两端直线形张弦桁架结构的力学性能研究

STUDY OF MECHANICAL PROPERTIES OF A TWO-END-LINEAR-TRUSS-STRING STRUCTURE

对一种两端直线形张弦桁架结构进行研究,建立了单榀圆弧形张弦桁架结构和不同端部倾角的两端直线形张弦桁架结构的有限元模型,利用实腹式截面等效法对比分析两种结构内力的差异,通过在典型荷载下的计算分析对比了两种结构的用钢量和力学性能,结果表明:端部倾角最优(60°)的两端直线形张弦桁架结构较圆弧形张弦桁架结构用钢量可以节省7%~18%;两端直线形张弦桁架结构的合位移更大,但小于JGJ 252—2012《索结构设计规程》限值;其水平支座最大反力较圆弧形张弦桁架结构最大可减小15%;两种结构屈曲形态接近,两端直线形张弦桁架结构具有更高的稳定承载力。

A kind of two-end-linear-truss-string structure was studied,and the finite element models of circular-arc truss string structure and two-end-linear-truss-string structure with different end inclination angles were modelled.The difference of internal forces between the two structures was analyzed by the equivalent method of solid web section,and the steel consumption and mechanical properties of the two structures were compared through calculation and analysis under typical loads.The results showed that the steel consumption of the two-end-linear-truss-string structure with the optimal inclination angle of 60°could be saved by about 7%to 18%compared with the circular-arc truss string structure;the combined displacement of the two-end-linear-truss-string structure was larger,but less than the requirement in JGJ 257-2012 Technical Specification for Cable Structures;the maximum horizontal support reaction force could be reduced by 15%compared with another structure;the buckling modes of the two structures were similar,and the two-end-linear-truss-string structure had higher stability bearing capacity.