Multi-scale mechanism of steel tube restraint effect on concrete of CFST

Abstract

A multi-scale numerical model was used to study the mechanism of steel tube restraint effect on the concrete of concrete-filled steel tube (CFST) columns under compression. In the developed model, aggregates, mortar, and interfacial transition zones (ITZ) of concrete core were fabricated in meso-scale; however, steel tube was considered to be in macro-scale to investigate the interactions of all phases. Parametric analyses with different diameters and steel ratios were conducted to evaluate multi-scale model. The developed multi-scale numerical simulation could be employed to provide a better understanding on cracking processes of concrete and stress paths of steel tubes in CFST.

Keywords:

• Concrete-filled steel tubular
• multi-scale
• interfacial transition zone
• finite element method
• restraint effect

Data availability statement

All data, models, and code included in this study are available upon request by contact with the corresponding author.

Additional information

Funding

This research was supported by Province Natural Science Foundation of Liaoning, China (No. 2022-KF-13-02, No. 2021-KF-13-07), Plan of Liaoning Province to revitalize Liaoning talents (No.XLYC1907121), and Scientific Research Project of Liaoning Provincial Department of Education (No. lnjc202019).