CN105318198A - Distributed monitoring system for span section strain of long-distance pipeline and monitoring method - Google Patents

Abstract

The invention provides a distributed monitoring system for span section strain of a long-distance pipeline. The system comprises a remote monitoring center and a plurality of distributed nodes, wherein each distributed node is set through the mode as follows: the monitored long-distance pipeline is divided into n sub-pipelines in the axis direction; for each sub-pipeline i, w monitoring sections perpendicular to an axis are set in the axis direction at equal intervals, and 4 monitoring points are distributed on each monitoring section, that is, a fiber bragg grating sensor is mounted on each of an upper bus, a lower bus, a left bus and a right bus of each monitoring section; all the fiber bragg grating sensors mounted on each sub-pipeline i and a data collecting and pre-processing device locally mounted on the sub-pipeline I constitute one distributed node. The system can be used for predicting whether a certain section of pipeline has a hidden danger in advance, if the hidden danger exists, a related worker can be informed to take related measures in advance, actual safety accidents of the pipeline are avoided, and the safety of pipeline operation is improved.

Description

The distributed monitoring system of long distance pipeline Crossover phase strain and monitoring method

Technical field

The invention belongs to long distance pipeline safety monitoring technology field, be specifically related to distributed monitoring system and the monitoring method of the strain of a kind of long distance pipeline Crossover phase.

Background technique

In recent years, along with the successful Application of optical fiber sensing technology in the field safety monitorings such as military affairs, aviation, bridge, optical fiber sensing technology is also introduced in submarine pipeline monitoring.In various optical fiber sensing technology, distribution type fiber-optic technology is measured along the continuous distributed on optical fiber each point Time and place owing to can realize physical quantity, therefore, is specially adapted to monitoring pipeline safety.

Present stage, utilize Distributed Optical Fiber Sensing Techniques to monitor submarine pipeline leak position, judge leak source position mainly through some Parameters variation of monitoring pipeline leak optical fiber.As BernhardVogel describes a kind of method utilizing distributed optical fiber temperature sensor to detect pipeline leakage ^[1], the method utilizes pipe leakage place temperature notable change can occur, and by contrast pepe standard temperature distribution history be embedded in the pipe temperature distribution curve that the fiber-optic monitoring on pipeline or below pipeline arrives, judges pipe leakage position.

Chen Baohuas etc. are introducing the article of pipe leakage detection method ^[2]in refer to a kind of hydrocarbon distributed fiberoptic sensor, the material that its utilization can be had an effect with hydrocarbon molecules in oil is as optical fiber jacket, when oil transport pipeline occurs to leak, the refractive index of optical fiber jacket material will change, thus cause the guide-lighting performance of optical fiber to change, by oil transport pipeline leak source position can be found to optical fiber light-guiding performance Real-Time Monitoring.

Mendoza describes a kind of optical fiber distributed type corrosion sensor ^[3], by comparing with index calibrated in advance judge whether pipeline corrodes to the monitoring of optical fiber jacket moisture and pH value.

But the various distributed optical fiber sensing systems of above-mentioned introduction, all judge for pipe leakage, premised on pipeline damage; That is, only have when pipeline has occurred to leak, pipe leakage phenomenon can be monitored, but now pipeline damage has caused the oil gas carried to be revealed, both polluted physical environment, and also affected the normal production of relevant enterprise and the normal life of resident, more serious situation has been blasted accident even, threaten human life's safety, cause huge economic loss.

[1]Bernhard,V.etal.LeakageDeteetionSystemsbyUsingDistributedFiberopticalTemperatureMeasurement[A]SPIE2001,Vol.4328,23-34.

[2]CHENHuaboetal.AMethodforoilPipelineLeakDetectionBasedonDistributedFiberOpticTechnology[A]SPIE1998,Vol.3555,77-82.

[3]Mendoza,E.A.etal.DistributedFiberOpticChemicalSensorsforDetectionofCorrosioninPipelinesandStrueturalComponents[A]SPIE1998,Vol.3398,136-143.

Summary of the invention

For the defect that prior art exists, the invention provides distributed monitoring system and the monitoring method of a kind of long distance pipeline Crossover phase strain, in order to solve the problem.

The technical solution used in the present invention is as follows:

The invention provides the distributed monitoring system of a kind of long distance pipeline Crossover phase strain, comprising: remote monitoring center and several distributed nodes, distributed node described in each carries out information interaction by signal transmission system and described remote monitoring center;

Each distributed node is arranged in the following ways:

Monitored long distance pipeline is divided in the axial direction n sub-pipes; For any one sub-pipes i, equidistant in the axial direction w the monitoring cross section perpendicular to axis is set, 4 monitoring points are arranged in each monitoring cross section, that is: a fiber-optic grating sensor is respectively installed at the Up Highway UHW in described monitoring cross section, Down Highway, left bus and right bus place; The all fiber-optic grating sensors be arranged on sub-pipes i form a distributed node with the data capture and pre-treater being arranged on sub-pipes i this locality.

