The concrete-filled in compressionchord can help compressionchord members very well, and reduce the steel tube strain;
受压弦杆内填混凝土能很好地协助钢管受力、减小钢管应变，提高受压节点的强度和刚度；
2
The lower chord of a vierendeel truss, when loaded, is subjected to the combined action of prestressed compression, large axial tension, moment and shear.