Coupled Bending And Torsion Analysis Of Tube Structures

Due to good lateral force-resistance and space stiffness performance, tube structure is used widely in high-rise buildings. The shear lag effect weakens structure’s space effect. The study of shear lag effect has been one of the important topics. In addition the effect of floor and coupling beam in tube structures and the coupling effect of bend-twist receives much concern. The main research contents are as follows:(1) According to the continuous pinciple, frame-tube structure is made equal to equivalent solid thin-walled tube which is enclosed with orthotropic plates and comer column, so its continuous mechanical model is founded.(2) The wraping displacement of flange frame is distributed along quadratic parabola when considering the shear-lag of the frame-tube structure. Use discontinuous method considering the floor effect.Hamilton duality solution system of frame-tube structure considering shear-lag and floor effect under bending-torsion moment. Coupling beams are regarded as external support.Hamilton duality solution system of tube-in-tube structure considering shear-lag under bending-torsion moment.(3) Precise integration method is applied to solve solution system above which is implemented by program upon MATLAB language. The wraping stress can be gained, and the shear-lag effect is evident. The result is compared with those from other methods which turns out to be good agreement. The effect of floor to vertical wraping is comparative analysis.(4) Analysis anti-torision function of the coupling beam in tube-core The results show that anti-torision function of the coupling beam is obviously, can’tbe ignored. Through the analysis of the tube-in-tube structure of bending-torsional coupling problem, results show that the solution system is effectively.This paper provide a new method to analysis the tube structure Compiled program applies to both symmetric section and asymmetric section, and has a variety of load loading forms for choice, can solve common form tube structures calculation. The research findings of this paper can guide the design in engineering.