Preferably, the outer surface of tube wall of described fiber-optic grating sensor and monitored sub-pipes fits tightly installation, for gathering the original strain information fitting tightly tube wall with it;

The original strain information that described data capture and pre-treater send for receiving each fiber-optic grating sensor, and data prediction is carried out to described original strain information, obtain the real-time strain information in monitoring point be applicable to after the process of transmission and analysis further;

Described signal transmission system is used for: real-time for described monitoring point strain information is stored in this locality; Meanwhile, real-time for described monitoring point strain information is sent to described remote monitoring center in real time.

Preferably, described remote monitoring center comprises pipe deforming computing module; Described pipe deforming computing module comprises sub module stored, the strain calculation submodule of Type of Welding sensor, the strain calculation submodule pasting form sensor and bending deflection of pipe calculating sub module;

Described sub module stored is for storing the corresponding relation between sub-pipes ID and sub-pipes attribute; Wherein, described sub-pipes attribute comprises fiber-optic grating sensor mounting type and sub-pipes essential information on the geographical position at sub-pipes place, sub-pipes; Wherein, described mounting type comprises two kinds: fiber-optic grating sensor is arranged on sub-pipes by Type of Welding, and fiber-optic grating sensor is arranged on sub-pipes by stickup form;

Wherein, for the sub-pipes of erecting and welding form sensor, the essential information of described sub-pipes comprises:

L ₁: optical fiber adhesive layer partial-length;

L ₂: optical fiber is without adhesive tape sections length;

L ₃: immovable point distance tip lengths:

R ₁: the outer radius of encapsulation steel pipe;

R ₂: the inside radius of encapsulation steel pipe, i.e. glue-line outer radius;

R ₃: fiber radius;

E _x: the Young's modulus of optical fiber;

E _g: the Young's modulus of sensor steel pipe;

E _j: the Young's modulus in mesosphere;

ε _s: the real-time strain value that fiber bragg grating measurement obtains;

G _jfor the shear modulus of glue line;

Wherein, for the sub-pipes installing stickup form sensor, the essential information of described sub-pipes comprises:

L ₁: optical fiber adhesive layer partial-length;

L ₂: optical fiber is without adhesive tape sections length;

L ₃: immovable point distance tip lengths:

R ₁: the outer radius of encapsulation steel pipe;

R ₂: the inside radius of encapsulation steel pipe, i.e. glue-line outer radius;

R ₃: fiber radius;

E _x: the Young's modulus of optical fiber;

E _g: the Young's modulus of sensor steel pipe;

E _j: the Young's modulus in mesosphere;

G _jfor the shear modulus of glue line;

ε _s: the real-time strain value that fiber bragg grating measurement obtains;

H ₁for the thickness of glue line;

H ₂for the thickness sum of glue line and substrate;

E _jpfor the Young's modulus of substrate;

G _jcfor the shear modulus of glue line;

L ₅for substrate end and steel tube end part distance;

L ₆for immovable point and the other end steel tube end part distance;

The strain calculation submodule of described Type of Welding sensor is used for: read described sub module stored, finds the sub-pipes essential information corresponding with it based on sub-pipes ID; Then by strain value ε that the relevant parameter in the sub-pipes essential information found and the measured point place fiber bragg grating measurement that receives obtain _ssubstitute into following formula, try to achieve the strain value ε at revised measured point place _t:

$\begin{array}{c}{\mathrm{\ϵ}}_t=\frac{\mathrm{\Δ}{l}_2+2\mathrm{\Δ}{l}_x}{l_2+2(l_1-l_3)}\\ =\frac{l_2+\{\frac{e^{{\mathrm{Kl}}_1}-e^{{\mathrm{Kl}}_3}}{K}-l_1+l_3+\frac{(1-e^{{\mathrm{kl}}_1})[\mathrm{ch}\left({\mathrm{Kl}}_1\right)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)]}{\mathrm{Ksh}\left({\mathrm{Kl}}_1\right)}\}\frac{2\mathrm{ch}\left({\mathrm{Kl}}_3\right)}{\mathrm{ch}({\mathrm{Kl}}_1+{\mathrm{Kl}}_3)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)}}{l_2+2(l_1-l_3)}{\mathrm{\ϵ}}_s\\ +\frac{\frac{2[\mathrm{ch}\left({\mathrm{Kl}}_1\right)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)]}{\mathrm{Ksh}\left({\mathrm{Kl}}_1\right)}}{l_2+2(l_1-l_3)}{\mathrm{\ϵ}}_s\end{array}---\left(34\right)$

Wherein:

$K=\sqrt{\frac{\frac{r_3^2{E}_x+(r_2^2-r_3^2)E_j}{(r_1^2-r_2^2)E_g}+1}{\frac{1}{G_j}[\frac{E_j}{4}(r_2^2-r_3^2)+\frac{r_3^2}{2}(E_x-E_j)\ln \frac{r_2}{r_3}]}}---\left(25\right)$

The strain calculation submodule of described stickup form sensor is used for: read described sub module stored, finds the sub-pipes essential information corresponding with it based on sub-pipes ID; Then by strain value ε that the relevant parameter in the sub-pipes essential information found and the measured point place fiber bragg grating measurement that receives obtain _ssubstitute into following formula, try to achieve the strain value ε at revised measured point place _t:

