| 摘要 |
PROBLEM TO BE SOLVED: To provide a stress evaluating method and a stress evaluating device for evaluating a curved pipe for simply and precisely calculating the stress generated in the curved pipe constituting a pipe line. SOLUTION: Regarding the curved pipe A to be evaluated, if a measuring limit is exceeded, the stress evaluation is performed as follows: a distribution of the stress in a curved pipe B being adjacent to the pipe A is measured by a magnetic anisotropy sensor, flatness value of the curved pipe B is obtained from the relational formula of the stress-moment relation and the moment-flatness value, and an initial diameter of the pipe B is obtained from a measure of the diameter of the pipe B. The flatness vale of the pipe A is obtained from the measurement of the diameter of the pipe A considering that the initial value of diameter of the pipe B is equivalent to that of the pipe A, and the distribution of the stress in the curved pipe A is calculated using the relational formula of moment-flatness value and the relational formula of stress-moment. Wherein, the relational formula of moment-flatness value is derived e.g. by developing the theoretical formula of Rodabaugh & George etc., regarding displacement in a sectional direction of the curved pipe. COPYRIGHT: (C)2004,JPO
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