Study On The Overall Performance Of Thin-walled Spatial Curved Beams

With the implementation of the double carbon strategy and the whole life cycle,steel structures are being used more and more widely.With the pursuit of a better life and the improvement of aesthetic awareness,thin-walled spatial curved beams are increasingly used.The stress and deformation of thin-walled spatial curved beams are very complex.The effect of torque cannot be ignored compared to elementary beam theory.Due to the influence of bending-torsion coupling,complex spatial alignment,and geometric nonlinearity,its stable bearing capacity is very difficult to determine.This paper verifies the effectiveness of the FEM by comparing it with the steel curved beam test.The FEM analysis and bearing capacity checking calculation of thin-walled spatial curved beams have been carried out by taking an actual project as an example,and the entire process of instability has been studied.This paper studies the effects of tilt angle,span,and height on the performance of spatial curved beams,and fitting the relationship between them through regression analysis.The main work of this paper is as follows:(1)The expressions of free torsion and constrained torsion of thin-walled bars are introduced,and the FEM of thin-walled curved beams,as well as the realization methods of geometric nonlinearity and material nonlinearity,are described.(2)Numerical simulation of curved beam tests conducted by other scholars was conducted,and the effectiveness and accuracy of the finite element method for thin-walled spatial curved beams were verified by comparing the numerical results and experimental results.(3)FEM analysis and bearing capacity checking of thin-walled spatial curved beams in practical projects are executed.Considering both geometric and material nonlinearities,the deformation,internal forces,stress distribution,and the entire process of instability of thin-walled spatial curved beams are analyzed.There is a large torque in thin-walled spatial curved beams,which has a significant impact on the displacement and stress distribution of characteristic points.The process develops rapidly from local buckling to overall instability,which exhibits certain suddenness.Attention should be paid to safety reserves in engineering,and the detailed structure should be reasonable.(4)The effects of inclination angle,span,and rise on the overall performance and ultimate stability bearing capacity of thin-walled spatial curved beams were studied,and the relationship between them was fitted through regression analysis.The stable bearing capacity decreases with the increase of inclination angle,span,and rise.The ultimate displacement is relatively complex which decreases first and then increases as the inclination angle and rise increases,so there is a reasonable inclination angle and vector height which minimizes the ultimate displacement.The ultimate displacement increases as the span increases.It generally occurs in the midspan,which shifts from the midspan to the 1/4 span position as the rise increases.