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Axial compressive behavior and capacity reduction of circular CFST stub columns with internal discrete voids

Year: 2026

Type: article

Abstract: To investigate the influence of internal discrete voids on the axial compressive behavior of circular concrete‐filled steel tubular (CFST) stub columns, 24 specimens were tested under axial compression. Regularly distributed spherical voids were introduced using thin‐walled hollow stainless steel spheres. The effects of nominal void volume ratio χ , tube wall thickness t , and column height L on failure mode, axial capacity, secant stiffness at 0.4 N u , and steel‐tube strain response were examined. Internal voids promoted local buckling near the hollow spheres and between adjacent voids, accompanied by localized crushing and circumferential cracking of the core concrete. Increasing χ generally reduced axial capacity and secant stiffness at 0.4 N u , whereas increasing t improved structural resistance and delayed local deformation. For the tested specimen dimensions and nominal void‐ratio range ( χ = 0%–12%), a linear capacity reduction factor kr = 1 − 0.0221 χ was established based on the normalized capacity ratio and combined with the GB 50936‐2014 reference capacity. The full‐dataset calibration and leave‐one‐out cross‐validation gave MAPEs of 4.45% and 4.66%, respectively.

Source: Structural Concrete

DOI: 10.1002/suco.70874

Authors: Yiwei Tang, Kun Li, Liu Yang, Ni Zhang, Yali Feng, Jixiang Li

Institutions: Yangtze University, Yangtze University College of Arts and Sciences, Wuhan Polytechnic University

Language: English

Topic: Structural Load-Bearing Analysis

Subfield: Civil and Structural Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Industry, innovation and infrastructure

Open Access status: bronze

Funders: Hubei Provincial Department of Education, National Natural Science Foundation of China