Theoretical prediction and experimental verification of thermomechanical deflection responses of geometrically nonlinear porous graded curved structure

The nonlinear flexural/stress (static/dynamic) behaviour of functionally graded (FG) curved panels is analyzed in the current article, considering thermomechanical loading. The finite element (FE) based mathematical model is developed utilizing higher-order shear deformation theory (HSDT) and Green–Lagrange strain tensor (GLST) (to introduce the geometrical nonlinearity). Various types of material grading types (GDT), i.e., power-law (GDT-I), sigmoid (GDT-II) and exponential (GDT-III), and porosity variation patterns, i.e., even (PRT-I) and uneven (PRT-II) are delved in the present work. Also, temperature-dependent (TMPD) and temperature-independent (TMID) properties are engrained in estimating accurate static and dynamic responses. A direct iterative technique is adopted to compute the nonlinear structural deflection values under variable loading (static and dynamic). The numerical solution consistency of the established model has been verified via convergence. Furthermore, the correctness is proven using numerical and experimental validations. The natural-fibre (luffa) reinforced layer-wise graded panels have also been fabricated for experimental validation. The study includes the effect of temperature on the panel micro level and the variations between constituents (fibre and epoxy), which were checked through microstructural imaging. The analysis is extended further to study the influence of variable parameters on the flexural/stress data of the FGM panel.