超大型钢-索-竹组合式筒仓中钢索受力机理研究

发布时间：2018-09-19 10:30

【摘要】：筒仓作为一种上世纪兴起的存储工具,现在已经被广泛应用于工业、农业等多个生产、生活领域。尽管现在常用筒仓的研究已经趋于成熟,但现有筒仓体系仍然不能满足储存需求。因此,迫切需要开展深入研究以适应新形式、新阶段的要求。以此背景,课题组提出了新型筒仓即超大型钢-索-竹组合式筒仓结构以满足超大型筒仓结构和粮食安全储备的要求。本文首先进行了钢索-筒仓缩尺模型在不同卸料方式及钢索不同布置方案下的卸料试验,对其卸料特点进行分析总结;其次,在研究仓壁刚度与钢索索力的关系基础上,对钢索(通风管)上储粮荷载理论计算公式进行研究并通过试验结果和有限元反分析结果进行验证;最后,利用有限元软件建立筒仓模型,进行钢骨架选型,并进一步对超大型钢-索-竹组合式筒仓中钢索的方案进行优化分析,最终得到较优的钢骨架结构、钢索布置方式及索的截面、预应力大小等,形成超大型钢-索-竹组合式筒仓结构体系较优的方案。本文主要结论如下:(1)筒仓卸料的形式主要分为管状式和整体式流动,这两种形式在卸料过程中交替出现,直至卸料结束;(2)钢索在筒仓结构中的索力变化与筒仓的仓壁刚度呈线性关系;相同的预应力下,仓壁刚度越大,卸料零时刻的钢索索力值越大;(3)组合式筒仓分析中,应考虑钢索索力动力荷载放大系数η。不同的钢索布置方案在卸料过程中,钢索索力会产生不同的动力荷载放大系数η,其范围为1.01~1.26,本文建议η取值1.3。(4)试验结果和有限元反分析结果表明,钢索(通风管)上储粮荷载理论计算公式可采用散粒体对埋深不大的管道压力简化计算公式。(5)钢索与钢骨架结构构成一种刚柔并济的自平衡体系,通过对钢索施加预应力可主动调节筒仓结构的内力和变形,可以很好的约束筒仓的变形;(6)在对钢骨架结构进一步优化基础上,在筒仓4.5m~16.5m高度范围内,布置5层钢索(隔跨错开)布置的方案较优,其变形与应力结果均较为理想。本文受国家自然科学基金(51008067)、中央高校基本科研业务费专项资金(NS2015006)的资助,在此表示诚挚的感谢
[Abstract]:As a storage tool, silos have been widely used in many fields such as industry, agriculture and so on. Although the current research on silo has matured, the existing silo system still can not meet the storage needs. Therefore, there is an urgent need to carry out in-depth research to adapt to the requirements of new forms and stages. In order to meet the requirements of super-large silo structure and grain security storage, a new type of silos, namely super-large steel cable-bamboo silo structure was proposed. In this paper, the unloading test of cable silo scale model under different discharge modes and cable arrangement schemes is first carried out, and the unloading characteristics are analyzed and summarized. Secondly, on the basis of studying the relationship between wall stiffness and cable force, The theoretical calculation formula of grain storage load on steel cable (ventilation pipe) is studied and verified by test results and finite element back analysis results. Finally, the silo model is established by using finite element software, and the steel skeleton is selected. Furthermore, the scheme of steel cable in super large steel cable bamboo silo is optimized and analyzed. Finally, the better steel skeleton structure, cable arrangement, cable section, prestressing force and so on are obtained. To form a super-large steel-cable-bamboo silo structure system is better. The main conclusions of this paper are as follows: (1) the discharge forms of silo are mainly divided into tubular flow and integral flow, which appear alternately in the discharge process. Until the end of unloading; (2) the change of cable force in silo structure is linearly related to the silo wall stiffness; under the same prestress, the greater the wall stiffness, the greater the cable force at zero unloading time; (3) in the combined silos analysis, The dynamic load magnification factor 畏 of cable force should be considered. In the discharge process of different cable arrangement schemes, the cable force will produce different dynamic load magnification factor 畏, which ranges from 1.01to 1.26.The 畏 value is suggested to be 1.3in this paper. (4) the experimental results and the finite element back-analysis results show that, The theoretical formula of grain storage load on steel cable (ventilation pipe) can be calculated by using a simplified formula for calculating the pressure of pipeline with little buried depth by granular body. (5) the steel cable and steel skeleton structure constitute a kind of self-balanced system which is rigid and flexible, The internal force and deformation of silo structure can be adjusted actively by applying prestressing force to steel cable, and the deformation of silo can be restrained well. (6) on the basis of further optimization of steel skeleton structure, within the 4.5m~16.5m height range of silo, The arrangement of 5-layer steel cable (spacer staggered) is better, and the results of deformation and stress are ideal. This article is supported by the National Natural Science Foundation of China (51008067) and the Special Fund for basic Scientific Research operating expenses (NS2015006) of Central Colleges and Universities. I would like to express my sincere thanks here.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU398.9

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