Compressive strengths of concrete-filled double-skin (circular hollow section outer and square hollow section inner) aluminium tubular sections

Abstract

Experimental and numerical investigations of concrete-filled double-skin aluminium stub column with a circular hollow section as the outer skin and a square hollow section as the inner skin are presented in this article. A test program was carried out to study the influences of aluminium tube geometric dimensions and concrete strength on structural performance and strength of composite columns. A series of composite columns was tested on outer circular hollow section tubes and inner square hollow section tubes; the spaces between them had been filled with concrete of different nominal cylinder strengths of 40, 70 and 100 MPa. The tubes were fabricated by extrusion using 6061T6 heat-treated aluminium alloy having a nominal 0.2% proof stress of 240 MPa. A non-linear finite element model was developed and verified against experimental results. The test and numerical results were compared with the design strengths to evaluate the applicability of the design rules in the American specifications for aluminium and concrete structures. In addition, the proposed design equations, developed by the authors for concrete-filled double-skin aluminium tubular stub columns with circular hollow section as both outer and inner skins, were used to calculate the design strengths and compared with the experimental and numerical results obtained in this study. The proposed design equations also predicted the ultimate strengths of the concrete-filled double-skin aluminium tubular stub columns accurately with circular hollow section as the outer skin and square hollow section as the inner skin.

Flexural buckling behaviour of concrete-filled double skin aluminium alloy columns

“…Few studies exist on the compressive response of CFDSAT stub columns. Zhou and Young [30,31] experimentally and numerically studied the influence of geometry and concrete strength on the structural response of 6061-T6 alloy CFDSAT stub columns made with circular and circular-square outer and inner profiles. They recommended design guidelines to determine the compressive capacity of these cross-sections.…”

Fiber element modeling of circular double-skin concrete-filled stainless-carbon steel tubular columns under axial load and bending

“…Furthermore, the flexural stiffness and capacity of CFDST columns, as well as their cyclic performance, are higher than CFST columns. Applications of such columns include the construction of offshore structures, bridge piers, and transmission towers (Ahmed et al, 2021; Nakanishi et al, 1999; Sasy Chan et al, 2020; Wei et al, 1995; Zhou and Young, 2019). However, the outer tube may be subjected to a harsh environment which may affect their performance remarkably.

Figure 1.A cross-sectional view of the circular concrete-filled double-skin steel tubular column.

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Flexural behaviour of concrete-filled double skin aluminium alloy tubes

“…Few research studies are available on the structural response of concrete-filled double skin aluminium alloy tubular (CFDSAT) members. Zhou and Young [35,36] carried out experimental and numerical research to examine the effect of geometric dimensions and concrete compressive strength on the compressive response of 6061-T6 alloy CFDSAT stub columns consisting of circular tubes and a combination of circular outer and square inner tubes. They proposed design equations for CFDSAT stub columns considering the composite response of aluminium tubes and concrete.…”