Study On Mechanical And Deformation Behavior Of Steel Beams With Multiple Web Openings

In recent years, with the rapid development and spread of steel structure buildings, the steel high-rise and steel super high-rise buildings are becoming more and more overwhelming. Due to the using of web opening beams in the structure industry, the cost of the projects can be reduced effectively and have good economic efficiency. In current China standards, however, it did not mention an integrated system about how to design this type of element, so in the practical project, it required a specialized study on how to design the web opening beams.The objectives of this research are as followings:(1)Studying about the effects on the stress and flexural deflection in the beams of the web openings and this was reached by seven tests which included six web opening beams tests and one integrated beam test. It was found that the shear force resulted the stress concentration happened at the corner of the openings rather than moment. Since the stress concentration which located at the corner of the openings did not change the member flexural deflection significantly so it matched the requirements in the standards that the small dimension openings in the beam should not have considerable reduction in the stiffness of the whole element.(2)For steel members, it was using the finite element method to analysis the influence of the web openings on the stress and flexural, then compared the results with the data that gained from the tests. It was observed that the finite element method can simulate the performance of the steel members properly. The influence of the web openings on the vierendeel sections was negligible. The maximum positive stress and shear stress can be analyzed and calculated by vierendeel truss theory, the shear stress calculation was relatively conservative. The stress concentration at the opening corner has significantly influence on the solid web. The distribution of the section positive stress near the openings become severe nonlinear and the maximum section positive stress was increased slightly. The range of the distribution of the section shear stress was large which the maximum shear stress increased more than doubled. The dimension of the openings did not change the length of the spectrum for the positive stress in the beam which was less than the 1/2 height of the beam. Comparing with the positive stress, the distribution of the shear stress was influenced more significantly on the length of the spectrum.(3)Parametric analysis was conducted to analysis the web opening beam, the parameters were the Area of the opening(A) and the spacing of the openings(L0). It was observed that the trend of the changing in L0 was linear with the changing in the flexural. With the increasing of the spacing between the openings, the openings were more close to the support which resulted the increasing in the flexural. As the opening area, there was also a linear relation between the changing in the(A/A0)2 and the flexural. The area of the openings and the spacing can be used as correction factors.