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This paper presents the first and third order shear deformation plate theory and von Karman theories to solve Thermo-elastic problems of functionally graded hollow rotating disk. The material properties of the disk are assumed to be graded in the direction of the thickness by a power law distribution of volume fractions of the constituents. New set of equilibrium equations with small and large deflections are developed. Using small deflection theory an exact solution for displacement field is given. Solutions are obtained in series form in case of large deflection. Numerical results are presented for various percentages of ceramic-metal volume fractions and have been compared with those obtained using first-and third-order shear deformation plate theories. Also the results are verified with ABAQUS soft, simulink method and the known data in the literature.

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This paper presents an elastic parametric analysis for the purpose of investigating the limit angular speed, displacement and stresses in rotating disks made of functionally graded materials (FGMs) based on Tresca yield criterion. The material properties obey the power law in radial direction. The Poisson’s ratio due to slight variations in engineering materials is assumed constant. For different values of inhomogeneity constant, limit angular speed, displacement and stresses in radial direction are plotted and for the commencement of the plastic flow, different states are investigated. state1: onset of plastic flow at the inner radius, state2: onset of plastic flow at the outer radius, state3: onset of plastic flow as the simultaneously at both radii and state4: onset of plastic flow between the inner and outer radii. To the best of the researchers’ knowledge, so far, in the papers which have been dealing with the investigation of onset yield analysis, the density and yield stress has been assumed constant; however, in this paper by assuming varying density and yield stress in rotating disks made of functionally graded materials and comparing results obtained by fixing these parameters, it has been observed that taking the density as a constant value is wrong and varying it has significant effects on the stresses.

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A family of rotating disks used in Iranian turbine and compressor industry is investigated. Mechanical and thermal loads due to working condition would lead to the crack initiation in the inner surface of the disk. The aim of this paper is the development of the two-dimensional weight function for the rotating disks containing semi-elliptical longitudinal cracks. The general form of the two-dimensional weight function is related to the proposed weight functions for embedded cracked domain in literature. In order to determine the unknown coefficient of the weight function, the reference stress intensity factors for cracked geometry subjected to reference loads are calculated. The analysis indicated that the results are independent of the number of terms in proposed weight function expansion. Extracting the weight function for disks with from 90 to 420 mm thickness enables one to predict the stress intensity factor for cracks in the structure subjected to arbitrary loading. The stress intensity factor for each point on the crack front subjecting to one or two dimensional loads would be calculated using the derived weight function. The results reveal that the increasing of the height to thickness ratio in rotating disks leads to the increase of the stress intensity factor for high depth ratio crack ones. Results show that the configuration of the disk sections affects the stress intensity factors of the same aspect ratio cracks in the structures. The comparison of the results obtained from the weight function method and those obtained with FEM are in good agreement.