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目的:常规索穹顶结构具有受预应力影响较大、不易于铺设刚性屋面等缺陷,且施工过程中存在变形较大及拉索松垂等问题,施工模拟难度较大。本文探讨一种新型索穹顶结构的构件性能和受力特点,研究结构施工过程分析的可行性及最优布置形式。创新点:1.提出一种易于铺设刚性屋面的新型拉梁式索穹顶结构;2.提出一种累积牵引提升施工技术;3.通过非线性动力有限元找形分析方法(NDFEM)实现施工模拟过程。方法:1.通过试验分析,证明NDFEM法可以实现拉梁式索穹顶的施工过程模拟(图11–13和表4);2.通过理论推导,对比两铰拉梁、三铰拉梁以及悬索单元在跨中集中荷载和均布荷载作用下的变形和受力特点(公式9–17);3.通过数值模拟分析,运用累积牵引提升施工方法(图4)在施工过程分析中对机构铰的布置形式进行可行性研究,并提出最优分布模式。结论:1.不同于常规索穹顶结构只受拉力的脊索,拉梁可以同时承受拉力与弯矩,并且弯曲应力较小,不易失稳;2.整体牵引提升可以很好地完成拉梁式索穹顶结构的施工成型过程;在此过程中应设置合理的机构铰将拉梁网格转化为机构;3.NDFEM找形分析方法能够有效跟踪分析施工全过程,分析精度较高;4.仅在中拉梁或内拉梁上布置机构铰可以在保证结构性能的同时最大限度地减少后期施工的工作量,为最优铰节点分布模式。
OBJECTIVE: The conventional cable dome structure has some problems such as large deformation, hard roofing and other defects which are greatly affected by prestressing. The deformation of the cable dome is large and the cable is sagging during construction. The construction simulation is more difficult. In this paper, the properties of a new type of cable dome structure and the characteristics of stress are discussed. The feasibility of the construction process analysis and the optimal layout are also studied. Innovative points: 1. Proposed a new type of cable-stayed roof structure easy to lay rigid roof; 2. Proposed a cumulative traction lifting construction technology; 3. Non-linear dynamic Finite Element Finding Analysis (NDFEM) to achieve the construction simulation process. Through the experimental analysis, it is proved that the NDFEM method can simulate the construction process of the cable-stayed cable dome (Figure 11-13 and Table 4); 2. By theoretical deduction, comparing the two hinged beams, (9-17); (3) Through the numerical simulation analysis, using cumulative traction to enhance the construction method (Figure 4) in the construction process analysis of the institutions The feasibility of the layout of the hinge is studied and the optimal distribution mode is proposed. Different from the conventional cable dome, the tension beam can bear the tension and bending moment at the same time, and the bending stress is small, so it is not prone to destabilization. (2) The overall traction and lifting can well complete the tension beam The construction of the dome structure forming process; in this process should be set up a reasonable body hinge will beam grid into institutions; 3.NDFEM looking for shape analysis method can effectively track the whole construction process, the analysis of high precision; 4. Only in The arrangement of the mechanical hinges on the middle or middle beam can minimize the workload of post-construction while ensuring the structural performance, which is the optimal hinge joint distribution mode.