【作者】 王雷；

【导师】 陈志平；

【作者基本信息】 浙江大学 ， 化工过程机械， 2011， 硕士

【摘要】 大型非锚固油罐是我国石油战略储备库的关键设备。在地震作用下,油罐的动力响应非常复杂。虽然从20世纪30年代开始,学者们就针对储油罐的动力响应进行了大量的研究,并编制了相应的规范,但是按规范设计的立式储油罐,在大的地震灾害中时有破坏发生,说明油罐动力响应机理和因素尚待进一步研究。本文针对大型非锚固十五万方油罐,进行地震时程响应分析,并利用等壁厚模型和简谐波加载对“象足”屈曲破坏行为进行研究,同时分析各种情况下动水压力产生的环向应力对“象足”屈曲的影响。开展的主要工作为：(1)对比分析中、美、日油罐抗震规范对地震力的考虑及对“象足”屈曲控制方法的异同；并以十五万方油罐为算例,采用无量纲参数法对中、美、日油罐规范的计算结果进行比较。(2)罐壁采用双线性弹塑性硬化材料,液体采用无旋、有粘、不可压缩流体,同时考虑材料、几何和接触状态非线性对十五万方油罐进行地震动力时程响应分析。分析了应力沿罐壁高度的分布情况,研究了储液的晃动、油罐的提离、油罐的滑移和罐壁加速度放大等现象,并得到了提离与晃动波高、轴向压应力之间的关系,以及比较了等壁厚和变壁厚模型对地震响应的异同等。(3)利用等壁厚模型和简谐波加载研究“象足”屈曲破坏的行为。研究结果表明：“象足”屈曲是弹塑性局部屈曲,是环向应力和轴向应力联合作用的结果。发生的条件是环向应力接近或者MISES应力超过材料的屈服应力,同时轴向压应力超过许用临界应力。油罐发生“象足”屈曲时,罐壁变形非常大会带动底板一起变形,底板也可能会发生塑性屈服破坏。(4)研究环向应力对“象足”屈曲的影响。研究结果表明：只有环向应力接近或MISES应力大于材料屈服应力时,油罐才会发生“象足”屈曲；环向应力越大,油罐越容易发生“象足”屈曲,在环向应力不高时,即使轴向压应力较大也不易发生“象足”屈曲。并从液面高度、载荷特征周期、载荷类型和载荷作用方向等方面研究动水压力产生的环向应力对“象足”屈曲的影响。更多还原

【Abstract】 The large self-anchored storage tanks are the key equipment of Strategic Oil Storage Base in china. Under the effect of the earthquake disaster, the dynamic response of tanks is very complex. Since 1930’s, scholars have been taking a lot of research on oil storage tanks of dynamic response and positive corresponding criterions too. However, the oil storage tanks that designed by the criterion are also destroyed in the seismic disaster sometimes. That indicates further study of seismic behavior and dynamic response of oil storage tank is still necessary.The dynamic response analysis of 15×104m3 oil storage tank has been carried out, also the "elephant foot" buckling failure behavior and the effect of hoop stress generated by hydrodynamic pressure on the "elephant foot" buckling are studied in this paper. The main research work in the study is concluded as follows:(1) Comparative analysis of the earthquake force and "elephant foot" buckling of American, Japan and Chinese seismic design codes on oil storage tanks; Take 15×104m3 oil storage tank as an example, compare the calculation results of these three seismic design codes by using dimensionless method.(2)Taking into account the material nonlinear, geometric nonlinearity and contact state nonlinear of model for dynamic response analysis. Study the distribution of stress along the tank wall; sloshing wave height, uplift, and acceleration amplification, obtained the relationship between the uplift, sloshing wave height and axial compressive stress. Besides, compare the difference of seismic response between one thickness and variable thickness model.(3) Discusses the "elephant foot" buckling failure behavior by using one thickness model and harmonic load. The results are as follows:the "elephant foot" buckling is one kind of plastic local buckling, which results from the effect of hoop stress and axial compress stress. The occurring condition of "elephant foot" buckling is axial compress stress exceeds the critical stress and hoop stress is near or more than the yield stress, when "elephant foot" buckling occurres, the tank wall deformation is too large to make the bottom plate deform, so that the bottom plate may occur plastic yield damage.(4) Study the effect of hoop stress on the "elephant foot" buckling. The results: Only the hoop stress is near or more than the material yield stress, the tank will occur "elephant foot" buckling. The greater hoop stress is, the easier the tank is to occur "elephant foot" buckling. When hoop stress is low, even great axial stress is also less prone to "elephant foot" buckling. And study the effect of hoop stress generated by hydrodynamic pressure on the "elephant foot" buckling from the liquid level, the characteristic period, type and direction of load.更多还原