## 1 Introduction
Stress intensity factors of composite media with cracked coating-substrate interfaces were investigated by [PERSON] and [PERSON] [19] utilizing the finite element method. The study highlighted the potential of FGM in mitigating stress singularities along the interfaces. Based on the Fourier series expansion method, [PERSON] et al. [20] conducted a comprehensive investigation on the buckling behavior of a cylindrical shell coated with FGM under thermal loading conditions. [PERSON] et al. [21] simulated the sliding interaction between an FGM-coated half-plane and a homogeneous half-plane to investigate the frictional heat and thermal contact resistance in brake systems. The research findings showed that an appropriate choice of gradient type can effectively regulate the coupled thermoelastic instability observed in the sliding system. Utilizing the higher-order shear deformation plate theory, [PERSON] and [PERSON] [22] conducted a research study to explore the effects of various factors, such as the plate aspect ratio and thermal loading conditions, on the critical buckling temperature of FGM sandwich plates. [PERSON] and [PERSON] [23] presented a comprehensive analysis of the post-buckling characteristics of eccentrically stiffened sandwich plates supported on elastic foundations under different loading conditions based on [PERSON]'s third-order shear deformation plate theory incorporating von Karman geometrical nonlinearity. [PERSON] et al. [24] employed a higher-order shear deformation theory and applied [PERSON]'s variational principle to investigate the free vibration characteristics of rectangular nanoplates with temperature-dependent FGM layers. [PERSON] et al. [25] investigated the nonlinear static behaviors of sandwich plates on an elastic foundation, taking into account the temperature dependency of the FGM material. The investigation of the dynamic behavior of multi-directional porous sandwich plates consisting of two functionally graded face sheets and a homogeneous core was studied by [PERSON] and [PERSON] [26] using [PERSON]'s solution technique. FCMs are microscopically inhomogeneous with the material properties varying continuously from one surface to the other obeying certain functions. Over the past few decades, a considerable number of studies [27; 28; 29; 30] corresponding to the FGM circular plates assumed the through-the-thickness FGM using either a power-law or exponential function. However, due to the phenomenon of the uncoupled stretching-bending problem of the through-the-radius FGM plate, the study of the radial FGM plate has been growing. [PERSON] and [PERSON] [31] assumed the material properties varying in the radial direction to study the axisymmetric bending of functionally graded circular and annular plates. By considering a radial variation of [PERSON]'s modulus employing a power-law relationship, [PERSON] [32] proposed an analytical solution to address the issue of the stress concentration factor of an isotropic homogeneous plate with a circular hole, and [PERSON] et al. [33] suggested that selecting an appropriate material gradation model and power-law index can significantly mitigate stress concentration factors. Although the radially FGM circular plates result in the uncoupled stretching-bending behavior, the bending equilibrium equation of the through-the-radius FGM circular plate is more complicated than that of the through-the-thickness FGM plate, and hence, only a limited number of analytical solutions have been derived for radially graded circular plates. To the best of the authors' knowledge, no thermal-bending analytical solution of the radially FGM-coated or FGM-undercoated circular plates has been reported. The point is that analytical solutions play a crucial role as reference benchmarks for researchers to validate the accuracy and reliability of their numerical methods.