Axial compression behaviour of circular concrete-filled titanium-clad bimetallic steel tubular stub columns

Titanium-clad (TC) bimetallic steel is a high-performance laminated steel with excellent corrosion resistance and mechanical properties as well as acceptable cost, which can be applied in ocean and offshore environments. This paper aims to study the axial compression behaviour of circular concrete-filled titanium-clad bimetallic steel tubular (CFTCBST) stub columns through experimental and numerical investigations. A total of seven specimens are manufactured and subjected to axial compression loading, with various geometric dimensions and concrete strengths. A three-dimensional finite element (FE) model is developed and validated against the experimental results to further study the axial compression behaviour of circular CFTCBST stub columns herein. The parametric study is carried out using the verified FE modelling approach with four major parameters considered, including the concrete strength, the substrate steel grade, the clad ratio, and the diameter-to-thickness ratio. Finally, the applicability of existing design methods for predicting the ultimate bearing capacity of circular CFTCBST stub columns is further analysed through comparisons with the FE results, and it is found that the Eurocode EN 1994–1–1 has the most accurate prediction that can be extended to predict the capacity of circular CFTCBST stub columns. © 2024 Elsevier Ltd