罐周不均匀沉降下在役储液罐变形分析

发布时间：2018-04-10 05:33

本文选题：储液罐　切入点：罐周不均匀沉降　出处：《浙江大学》2015年硕士论文

【摘要】：立式圆筒形钢制储罐通常由顶盖、罐壁、底板以及附件组成,广泛应用于气体、液体和固体的储存。为了便于运输和装卸,大多数储罐建造在沿海沿江地区,由于地基承载力小,储罐通常会出现不同程度的沉降变形,其中罐周的不均匀沉降对储罐的影响最为不利。本文将采用有限元数值模拟方法,针对在役储液罐在实测罐周不均匀沉降下的应力和变形开展研究,提出一种新的沉降数据处理方法,探讨储液高度对罐周不均匀沉降储液罐变形量的影响。主要工作如下：(1)针对国内外对罐周不均匀沉降数据处理方法的不足,提出了一种新的罐周不均匀沉降曲线拟合方法；同时结合储液罐实测沉降案例,应用罐周不均匀曲线拟合方法对其沉降数据进行处理,发现拟合效果较好。(2)探讨罐周不均匀沉降函数形式对变壁厚钢制储罐变形量的影响。分别计算了正弦谐波沉降函数和余弦谐波沉降函数下储罐罐壁应力并进行线性叠加,其结果与不均匀沉降函数下储罐罐壁应力值进行比较并计算两者间的相对误差；同样计算得到罐壁径向位移的相对误差。研究发现,随着谐波沉降幅值的增大,罐壁应力和径向位移的相对误差均呈现逐渐增大的趋势；随着谐波阶数的增大,罐壁径向位移的相对误差呈现先增大后减小的趋势,而应力的相对误差影响规律不明显。(3)分析储液高度对罐周不均匀沉降下储液罐变形量的影响。计算了不同储液高度下,发生罐周不均匀沉降储液罐的Mises应力和径向位移,比较得到了随着储液高度变化Mises应力和径向位移的变化趋势；并以一个固顶罐和一个浮顶罐作为计算案例开展分析。研究发现,随着储液高度的降低,罐壁的Mises应力最大值呈现先减小后基本不变的趋势；对于浮顶罐,储液高度对其径向位移的影响很小,可以忽略；而对于固顶罐,只有当储液高度较高时,才需要考虑储液高度对其径向位移的影响。(4)提出了储罐在罐周不均匀沉降下的屈曲分析方法,并运用该方法,分析了固顶罐和浮顶罐在实测罐周不均匀沉降下的屈曲行为。结果表明,采用该方法可以在确保罐周不均匀沉降载荷完全加载的前提下,减少计算成本,为储罐的屈曲分析提供参考依据。
[Abstract]:Vertical cylindrical steel storage tanks are usually made up of top caps, tank walls, bottom plates and accessories. They are widely used in gas, liquid and solid storage.In order to facilitate transportation and loading and unloading, most storage tanks are built in the coastal areas along the Yangtze River. Due to the small bearing capacity of the foundation, the tanks usually have different degrees of settlement deformation, among which the uneven settlement around the tanks is the most unfavorable to the storage tanks.In this paper, the finite element numerical simulation method is used to study the stress and deformation of in-service liquid storage tanks under the measured non-uniform settlement around the tank, and a new settlement data processing method is proposed.The effect of liquid storage height on the deformation of tank with uneven settlement around the tank was discussed.The main work is as follows: (1) aiming at the shortage of the domestic and foreign data processing methods for the non-uniform settlement around the tank, a new fitting method of the non-uniform settlement curve around the tank is proposed, and the case of the actual settlement of the liquid storage tank is combined with the method of fitting the curve of the non-uniform settlement around the tank.This paper deals with the settlement data by using the inhomogeneous curve fitting method of the tank circumference, and finds that the fitting effect is good.) the influence of the non-uniform settlement function on the deformation of the steel storage tank with variable wall thickness is discussed.The tank wall stress under sinusoidal harmonic settlement function and cosine harmonic settlement function is calculated and linear superimposed. The results are compared with the tank wall stress values under non-uniform settlement function and the relative errors between the two are calculated.The relative error of radial displacement of tank wall is also calculated.It is found that with the increase of harmonic settlement amplitude, the relative error of wall stress and radial displacement increases gradually, and with the increase of harmonic order, the relative error of radial displacement of tank wall increases first and then decreases.However, the relative error of stress is not obvious.) the influence of liquid storage height on the deformation of the tank under uneven settlement around the tank is analyzed.The Mises stress and radial displacement of the tank with different liquid storage heights are calculated, and the variation trends of Mises stress and radial displacement with the change of liquid storage height are compared.A fixed roof tank and a floating roof tank are taken as calculation cases.It is found that with the decrease of liquid storage height, the maximum Mises stress of the tank wall decreases first and then remains unchanged; for floating roof tank, the effect of liquid storage height on its radial displacement is negligible, but for the fixed top tank, the effect of liquid storage height on the radial displacement of the tank is negligible.Only when the liquid storage height is high, the influence of liquid storage height on its radial displacement should be considered. (4) the buckling analysis method of the tank under uneven settlement around the tank is put forward, and the method is used.The buckling behavior of fixed roof tank and floating roof tank under the measured non-uniform settlement around the tank was analyzed.The results show that this method can reduce the calculation cost and provide a reference for the buckling analysis of the tank under the premise of ensuring the complete loading of the non-uniform settlement load around the tank.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE972

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