Nonlinear transient behavior of fiber-metal laminated (FML) composite plates under non-ideal blast loads are investigated by both experimental and numerical techniques. In the experiments three plates with different aspect ratios are tested under blast loads and their response is also simulated and compared with both the developed mixed finite element method and the commercial software ANSYS. Furthermore parametric numerical analyses are conducted for nonlinear transient behavior of functionally graded (FGM) thin plates under blast loads with mixed FEM. In these parametric analyses the effect of aspect ratio, load distribution and impulse function in time domain are investigated. In the developed mixed FE formulation, the von Karman plate theory is used. Nonlinear functional is developed using the Hellinger-Reissner principle and linearized with the incremental formulation. Dynamic analyses are carried using the Newmark method with the Newton-Raphson iterations. Condensation is not performed hence time derivative of internal forces are also calculated during the solutions. Damping is incorporated to the analysis in the sense of the Rayleigh damping. As a result of conducted analyses, there is a good and reliable agreement between the numerical and the experimental results. Moreover, the developed mixed FEM results are almost identical to the ANSYS results. (C) 2011 Elsevier Ltd. All rights reserved.