A Whole Process Finite Element Analysis of the Construction of an Open Steel Structure Glass Dome in an University

This article conducted numerical simulation research on the entire construction process of the steel structure dome project in a new campus of a college. The stress situation of the grid structure during the construction process was analyzed， and the stress and deformation at key positions were monitored， in order to provide a theoretical basis for the construction of open steel structure glass domes and ensures construction safety. This article used the life and death element method to numerically simulate the installation and unloading process of fish belly support， circular truss， and temporary support in dome structures， and devided the entire process into three parts： fish belly support installation， circumferential truss installation， and construction unloading. By comparing and analyzing the different installation methods of fish belly support， it was found that if sequential installation was used， there will be significant lateral displacement in the structure， which is prone to instability and damage. Therefore， in construction and installation， a central symmetric method should be adopted， with minimal deformation of the top pressure ring and overall lateral deformation of the structure， showing good stability. The main manifestation of structural deformation is vertical displacement， with a maximum vertical displacement of the top pressure ring reaching 24.5 mm， and the maximum vertical displacement of the circular truss reaching 28.65 mm. The maximum lateral displacement of the dome structure was only 15 mm， and after the installation of the sixth group of fish belly support， the maximum lateral displacement began to decrease. After the installation of the three sets of fish belly support， the maximum bending stress and combined stress appeared at the top pressure ring， and the stress value increased rapidly. The bending moment at the welding point between the temporary support and the top pressure ring also increased sharply. After the installation of all fish belly support and circumferential truss， the maximum combined stress was 141.4 MPa， which is far from reaching the yield stress of the steel. The maximum lateral displacement of the dome structure was only 9 mm， less than 1/400 of the temporary support height. The construction unloading adopted a graded unloading mode， with each level unloading 3mm downward.During the unloading process， the deformation of the members in the dome structure showed a linear trend. Therefore， the unloading method selected in this article was reasonable. After the temporary support removal was completed， the structure transformed from the stress state of the temporary support system to the free stress state of the structure. The dome structure showed good stability throughout the whole construction process.