Authors: Sun Bae Kim, Ji Hwan Kim

Abstract: In this study, thermal post-buckling characteristics of functionally graded (FG) panels in
hypersonic airflows are investigated. The volume fraction and the material properties of FGMs are
continuously changed from ceramic to metal in the thickness direction agreeably to a simple power
law distribution and a linear rule of mixture, respectively. Using the principle of virtual work, the
governing equations are derived and the finite element method is applied to obtain the solutions.
Based on the first-order shear deformation theory (FSDT), the FG panels are modeled by the von
Karman strain-displacement relation for the structural non-linearity. Also, the third-order piston
theory is employed to consider the aerodynamic non-linearity.

387

Authors: Saeid Rasouli Jazi, Fatemeh Farhatnia

Abstract: In this paper, buckling analysis of functionally graded super-elliptical plates is investigated by pb-2 Ritz method. The governing equation is derived based on classical plate theory (CLP). Since closed form solution of buckling differential equation is not available under various boundary conditions, pb-2 Ritz method (energy method) is applied to calculate non-dimensional buckling load. Total potential energy is given as summation of strain energy and work done by applied in-plane compression load. In order to obtain the buckling load, pb-2 Ritz method is applied corresponding to different peripheral supports (Clamped and Simply Supported) are used in the present study. The plates are assumed to have isotropic, two-constituent material distribution through the thickness and the modulus of elasticity of the plate is assumed to vary according to a power-law distribution in terms of the volume fractions of the constituents. Variation of buckling non-dimensional parameter is considered with respect to various powers of super–elliptic, FGM power law index and aspect ratio.

5387

Authors: Xiu Ling Qi, Yong Zhang

Abstract: There exists a large amount of longitudinal tensile stress in the weld bead of the TC4 thin plate for the uneven heating of the welding thermal resource. Owing to the equilibrium of the internal stress, longitudinal compressive stress is also large on the edge of the thin plate. When the compressive stress is larger than the critical buckling stress, the buckling distortion can take place. Therefore, the value of the critical buckling stress is important to judge the distortion. Some theoretical formula and empirical equation can not give the suitable solution to the judge of the critical value of the certain TC4 thin plate weldment because of the difficulty in the analytic solution and difference in the feature of the material and boundary condition. Finite element method was utilized to estimate the value of the buckling stress in the thin plate. Based on the solution, the adjustment of welding longitudinal compressive stress model is done. Henceforth, the critical buckling stress can be determined by the method. Keywords: critical buckling stress, TC4 thin plate, welding longitudinal residual stress

1387

Authors: Yu Liang, Song Xiang, Wei Ping Zhao

Abstract: Stress of simply functionally graded plates is predicted by the meshless method based on inverse multiquadrics radial basis function. The genetic algorithm is utilized to optimize the shape parameter of inverse multiquadrics radial basis function. The stress of simply functionally graded plates is calculated using the inverse multiquadrics with optimal shape parameter and compared with the analytical results of available literatures.

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