Parametric Analysis of Meridional and Hoop Forces Response with Respect to Rise to Radius Ratio of Spherical Concrete Shell
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Date
2020-10
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Addis Ababa University
Abstract
This paper considers a spherical concrete dome of constant span length sixty-meter and ten-centimeter thickness. Analytical and SAP2000 finite element software are employed for analysis. Ten different models for dead load, live load and wind load are done. All together thirty models are conducted and analyzed. Analysis results are done in analytically using Microsoft excel and SAP2000. Ten different rises to radius ratios are taken to determine the most efficient load carrying capacity of the shell under the action of dead, live and wind loads one after the other that generates various meridional and hoop forces. The behavior of the shell roof changes as its rise to radius ratio changes. The numerical value of rise to radius ratio that corresponds to 0.73 is taken as a reference point to study the behavior of hoop and meridional forces under gravity loads. This is the value at which edge forces are minimum. When rise to radius ratio decreases, the edge shear and edge moment increases in magnitude. As a result, the compressive hoop force is changed from compressive to tensile force drastically while the meridional force remains compressive but gets reduced in magnitude. When rise to radius ratio increases, the behavior of edge shear and edge moment increases in magnitude but show opposite sign to that of decrease in rise to radius ratio. As a result, the hoop force is changed from tensile to compressive force gradually while the meridional force remains compressive but gets negligibly increased in magnitude. Figures 5- 1, 5- 2, 5-3, 5- 4, and 5- 5 illustrate more. On this paper, the best rise to radius ratio for minimum edge disturbance effects due to gravity loads ranging from 0.72−0.74, is recommended to resist the loads in membrane actions with negligible bending forces. However, for minimum effect of membrane meridional and hoop forces due to wind load, the best rise to radius ratio recommended ranges from 0.5−0.7.
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spherical concrete shell roof, meridional force, hoop force, rise to radius ratio, SAP2000