lower chord

基本解釋

The lower chord of a vierendeel truss, when loaded, is subjected to the combined action of prestressed compression, large axial tension, moment and shear.
空腹屋架下弦處于預壓力、強大的軸拉力、彎矩和剪力共同作用下工作。
End face with a gap, no boss butt is refers to the upper and lower casing left a certain gap between the upper and lower main chord rod end face at the same time contact.
端面無間隙對接是指將套管與主弦桿焊接后，端面經過機械加工，上、下主弦桿與套管端面依靠螺栓外徑與套管內徑定位對接。
End face with a gap, no boss butt is refers to the upper and lower casing left a certain gap between the upper and lower main chord rod end face at the same time contact.
端面有間隙、帶凸臺對接外形是指在標準節(jié)上部主弦桿上焊有定位凸臺，定位凸臺伸人另一標準節(jié)主弦桿內，上、下套管之間留有一定間隙配合定位。