| 摘要 |
One or more predetermined physical dimensions of the long element (2) are measured simultaneously, notably at a radial distance from its axis and at at least two measuring points (A, B, C) spaced along the axis. At least one parameter characteristic of the element at these measuring points is derived from these measurements and thence a characteristic parameter at other points is determined At least one characteristic parameter is chosen from the radius of curvature, the position of the center of curvature and the axial deformation of the long element on its axis (X). From these measurements the stresses and the level of fatigue in the element at the measuring point are determined. There are at least two and preferably three measuring points, spaced angularly from each other around the axis. At least one measurement is of the deformation in the axial direction of part of the element at a radial distance from the axis. The long element is intended to be immersed and has a connecting point (5) with the measuring points near this connecting point. The axial deformation is measured using an optical detector (8) with two optical fibres (9a, 9b), one of which is fixed at two points to the long element, to follow its deformation locally, and the other acts as a reference fibre extended between the two points. An Independent claim is given for a system for evaluating the stresses in a long element such as a pipe, with at least two measuring modules (6) designed to be fixed to the long element at two points spaced along the axis. Each module contains one or more detectors, preferably at least three detectors, placed at a distance from the axis of the element and operated to measure a physical dimension of the element such as axial elongation. A data treatment unit (19) receives the data from the measuring modules and determines at least one characteristic parameter such as the radius of curvature and the axial deformation of the element at the measuring points and at other points on the element. At least one of the detectors is an optical detector as described above, and the module(S) are equipped with electronic components and/or means of recording data. |