$\begin{array}{c}{\mathrm{\ϵ}}_t=\frac{l_2{\mathrm{\ϵ}}_s+2\mathrm{\Δ}{l}_x+2[u_{\mathrm{jp}}\left(l_3\right)-u_{\mathrm{mt}}\left(l_3\right)]}{l_2+2(l_1-l_3)}\\ =\frac{l_2+\{\frac{e^{{\mathrm{Kl}}_1}-e^{{\mathrm{Kl}}_3}}{K}-l_1+l_3+\frac{(1-e^{{\mathrm{Kl}}_1})[\mathrm{ch}\left({\mathrm{Kl}}_1\right)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)]}{\mathrm{Ksh}\left({\mathrm{Kl}}_1\right)}\}\frac{2\mathrm{ch}\left({\mathrm{Kl}}_3\right)}{\mathrm{ch}({\mathrm{Kl}}_1+{\mathrm{Kl}}_3)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)}}{l_2+2(l_1-l_3)-\frac{(h_2-h_1)h_1{E}_{\mathrm{jp}}T}{G_{\mathrm{jc}}}[\frac{e^{-T(l_3+l_6)}-e^{{\mathrm{Tl}}_5}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{e}^{{\mathrm{Tl}}_3}-\frac{e^{{-\mathrm{Tl}}_5}-e^{T(l_3+l_6)}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{e}^{-{\mathrm{Tl}}_3}]}{\mathrm{\ϵ}}_s\\ +\frac{\frac{2[\mathrm{ch}\left({\mathrm{Kl}}_1\right)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)]}{\mathrm{Ksh}\left({\mathrm{Kl}}_1\right)}}{l_2+2(l_1-l_3)-\frac{(h_2-h_1)h_1{E}_{\mathrm{jp}}T}{G_{\mathrm{jc}}}[\frac{e^{-T(l_3+l_6)}-e^{T{l}_5}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{e}^{{\mathrm{Tl}}_3}-\frac{e^{-{\mathrm{Tl}}_5}-e^{T(l_3+l_6)}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{e}^{-{\mathrm{Tl}}_3}]}{\mathrm{\ϵ}}_s\end{array}---\left(53\right)$

Wherein, $T=\sqrt{\frac{2G_{\mathrm{jc}}}{(h_2-h_1)h_1{E}_{\mathrm{jp}}}}---\left(46\right)$

$K=\sqrt{\frac{\frac{r_3^2{E}_x+(r_2^2-r_3^2)E_j}{(r_1^2-r_2^2)E_g}+1}{\frac{1}{G_j}[\frac{E_j}{4}(r_2^2-r_3^2)+\frac{r_3^2}{2}(E_x-E_j)\ln \frac{r_2}{r_3}]}}---\left(25\right)$

Described bending deflection of pipe calculating sub module is for calculating the combined deflection of any one monitored sub-pipes, and method is as follows:

(1) for any one monitored sub-pipes, if its total m monitoring cross section, numbering is respectively 1,2 in order ... m; Distance between adjacent monitoring cross section is all equal, is h; The diameter of sub-pipes is D;

Each monitoring Up Highway UHW in cross section, Down Highway, left bus and right bus position arrange a fiber-optic grating sensor respectively, that is: each monitoring cross section arranges 4 monitoring points;

(2) the amount of deflection derivative value of monitoring cross section i is calculated:

For monitoring cross section i, receive the real-time strain value ε in Down Highway place uploaded respectively 4 monitoring points simultaneously _{under is}, the real-time strain value ε in Up Highway UHW place _{on is}, the real-time strain value ε in left bus place _{is is left}strain value ε real-time with right bus place _{is is right};

Then, read sub module stored, judge fiber-optic grating sensor mounting type, if be welded and installed form, then by formula (34) (25), by ε _{under is}be converted into revised Down Highway place strain value ε _{under it}, by ε _{on is}be converted into revised Up Highway UHW place strain value ε _{on it}, ε _{is is left}be converted into revised left bus place strain value ε _{it is left}, ε _{is is right}be converted into revised right bus place strain value ε _{it is right};

Then, to ε _{it is left}and ε _{it is right}carry out COMPREHENSIVE CALCULATING, obtain revised axis place strain value ε _{it axle};

By ε _{it axle}substitute into following formula, try to achieve monitoring cross section i amount of deflection derivative value:

W ' _i=λ _isin θ _i=(ε _{it axle}+ 1) sin θ _i(7)

Wherein, w ' _ifor monitoring cross section i amount of deflection derivative value;

θ _ifor monitoring cross section i is relative to the absolute rotational angle theta of y-axis _i, θ _ifor the algebraic sum of the relative rotation in all monitoring cross sections in this sub-pipes before monitoring cross section i, that is:

${\mathrm{\θ}}_i=\underset{j=1}{\overset{i}{\mathrm{\Σ}}}{\mathrm{\θ}}_j^{*}---\left(5\right)$

Before monitoring cross section i, in this sub-pipes, any one monitors the relative rotation of cross section j, by following formulae discovery:

Wherein, D is the diameter of sub-pipes i; H is the distance between adjacent monitoring cross section;

(3) by step (2) mode, calculate the amount of deflection derivative value in sub-pipes m monitoring cross section respectively, count w ' respectively ₁, w ' ₂w ' _m;

(4) after obtaining discrete m amount of deflection derivative value, adopt numerical computation method to calculate m amount of deflection derivative value, reduction obtains the combined deflection value of sub-pipes.

