Strain measurement device and installation of such a device in an element

Patent metadata

Field	Value
Publication number	US-2016334206-A1
Application number	US-201615223366-A
Country	US
Kind code	A1
Filing date	Jul 29, 2016
Priority date	Nov 23, 2012
Publication date	Nov 17, 2016
Grant date	—

Abstract

A strain measurement method and device are provided. The strain measurement device includes at least one filiform strain sensor and a support of longilinear shape on which the filiform strain sensor is positioned. The strain measurement device also includes a stiffener.

First claim

What is claimed is :

1 . A method for measuring a strain in a given direction within a structural element, comprising:
introducing a binder into a hole formed in the structural element; inserting a strain measurement device into the hole filled with the binder, the strain measurement device including at least one filiform strain sensor, a support of longilinear shape on which the filiform strain sensor is positioned and a stiffener; and connecting the filiform strain sensor of the strain measurement device to a measurement device.

2 . The method according to claim 1 , wherein the strain measurement device is introduced at the same time as the stiffener arranged inside a hollow support of the strain measurement device and the stiffener is withdrawn once the strain measurement device is inserted into the hole.

3 . The method according to claim 2 , wherein the strain measurement device is introduced using the stiffener.

4 . The method according to claim 1 , wherein the filiform strain sensor is an optical fibre Bragg grating.

5 . The method of claim 1 , wherein the stiffener is at most fixed to the support at one point.

6 . The method of claim 1 , wherein the support is hollow, has a longitudinal direction and width, with the support further comprising a wall having a thickness and having an external surface on which the filiform strain sensor is positioned by one or more connecting points, a main strain direction of the filiform strain sensor being arranged parallel to the longitudinal direction of the support.

7 . The method of claim 1 , wherein one end of the support is blocked.

8 . The method of claim 7 , wherein the support is blocked by a cap, an end of which extends beyond an end of the support.

9 . The method of claim 1 , wherein the strain measurement device comprises a thin tube encapsulating at least the filiform strain sensor with a binder.

10 . The method of claim 1 , wherein the support is hollow, further introducing a second strain sensor, free of deformation with respect to the support, and situated in an internal volume defined by the wall of the hollow support.

11 . A method of forming a strain measurement device, the method comprising:
providing at least one filiform strain sensor; providing a hollow support of longilinear shape relative to which the filiform strain sensor is positioned; providing a stiffener; and coupling the stiffener and a wall of the support together so as to define a space between the stiffener and the wall of the support so that the support retains a freedom of movement with respect to bending.

12 . The method of claim 11 , further including coupling the stiffener to the support at only one point.

13 . The method according to claim 11 , wherein the filiform strain sensor is an optical fibre Bragg grating.

14 . A method of forming a structural element, the method comprising:
providing a structure having a first surface and a hole having a first end that opens onto a first surface; inserting a strain measurement device into at least one measurement zone associated with the hole, the strain measurement device including at least one filiform strain sensor, a support of longilinear shape on which the filiform strain sensor is positioned and a stiffener; and providing a binder forming a film surrounding the strain measurement device such that the stiffener and a wall of the support are coupled together so as to define a space between the stiffener and the wall of the support so that the support retains a freedom of movement with respect to bending.

Assignees

• Airbus Operations Sas

Inventors

• Sartor Marc
• Morgue Patricia
• Paredes Manuel

Classifications

• G01L1/246

  using integrated gratings, e.g. Bragg gratings · CPC title

• G01M5/0025

  of elongated objects, e.g. pipes, masts, towers or railways (G01M5/0058 takes precedence) · CPC title

• G01B11/165 Primary

  by means of a grating deformed by the object · CPC title

• G01D5/35316

  using a Bragg gratings · CPC title

• G01M11/086 Primary

  Details about the embedment of the optical fiber within the DUT · CPC title