The impact of diameter, number of ribs, percentage of steel, compressive strength and cover thickness on the large concrete dome

Abstract

This paper presents an investigation of the finite element analysis via ANSYS12 software for the large concrete dome. Very few studies have been devoted to the case of the analysis of large concrete dome. The prediction of the analysis of large diameter concrete dome is a challenging task. This paper have a novel discussion for the non linear analysis of reinforced concrete or composite hemispherical dome of monolithically or partially interconnected ribs, running in the meridional of the dome. A simplified three dimensional finite element model is developed in ANSYS12, this analysis, which may be applied to three cases of hemispherical dome: unribbed, monolithic ribs, and composite ones. The interfaces between the precast radial ribs and the abutting cover in composite dome is modeled. Material non-linearity due to the cracking and crashing of the concrete and yielding of the reinforcing steel bars are taken into consideration during the analysis. The current application included initially, the analysis of unribbed hemispherical reinforce concrete dome by the recent finite element model and by the membrane theory of shells, have shown very high agreement in the membrane meridional and hoop normal stresses values which were all within the 3.3% margin of difference. Application of the present numerical model to hemispherical ribbed dome of the two specified types (monolithic concrete and composite ones) has produced variations of the three orthogonal normal stresses and the vertical displacement along meridional path from apex to base of dome, which are in perfect agreement with the logical structure behavior of such dome that is drawn by high structural inspection. A wide parametric study the impact of diameter, number of ribs, percentage of Steel, compressive strength and cover thickness on the large dome for the three cases to evaluate the quantities affect of the main parametric in the aspects of geometry, constitutions and material properties. Numerical percentages of the variation of ultimate loads and vertical deflection at dome apex with variation of each of those parametric has been computed when given the fundamental guidelines for the structural design of such dome.