Preferably, described remote monitoring center also comprises sub-pipes monitoring modular, system function module and analysis report module;

Wherein, the real-time stress value uploaded for the fiber-optic grating sensor receiving each monitoring point of described Monitoring Pinpelines module;

Described system function module comprises systems management submodule, server resource management submodule, network connection management submodule and system log management submodule;

Described analysis report module comprises: every day, assessment report generated submodule, healthy trend report generation submodule, emergent report generation submodule and instant report generation submodule;

Wherein, described assessment report generation every day submodule is used for: according to the combined deflection value of the sub-pipes that described bending deflection of pipe calculating sub module calculates, the health status of assessment this sub-pipes on the same day;

Described healthy trend report generates submodule and is used for: the result generated according to described assessment report generation every day submodule, sums up sub-pipes history health status situation, generates the healthy trend of this sub-pipes in following certain hour;

Described emergent report generation submodule is used for: the healthy trend generating the sub-pipes that submodule generates according to described healthy trend report, judge whether this sub-pipes is dangerous in future certain hour, if had, then generate the emergent report of measure scheme characterizing this sub-pipe risk factor and can take;

Described instant report generation submodule is used for: according to the combined deflection value of the sub-pipes that described bending deflection of pipe calculating sub module calculates, and generates the report of this sub-pipes current health state in real time.

Beneficial effect of the present invention is as follows:

The invention provides distributed monitoring system and the monitoring method of the strain of a kind of long distance pipeline Crossover phase, can be used for a certain segment pipe of look-ahead and whether there is hidden danger, if there is hidden danger, can notify that related personnel takes measures on customs clearance in advance, avoid pipeline actual generation security incident, improve the Security of conduit running.

Accompanying drawing explanation

Fig. 1 is the network architecture diagram of the distributed monitoring system of long distance pipeline Crossover phase provided by the invention strain;

Fig. 2 is the structural representation of remote monitoring center provided by the invention;

Fig. 3 is the mounting structure schematic diagram of the clipping fiber Bragg grating strain sensor of Type of Welding;

Fig. 4 is the stressing conditions figure of sensor parts;

Fig. 5 is the left-half structural representation adopting stickup form fixation of sensor;

Fig. 6 is the force analysis schematic diagram of sensor parts and glue line;

Fig. 7 is that conduit axis bends schematic diagram.

Embodiment

Below in conjunction with accompanying drawing, the present invention is described in detail:

The invention provides the distributed monitoring system of a kind of long distance pipeline Crossover phase strain, can monitor in real time long distance oil-gas conveyance conduit, the current working state of real-time acquisition long distance pipeline, thus the potential safety hazard that Timeliness coverage long distance pipeline exists, ensure normally carrying out of productive life; In addition, the Historical Monitoring data reduction of long distance pipeline can also be got up, form monitoring historical record, for the design of long distance pipeline, manufacture and safe operation provide basic data, for the life appraisal of long distance pipeline and safety evaluation provide new monitoring means, ensure the long period safe operation of long distance pipeline, better serve socio-economic development.

Concrete, as shown in Figure 1, for the network architecture diagram of the distributed monitoring system of long distance pipeline Crossover phase strain provided by the invention, for two distributed nodes in figure, comprise: remote monitoring center and several distributed nodes, distributed node described in each carries out information interaction by signal transmission system and described remote monitoring center;

Each distributed node is arranged in the following ways:

Monitored long distance pipeline is divided in the axial direction n sub-pipes; For any one sub-pipes i, equidistant in the axial direction w the monitoring cross section perpendicular to axis is set, 4 monitoring points are arranged in each monitoring cross section, that is: a fiber-optic grating sensor is respectively installed at the Up Highway UHW in described monitoring cross section, Down Highway, left bus and right bus place; The all fiber-optic grating sensors be arranged on sub-pipes i form a distributed node with the data capture and pre-treater being arranged on sub-pipes i this locality.

Wherein, fiber-optic grating sensor installs in the lump with during pipeline laying construction, primarily of fiber-optic grating sensor and relevant secondary component and high reliability industry control element composition.The outer surface of tube wall of fiber-optic grating sensor and monitored sub-pipes fits tightly installation, thus can gather the original strain information fitting tightly tube wall with it more accurately; In the present invention, following two kinds of mounting types between the outer surface of tube wall of fiber-optic grating sensor and monitored sub-pipes, can be adopted: welded and installed mode or paste mounting type.

