Application of Regularization Method for Improved Magnetic Evaluation of Mechanical Strain of Metal Products
Results obtained in evaluation of stress-strain state of metal products by one parameter have significant error caused by random factors and prone to fluctuations. A problem of metal strain evaluation on experimentally measured structure-sensitive magnetic parameters is inverse physical problem, which belongs to incorrect problems of mathematical physics. A mathematical method of description the evaluation of metal mechanical strain by magnetic means is based on variation principle (regularization method). As a sign of metal stress-strain state classification, the variation of residual magnetic field strength value measured above surface of metal is used. Metal stress-strain state evaluation is carrying by minimizing of smoothing functional. An optimal shape of regularization factor is found on empirical dependence of stress-strain state classification signs on mechanical strain in conditions of linear stress-strain state. It was found that stress-strain state evaluation of metal preloaded and metal under loading process could be carried out from one type of functional. In order to obtain stable evaluations of mechanical strain, we should find signs of metal stress-strain state classification. At the same time, the optimal values of general functional parameters remains constant.