【作者】 周波；

【导师】 杨建江；

【作者基本信息】 天津大学 ， 结构工程， 2012， 硕士

【摘要】 近年来,在国外技术的支持下,我国多个地区建设了多座大型LNG全容式储罐。同时,在从事储罐建设事业的人员和科研人员的共同努力下,国内在大型LNG储罐的建造和设计技术上也取得了很大的进步,但在很多方面仍然存在技术上的问题,不能完全实现LNG储罐国产化,这就需要更多的后来人员在关键技术上的关注和研究分析。本文以大型LNG储罐预应力钢筋混凝土外罐壁为研究对象,所做的主要工作如下:1.采用ANSYS有限元软件建立了16万m3容积的大型LNG储罐外罐的有限元三维模型。2.参考国内外荷载规范及工程经验资料,确定了各种荷载的取值。同时,采用规范中提出的极限状态设计法,给出了正常荷载工况和偶然荷载工况下各荷载组合公式,并明确了可变荷载组合系数及各荷载偏系数(中国规范称为分项系数)的取值。3.对LNG储罐外罐在不同工况下进行了有限元计算和分析,得出各种荷载组合工况作用下LNG储罐外罐水平截面和竖直截面的内力沿着高度的变化规律,并对各项结果进行了对比分析。通过对ANSYS软件计算出的结果的分析发现:LNG储罐在各工况下,罐体顶部和底部所受的内力最大,且拉应力值超出了混凝土抗拉强度设计值,相应部位属于带裂缝工作状态;在荷载(荷载效应)组合中,欧洲规范能适用于荷载组合及荷载效应组合,中国规范只适用荷载效应组合,中国规范的得出的结果较欧洲规范更加偏于安全;在欧洲规范组合中,工况2和工况4在设计中占主导地位,即对罐体产生的内力最为不利。更多还原

【Abstract】 In recent years, with the support of foreign technology, many large-scale full containment storage tanks of LNG were built in various parts of China. Meanwhile, with the joint efforts of researchers and the persons engaged in construction of the tanks, domestic large-scale LNG storage tank in this field of construction and design technology have made great progress, but there are still so many technical problems not being solved in many ways that localization of LNG storage tanks is not realized completely, so more concern and technical research and analysis are required.In this paper, the large-scale outer tank of prestressed reinforced concrete is as the object of research, the main work is as follows:Firstly, the ANSYS finite element software was used, the 3D finite element model of large volume of 160 000 m3 LNG storage tank of outer wall was established.Secondly, based on domestic/international load standards and the data of engineering experiences, the value of the various loads were determined. At the same time, the limit state design method proposed in relevant codes was adopted, the action or action effect combination formula under the normal and accidental action conditions were given, and the combination coefficients and the partial factor values of the variable load were listed clearly. Thirdly, the outer tank in different cases was caculated and analysed through the finite element software. Under the cases of the various action or action effect combination, the internal forces (axis force, shear force, bending moment) of the horizontal sections and vertical cross-section of the outer tank along the height variation were got, and the results were analyzed.Through the calculation of using ANSYS software and the analysis of results, some conclusions can be drawn. In various cases, the top and bottom of the tank suffer the maximum of the forces, and the tensile stress exceeds the tensile strength of concrete design value, with corresponding parts are cracking in working condition; In action or action effect combination, the European codes can be applied to the load combinations and load effect combination, but the Chinese codes only can be applied to action effect combination, the calculation result of Chinese codes is more safety than the European codes; Just considering European codes, case 2 and case 4 in the design conditions dominate, at that case, the most negative forces in the outer tank can be generated.更多还原