OPTIMAL SAMPLE SHAPE AND SIZE DETERMINATION OF TANK JUNCTIONAL UNIT FOR MECHANICAL ENDURANCE TESTS

Abstract

Steel storage tanks are widely used in the oil and gas industry. Steel storage tanks repre-sent the constructions intended for accumulation, storage, performance of technological operations and the account of oil and oil products. One of the important elements of steel storage tanks is junctional unit between the wall and the bottom of tank. The lack of fusion at the tank junctional unit does not allow to reliably determine the presence of defects in the assembly that arise during the construction and operation, by existing methods of nondestructive testing. This is, in turn, imposes higher requirements on the accuracy of the method of determining the resource of the tank junctional unit and the size of the permissible defects. The existing model of the test sample does not allow to reliably reflect the nature of stress distribution at the tank junctional unit, arising from operational loads. There are some drawbacks of the current model. First of all is the discrepancy between the results of the real wrecking unit and the test sample at wall thicknesses close to or equal to the thickness of the edge. The second is the existing technique, there is no definition of which part of the joint (wall-weld, weld-seam welded), and the sample will be destroyed. As a result of the numerical simulation of the distribution obtained equivalent stresses according to the inner surface of the tank junctional unit. The design of the rigging and the test sample is proposed in this research, which allows increasing the reliability of the tests at all standard sizes. a new model of tank junctional unit testing for endurance and tools for its implementation, allowing you to improve the reliability of the test results compared to existing samples for testing.