Data capture and pre-treater can be arranged at the pipe end by special geology location, for receiving the original strain information that each fiber-optic grating sensor sends, and according to system functional requirement, the data prediction such as decomposition transform are carried out to described original strain information, obtain the real-time strain information in monitoring point be applicable to after the process of transmission and analysis further;

Signal transmission system is used for: real-time for described monitoring point strain information is stored in this locality; Meanwhile, complete, accurate, real-time for the real-time strain information in monitoring point after data capture and pre-treater process is sent to described remote monitoring center.The multiple transmission means of taking that can suit measures to local conditions communicates, in view of most of pipeline is all more severe, the meagrely-populated regions of physical environment by region, again in conjunction with the dispersion of pipeline measuring point, the feature that data traffic is little, preferably takes the wireless communication mode of the GPRS technology based on maturation.In location with good conditionsi, more reliable wire communication mode also can be taked to communicate with remote monitoring center.

The machine room of remote monitoring center mainly should be equipped with the equipment such as big-and-middle-sized server, supervisory control comuter, data storage, drawing printing, standby power supply.The software systems of remote monitoring center as shown in Figure 2, major function is: revise field measurement data, obtains revised strain information, then carries out computational analysis to it, obtain pipe deforming real-time condition, thus judge pipe deforming trend, make pipe deforming health evaluating report.Mainly comprise: pipe deforming computing module, sub-pipes monitoring modular, system function module and analysis report module; Major function is concentrated on an interface, facilitates user to select different functions of modules according to demand.

The final purpose of remote monitoring center is: the actual conditions obtaining pipe deforming according to the field measurement data collected, and core component is pipe deforming computing module; Wherein, described pipe deforming computing module comprises sub module stored, the strain calculation submodule of Type of Welding sensor, the strain calculation submodule pasting form sensor and bending deflection of pipe calculating sub module.The core algorithm of strain calculation of the present invention is based on the theoretical formula studied herein, and the many factors such as the strain transfer error that in comprehensive reality, different conduit types, sensor installation form cause are improved through error correction.In the present invention, the automatic calculation method of monitored sub-pipes stress can be adopted, also can adopt monitored sub-pipes stress manual calculations mode.When the automatic calculation method of the monitored sub-pipes stress of employing, the relevant parameter that strain calculation submodule Automatically invoked sub module stored stores, then calculates the stress modifier value of monitored sub-pipes automatically; When adopting monitored sub-pipes stress manual calculations mode, eject the inputting interface of all kinds of parameter, user, according to the actual parameter of monitored sub-pipes, manually inputs relevant parameter, then can calculate the stress modifier value of monitored sub-pipes.

Below the function of above-mentioned a few seed module is introduced respectively in detail:

(1) sub module stored

Sub module stored is for storing the corresponding relation between sub-pipes ID and sub-pipes attribute; Wherein, described sub-pipes attribute comprises fiber-optic grating sensor mounting type and sub-pipes essential information on the geographical position at sub-pipes place, sub-pipes; Wherein, described mounting type comprises two kinds: fiber-optic grating sensor is arranged on sub-pipes by Type of Welding, and fiber-optic grating sensor is arranged on sub-pipes by stickup form.Sub-pipes essential information is mainly the installation parameter information of sub-pipes, and for different mounting types, the installation parameter information stored is not identical yet.

For the sub-pipes of erecting and welding form sensor, the essential information of described sub-pipes comprises:

L ₁: optical fiber adhesive layer partial-length;

L ₂: optical fiber is without adhesive tape sections length;

L ₃: immovable point distance tip lengths:

R ₁: the outer radius of encapsulation steel pipe;

R ₂: the inside radius of encapsulation steel pipe, i.e. glue-line outer radius;

R ₃: fiber radius;

E _x: the Young's modulus of optical fiber;

E _g: the Young's modulus of sensor steel pipe;

E _j: the Young's modulus in mesosphere;

ε _s: the real-time strain value that fiber bragg grating measurement obtains;

G _jfor the shear modulus of glue line;

Wherein, for the sub-pipes installing stickup form sensor, the essential information of described sub-pipes comprises:

L ₁: optical fiber adhesive layer partial-length;

L ₂: optical fiber is without adhesive tape sections length;

L ₃: immovable point distance tip lengths:

R ₁: the outer radius of encapsulation steel pipe;

R ₂: the inside radius of encapsulation steel pipe, i.e. glue-line outer radius;

R ₃: fiber radius;

E _x: the Young's modulus of optical fiber;

E _g: the Young's modulus of sensor steel pipe;

E _j: the Young's modulus in mesosphere;

G _jfor the shear modulus of glue line;

ε _s: the real-time strain value that fiber bragg grating measurement obtains;

H ₁for the thickness of glue line;

H ₂for the thickness sum of glue line and substrate;

E _jpfor the Young's modulus of substrate;

G _jcfor the shear modulus of glue line;

L ₅for substrate end and steel tube end part distance;

L ₆for immovable point and the other end steel tube end part distance.

That is, each installation parameter information that sub module stored stores, is known parameters, calculates input parameter when sub-pipes strains for follow-up strain calculation submodule.

