Study of the Dynamic Strength of Reticulated Domes under Severe Earthquake Loading

Abstract

The behaviour of selected steel domes subject to severe earthquake loading has been investigated and reported. Particular attention has been given to assess the development and spread of plasticity throughout these structures. Several dome configurations have been considered, both perfect and imperfect, together with a range of varying rise to span ratios. Finite element analysis of these structures has been undertaken to determine the rate of spread of plasticity and the rate of increase in node displacement under seismic loading. The dynamic strength failure acceleration (DSFA) has been defined as the acceleration at which the rate of spread of plasticity and node displacement reaches a runaway level and the structure becomes dynamically unstable. For the dome structures under consideration DSFA occurred at an acceleration of approximately 8 m/s2. In addition, the DSFA decreased by 15%–50% for the imperfect structures when compared with the perfect domes and was lower for the multi-directional seismic input. Also, the DSFA decreased gradually with a corresponding increase in the rise to span ratio.