Papers by Keyword: I-Beam

Abstract: This article presents the results of determining the fire-retardant efficiency of heat-insulating granular plate based on geocement to protect metal structures from fire. According to the results of fire tests, it they found that with a plate thickness of 40 mm, the metal surface of an I-beam they heated to a critical temperature of 500 °C after 100 minutes of fire tests. This indicator provides the fire resistance class of metal structures P90 and the III group of fire retardant efficiency of metal structures. Based on the calculated data according to Eurocode 3, it they found that the critical heating temperature of an I-beam up to 538 °C with a plate thickness of 40 mm they achieved after 105 minutes of fire tests. This provides the fire resistance class of the steel column P90 and the III group of fire retardant efficiency. In order to ensure the fire resistance class P120, in the future, it is necessary to increase the thickness of the heat-insulating granular plate to 50 mm, which will allow transferring metal structures to the II group of fire retardant efficiency.

Abstract: This paper presents the results of fire test of an I-beam protected by a combined magnesite plate-magnesite mixture heat-insulating material. It was shown that a composite with an average thickness of 37 mm maintained an average temperature of 380 °C on the metal surface after 150 minutes of fire exposure, not exceeding the critical value of 500 °C. From 60 to 100 minutes of fire testing (furnace temperature of 980-1025 °C), the temperature of the metal did not exceed 100 °C. This was achieved both due to the high thermal insulation properties of the magnesite mixture, and due to gas and vapor release from the hydration products of magnesia cement. The developed fire-retardant material provides the first group of fire-retardant efficiency (150 minutes) and, after the fire test, is characterized by density of 352.4 kg/m³ and compressive strength of 0.85 MPa, which is three times lower than the original.

Abstract: Increasing pressure in separate areas when reconstructing and improving industrial buildings, may necessarily mean strengthening structural surfaces of buildings. In experimental and analytical assessment hollow cores slabs are represented as T-beams and I-beams. The width of the beam edge decreases according to the dimensions of the voids inside the slab. In this paper the authors test bearing strength and deformability of hollow core slabs in different conditions of strengthening. Furthermore, the scholars perform their calculations in a non-linear system, with a progressive loading, until the samples are destroyed, with a plastic hinge formed in the area extended in a slab cross section. Simulation and figure analyses were designed in ANSYS program. The researchers’ resulting of the stress-strain state of hollow core slabs is observed experimentally at various stages of loading. The researchers compared calculations of slabs with the full-scale cross section shape and calculations of the same I-beam slabs. Though, the investigators dwell on the impact of the cross-section on the results of the maximum slab deflections. The paper is also dedicated to a variety of strengthening modes and it explains that the cracking point for full-scale slabs comes after.

Abstract: Triangular web profile (TriWP) is a structural steel section made of two flanges connected to a web plate of triangular profile. The ability of TriWP to resist lateral–torsional buckling (LTB) is one of the most important criteria considered in the design of this steel section. This study examined the LTB behavior of TriWP steel section and determined the buckling moment resistance (M_b,Rd) for TriWP. Beam specimens were analyzed using a four-point bending test. Four types of specimen sizes were used: 200 mm × 100 mm × 6.3 mm × 6 mm; 200 mm × 100 mm × 9 mm × 6.3 mm; 200 mm × 100 mm × 8 mm × 6 mm; and 200 mm × 100 mm × 6 mm × 5 mm sections. Testing results for all specimen sizes showed that the values for M_b,Rd of the TriWP steel sections were higher than those of the flat web section. The percentage difference of M_b,Rd from the experimental results for all specimen sizes ranged from 10.38% to 17.37%. The percentage difference of M_b,Rd of the experimental and design values based on manual calculation by using Eurocode 3 ranged from 9.13% to 43.8%.

