考虑腐蚀罐壁抗风稳定性的可靠性分析

Reliability Analysis of Tank Shell Wind-resistant Stability Considering Corrosion

为准确掌握在役储罐的抗风稳定性,满足油田储罐健康管理的需要,分析影响罐壁稳定性的各种因素,建立罐壁结构抗力的衰减模型;根据储罐的历年检测资料,利用灰色系统理论建立罐壁腐蚀深度随服役时间变化的模型;利用极值Ⅰ型分布对罐区的年最大风速进行极值统计,得到风载荷的统计模型;根据可靠性理论建立罐壁抗风稳定性的可靠性模型,分析储罐随服役时间的增长其抵抗风载荷的可靠性,并进行实例计算,结果表明,罐壁的腐蚀深度随服役时间的增长呈指数增长,其抗风稳定性的可靠度逐渐减小,罐服役19年后其抗风稳定性的可靠度迅速降低,服役24年后失去抵抗年最大风载荷的能力,此结果可为储罐的维护维修提供决策支持。

To accurately grasp the wind-resistant stability of the tank and meet the needs of health management of the storage tank on oilfield, various factors which impacts the stability of the tank shell are analyzed and the degradation model of structural resistance of tank shell is established. A model on corrosion depth with the service time is established by using the grey theory according to the past test data. The extreme statistics of annual maximum wind velocity are done by using extreme distribution I and the wind load model is achieved. A reliability model on the wind stability of the tank shell is established on the basis of reliability theory, the wind-resistant stability is analyzed with the growth of service time, and a real example is given. The results show that the corrosion depth grows exponentially with the service time, the wind-resistant stability reliability decreases gradually and the wind-resistant stability reliability decreases quickly after the 19 years service. After serving 24 years the tank shell loses the ability to resist annual maximum wind load. The results can provide technical support to the storage tank maintenance.