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Smaller Internal Forces
Published in Tianjian Ji, Structural Design Against Deflection, 2020
Figure 4.5 shows a steel-framed two-storey car park building, which embodies the study of Beam 3. The vertical loads from floors are transmitted to the cellular beams and then from the cellular beams to the supporting columns. Overhangs are purposely designed in the structure to reduce the bending moments and deflections of the cellular beams. Examining the first overhang, two steel cables link the free end of the overhang and a concrete support. A downward force at the free end of the overhang is provided by tensions induced in the cables. This force, similar to P in Figure 4.2c, will generate a negative bending moment in the beam over the column support which will partly offset the positive moments in the beam induced by the floor loading. The length of overhangs and the force in the steel cables could be the design parameters actively selected to reduce the bending moments and deflections of the cellular beam.
Harmony Search
Published in Nazmul Siddique, Hojjat Adeli, Nature-Inspired Computing, 2017
The optimum design problem of cellular beams turns out to be a discrete nonlinear programming problem when formulated according to the constraints specified in Steel Construction Institute Publication Number 100. The constraints to be considered in the design of a cellular beam include the displacement limitations, overall beam flexural capacity, beam shear capacity, overall beam buckling strength, web post flexure and buckling, Vierendeel bending of upper and lower tees, local buckling of the compression flange, and practical restrictions for cell diameter and the spacing between cells. The design problem also needs to include the sequence number of the universal beam section, diameter and total number of holes, and the space between holes in the beam as design variables. Erdal et al. (2011) applied the HSA to the optimum design of cellular beams and compared the performance to that of PSO. Saka (2007, 2009a,b) applied HSA design of geodesic domes and steel sway frames.
Critical study of steel beams with web openings
Published in Australian Journal of Structural Engineering, 2023
Samadhan G. Morkhade, Laxmikant M. Gupta
The test results in terms of ultimate load, deflection and corresponding failure modes for the beams are presented in Table 3. The test has been performed with utmost care and precautions in order to prevent error in the results. The consequence of this is that test and FE results are matched closely with each other. The minimum and maximum percentage difference in results found are 3.16 and 7.50 respectively in case of load and deflection. Figures 7, 8 and 9 show the response of tested parent and perforated beams. Figures 8 and 9 show that amount of displacement resulting from FE analysis is less than that resulting from the test at each load step for SBWO-100-6-1650 and CB-160-6-1150. While this is not occurred for PB-100-0-1000 at all the load steps specially in nonlinear zone. The reason for this may be due to the non-convergence of solution and excessive distortion of some of the elements in case of perforated beams. The failure modes are excessive bending failure in case of parent beam, vierendeel mechanism in steel beam with web openings and vierendeel mechanism as well as compression flange local buckling in case of cellular beam. The lateral torsional buckling failure is not observed in the present study because, the beams are provided with sufficient lateral restrained in the FE models as well as span of tested is small considering the limitations of experimental study. Figure 10 shows the failure modes during the test. After the validation of test results with FE analysis the comprehensive parametric study has been carried out which is discussed in the next section of the paper.
Experimental study on structural performance of new steel-concrete composite beam for both long-span and low-height parking structures
Published in Journal of Asian Architecture and Building Engineering, 2023
Yun-Chul Choi, Jin-Young Kim, Kang-Seok Lee, Ju-Seong Jung
Current techniques for decreasing floor height and increasing the beam span of parking structures with height < 8 m have been described for the Hoesch additive floor (H-floor; Hoesch, Germany) (Hoesch Building System (HBS) 2019; Darko, Boris, and Ivan 2015), cellular beam (Westok Co., UK) (Pachpor, Gupta, and Deshpande 2014), ultra-shallow floor beam (Westok Co.) (Tsavdaridis, D’Mello, and Hawes 2009), and delta beam (Peico Group Corp., Finland) (Delta Composite Beam (DCB) 2014; Nadasky 2012) systems. However, these techniques are unsuitable for long-span, low-height composite structures; they cannot be adjusted to shorten the construction period.