parallel chords

• 平行弦

parallel chords的用法和样例：

例句

1. For a complanate parallel chords truss, the axial forces of a member can be solved by the shear-diagram and two simple expressions.
   借助与桁架对应的梁的剪力图和弯矩图根据两个关系式可直接求出一般平面平行弦桁架任一根杆件的轴力。