Abstract: In order to improve the precision of stress calculation of large unanchored oil storage tanks, a new method based on a combined cylindrical shell theory is presented to replace the long cylindrical shell method through comparing the difference between solutions of exiting theory analysis, finite element calculation and test data; In addition, another new method, which takes foundation-settlement as the boundary-condition in finite element analysis, is presented to improve the means of spring-beam element in finite element analysis. A 15 000 m3 oil storage tank is taken as a research object to conduct stress and foundation-settlement test during watering experimentation time. The test data of the new method are compared with the values of theory calculation and finite element analysis. The results show that the new methods proposed have much higher accuracy than the existing ones.

Key words: Finite element analysis, Oil storage tank, Stress test, Theory analysis, Split magnetic liquid sealing Plane sealing Structure parameter Sealing performance Finite element