(2) the strain calculation submodule of Type of Welding sensor

The strain calculation submodule of Type of Welding sensor is used for:

Read described sub module stored, find the sub-pipes essential information corresponding with it based on sub-pipes ID; Then by strain value ε that the relevant parameter in the sub-pipes essential information found and the measured point place fiber bragg grating measurement that receives obtain _ssubstitute into following formula, try to achieve the strain value ε at revised measured point place _t:

$\begin{array}{c}{\mathrm{\ϵ}}_t=\frac{{\mathrm{\Δl}}_2+2{\mathrm{\Δl}}_x}{l_2+2(l_1-l_3)}\\ =\frac{l_2+\{\frac{e^{{\mathrm{Kl}}_1}-e^{K{l}_3}}{K}-l_1+l_3+\frac{(1-e^{{\mathrm{Kl}}_1})[\mathrm{ch}\left({\mathrm{Kl}}_1\right)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)]}{\mathrm{Ksh}\left({\mathrm{Kl}}_1\right)}\}\frac{2\mathrm{ch}\left({\mathrm{Kl}}_3\right)}{\mathrm{ch}({\mathrm{Kl}}_1+{\mathrm{Kl}}_3)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)}}{l_2+2(l_1-l_3)}{\mathrm{\ϵ}}_s\\ +\frac{\frac{2[\mathrm{ch}\left({\mathrm{Kl}}_1\right)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)]}{\mathrm{Ksh}\left({\mathrm{Kl}}_1\right)}}{l_2+2(l_1-l_3)}{\mathrm{\ϵ}}_s\end{array}---\left(34\right)$

Wherein, $K=\sqrt{\frac{\frac{r_3^2{E}_x+(r_2^2-r_3^2)E_j}{(r_1^2-r_2^2)E_g}}{\frac{1}{G_j}[\frac{E_j}{4}(r_2^2-r_3^2)+\frac{r_3^2}{2}(E_x-E_j)\ln \frac{r_2}{r_3}]}}---\left(25\right)$

Introduce the derivation of formula (34) below:

As shown in Figure 3, the mounting structure schematic diagram for the clipping fiber Bragg grating strain sensor of Type of Welding: wherein, 1-glue-line; 2-fiber-optic grating sensor; 3-matrix; The copper pipe that 4-is connected with matrix; 5-optical fiber; 6-immovable point; 7-center line; In the holding element region at two ends, be the region of strain transfer, holding element is fixed on measured article surface, by the transmission of glue line, makes optical fiber produce strain, then carries out measurement acquisition strain value.As can see from Figure 6, fiber-optic grating sensor does not directly contact with glue line, and fiber bragg grating is sensor, strains the optical fiber encapsulated by two ends and transmits.

Because sensor is symmetrical, so get left-half to carry out force analysis.Fig. 4 is the stressing conditions of sensor parts.

The infinitesimal getting length dx carries out force analysis, and the equation of equilibrium of optical fiber is:

$\left(\mathrm{\π}{r}_3^2\right)\·{\mathrm{\σ}}_x=\left({\mathrm{\πr}}_3^2\right)\·({\mathrm{\σ}}_x+d{\mathrm{\σ}}_x)+(2{\mathrm{\πr}}_3\·\mathrm{dx})\·{\mathrm{\τ}}_x(x,r_3)---\left(8\right)$

In formula, r ₃for the radius of optical fiber;

σ _xfor the stress of optical fiber;

τ _x(x, r ₃) be the shearing stress of optical fiber surface.

After arrangement, formula (8) is written as:

${\mathrm{\τ}}_x(x,r_3)=-\frac{r_3}{2}\frac{{\mathrm{d\σ}}_x}{\mathrm{dx}}---\left(9\right)$

Analyze glue line, representation is:

$\mathrm{\π}(r^2-r_3^2)\·{\mathrm{\σ}}_j+(2\mathrm{\π}{r}_3\·\mathrm{dx})\·{\mathrm{\τ}}_x(x,r_3)=\mathrm{\π}(r^2-r_3^2)\·({\mathrm{\σ}}_j+d{\mathrm{\σ}}_j)+(2\mathrm{\πr}\·\mathrm{dx})\·{\mathrm{\τ}}_j(x,r)---\left(10\right)$

In formula, r is the radius of random layer in intermediate gelatine layer;

σ _jfor the stress of intermediate gelatine layer;

τ _jthe shearing stress that (x, r) is intermediate gelatine layer.

Arrangement formula obtains after (10):

${\mathrm{\τ}}_j(x,r)=\frac{r_3}{r}\·{\mathrm{\τ}}_x(x,r_3)-\frac{r^2-r_3^2}{2r}\·\frac{d{\mathrm{\σ}}_j}{\mathrm{dx}}---\left(11\right)$

The steel pipe used for packaged fiber is analyzed:

$\mathrm{\π}(r_1^2-r_2^2)\·{\mathrm{\σ}}_g+(2\mathrm{\π}{r}_2\·\mathrm{dx})\·{\mathrm{\τ}}_j(x,r_2)=\mathrm{\π}(r_1^2-r_2^2)\·({\mathrm{\σ}}_g+d{\mathrm{\σ}}_g)---\left(12\right)$

In formula, r ₁for encapsulating the outer radius of steel pipe;

R ₂for encapsulating the inside radius of steel pipe;

σ _gfor the stress of steel pipe.

