| 摘要 |
PURPOSE:To detect the shape of a crack accurately, by repeatedly analyzing an electric field as obtained when shapes of various elements previously inputted into a computer are corrected to match measured values. CONSTITUTION:A direct current is applied to a feeder terminal 5 provided on a flaw detection head 20 through a switching unit 67 from a plurality of a DC power source 66 to form an electric field in a structural member. A poten tial difference between a number of measuring terminals 10 is brought into a fine potentiometer 71 through a scanner 70 to be measured and the results are inputted into a computer 100 to be memorized into a memory 103 as poten tial distribution together with position information from a driver controller 65 through an interface 72. The aspect ratio of a crack is determined by perform a computation in comparison with various master curves stored in a potential difference distribution memory 102. Then, the potential distribution is analyzed based on node element data of various aspects memorized in a mesh shape memory 101. The node elements at the tip of the crack are corrected repeatedly only confined to those coinciding with the results of measurement and when the final coincidence is given, the corresponding shape is identified as the shape of the actual crack. |
