Ultimate load behaviour of steel beams with web openings

The paper presents a numerical research on the behavior of steel I-beams with web openings. The influence of web openings in the load carrying capacity of steel beams and failure mechanisms are investigated. The non-linear numerical analysis performed was calibrated with results from other similar non-linear numerical analysis and experimental test data. Comparison between numerical results with the available experimental for yielding patterns, ultimate load values and load-deflection relationships show a good agreement. The numerical model developed was used to carry out a parametric study taking into account some parameters, such us: opening shape, opening size, and the location of the opening throughout the span. Three different beam spans were considered. A contribution to the analysis and selection of the web openings best solutions is presented in the conclusions.

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Experimental study of composite concrete cellular steel beams

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/961/1/012095 ◽

2022 ◽

Vol 961 (1) ◽

pp. 012095

Author(s):

Mustafa Kamil Abbas ◽

Hayder Wafi Al_Thabhawee

Keyword(s):

Concrete Beam ◽

Ultimate Load ◽

Steel Beams ◽

Web Openings ◽

Control Beam ◽

Geometrical Properties ◽

Shear Connectors ◽

Depth Ratio ◽

Post Buckling ◽

Composite Steel

Abstract The main objective of this study is to compare the structural behavior of composite steel– concrete beams using cellular beams with and without steel ring stiffeners placed around the web openings. An IPE140 hot rolled I-section steel beam was used to create four specimens: one without openings (control beam); one without shear connectors (non-composite); a composite steel–concrete beam using a cellular beam without strengthening (CLB1); and a composite steel–concrete beam using a cellular beam (CLB4-R) with its openings strengthened by steel ring stiffeners with geometrical properties Br = 37mm and Tr = 5mm. CLB1 was fabricated with openings of 100mm diameter and a 1.23 expansion depth ratio, while CLB4-R was fabricated with openings of 130mm diameter, a 1.42 expansion depth ratio. Both beams were 1700mm in length with ten openings. The results of this experiment revealed that the loads applied to CLB1 and CLB4-R at deflection L/360 exceeded the load applied to the control specimen at the same deflection by 149.3% and 177.3%, respectively. The results revealed that the non-composite beam had an ultimate load 29% lower than that of the control beam. The ultimate load on CLB1 was 5.3% greater than that of the control beam, and failure occurred due to web-post buckling. While the ultimate load of the CLB4-R beam was 18.43% greater than that of the control beam, the Vierendeel mechanism was indicated as the failure mode.

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Reinforcing the Octagonal Web Openings of Castellated Beam by Steel Rings

Al-Qadisiyah Journal for Engineering Sciences ◽

10.30772/qjes.v12i1.581 ◽

2019 ◽

Vol 12 (1) ◽

pp. 7-16

Author(s):

Hayder W. Al-Thabhawee ◽

Abbas A. Mohammed

Keyword(s):

Failure Modes ◽

Ultimate Load ◽

Steel Beams ◽

Failure Behavior ◽

Web Openings ◽

Finite Element Software ◽

Steel Material ◽

Allowable Load ◽

Castellated Beam ◽

The Web

Castellated steel beams are section steel members with hexagonal or octagonal web openings which they are made from standard hot rolled steel section I or H. The main advantage of these members is their economic material. An additional important advantage is a possibility to guide service ducts through the openings. The presence of the web openings influences the members’ failure behavior around the openings, new local failure modes will come into existence, such as the buckling of the web post between the openings, or yielding around the openings. Castellated beams with octagonal openings usually fail due to web post-buckling because of the increase in depth. The current study focused on improving the behavior of the castellated beam with octagonal openings using steel ring stiffener and adjusting the best dimension and distribution for the stiffeners. All the models of specimens have been fabricated from a parent I section (IPE 140). The models have been modeled and analyzed using finite element software ANSYS (version 15). The analysis results showed that reinforcing octagonal castellated beams by adding steel ring stiffeners around octagonal web opening was very active way to increase the ultimate load for long span, where the ultimate load of reinforced octagonal castellated beam increased up to (286%) compared with parent I-section beam. Economically, the percentage of additional steel material which used to expansion and reinforce the castellated beams (spacer plate and steel ring stiffeners) was (36%) when compared with the weight of parent I-section beam. While the allowable load at deflection (L/180) was (260 %) compared to the allowable load of parent section at the same deflection. The gained benefit was increasing the ultimate and allowable load of reinforced octagonal castellated beams by (186%) and (160%) respectively by using additional steel material only (36%) from the weight of parent I- section, which the additional steel material consisted from the spacer plates and steel rings. Also, the results indicate that the best dimensions for the ring were when thickness equal to the web thickness of the parent section and the width equal to the half of the parent section flange width.

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