Stress state of metal dome meridional ribs at different stages of overhang erection process

Research aim. The aim of the present research was an analysis of a metal ribbed ring-shaped dome metallic ribs stress state at different stages of a skeleton overhang erection process. The considered dome is hemispherical and is assembled bottom-up of individual elements. Due to a varying slope of meridional ribs elements at different relative elevations their stress state changes during mounting. The effect of the overhang erection process onto the stress state of the metal dome meridional ribs has been investigated. The relationship between the stress state of a meridional rib and mounting of each next dome skeleton tier has been established. Methods. A mathematical model of the metal ribbed ring-shaped dome assembled of steel H-shaped elements with rigid connections has been developed. Several extra models corresponding to different skeleton erection stages have been also generated to determine stresses in the meridional ribs at these stages. Response of each dome mathematical model under dead-weight load has been simulated. The obtained values of stresses in the meridional ribs within different models have been compared with corresponding design stresses values. Results. The dependence of the metal dome meridional rib stress state onto the stages of overhang erection process has been plotted. A degree of utilization of ribs steel strength at different erection stages has been represented by diagrams. An estimation of the dome skeleton stress state during overhang erection has been given. Imminence of assembly stresses during overhang erection and their influence onto dome structural reliability has been pointed out.