparing the results with special case in other literatures. A Multi objective genetic algorithm (NSGA-II) is implemented to optimize the volume fraction variables to reach the optimization purposes. By applying the constrained multi-objective genetic algorithm, with the aims of minimizing mass and maximum Von-Misses stress in the cylinder, a chart of the Pareto front is obtained. By selecting one of the optimal points of the graph, a distribution profile can be obtained. Problem is solved for three arbitrary conditions. The results are shown separately for every condition and then compared with each other. After analyzing and finding the optimal profile, a prototype model is built that tried to match up with theoru with existing facilities. Finally, theoretical and experimental results are compared and experimental error is determined. Finally, after analyzing and finding the optimal profile, a prototype model built that we tried to match up with theory.
Keywords: FGM, Cylinder, Optimization, Volume fraction, Genetic algorithm
