The effect of nonlinear temperature distribution on the vibrational behavior of a size‐dependent FG laminated rectangular plates undergoing prescribed overall motion

2018 ◽  
Vol 40 (2) ◽  
pp. 766-778 ◽  
Author(s):  
Abolfazl Fallah ◽  
Korosh Khorshidi
2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Liang Zhao ◽  
Zhiyong Yang ◽  
Lijie Wang

There is a growing demand for silos with large diameters and volumes; hence, the stresses induced by the temperature differences between the inner and the outer surfaces of the concrete walls of the large silos become significant. Sunshine is the main source of the temperature differences; and it is necessary to investigate the influences of sunshine on large concrete silos and ensure their safety and durability. In this paper, the temperature distribution of a concrete silo exposed to the sunshine was measured on site. A finite element (FE) model was built to analyze the temperature distribution under the sunshine, and the FE model was validated by comparing the yielded temperature field with that obtained on site. Based on the temperature field yielded in the FE model, the internal forces of the silo were determined by performing a structural analysis. After that, the FE model was extended and used for a parametrical study, and the influences induced by the factors like meteorological parameters, dimension of silos, and reference temperature on the temperature effects of the silo were investigated. The simulation results showed that the temperature gradient exhibited significant nonlinearities along the wall thickness. The performance of a steady-state analytical method was evaluated, which is conventionally used for the design of silos. It was found that, for the silos with the thicknesses of more than 30 centimeters, the steady-state method overestimated the temperature effects. It is suggested here that nonlinear temperature gradients should be employed for considering the temperature effects of large silos.


1984 ◽  
Vol 106 (1) ◽  
pp. 137-142 ◽  
Author(s):  
M. Kaviany

The onset of convection due to a nonlinear and time-dependent temperature stratification in a saturated porous medium with upper and lower free surfaces is considered. The initial parabolic temperature distribution is due to uniform internal heating. The medium is then cooled by decreasing the upper surface temperature linearly with time. Linear stability theory is applied to the more formally developed governing equations. In order to obtain an asymptotic solution for transient problems involving very long time scales, the critical Rayleigh number for steady-state, nonlinear temperature distribution is also obtained. The effects of porosity, permeability, and Prandtl number on the time of the onset of convection are examined. The steady-state results show that the critical Rayleigh number depends only on the ratio of porosity to permeability and when this ratio exceeds a value of one thousand, the critical Rayleigh number is directly proportional to this ratio.


2011 ◽  
Vol 354-355 ◽  
pp. 1241-1244
Author(s):  
Yan He ◽  
Man Ding ◽  
Qian Zhang

In this paper the temperature field of Concrete Filled Steel Tube (CFST) member under solar radiation is simulated. The results show that temperature distribution caused by solar radiation is nonlinear over the cross-section of CFST member, and it is significantly varied with time and sections, the largest nonlinear temperature difference is over 26.3°C.


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