• Steel and Composite Structures
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• v.47 no.1
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• pp.103-117
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• 2023

This paper presents an investigation on the shear resistance of corrugated web steel beams (CWBs) with a circular web opening. A total of five specimens with different diameters of web openings were designed and tested with vertical load applied on the top flange at mid-span. The ultimate strengths, failure modes, and load versus middle displacement curves were obtained from the tests. Following the tests, numerical models of the CWBs were developed and validated against the test results. The influence of the web plate thickness, steel grade, opening diameter, and location on the shear strength of the CWBs was extensively investigated. An XGBoost machine learning model for shear resistance prediction was trained based on 256 CWB samples. The XGBoost model with optimal hyperparameters showed excellent accuracy and exceeded the accuracy of the available design equations. The effects of geometric parameters and material properties on the shear resistance were evaluated using the SHAP method.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.10a
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• pp.162-169
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• 1999

Intentionally weakened girders near the beam-to-colum connection lead ductile failures at the weakened points prior to potential brittle failure at the connection points subjected to strong earthquake. Recent research investigated cyclic behavior of composite beams with a rectangular web opening and find out ductile failure of such beams due to plastic hinge formation of T-section at the four corners of the rectangular opening. But eventual failures of T-sections are resulted from local buckling of T-section having a narrow stem and a narrow bound of plastic hinge formation. This continuing research proposes double-circular opening instead of rectangular one in ofter to improve energy dissipation capacity as well as composite beam strength, Experimental test of two specimens was carried out and its results are compared with those of nonlinear finite element analyses

• Advances in concrete construction
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• v.15 no.5
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• pp.321-331
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• 2023

The effect of fibre-reinforced polymer (FRP) strengthening on the behaviour of reinforced concrete (RC) beams with web openings is studied. It has been observed that the load-carrying capacity and deflection in the presence of an opening reduced by approximately 50% and 75%, respectively. Three-dimensional nonlinear finite models are first validated with the results obtained from experimental data. Thereafter, a series of parametric studies are conducted for the beam with an opening. In the study, it is observed that a square opening shape is critical in comparison to the elliptical and circular-shaped opening. The web opening located near the support is found to be critically compared to the opening in the middle of the beam. Given the critical opening shape situated at the critical location, the increase in FRP layers enhances the load-deformation behaviour of the FRP-wrapped RC beam. However, the load-deformation responses are not significantly improved beyond a certain threshold value of FRP layers.

• Structural Engineering and Mechanics
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• v.84 no.1
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• pp.49-61
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• 2022

This paper presents an experimental investigation into the effectiveness of using carbon fibre reinforced polymer (CFRP) and steel plates to repair damaged reinforced concrete (RC) beams with circular web openings at shear zones. It highlights the effectiveness of externally bonded CFRP and steel plates in repairing damaged RC beams by analysing the repaired beams'load capacity, deflection, strain, and failure mode. For the experiment, a total of five beams were used, with one solid beam as a control beam and the other four beams having an opening near the shear zone. Two beams with openings were repaired using inclined and vertical configuration CFRP plates, and the other two were repaired using inclined and vertical configuration steel plates. The results confirm the effectiveness of CFRP and steel plates for repairing damaged RC beams with circular openings. The CFRP and steel plates significantly increase ultimate capacity and reduce deflection under the openings. The inclined configuration of both CFRP and steel plates was more effective than the vertical configuration. Using an inclined configuration not only increases the ultimate capacity of the beams but also changes the mode of failure from shear to flexural.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.609-614
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• 2000

This paper is an experimental study of the normal strength concrete beam and high strength concrete beam for the analysis of bending and shear behavior. In building structure, the story height can be minimized by providing openings in beams which serves for the utility equipments passing through. The dead space in false ceiling increase construction cost, the good ceiling system such as beam with opening give to economical merits because of a substantial reduction in materials and construction cost. For the analysis on the mechanical behavior of the reinforced high strength and normal strength concrete beams with circular opening in the web, the stress concentration of the circular opening, crack pattern and reinforcing methods were studied. Twenty test pieces with different reinforcing methods and difference concrete strength were tested and their resisting forces and load deflection curves were defined in this study.

• Steel and Composite Structures
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• v.10 no.1
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• pp.69-85
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• 2010

The present paper presents a study on the behavior and design of corrugated web steel beams with and without web openings. In the literature, the web opening problem in steel beams was dealt with mostly for steel beams with plane web plates and research on the effect of an opening on a corrugated web was found out to be very limited. The present study deals mainly with the effect of web openings on the transverse load carrying capacity of steel beams with sinusoidally corrugated webs. A general purpose finite element program (ABAQUS) was used. Simply supported corrugated web beams of 2 m length and with circular web openings at quarter span points were considered. These points are generally considered to be the optimum locations of web openings for steel beams. Various cases were analyzed including the size of the openings and the corrugation density which is a function of the magnitude and length of the sine wave. Models without web holes were also analyzed and compared with other cases which were all together examined in terms of load-deformation characteristics and ultimate web shear resistance.

