Robustness of structures

Abstract

Disproportionate collapse is prevented by ensuring collapse resistance, a property defined as the insensitivity of a structure to abnormal events. Enhancing robustness and reducing vulnerability are two different structural measures for achieving collapse resistance. The vulnerability of a structure is its susceptibility to become initially damaged by abnormal events; robustness is its insensitivity to such initial damage. Another option for preventing disproportionate collapse is the reduction of the exposure of the structure to abnormal events. The design strategy reducing vulnerability aims at preventing failure initiation whereas the strategy enhancing robustness aims at preventing disproportionate failure spreading. These two approaches are compared. Robustness can be achieved by the design methods alternative load paths and segmentation, which are also discussed. Furthermore, measures for the quantification of robustness are discussed.