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Concurrent effects of the shear-lag and warping torsion on the performance of non-rectangular RC shear walls

Tabiee Mohammad, Abdoos Hatef, Khaloo Alireza

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 2

art. no. e138, 2023

EN

This paper aimed at analytically investigating the simultaneous effects of the shear-lag and warping torsion on the performance of non-rectangular reinforced concrete (RC) shear walls. Under the concurrent action of shear and axial loadings, the induced warping deformation due to the shear-lag as well as the warping torsion has been accounted for in the elastic region. On the strength of the minimum potential energy principle, a general formulation has been derived for the stress distribution of non-rectangular RC shear walls. By introducing the appropriate geometrical assumptions, the established formulations have then been re-written for conventional T-, U-, and L-shapes RC shear walls. The veracity of the results is ascertained through a comparative study employing finite element simulations for a U-shaped wall, and good agreement has been achieved to an extent that the proposed analytical formulation is capable to, respectively, predict the axial deformation and stress distribution with an accuracy of 95 and 90%. Also, the findings for the U-shaped wall indicate that the shear-lag can significantly affect the axial stress distribution and cracking load, and neglecting the influence of this phenomenon can lead to an inaccurate and a non-conservative design. Moreover, the contribution of the shear-lag and warping torsion has separately been highlighted for the U-shaped RC wall considered in this study.

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Stress Analysis of Steel Beams Made of Sigma Cross-Section

Dybizbański Maciej A., Rzeszut Katarzyna, Szczepańska Aleksandra

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 4

106--118

EN

This paper presents a stress analysis of elements made of a steel cold-formed sigma cross-section, uniformly loaded in a plane parallel to the web and not passing through the shear centre. Such an application of a load very often occurs in engineering practice and corresponds to the application of a load to the upper flange of the cross-section. It usually result in an additional torsional moment. In this paper, special attention is paid to normal stresses from the bi-moment, and shear stresses from restrained and free torsion. The contribution of these stresses to the section utilization was evaluated on the example of a sigma cross-section with different thicknesses of the wall. Furthermore, the paper also included the stresses analysis concerning different load locations at the upper flange. All numerical calculations were made using analytical approach based on Vlasov beam theory.

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Nośność i stateczność stalowych belek o przekroju ceowym

Szczerba R

Budownictwo i Architektura

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2013

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Vol. 12, nr 2

283--290

PL

W pracy przedstawiono analizę nośności i stateczności elementów o przekroju ceowym, obciążonych w płaszczyźnie równoległej do środnika, nie przechodzącej przez środek ścinania. Następstwem tego jest powstanie momentu skręcającego, który generuje powstanie naprężeń normalnych od bimomentu oraz naprężeń stycznych od skręcania skrępowanego i swobodnego. Oszacowano udział tych naprężeń w wytężeniu przekroju na przykładzie belki wolnopodpartej obciążonej obciążeniem ciągłym oraz siłą skupioną. Przy weryfikacji prętów odniesiono się do obowiązujących obecnie Eurokodów oraz do Normy Polskiej PN-90/B-3200. Do obliczenia momentu krytycznego przy zwichrzeniu sprężystym wykorzystano program Autodesk Algor Simulation Professional 2012.

EN

Analysis of the resistance and stability of steel beam of channel section loaded in the plane parallel to beam web, which does not pass through shear center, is presented in the paper. The consequence of this is the creation of a torsional moment that generates normal stresses due to bimoment and shear stresses as a result of St. Venant and warping torsion. In the paper, the contribution of those stresses to the global state of stress of simply supported beam is presented. Calculations were made according to Eurocodes and to the Polish Standard PN-90/B-3200. The elastic critical moment for lateral-torsional buckling was calculated with the use of Autodesk Algor Simulation Professional 2012 program.