• Steel and Composite Structures
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• v.33 no.4
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• pp.569-581
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• 2019

Corrugated steel plate shear wall (CSPSW) as an innovative lateral load resisting system provides various advantages in comparison with the flat steel plate shear wall, including remarkable in-plane and out-of-plane stiffnesses and stability, greater elastic shear buckling stress, increasing the amount of cumulative dissipated energy and maintaining efficiency even in large story drifts. Employment of low yield point (LYP) steel web plate in steel shear walls can dramatically improve their structural performance and prevent early stage instability of the panels. This paper presents a comprehensive structural performance assessment of corrugated low yield point steel plate shear walls having circular openings located in different positions. Accordingly, following experimental verification of CSPSW finite element models, several trapezoidally horizontal CSPSW (H-CSPSW) models having LYP steel web plates as well as circular openings (for ducts) perforated in various locations have been developed to explore their hysteresis behavior, cumulative dissipated energy, lateral stiffness, and ultimate strength under cyclic loading. Obtained results reveal that the rehabilitation of damaged steel shear walls using corrugated LYP steel web plate can enhance their structural performance. Furthermore, choosing a suitable location for the circular opening regarding the design purpose paves the way for the achievement of the shear wall's optimal performance.

• Journal of Korean Society of Steel Construction
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• v.30 no.1
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• pp.37-48
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• 2018

Cyclic loading tests for shear dominant hybrid steel link beams with circular web openings were performed to evaluate the seismic performance. Four half-scaled specimens with bolted connections were tested. The test parameter is a diameter of the web opening, i.e., shear strength ratio ($V_{pw}/V_p$) of the link beam and presence of top-seat angles. Using test results, adequate design shear strength of link beam was finally suggested. Test results showed that when the shear capacity is less than half of the plastic shear strength, seismic performance was improved due to mitigation of pinching under reversed cyclic inelastic deformations.

• Steel and Composite Structures
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• v.22 no.6
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• pp.1417-1443
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• 2016

Cellular and castellated steel beams are used to obtain higher stiffness and bending capacity using the same weight of steel. In addition, the beam openings may be used as a pass for different mechanical fixtures such as ducts and pipes. The aim of this study is to investigate the effect of different parameters on both elastic and inelastic critical buckling stresses of steel web plates with openings. These parameters are plate aspect ratio; opening shape (circular or rectangular); end distance to the first opening; opening spacing; opening size; plate slenderness ratio; steel grade; and initial web imperfection. The web/flange interaction has been simplified by web edge restraints representing simply supported boundary conditions. A numerical parametric study has been performed through linear and nonlinear finite element (FE) models, where the FE results have been verified against both experimental and numerical results in the literature. The web plates are subject to in-plane linearly varying compression with different loading patterns, ranging from uniform compression to pure bending. A buckling stress modification factor (${\beta}$-factor) has been introduced as a ratio of buckling stress of web plate with openings to buckling stress of the corresponding solid web plate. The variation of ${\beta}$-factor against the aforementioned parameters has been reported. Furthermore, the critical plate slenderness ratio separating elastic buckling and yielding has been identified and discussed for two steel grades of DIN-17100, namely: ST-37/2 and ST-52/3. The FE results revealed that the minimum ${\beta}$-factor is 0.9 for web plates under uniform compression and 0.7 for those under both compression and tension.

• Steel and Composite Structures
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• v.20 no.4
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• pp.913-930
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• 2016

It is common practice to use Reduced Web Beam Sections (RWBS) in steel moment resisting frames. Perforation of beam web in these members may cause stress and strain concentration around the opening area and facilitate ductile fracture under cyclic loading. This paper presents a numerical study on the cyclic fracture of these structural components. The considered connections are configured as T-shaped assemblies with beams of elongated circular perforations. The failure of specimens under Ultra Low Cycle Fatigue (ULCF) condition is simulated using Cyclic Void Growth Model (CVGM) which is a micromechanics based fracture model. In each model, CVGM fracture index is calculated based on the stress and strain time histories and then models with different opening configurations are compared based on the calculated fracture index. In addition to the global models, sub-models with refined mesh are used to evaluate fracture index around the beam to column weldment. Modeling techniques are validated using data from previous experiments. Results show that as the perforation size increases, opening corners experience greater fracture index. This is while as the opening size increases the maximum observed fracture index at the connection welds decreases. However, the initiation of fracture at connection welds occurs at lower drift angles compared to opening corners. Finally, a probabilistic framework is applied to CVGM in order to account for the uncertainties existing in the prediction of ductile fracture and results are discussed.