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- Hilo, Salam J., et al.
(författare)
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Structural Performance of Internally Stiffened Double-Skinned Profiled Composite Walls with Openings
- 2023
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Ingår i: Buildings. - 2075-5309. ; 13:6
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Tidskriftsartikel (refereegranskat)abstract
- The double-skin profiled composite wall (DSPCW) system, filled with concrete material, is favorable in modern structures due to its high strength and ductility. Openings may be required within this composite wall (DSPCW) for various reasons, similar to a conventional bearing wall, which can lead to a reduction in bearing capacity. Therefore, to avoid changes in the geometry, materials, and thickness of this DSPCW wall, a new internally stiffening concept has been suggested by providing embedded cold-formed steel tube (CFST) columns. For this purpose, two full-scale DSPCW specimens were tested under static axial load, one of which was fabricated with a large opening size and stiffened with two octagonal CFST columns, while the other was designed without an opening and served as a control wall specimen. The results showed that the stiffened DSPCW with an opening achieved a slightly lower ultimate bearing strength (-9.4%) than the control wall specimen, with no reduction in the ductility behavior. Furthermore, several finite element models of DSPCW have been analyzed and designed to investigate additional parameters that were not experimentally tested, including the effects of the embedded CFST column's shape and different types of internal stiffeners longitudinally provided inside these columns. The numerical investigation confirmed that the embedded CFST column with an octagonal cross-section was more efficient compared to the hexagonal and rectangular shapes by about 11% and 18.4%, respectively. Furthermore, using internal steel stiffeners for embedded tubes with a T-shape improved the axial bearing capacity of the DSPCW with an opening slightly higher than the corresponding stiffened walls with other investigated stiffener shapes (V-shaped, U-shaped, and L-shaped).
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| 2. |
- Sabih, Saba M., et al.
(författare)
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Numerical Investigation into the Strengthening of Concrete-Filled Steel Tube Composite Columns Using Carbon Fiber-Reinforced Polymers
- 2024
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Ingår i: Buildings. - 2075-5309. ; 14:2
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Tidskriftsartikel (refereegranskat)abstract
- Hollow and concrete-filled steel tubes (CFSTs) are extensively employed as columns in various structural systems, yet they are susceptible to local buckling under axial compression loading. Local buckling tends to manifest near the column ends where moments are the highest. To address this issue and enhance the strength and ductility of CFSTs, carbon fiber-reinforced polymers (CFRPs) emerge as a simple and effective solution, having been successfully utilized in prior studies. This investigation focuses on assessing the axial load behavior of CFRP-strengthened CFST slender columns using the finite element (FE) method. The study begins with a verification phase, followed by comprehensive parametric studies exploring the impact of CFRP layers, numbers, confinement lengths, and positions. The FE results demonstrate that a single CFRP sheet, with a thickness of 1.2 mm, enhances the composite column’s axial load resistance by 8.5%. Doubling the CFRP sheets to a total thickness of 2.4 mm increases the resistance to 23.5%, while three sheets totaling 3.6 mm and four sheets totaling 4.8 mm result in axial load resistances of 35.1% and 44.5%, respectively. Furthermore, the study reveals that varying the lengths of CFRP sheets improves axial load resistance by 8.5%, 4.6%, 0.1%, and 0.5% for length percentages of 100%, 75%, 50%, and 25%, respectively. These findings underscore the efficacy of CFRP in strengthening CFST columns and provide valuable insights into optimizing the design parameters for an enhanced structural performance.
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