For the substantiation of such possibility, destructive tests of the most applicable structural steel specimens were made in the civil engineering. In one case - the loading on the specimen was increased in a step like way, and, after each an increment of load, the coercive force, the measurement of coercive force was measured in the direction along the tensile force. In the second case - the loading was increased in the same manner, but with the subsequent off - loading until zero point after every regular increment the coercive force is measured, as it was before, at each an increment of loading and after setting to zero. The coercive force values in the off - loading state are the accumulation standard of the specimen's strain variations during every similar solitary loading, off-loading of the specimen. As a result, the possibility is to identify by the coercive force the particular points of Stress-Deformation diagram , such as yield point, ultimate strength, etc. It is determined unambiguously, to what area of diagram ( of elasticity, elasticity-ductility, destructive zone) corresponds the metal structure of the metalwork under inspection at that very instant.
In addition, on the basis of analogous specimens, the accumulation of damage and plastic deformation of metal structure were simulated. These results provide the possibility to obtain the prediction charts of the metal work's residual resource.For the practical implementation of the above mentioned facts, the portable electronic digital coercive force meter with self-contained power supply, attached converter and closed type magnetic core. Instrument error is 5 % .
The suggested method is appropriately implemented at the practice. The cost and working hours of unit measurement of it is less than of any alternative method of destructive test and with respect to the authenticity inspection of Stress-Deformation the given method is inferior only to destructive testing. The method was successfully implemented while evaluation of service life of main pipe-lines sections and pressure vessels as well. Data of method and instrument are used as official data equally with ultrasonic, radiation, magnetic particles methods, adding them by the previously non available information about " fatigue " metalwork structure.
Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00
Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:
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