Mechanical Performance of Ultralightweight Cement Composite-Filled CFRP-Wrapped Steel Tube Arches with Compression-Yield Systems

Abstract

One of the main barriers to the acceptance and adoption of fiber-reinforced polymers (FRPs) in structural engineering is the brittle failure mode and limited ductility caused by the elastic-brittle behavior of FRP materials. Introducing a compression-yield (CY) system is a promising way to improve the ductility of the structures. This study adopted perforated steel cylinders as CY systems. Six perforated steel cylinders with different parameters were tested, and the applicability of the existing constitutive model on the perforated steel cylinders was verified. A design approach for perforated steel members on the structures was proposed. Based on the proposed design approach, ultralightweight cement composite (ULCC)-filled carbon fiber-reinforced polymer (CFRP)-wrapped steel tube arches with perforated steel cylinders were designed and experimentally investigated. The ULCC-filled CFRP-wrapped steel tube arches with CY systems achieved high ductility while maintaining favorable bearing capacity. A model was then proposed to evaluate the damage degree of the structures based on the longitudinal strain in the CY system. The damage development of the structures can be detected based on the measurement of the CY system, which enables early warning to be provided before structural failure.