| 摘要 |
PROBLEM TO BE SOLVED: To provide a crack size estimation method capable of estimating not only a depth but also a surface length of a crack on an interior surface of a structure subject to internal pressure. SOLUTION: A crack size estimation method includes: a first step to preliminarily detect a crack on an interior surface of a structure; a second step to measure strain on an exterior surface of the structure corresponding to the detected crack by a plurality of strain gauges stuck on the exterior surface of the structure; a third step to derive depths and surface lengths of virtual cracks respectively corresponding to a plurality of strain measurement values measured by the plurality of the strain gauges by entering the same into a preliminary obtained relation, with a finite element analysis, between the depth as well as the surface length of the virtual crack on the interior surface of a virtual structure and the strain on the exterior surface of the virtual structure; a fourth step to make a graph indicating, as a plurality of curves, the relation between the depths and the surface lengths of the virtual cracks respectively corresponding to the plurality of the strain measurement values; and a fifth step to estimate the depth and the surface length of the detected crack by obtaining the depth and the surface length of an intersection point of the plurality of the curves on the graph. COPYRIGHT: (C)2012,JPO&INPIT |
