Identification of Nodal Snap-Through Instability in Civil Space Structures

In the community of structural health monitoring (SHM) and damage detection, the majority of previous research efforts has been focused on the detection of the reduction in cross-sectional areas of structural components or connections. However, the detection of the loss of stability, which can easily result in a structural failure, has been lacking. The objective of this study is to identify the occurrence of instability in civil space structures, such as domes, shells and reticulated shell structures. For this type of structure, nodal snap-through instability occurs, where a node and connected members jump to a new equilibrium position, leading the geometric shape/pattern in a local area to change significantly. In this study, we propose to use tilting angles of members to identify the nodal snap-through instability of civil space structures. Tilting angles of members actually reflect the change in geometric shape caused by instability. The effectiveness of this approach will be validated on numerical simulations of a reticulated shell structure. This research will bridge the gap between SHM and structural stability research and will make important contributions to the science of both SHM and structural instability.