不同节间长度下钢桁架结构受力性能研究

Study on mechanical behavior of steel truss structure with different length of joints

基于实际工程,选取一榀跨度36 m的钢桁架结构作为研究对象,采用3D3S设计软件,分析不同节间长度对桁架的受力、变形性能及含钢量等的影响规律。结果表明:节间长度的变化对桁架跨中构件最大内力影响不大,对支座构件影响较为明显。随着节间长度的增加,支座上弦轴力减小,剪力和弯矩变化不大;支座下弦轴力先减小后增大,当节间长度为2.8 m时最小,剪力和弯矩逐渐减小;支座腹杆轴力逐渐增大,影响显著。增大节间长度,桁架最大位移减小,整体强度应力水平和稳定应力比增大。增大节间长度,桁架含钢量降低,但对含钢量的影响逐渐减小。节间长度建议取1/13~1/12;腹杆间夹角建议取60°。

Based on the actual project,a steel truss structure with a span of 36m is selected as the research object,and the influence of different section length on the stress,deformation performance and steel content of the truss is analyzed by using 3D3S design software.The results show that the change of the section length has little influence on the maximum internal force of the truss mid span members,but has obvious influence on the support members.With the increase of the length of the joint,the axial force of the top chord of the support decreases,while the shear force and bending moment change little;The axial force of the lower chord first decreases and then increases.When the length of the joint is 2.8m,it is the minimum,and the shear force and bending moment gradually decrease;The results show that the axial force of web member increases gradually and the influence is significant.With the increase of the length of the truss,the maximum displacement of the truss decreases,and the overall strength stress level and stability stress ratio increase.With the increase of the length of the truss,the steel content of the truss decreases,but the influence on the steel content gradually decreases.The internode length is suggested to be 1/13~1/12.The angle between web member is suggested to be 60°.