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Novel angle bracket used for (a) connecting CFS beam trusses, and (b) column anchoring of CFS column base.
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![Figure 2. Geometry and dimensions of novel angle bracket [mm].](profile/Paulina-Krolo/publication/362336580/figure/fig2/AS:1184190091526156@1659344327560/Geometry-and-dimensions-of-novel-angle-bracket-mm_Q320.jpg)
![Figure 5. Geometry and dimensions of steel specimens [mm].](profile/Paulina-Krolo/publication/362336580/figure/fig5/AS:1184190095728656@1659344328268/Geometry-and-dimensions-of-steel-specimens-mm_Q320.jpg)
In this study, an innovative fabricated angle bracket connection for joining cold-formed steel structures is presented and investigated. The innovation lies in the especially designed and manufactured angle bracket and in the method of connecting the angle bracket for the C-profile using clinch pressing. This novel angle bracket can be used to conn...
Contexts in source publication
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... or back-to-back channel sections are used as chord and web members, connected with bolts or screws, to transfer axial forces to other members through shear in the connector [8]. On the truss ends, where shear forces are greater, gusset plates are used to ensure force transfer to the ends of trusses without failure, as shown in Figure 1a. ...
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... this study, a novel angle bracket for CFS bolted connection in a thin-walled structure is proposed. A novel angle bracket can be used to connect CFS beam trusses on the ends of the chords (Figure 1a) or for anchoring the CFS column base, as shown in Figure 1b. In practice, truss floor beams or joists are generally embedded in-between the walls to reduce the height of the building, but then they behave as freely supported beams. ...
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... this study, a novel angle bracket for CFS bolted connection in a thin-walled structure is proposed. A novel angle bracket can be used to connect CFS beam trusses on the ends of the chords (Figure 1a) or for anchoring the CFS column base, as shown in Figure 1b. In practice, truss floor beams or joists are generally embedded in-between the walls to reduce the height of the building, but then they behave as freely supported beams. ...
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... specimens were tested using hydraulic jaws with a capacity of up to 500 kN. The test setup is shown in Figures 9 and 10. The tension in the specimen is applied using the displacement control of the movable crosshead at a test speed of 2.5 mm/min. ...
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... better visibility with the DIC system, the specimen was painted with a matt white primer spray over a length of 200 mm to reduce reflections from the galvanised steel. After priming, a black spray was used for the pattern and dot markings were applied to the test tool and the edge of an angle bracket as shown in Figure 10 ...
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... time-displacement curves and the force-displacement curves obtained by measurements with an LVDT and a universal testing machine (UTM) are shown in Figure 11a,b, while the measurements with the DIC system and the universal testing machine are shown in Figure 11c,d. The dashed lines represent the results of specimens (Ab-1-Ab-3) measured with the LVDT devices, while continuous lines represent the results of specimens (Ab-1-M-Ab-3-M). ...
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... time-displacement curves and the force-displacement curves obtained by measurements with an LVDT and a universal testing machine (UTM) are shown in Figure 11a,b, while the measurements with the DIC system and the universal testing machine are shown in Figure 11c,d. The dashed lines represent the results of specimens (Ab-1-Ab-3) measured with the LVDT devices, while continuous lines represent the results of specimens (Ab-1-M-Ab-3-M). ...
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... dashed lines represent the results of specimens (Ab-1-Ab-3) measured with the LVDT devices, while continuous lines represent the results of specimens (Ab-1-M-Ab-3-M). In Figure 11c,d, the letter A in Ab-4-A represents the results of ARAMIS 12M cameras, while M in Ab-4-M stands for the machine in the UTM. Due to the eccentricity of the specimen, there is a rotation of the sample at the beginning of the test. ...
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... the component of the displacement caused by the rotation of the specimen must be subtracted from the measured displacement. When the rotation of the specimen is completed and there is only axial displacement, the LVDTs continue to measure correctly, which is visible in the diagrams in Figure 11a,b as horizontal displacement shifts from 0 to 2 mm. The displacements on the specimens from Ab-1 to Ab-3 measured by LVDT measuring devices have a scatter of ±33%, so the displacements on specimen Ab-4 were measured using the digital image correlation technique. ...
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... ductility of the angle bracket was manifested by a plastic deformation that is 3.7 times greater than the elastic one. The deformation of the angle bracket connection was primarily characterised by the bending of the angle bracket, which caused plastic deformation of the web edge of the C-profile due to the rigid connection visible in Figure 10. In addition, the plastic deformation of the radius area between the web and the flange caused a narrowing of the profile at the edge, as shown in Table 7 as the difference between the dimensions measured before and after the test. ...
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... bolt was pulled through at the connection with the angle bracket at a force between 37.4 and 38.8 kN and a displacement between 10.37 and 11.01. During bolt penetration of the angle bracket flange, the bolt hole widened at the top near the stiffening darts, as shown in Figure 12a,b. Force-displacement curves for the Ab test specimens represent the described behaviour and are shown in Figure 13. ...