Arrangement formula obtains after (12):

$\begin{array}{c}{\mathrm{\τ}}_j(x,r_2)=\frac{r_1^2-r_2^2}{{2r}_2}\frac{{\mathrm{d\σ}}_g}{\mathrm{dx}}\\ =\frac{r_1^2-r_2^2}{2r_2}\·E_g\·\frac{d{\mathrm{\ϵ}}_g}{\mathrm{dx}}\end{array}---\left(13\right)$

In formula, E _gfor encapsulating the Young's modulus of steel pipe;

ε _gfor encapsulating the strain of steel pipe.

Formula (10) is substituted into formula (12) arrange, because optical fiber is out of shape together with glue line, is similar to and thinks that both rate of strains are equal, this condition is substituted into and derives, obtain:

$\begin{array}{c}{\mathrm{\τ}}_j(x,r)=\frac{r_3}{r}\·(-\frac{r_3}{2}\frac{d{\mathrm{\σ}}_x}{\mathrm{dx}})-\frac{r^2-r_3^2}{2r}\·\frac{d{\mathrm{\σ}}_j}{\mathrm{dx}}\\ =-\frac{r_3^2}{2r}\·E_x\frac{d{\mathrm{\ϵ}}_x}{\mathrm{dx}}-\frac{r^2-r_3^2}{2r}\·E_j\frac{d{\mathrm{\ϵ}}_j}{\mathrm{dx}}\\ =(-\frac{r_3^2}{2r}\·E_x-\frac{r^2-r_3^2}{2r}\·E_j)\frac{d{\mathrm{\ϵ}}_x}{\mathrm{dx}}\end{array}---\left(14\right)$

In formula, ε _xfor fibre strain;

E _jfor the Young's modulus of glue line;

ε _jfor the strain of glue line.

The slenderness ratio of optical fiber is very large, ignores its radial displacement, can obtain:

$G_j\frac{\∂u}{\∂r}\≈{\mathrm{\τ}}_j(x,r)=(-\frac{r_3^2}{2r}\·E_x-\frac{r^2-r_3^2}{2r}\·E_j)\frac{d{\mathrm{\ϵ}}_x}{\mathrm{dx}}---\left(15\right)$

In formula, G _jfor the shear modulus of glue line;

U is the axial displacement of glue line.

Quadrature to r in equation (15) both sides simultaneously, shown in (16):

${\∫}_{r_3}^{r_2}\left(G_j\frac{\∂u}{\∂r}\right)\mathrm{dr}={\∫}_{r_3}^{r_2}\left[(-\frac{r_3^2}{2r}\·E_x-\frac{r^2-r_3^2}{2r}\·E_j)\frac{d{\mathrm{\ϵ}}_x}{\mathrm{dx}}\right]\mathrm{dr}---\left(16\right)$

Carry out integral and calculating, arrange the relation obtaining displacement and strain:

$u_g-u_x=-\frac{1}{G_j}[\frac{E_j}{4}(r_3^2-r_3^2)+\frac{r_3^2}{2}(E_x-E_j)\ln \frac{r_2}{r_3}]\frac{d{\mathrm{\ϵ}}_x}{\mathrm{dx}}---\left(17\right)$

In formula, u _gfor encapsulating the axial displacement of steel pipe;

U _xfor the axial displacement of optical fiber.

Analyze formula (17), axial displacement belongs to unknown quantity, and strain can be obtained by measurement, and displacement is converted to strain and just can solve, so both members asks two subderivatives to x simultaneously, process is as follows:

${\mathrm{\ϵ}}_g-{\mathrm{\ϵ}}_x=-\frac{1}{G_j}[\frac{E_j}{4}(r_2^2-r_3^2)+\frac{r_3^2}{2}(E_x-E_j)\ln \frac{r_2}{r_3}]\frac{d^2{\mathrm{\ϵ}}_x}{d{x}^2}---\left(18\right)$

$\frac{d{\mathrm{\ϵ}}_g}{\mathrm{dx}}-\frac{d{\mathrm{\ϵ}}_x}{\mathrm{dx}}=-\frac{1}{G_j}[\frac{E_j}{4}(r_2^2-r_3^2)+\frac{r_3^2}{2}(E_x-E_j)\ln \frac{r_2}{r_3}]\frac{d^3{\mathrm{\ϵ}}_x}{d{x}^3}---\left(19\right)$

Work as r=r ₂time, formula (14) can be written as:

${\mathrm{\τ}}_j(x,r_2)=-(\frac{r_3^2}{2r_2}\·E_x+\frac{r_2^2-r_3^2}{2r_2}\·E_j)\frac{d{\mathrm{\ϵ}}_x}{\mathrm{dx}}---\left(20\right)$

Following relation is obtained with formula (13) simultaneous:

${\mathrm{\τ}}_j(x,r_2)=\frac{r_1^2-r_2^2}{2r_2}\·E_g\frac{d{\mathrm{\ϵ}}_g}{\mathrm{dx}}=-(\frac{r_3^2}{2r_2}\·E_x+\frac{r_2^2-r_3^2}{2r_2}\·E_j)\frac{d{\mathrm{\ϵ}}_x}{\mathrm{dx}}---\left(21\right)$

