Aluminum dome structures' stability study

Abstract

The large spans dome structures made of aluminum alloys work is considered. The dome elements material choice is due to the lower weight compared to steel elements, the material corrosion resistance and the lower thermal expansion coefficient. An existing scientific research analysis related to the structures made of aluminum or aluminum alloys stability loss problem was carried out. A two-rod three-hinged model — the von Mises truss (MT) — was used as the research model. The normal stresses on relative deformations dependences graphs for a low-pitched truss with rod inclination angles of 80 and 85 degrees from the vertical for aluminum alloy 5083 with different tubular profiles thicknesses were obtained. The research was carried out in accordance with the provisions described in DSTU-NB EN 1999. An analytical expressions system was derived for determining the aluminum alloy elasticity modulus on strain diagrams. Analytical dependences describing the aluminum MT trusses' operation for all alloys with known mechanical and deformation properties have been obtained. The relative concentrated force in the truss's ridge node on the relative vertical deformations dependences graphs are plotted, taking into account the geometric and physical nonlinear material operation. The conducted research practical significance is that the obtained dependencies allow modeling the MT trusses with aluminum-based rods operation, taking into account various truss geometries. When modeling trusses, an inclined load and the presence of elastic supports in the ridge node were taken into account. Dependencies make it possible to predict the aluminum ribbed-ring domes stability loss, which are modeled by MT trusses.