大型工业钢板筒仓的优化设计分析研究

发布时间：2019-05-20 04:34

【摘要】：钢板筒仓以其优越的结构性能广泛应用于粮食、煤炭、水泥、电力、化工等各行业。但由于相关理论的研究滞后于实际工程的建设,不可否认的是关于钢板筒仓的破坏事故也越来越多。其理论研究的关键和难点主要表现在储料荷载的正确计算、缺陷对钢板筒仓结构的稳定性影响以及地震中储料颗粒间的摩擦对地震作用的减弱等方面。同时,钢板筒仓常年暴露在大气中,受到太阳辐射而产生非均匀的温度效应,对结构产生不利影响。本文即结合实际工程,采用数值模拟分别对钢板筒仓由于卸料引起的压力增大效应、太阳辐射对结构性能的影响以及其结构形式进行了分析和研究,最后,对一大型水泥钢板仓进行了结构设计,并用ANSYS对其进行了稳定性分析。通过和国外规范的对比,发现我国规范深仓采用Janssen理论,浅仓采用Rankine理论,而国外均采用Janssen理论,且我国水平侧压力修正系数取值偏大,竖向摩擦力修正系数偏小,未考虑储料偏心的影响。针对大型落地式钢板筒仓,采用颗粒流分析程序PFC2D对其进行了装料和卸料过程的数值模拟,并结合国外规范给出了笔者对于这两个修正系数的建议取值。在分析太阳辐射时,考虑了辐射阴影的影响,并提出了阴影的计算方法,然后通过ANSYS,分四种工况分析了各自的非均匀温度场分布,进而得到了考虑太阳辐射阴影引起的非均匀温度场对结构性能的影响,发现考虑太阳辐射阴影,单面对流换热工况对结构的影响最大。将通常钢板筒仓结构的纵向柱和环梁尺寸加大,并采取合理的布置方式,提出以梁柱为受力主体的筒仓梁柱结构形式,通过36个不同高径比和直径MIDAS模型的对比分析,得到一些关于钢板筒仓结构设计时,结构布置的合理化建议,包括结构形式的选择、纵向立柱和环梁的变截面布置方案以及需要加强的区域。对于更大直径的钢板筒仓(R30m),可考虑采用梁柱结构形式。最后对一个23m直径的水泥钢板筒仓进行了结构设计,包括结构方案到构件布置、荷载的确定、模型的建立、静动力分析以及对结果的评价,在满足规范要求下,结构安全性较好。在此基础上,用ANSYS对其进行了特征值屈曲分析和考虑几何材料双重非线性的分析,分析时按空仓和实仓进行,结果表明风荷载对空仓的稳定性影响较大,水平内压对实仓稳定的有利作用不可小觑,钢板筒仓结构具有相当敏感的非线性特性,表现出“象脚”式破坏。
[Abstract]:Steel silo is widely used in grain, coal, cement, electric power, chemical industry and other industries because of its superior structure and performance. However, because the research of related theory lags behind the construction of practical engineering, it is undeniable that there are more and more damage accidents about steel plate silo. The key and difficult points of its theoretical research are mainly manifested in the correct calculation of storage load, the influence of defects on the stability of steel plate silo structure and the weakening of seismic action by friction between storage particles during earthquake. At the same time, the steel plate silo is exposed to the atmosphere all the year round, resulting in non-uniform temperature effect caused by solar radiation, which has a negative effect on the structure. In this paper, combined with practical engineering, the effect of pressure increase caused by unloading, the influence of solar radiation on structural performance and its structural form are analyzed and studied by numerical simulation. The structural design of a large cement steel plate silo is carried out and its stability analysis is carried out by ANSYS. By comparing with foreign codes, it is found that Janssen theory is used in deep warehouse and Rankine theory in shallow warehouse, while Janssen theory is used in foreign countries, and the correction coefficient of horizontal side pressure in China is too large and the correction coefficient of vertical friction is too small. The influence of material eccentricity is not taken into account. Aiming at the large landing steel plate silo, the numerical simulation of the loading and unloading process is carried out by using the particle flow analysis program PFC2D, and the author's suggested values for these two correction coefficients are given in combination with the foreign codes. In the analysis of solar radiation, the influence of radiation shadow is considered, and the calculation method of shadow is put forward, and then the distribution of non-uniform temperature field is analyzed by ANSYS, in four working conditions. Furthermore, the influence of non-uniform temperature field caused by solar radiation shadow on the structure performance is obtained. It is found that the single side convective heat transfer condition has the greatest influence on the structure considering the solar radiation shadow. The longitudinal column and ring beam size of the steel plate silo structure are increased, and the structure form of the silo beam column with Liang Zhu as the main force is put forward by adopting a reasonable arrangement. Through the comparative analysis of 36 MIDAS models with different height to diameter ratio and diameter, the structure of the silo beam column with Liang Zhu as the main force is put forward. Some reasonable suggestions on the structural layout of steel plate silo structure are obtained, including the selection of structural form, the variable section arrangement scheme of longitudinal column and ring beam, and the areas to be strengthened. For larger diameter steel plate silo (R 30m), Liang Zhu structure can be considered. Finally, a 23m diameter cement steel plate silo is designed, including structural scheme to member arrangement, load determination, model establishment, static and dynamic analysis and evaluation of the results, under the condition of meeting the requirements of the code, The structure is safe. On this basis, the eigenvalue buckling analysis and the double nonlinear analysis considering geometric materials are carried out by ANSYS. The results show that the wind load has a great influence on the stability of the empty warehouse. The favorable effect of horizontal internal pressure on the stability of the silo should not be underestimated. The steel silo structure has very sensitive nonlinear characteristics, showing "elephant foot" failure.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU392.4

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