Collapse-Resisting Mechanisms of Planar Trusses Following Sudden Member Loss

Progressive collapse incidents of truss structures are often reported; however, studies on the collapse resistance of truss structures are comparatively few. In order to investigate the collapse-resisting mechanisms of truss structures, this paper presents a comprehensive and detailed study on the collapse-resisting performance of planar trusses subjected to local damage at various locations, using both finite-element (FE) and analytical approaches. An improved FE analysis procedure is proposed to improve the computational efficiency. The main conclusions include the following: (1) in the case of a sudden loss of a top chord member or a diagonal member, catenary action will be the primary mechanism to provide the bridging-over capacity of the remaining structure, and severer damage can result when the removed member locates in the midspan; and (2) if a bottom chord member is suddenly lost, arch action will be the main mechanism to provide the bridging-over capacity of the remaining structure, and severer damage can result when the removed member locates next to the support or in the midspan. (C) 2017 American Society of Civil Engineers.