الفهرس | Only 14 pages are availabe for public view |
Abstract In this research, a finite element technique has been employed for the displacements, and the internal stress analysis distribution of the circular steel stiffened shell structures. Two problems have been studied, an elevated water steel tank and a circular steel silo with two different storage materials. In the first problem the storage material was water which causes a lateral pressure force only to the shell structure, while in the second problem the storage material was a solid material which causes a lateral pressure force and a vertical compression force due to the friction to the shell structure. In the first problem, the effect of: 1- Using horizontal stiffener at the top line of the tank cylinder. 2- Using horizontal stiffener at the intersection between the cylinder and the conical bottom. 3- Using horizontal stiffener above the intersection by O.50m. 4- The change of the conical bottom slope angle. 5- The change in cross-sectional area of the stiffeners. 6- The change in the cylindrical shell diameter and height. Were all discussed in details. In the second problem, the effect of: 1 - Using horizontal stiffener at the top line of the silo cylinder and at the intersection between the cylinder and the conical bottom. 2- Using horizontal stiffener above the intersection by 3.00m. 3- Using vertical stiffeners at supports with length 1.00m, and 3.00m above the supports. 4- The variation of storage material (powdered Portland cement and Wheat). 5- The change in cross-sectional area of the stiffeners. 6- The change in the cylindrical shell height. Were all discussed in details. In this research, the finite element method has been implemented into the used (FEA) program, ADINA. The total structure -not any symmetrical part has been modeled assuming that the body of the structure can be represented by shell elements -with a Linear elastic material model in the case of the linear analysis, and by an Elastic-plastic (Isotropic hardening) material model in the case of the nonlinear analysis-, and both of the support column, and horizontal and vertical stiffeners can be represented by a series of beam elements -with a Linear elastic material model in the case of the linear analysis, and by an Elastic-plastic material model in the case of the nonlinear analysis. |