材料特性对大型油罐象足屈曲临界应力的影响  

Effect of material characteristics on the critical stress of elephant foot buckling on large-scale oil tanks

作　　者：石磊 李在蓉[2] 帅健[3] 许葵[3] 王晓霖 SHI Lei;LI Zairong;SHUAI Jian;XU Kui;WANG Xiaolin(SINOPEC Dalian Research Institute of Petroleum and Petrochemicals;PetroChina Pipeline R ＆ D;College of Mechanical and Transportation Engineering,China University of Petroleum（Beijing)

机构地区：[1]中国石油化工股份有限公司大连石油化工研究院 [2]中国石油管道科技研究中心 [3]中国石油大学(北京)机械与储运工程学院

出　　处：《油气储运》2018年第8期873-877,共5页Oil & Gas Storage and Transportation

基　　金：国家重点研发计划资助项目"油气管道及储运设施完整性评价技术研究";2016YFC0802105

摘　　要：象足屈曲是大型油罐在地震载荷作用下的典型破坏方式。在国内外规范中,油罐抗震设计公式均基于薄壳的弹性稳定理论,而象足屈曲属于弹塑性屈曲,因此,有必要研究储罐材料特性对象足屈曲临界应力的影响。基于Ramberg-Osgood材料模型,提出大型油罐象足屈曲的临界应力计算公式,分析材料参数的屈强比、屈服强度以及罐壁环向应力对罐壁屈曲临界应力的影响。研究结果表明:大型油罐发生象足屈曲时,材料幂硬化指数与罐壁屈曲临界应力的关系受罐壁环向应力的影响,环向应力的增大能够有效降低储罐的屈曲临界应力,且屈曲临界应力随着屈强比的增大而降低。当环向应力与屈服强度之比一定时,材料屈服强度的增大能够适当提高罐壁屈曲临界压应力,但效果并不显著。Elephant foot buckling is a typical damage form on large-scale oil storage tanks under the effect of earthquake loading. The anti-earthquake design formulas of oil storage tank stipulated in domestic and foreign specifications are all based on thin-walled elastic stability theory, but elephant foot buckling is in the category of elastic-plastic buckling. Therefore, it is necessary to study the effect of material characteristics on the critical stress of elephant foot buckling on large-scale oil tanks. In this paper, the formula for calculating the critical stress of elephant foot buckling on large-scale oil storage tanks was established on the basis of Ramberg-Osgood material model. Then, the effects of material parameters on the buckling critical stress of tank shell were analyzed, including yield-tensile ratio, yield strength and circumferential stress of tank shell. It is shown that the relationships between the power hardening exponent of material and the buckling critical stress of tank shell are affected by circumferential stress of tank shell at the occurrence of elephant foot buckling on the large-scale oil storage tank. The increase of circumferential stress can effectively reduce the buckling critical stress of the tank. The buckling critical stress decreases with the increase of yield-tensile ratio. When the ratio of circumferential stress to yield strength is constant, the buckling critical compressive stress of tank shell can be increased appropriately by increasing the yield strength of material, but the effect is not remarkable.

关 键 词：大型油罐 象足屈曲 屈强比 屈服强度 环向应力 

分 类 号：X913.4[环境科学与工程—安全科学] TE88[石油与天然气工程—油气储运工程]