Abstract: Fibre reinforced polymer composites have been widely used in automotive industries due to its high tensile strength, lightweight and potential resistance towards environmental conditions. This paper presents a study on the fatigue life prediction of fibre-reinforced polymer (FRP) and the application of FRP composite in manufacturing engineering industries. Four designs of I-beam with different thickness and fillet were studied. The analyses of fatigue life of the designs were done using ANSYS software. Results from the analysis showed that the combination of glass/polyester and the design of I-beam with a fillet of 10mm and thickness of 20mm was the best combination in terms of its good fatigue life, factor of safety and stronger top surface.

Abstract: This study deals with design and evaluation of mechanical properties of the I-shape beam made from plain weave fiberglass fabric and epoxy resin. The possibility of production of I-beam with fiberglass laminate stitched layers has been demonstrated and the prototype of glass-fibre-reinforced epoxy I-beam was manufactured. Tensile properties of fiberglass of manufactured samples were investigated. The results showed that the investigated fiberglass composite has a sufficiently high tensile strength comparable to steel. However, the modulus of elasticity of the samples is quite low.

Abstract: Multi-objective cellular genetic algorithm is obviously superior to the traditional multi-objective evolutionary algorithms in terms of testing performance of algorithm. However, the algorithm still needs to be used in practical engineering problems. In consideration of the above, this paper tries to apply the multi-objective cellular genetic algorithm to solve the problem of design of I-beam. Finally, the results show that multi-objective cellular genetic algorithm has more advantages than the traditional multi-objective evolutionary algorithms in solving this kind of multi-objective problems, no matter in uniformity or expansibility of best solutions.

Abstract: This paper presents the experimental and numerical studies on the flexural strengthened steel I-beams by using Carbon Fiber Reinforced Polymer (CFRP) strips. Nowadays, strengthening existing steel structures by using CFRP has been widely interested. One of the common usages of CFRP to strengthen steel beams is the flexural upgrading. In this case, CFRP strips are pasted on the tensile flange to improve flexural behaviors. The problems that are frequently reported for CFRP strengthened steel beams are the debonding, delaminating (peeling), and splitting. Identification these failure modes are essential to provide an appropriate level of safety for strengthened steel beams. To investigate the CFRP failure modes, four strengthened steel I-beams were chosen. The CFRP plates with different thicknesses in single and double (splice) layers were used. Both experimental test (four-points bending test) and numerical simulation (full 3D simulation with ANSYS) were employed. The incremental loading was applied until failure while deformations in the critical regions were recorded. The results reveal that for the CFRP flexural strengthened steel beams the following failure modes occurred: (a) debonding at the CFRP plate tips, (b) debonding below point loads, (c) delaminating at the ends of CFRP plate, and (d) splitting below point loads. The sequence of failure modes depended on the specifications of CFRP plate. Some recommendations are provided to overcome/retard these failures.

Abstract: This paper reports the experimental studies on the local stiffening of steel I-beams by using Carbon Fiber Reinforced Polymer (CFRP) strips. One of the problems which frequently occur for steel section is the large local deformation under point loads. To study the effects of applying CFRP for local stiffening, four steel I-beams were selected and tested to failure. The first beam had no steel stiffeners below the point loads and used as the control beam. The second beam had steel stiffeners and was not enhanced by using CFRP strip. The third and fourth beams had no steel stiffeners below the point loads and were strengthened on the compressive flanges by using two longitudinal CFRP strips. Also, the third and fourth specimens were strengthened on the web by using the latitudinal CFRP strips in the discrete and continual types, respectively. The results show that applying CFRP on the compressive flange and web increased the load bearing capacity and decreased the local and overall deformations appropriately. Also, the full-covering of the web seems to be the best type of web strengthening.

Abstract: In this paper the fabricating technology of three dimensional (3D) integrated braided composite I beam is researched, including: braiding technology of 3D braided I beam preform, the orientation of fiber-tow in the I beam preform, the optimizing of process parameters of resin transfer molding (RTM) for 3D braided composite I beam, and the design of mould for consolidation of composite I beam. The quality of 3D braided composites is good analyzed by ultrasonic A-scan, void content calculation and microscope observation. The research result will provide a good way for designing and fabricating high performance 3D integrated braided composite components with irregular cross section.