08.19: Tests on concrete‐filled double skin tubular beams with circular stainless steel outer tubes

Abstract

A test program on concrete-filled double skin tubular (CFDST) beams with austenitic stainless steel outer tubes and high strength steel inner tubes is presented in this paper. A total of 22 four-point bending tests was carried out to study the behaviour and strengths of CFDST beams. The stainless steel outer tubes were circular hollow sections (CHS) with average diameter-to-thickness ratios of 56.8 and 48.5, and the measured 0.2% proof strengths of 276 MPa and 300 MPa, respectively. The high strength steel inner tubes were also circular hollow sections (CHS) with diameter-to-thickness ratios ranging from 5.0 to 22.8, and corresponding measured 0.2% proof stress ranging from 433 to 1029 MPa. The annuli were filled with concrete with three different concrete cylinder strengths of 40, 80 and 120 MPa. The moment capacities, moment-curvature relationships and failure modes of the beams are reported in this paper. It should be noted that currently there are no design provisions for concrete-filled stainless steel members. The test strengths were therefore compared with the moment capacity predictions in existing design codes (the European Code and American Specification) for concrete-filled carbon steel tubes. The comparisons revealed that both design codes provide very conservative resistance predictions.

Flexural performance of circular concrete‐filled double steel tubular members: Testing, modeling, and strength predictions

“…Test results showed that the flexural resistance of CFDST members was higher compared to CFST members. Furthermore, Uneka et al, 28 Wang et al, 29 Li et al, 26 Zhao et al, 30 Wang et al, 31 and Wang et al 32 studied the performance of double‐skin concrete‐filled steel tubular (DCFST) members with an inner hollow tube under different loading conditions including flexural load. However, due to the presence of the hollow inner tube, the performance of the DCFST member is different from its CFDST counterparts.…”

Evaluation of ultimate bending moment of circular concrete–filled double skin steel tubes using finite element analysis

“…By using finite element analysis (FEA), Huang [10] investigated the effects of important parameters which are used to determine sectional capacities of CFDST stub columns. In the other hand, many researchers have investigated the CFDST subjected to only pure bending [11][12][13][14][15], however, comprehensive studies in ultimate bending moment of CFDST, especially with a full scale CFDST, have not been reported so far.…”