Reliability analysis of tank shell wind-resistant stability considering corrosion

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.