Damage Measures for Performance-Based Design of Rectangular Concrete-Filled Steel Tube Members and Connections

Damage evolution of rectangular concrete-filled steel tube (RCFT) column and beam-column members as documented in experimental tests is presented in this paper. An experimental database was first constructed that included RCFT tests available in the worldwide literature. Based on the experimental data, appropriate damage states for RCFT members, connections, and frames were defined at different levels of loading. For each damage state, the performance of the specimens was documented quantitatively with the use of damage and ductility functions developed in this work. The paper then documents how to use these damage measures to assess the capacity of RCFT columns and beam-columns within the context of a performance-based design methodology.