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... bolt penetration of the angle bracket flange, the bolt hole widened at the top near the stiffening darts, as shown in Figure 12a,b. Force-displacement curves for the Ab test specimens represent the described behaviour and are shown in Figure 13. The test was stopped when a force drop of 15% was recorded on the test device. ...
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... 1 was allocated to the C profile, and Point 2 to the angle bracket. Figure 14a shows the displacement of points in time, while Figure 14b shows a relative displacement of 0.02 mm at a test time of 245 s. The relative displacements are negligible, confirming the rigidity of the connection between the C-profile and the angle bracket. ...
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... 1 was allocated to the C profile, and Point 2 to the angle bracket. Figure 14a shows the displacement of points in time, while Figure 14b shows a relative displacement of 0.02 mm at a test time of 245 s. The relative displacements are negligible, confirming the rigidity of the connection between the C-profile and the angle bracket. ...
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... relative displacements are negligible, confirming the rigidity of the connection between the C-profile and the angle bracket. In addition, due to the very rigid connection of the clinch-pressed connectors, the C-profile follows the deformation of the angle, which is also shown as a displacement field in Figure 14c. Analysing the field reveals that the lever arm, z, is formed between the edge of the web of the C-profile and the outermost row of connectors, which helps to limit the angle bracket's rotation. ...
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... the field reveals that the lever arm, z, is formed between the edge of the web of the C-profile and the outermost row of connectors, which helps to limit the angle bracket's rotation. The tested specimens are shown in ascending order from the left in Figure 15. During the removal of the test tool, the M12 bolt was removed without damaging the specimens Ab-2, Ab-3 and Ab-4. ...
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... Kako bi se utvrdilo ponašanje kutne spojnice i U-spojnice unutar vlačne komponente priključka, provedena su tri eksperimenta prilikom kojih su osmišljeni i izrađeni specijalni alati za prihvat uzorka u ispitnom stroju (Slika 5). Ispitivanje kutne spojnice na vlak (test A1) [12], provedeno je na 5 uzoraka C-profila duljine 405 mm, kojemu je kutna spojnica ugrađena na gornjem kraju profila (Slika 5a), dok je ispitivanje U-spojnice na vlak (test (A2) [13] provedeno na 3 uzorka koji se sastoje od dva C-profila duljine 305 mm međusobno spojenih U-spojnicom (Slika 5b). Uzorci A3 u odnosu na A2 imaju dodatnu produženu maticu duljine 80 mm ugrađenu unutar Uspojnice (Slika 6c). ...
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... To achieve continuity of the beam trusses over more spans while keeping the truss beams in between wall panels, a connection with two innovative connectors for the CFS members has been designed ( Figure 1). One of these connectors is a novel angle bracket that was introduced in a previous study [2]. It can be used to anchor CFS members and panels and to connect truss ends to steel, concrete, or other common structures. ...
... To ensure a rigid, slip-free connection between the rigid steel block and the specimen, the M12 bolts are preloaded with a tightening torque of 120 Nm. More detailed data on the test tools can be found in the earlier paper [2]. ...
... The Partial safety factor 2 was neglected to obtain the characteristic value of the bearing resistance. Both calculation methods used average values of experimentally determined material properties [2]. The 3 mm ( 1 ) thick DX51D steel of the U-connector has an average tensile strength of 414.07 MPa ( ,1 ), while the 1.15 mm ( 2 ) thick S550 GD steel of the C-profile has an average tensile strength of 704.98 MPa ( ,2 ). ...
This research investigates the behaviour of the novel U‐connector used in cold‐formed steel (CFS) truss‐to‐column connection. The novelty is reflected in the specially designed connector geometry and the connection method within the cross‐section of the thin‐walled C‐profile. The U‐connector installed inside the truss‐to‐column connection can be exposed to tensile, compressive and shearing action. The shear behaviour of the U‐connector is thoroughly investigated using laboratory tests. Three different loading scenarios are carried out to evaluate the shear strength of the U‐connector within the C‐profile connection. The detailed analysis is carried out using Digital Image Correlation (DIC) technique for measuring the displacement. The failure modes observed during the experiments are described and analysed. DIC technology is used to accurately identify the failure initiation of each component in the connection. In addition, two different methods for calculating the bearing resistance of the U‐connector and the C‐profile connection are proposed according to recommendations given in the standard EN 1993‐1‐3. These methods aim to provide accurate estimates of the connection's bearing capacity.
... The tests were performed at room temperature according to method A of the Standard EN ISO 6892-1:2019 for metallic materials [30]. The results of these tests, including the average values of the modulus of elasticity E, the upper yield stresses R , and the tensile strengths R for each steel, can be found in the article [31]. In addition, Table 2 provides a summary of these average values as well as the strains measured with an external extensometer at a gauge length of 50 mm, including the average values of strain at yield A , and total percentage strain at maximum force A and at break A . ...
