Open Access. © 2019 A. K. Thawait et al., published by Sciendo. This work is licensed under the Creative Commons Attribution- NonCommercial-NoDerivatives 4.0 License Mechanics and Mechanical Engineering 2019; 23:202ś211 Research Article Amit K. Thawait*, Lakshman Sondhi, Shubhashis Sanyal, and Shubhankar Bhowmick Stress and Deformation Analysis of Clamped Functionally graded Rotating Disks with Variable Thickness https://doi.org/10.2478/mme-2019-0027 Received Mar 29, 2018; revised Sep 01, 2018; accepted Nov 20, 2018 Abstract: The present study reports the linear elastic analy- sis of variable thickness functionally graded rotating disks. Disk material is graded radially by varying the volume fraction ratios of the constituent components. Three types of distribution laws, namely power law, exponential law and MoriśTanaka scheme are considered on a concave thickness profle rotating disk, and the resulting deforma- tion and stresses are evaluated for clamped-free boundary condition. The investigation is carried out using element based grading of material properties on the discretized el- ements. The efect of grading on deformation and stresses is investigated for each type of material distribution law. Further, a comparison is made between diferent types of distributions. The results obtained show that in a rotating disk, the deformation and stress felds can be controlled by the distribution law and grading parameter n of the vol- ume fraction ratio. Keywords: Functionally graded material (FGM), linear elastic analysis, rotating disk of variable thickness, ele- ment based material gradation 1 Introduction Components made of functionally graded materials (FGMs) are widely used in space vehicles, aircrafts, nu- clear power plants and many other engineering applica- tions. FGMs are special composites with continuous spa- tial variations of physical and mechanical properties. A *Corresponding Author: Amit K. Thawait: Institute of Technology, Guru Ghasidas Vishwavidyalaya, Bilaspur, 495009, Chhattisgarh, India; Email: amkthawait@gmail.com; Tel.: +91 8103180085 Lakshman Sondhi: Shri Shankaracharya Technical Campus (SSGI), Bhilai, 490020, Chhattisgarh, India Shubhashis Sanyal, Shubhankar Bhowmick: National Institute of Technology, Raipur, 492010, Chhattisgarh, India rotating disk, made up of such an FGM is widely used in the feld of aerospace, mechanical and marine industry for machines and machine elements like gas turbines, gears and fywheels. In rotating disks, the centrifugal load pro- duces deformation and stresses, thus limiting the applica- tion range, and as a result, these need to be constrained by varying the material property and thickness of the disk. Disks made up of functionally graded materials and of variable thickness have signifcant stress reduction over the disks made up of homogeneous material and of uni- form thickness. Therefore, a higher limit speed and higher pressure is permissible for FGM disks. A few researchers have reported their work on the anal- ysis of FGM disks, plates, shells, beams and bars using the analytical and fnite element method. Gupta et al. [1] reported creep stress and strain rates for a rotating thin annulus of varying density based on Seth’s transition the- ory. Based on Tresca’s yield criterion under plane stress assumption, Eraslan [2] presented analytical solutions for stresses in elasticśplastic regime of rotating parabolic disks. Using von Mises yield criterion, J2śdeformation the- ory and nonlinear isotropic hardening, Eraslan et al. [3] conducted the parametric elasticśplastic analysis of rotat- ing annular disks of variable thickness under pressurized boundary condition. Ramanjaneyulu et al. [4] have stud- ied the efect of tapper stifeners and material properties on critical speeds of very thin spinning disc. Analysis was carried out for diferent numbers of stifeners and vari- able geometry of disk under clamped-free boundary condi- tion. Stump et al. [5] explained the topology optimization framework for material distribution of an FG rotating disk under mechanical stress constraints. The scheme of func- tionally graded material distribution is based on the mate- rial model derived using the Hashin-Strikhman upper and lower bounds. Bayat et al. [6] reported the analysis of variable thick- ness FGM rotating disk with power law property distri- bution and the disk is subjected to both mechanical and thermal loads. Afsar et al. [7] analyzed a rotating FGM cir- cular disk subjected to thermo-mechanical load using f- nite element method. The disk has exponentially varying