TY - JOUR N2 - Analytical and numerical nonlinear solutions for rotating variable-thickness functionally graded solid and annular disks with viscoelastic orthotropic material properties are presented by using the method of successive approximations. Variable material properties such as Young’s moduli, density and thickness of the disk, are first introduced to obtain the governing equation. As a second step, the method of successive approximations is proposed to get the nonlinear solution of the problem. In the third step, the method of effective moduli is deduced to reduce the problem to the corresponding one of a homogeneous but anisotropic material. The results of viscoelastic stresses and radial displacement are obtained for annular and solid disks of different profiles and graphically illustrated. The calculated results are compared and the effects due to many parameters are discussed. L1 - http://journals.pan.pl/Content/104254/PDF/ame-2017-0025.pdf L2 - http://journals.pan.pl/Content/104254 PY - 2017 IS - No 4 EP - 440 DO - 10.1515/meceng-2017-0025 KW - nonlinear rotation KW - viscoelastic KW - functionally graded KW - successive approximations KW - solid and annular disks KW - gradually varying thickness A1 - Allam, M.N.M. A1 - Tantawy, R. A1 - Yousof, A. A1 - Zenkour, Ashraf M. PB - Polish Academy of Sciences, Committee on Machine Building VL - vol. 64 DA - 2017 T1 - Elastic and viscoelastic stresses of nonlinear rotating functionally graded solid and annular disks with gradually varying thickness SP - 423 UR - http://journals.pan.pl/dlibra/publication/edition/104254 T2 - Archive of Mechanical Engineering ER -