弦支穹顶静力性能的理论分析及实物加载试验

分别采用上弦节点刚接和铰接的假定，利用ANSYS程序分析了某弦支穹顶屋盖结构的静力性能．结果表明，两种情况下的杆件内力和位移接近，可以采用上弦铰接假定进行弦支穹项的理论分析．对半索半杆形式的弦支穹顶进行了实物加载试验，阐述了加载制度、测点布置及试验过程，同时进行了钢丝绳弹性模量测试试验．比较分析了杆件应力和节点的试验值与理论值，结果表明：在低水平荷载下，杆件应力和节点位移吻合较好，高水平荷载下受试验环境影响，试验值大于理论值；随着荷载的增加，均出现外圈索张紧而内圈索松弛的现象，指出在弦支穹顶设计时应合理设置内环索的预应力值．理论分析和实物加载试验均表明弦支穹顶具有良好的受力性能，用钢量少，施工方便，造价低，具有广阔的应用前景。

Theoretical Analysis and Actual Experimental Research on Static Characteristics of Suspendome Structure

The suspendome used as the roof of the VIP hall in Tianjin Museum was analyzed by ANSYS respectively under the assumptions of hinged joint and rigid joint in up chord. And the result shows that the member force and nodal displacement under the two assumptions have little difference. Thus it is attained that the suspendome can be analyzed with the assumption of hinged joint. A full scale test on the suspendome with half-cable and half-pipe was carried out. The loading system, arrangement of measuring points, and the test procedure were introduced. Also a test on steel wire ropes for elastic modules was carried out. The experimental and theoretical values of member force and nodal displacement were compared and it shows that they accords well with each other under low-level load, while under high-level load, the experimental value is bigger than the theoretical value due to the influence of the test environment. With the increase of the load, tension of outside cables and looseness of inside cables occur, which indicates that the prestressing value in inside cables should be properly assigned. Both the experimental and theoretical results verify that the suspendome has a wide application prospect with the advantages of perfect mechanical performance, little steel consumption, convenient construction, and low cost.