Nonlinear Thermomechanical Static and Dynamic Responses of Bidirectional Porous Fg Shell Panels and Experimental Verifications

The nonlinear static and dynamic deflection/stress characteristics of the porous FG shell panel with various geometrical shapes subjected to thermomechanical load are studied in the present article. The nonlinear flexural and stress responses are computed using the FE-based mathematical model developed using higher-order shear deformation theory (HSDT). The large-deformation induced geometric nonlinearity is incorporated using Green-Lagrange nonlinear strains (GLNS). Voigt's micromechanical model, in association with power-law (GT-I), sigmoid (GT-II) and exponential (GT-III) kinds of material grading patterns, are utilized to evaluate the effective properties of the graded panel. Also, even (PRT-I) and uneven (PRT-II) porosity distributions are considered in the present work. The temperature-dependent (TD) properties are adopted in association with variable temperature fields, i.e. uniform (TD-I), linear (TD-II) and nonlinear (TD-III) for the computation of flexural responses. The direct iterative method is used to evaluate the desired nonlinear responses. The stability of the computational model is verified using elemental sensitivity analysis. Also, the proposed model's accuracy is checked by comparing the present numerical results with the available published data and experimentally evaluated results. The experiment was carried out by fabricating a few natural fibre-reinforced linearly varying layerwise panels for the test run. Finally, the analysis is extended to examine the influence of several design-associated parameters on the nonlinear static and transient flexural and stress responses of the FG curved/flat panel considering thermal environmental conditions.