Nonlinear analysis of thin-walled Al/Al2O3 FG sandwich I-beams with mono-symmetric cross-section

In this study, a geometrically nonlinear analysis of thin-walled Al/Al2O3 functionally graded (FG) sandwich I-beams with mono-symmetric cross-section is presented. The FG beam consists of ceramic (Al2O3) and metal (Al) phases varying through the wall thickness. The Euler-Bernoulli beam theory and the Vlasov one are applied for bending and torsional problems, respectively. The analysis model considers the elastic couplings and constrained warping, and the geometric nonlinearity is accounted for in the von Kármán sense. The nonlinear governing equations are derived and the finite beam element model considering the Hermite cubic interpolation polynomials is employed with the scope to discretize the nonlinear governing equations. The results of Al/Al2O3 FG sandwich I-beams with mono-symmetric cross-section are validated with available results. In all cases, good correlation has been observed. Two types of material distributions are considered to investigate the influences of geometric nonlinearity, gradient index, thickness ratio of ceramic, material ratio, and span-to-height ratio on the coupled nonlinear responses of FG sandwich I-beams. Numerical results show that the above mentioned effects play an important role on the nonlinear structural responses.