Research On Calculation Methods Of Shear Capacity Of Reinforced Concrete Beams Under Biaxial Bending

In the paper, the shear-resistant mechanism and the calculation methods of theshear capacity, of reinforced concrete biaxial bending beams acted by concentratedloads were performed.Firstly, the applicability of the calculation methods for the shear capacity ofreinforced concrete biaxial bending beams acted by concentrated loads wasresearched. The first method was a calculation way of simplifying the biaxial bendingbeams to two unixial bending beams for obtaining each shear capacity, and then piledthem up for the results of the shear capacity of the biaxial bending beams. The secondmethod was a way of the calculation formula of rectangular section columns of theframe structures under biaxial bending for obtaining the shear capacity of the biaxialbending beams in the Code for Design of Concrete Structures (GB50010-2002). Twomethods above were used to calculate the shear strength of 32 experimental biaxialbending beams reasearched by the others, and the applicability of the methods wasdiscussed by comparing the results of the two calculation methods with the tests.The shear-resistant mechanism of the simply-supported biaxial bending beamsacted by concentrated loads was simulated and analyzed by ANSYS finite elementsoftware. The developmental regularity of the diagonal cracks and the mechanicalcharacteristics of the diagonal sections were explored. The major influence factorsβand h/b on the shear-resistant capacity of the biaxial bending beams was analyzed.Based on the results by ANSYS finite element software, the high-point balanceequations of the shear capacity of the biaxial bending simply-supported beam actedby concentrated load were found, through studying the mechanical balance of theseparated style which was taken from the section of diagonal cracks. Then a programfor calculating shear capacity of biaxial bending beams was performed, and the shearcapacity of the biaxial bending members was analyzed by using this program. It wasshown that the calculation results were good agreement with the experimental results.Finally, under the precondition that the shear strength and pressing stress ofconcrete in beams being equality distribution, the equivalent commutation's sectionmethod forcalculating the shear capacity of the biaxial bending beams was putforwarded, then the simplified formula of the shear capacity of the biaxial bendingbeams were found. Further, the regression formula of the shear capacity of the biaxialbending beams was built on basis of the experimental results researched by others.The calculation results above formulae were good agreement with the results ofexperimental beams, and it may offer reference for the engineering design and the revision of the correlative engineering technology codes.