bottom chord

基本解释

The single-chorded plane space truss have the low flexural rigidity out of plane because of lacking bottom chord.
单弦杆平板网架由于无下弦杆，因而具有平面外抗弯刚度较低的特点。
The analysis reveals that the dynamic behavior of the converse trapezoid CHS truss with double pipe bottom chord is quite good.
分析表明以下弦双钢管为特征的倒梯形立体管桁架的动力特性非常理想；
The double groove steel is suspended under the two nodes of bottom chord of steel roof truss to prevent the bottom chord from stretch bending.
文章论述了在设计中采用钢屋架下弦两节点下悬吊双槽钢作为分布梁避免钢屋架下弦拉弯工作。