... The tests were performed at room temperature according to method A of the Standard EN ISO 6892-1:2019 for metallic materials [30]. The results of these tests, including the average values of the modulus of elasticity E, the upper yield stresses R eH , and the tensile strengths R m for each steel, can be found in the article [31]. In addition, Table 2 provides a summary of these average values as well as the strains measured with an external extensometer at a gauge length of 50 mm, including the average values of strain at yield A e , and total percentage strain at maximum force A gt and at break A t . ...
... Results of tensile tests for S550 GD and DX51D Z275[31]. ...
This study presents an innovative design for a cold-formed steel polyurethane (CFS-PU) composite wall panel, combining a cold-formed steel frame, a polyurethane foam infill, and a gypsum fibreboard sheathing. The foam filling process, in which the foam is injected under pressure, ensures uniform distribution, bonding, and interaction of all panel components. The aim of the study is to evaluate the behaviour of the CFS-PU composite panels and the influence of the PU foam and sheathing on the performance of the CFS frame structure. For this purpose, a comprehensive test programme was conducted with nine full-scale specimens, including four CFS-F specimens without infill and sheathing and five CFS-PU specimens with infill and sheathing on both sides. The study examined various aspects of the specimens, including failure modes, stability, stiffness, load-bearing capacity, and ductility index. By analysing these parameters, valuable insights were gained into the performance characteristics of the composite wall panels. The load-bearing capacity of the CFS-PU test specimens was improved by 2.34 times and the stiffness by 1.47 times compared to the CFS-F test specimens. The positive results highlight the potential of foam and sheathing in improving the axial compression performance of CFS walls.
... In order to achieve continuity of the trusses over more spans and at the same time keep the trusses submerged between walls, a connection with two innovative connectors for CFS members has been designed ( Figure 1). One of these connectors is a novel angle bracket that was presented in a previous study [19]. It can be used to anchor CFS members and panels and to connect truss ends to CFS columns, concrete, steel or other common structures. ...
... The U-connector has pre-drilled holes for self-tapping screws with a diameter of 5.2 mm, while the C-profile has clearance holes with a diameter of 6 mm. The One of these connectors is a novel angle bracket that was presented in a previous study [19]. It can be used to anchor CFS members and panels and to connect truss ends to CFS columns, concrete, steel or other common structures. ...
... In order to address this issue and increase the initial elastic stiffness, an optimization of the proposed connection was carried out. Furthermore, an analysis of the angle bracket alone in the previous work showed that its elastic stiffness was about 7.7 kN/mm [19]. The optimization was designed to maximize the use of the angle brackets in the truss beams while minimizing the load-transmitting role of the U-connector and CFS column in the tension and compression components of the connection. ...
This paper presents an experimental and numerical investigation of the tensile and compressive behaviour of a novel U-connector in the cold-formed steel (CFS) truss-to-column connection. Tensile tests were performed on 12 specimens representing the tension chords of the trusses in the connection. The results were used to validate a finite element model. The validated model was then subjected to both compressive and tensile loads, which revealed low stiffness in both the compressive and tensile components of the proposed connection. An optimisation of the geometry by using one long nut instead of two nuts was carried out to improve the behaviour and stiffness of the connection. The optimised results were compared with both experimental and numerical data, and conclusions were drawn regarding the effectiveness of the components in the proposed connection. The use of long-nut optimisation in the tension and compression components of the proposed connection shows a significant increase in load-bearing capacity, which makes it very promising for future applications in CFS truss-to-column connections. However, further validation through experimental testing is required to confirm the effectiveness and reliability of the connection in full-scale structures.
... Lukačević et al. [22] investigated an innovative fabricated angle bracket connection to join cold-formed steel structures. This angle bracket can be used to connect cold-formed steel elements such as beam trusses at the ends of the chords or to anchor the column base. ...
Corrugated web beams made of cold-formed steel components represent an economical solution for structures, offering high flexural capacity and deformation rigidity. For conventional corrugated web beams, made of thick plates for the flanges and thin sinusoidal steel sheets for the web, the elements can be joined by standard bolted end-plate connections. In the case of corrugated web beams made of thin-walled cold-formed steel components only, additional plates are required to accommodate the shape and position of the profiles. A large experimental program was carried out on corrugated web beams made of cold-formed steel elements. One of the objectives was to determine the capacity of these beams and the influence of several parameters on the response of the beam, but also very important were the end connections of these beams. The recordings obtained from the tests were used to validate a numerical model. Based on the validation of the numerical model, finite element analyses were performed to study four solutions for end connections to facilitate assembly, optimise the number of bolts, and increase the capacity and rigidity. Although the connection can be improved for assembling reasons with the presented solutions, the overall capacity is limited by the components subjected to compression that lose their stability. Doi: 10.28991/CEJ-2023-09-04-01 Full Text: PDF