Arrangement formula (21), obtains the relation of fibre strain rate and steel pipe rate of strain:

$\frac{d{\mathrm{\ϵ}}_g}{\mathrm{dx}}=-\frac{r_3^2{E}_x+(r_2^2-r_3^2)E_j}{(r_1^2-r_2^2)E_g}\frac{{\mathrm{d\ϵ}}_x}{\mathrm{dx}}---\left(22\right)$

Formula (22) is substituted into formula (19), the calculating formula obtained about fibre strain of deriving:

$\frac{d^3{\mathrm{\ϵ}}_x}{{\mathrm{dx}}^3}=\frac{\frac{r_3^2{E}_x+(r_2^2-r_3^2)E_j}{(r_1^2-r_2^2)E_g}+1}{\frac{1}{G_j}[\frac{E_j}{4}(r_2^2-r_3^2)+\frac{r_3^2}{2}(E_x-E_j)\ln \frac{r_2}{r_3}]}\frac{{\mathrm{d\ϵ}}_x}{\mathrm{dx}}---\left(23\right)$

Because research to as if strain value, so mathematical method will be utilized to be strained, integration is carried out to formula (23), obtain a Second Order with Constant Coefficients nonhomogeneous linear equation such as formula shown in (24), in order to reduced equation, setting parameter K, its representation is shown in formula (25), wherein C ₃for arbitrary constant:

$\frac{d^2{\mathrm{\ϵ}}_x}{{\mathrm{dx}}^2}-K^2{\mathrm{\ϵ}}_x=C_3---\left(24\right)$

$K=\sqrt{\frac{\frac{r_3^2{E}_x+(r_2^2-r_3^2)E_j}{(r_1^2-r_2^2)E_g}+1}{\frac{1}{G_j}[\frac{E_j}{4}(r_2^2-r_3^2)+\frac{r_3^2}{2}(E_x-E_j)\ln \frac{r_2}{r_3}]}}---\left(25\right)$

Utilize characteristic equation method to calculate equation equally, obtain non trivial solution:

${\mathrm{\ϵ}}_x=C_4{e}^{\mathrm{Kx}}+C_5{e}^{-\mathrm{Kx}}-\frac{C_3}{K^2}---\left(26\right)$

In formula, C ₄, C ₅for arbitrary constant.

True origin place optical fiber is free end face, does not have Stress transmit phenomenon to occur, and at the other end of bonding packaging area, the strain facies that the strain of optical fiber and fiber bragg grating are measured is same, calculates, can obtain C so substitute into boundary conditions formula (27) ₄, C ₅representation, shown in (28):

$\left\{\begin{array}{cc}{\mathrm{\ϵ}}_x=0& (x=0)\\ {\mathrm{\ϵ}}_x={\mathrm{\ϵ}}_s& (x=l_1)\end{array}\right.---\left(27\right)$

$\begin{array}{c}{C}_4=\frac{C_3}{K^2}+\frac{{\mathrm{\ϵ}}_s+(1-e^{{\mathrm{Kl}}_1})\frac{C_3}{K^2}}{2\mathrm{sh}\left({\mathrm{Kl}}_1\right)}\\ C_5=\frac{{\mathrm{\ϵ}}_s+(1-e^{{\mathrm{Kl}}_1})\frac{C_3}{K^2}}{-2\mathrm{sh}\left({\mathrm{kl}}_1\right)}\end{array}---\left(28\right)$

Therefore, can write out containing constant C ₃fibre strain representation, and the representation of rate of strain:

${\mathrm{\ϵ}}_x=[\frac{C_3}{K^2}+\frac{{\mathrm{\ϵ}}_s+(1-e^{{\mathrm{Kl}}_1})\frac{C_3}{K^2}}{2\mathrm{sh}\left({\mathrm{Kl}}_1\right)}]e^{\mathrm{Kx}}+\left[\frac{{\mathrm{\ϵ}}_s+(1-e^{{\mathrm{Kl}}_1})\frac{C_3}{K^2}}{-2\mathrm{sh}\left({\mathrm{Kl}}_1\right)}\right]e^{-\mathrm{Kx}}-\frac{C_3}{K^2}---\left(29\right)$

$\frac{{\mathrm{d\ϵ}}_x}{\mathrm{dx}}=K\left\{\right[\frac{C_3}{K^2}+\frac{{\mathrm{\ϵ}}_s+(1-e^{{\mathrm{Kl}}_1})\frac{C_3}{K^2}}{2\mathrm{sh}\left({\mathrm{Kl}}_1\right)}]e^{\mathrm{Kx}}-[\frac{{\mathrm{\ϵ}}_s+(1-e^{{\mathrm{Kl}}_1})\frac{C_3}{K^2}}{-2\mathrm{sh}\left({\mathrm{Kl}}_1\right)}\left]e^{-\mathrm{Kx}}\right\}---\left(30\right)$

In the position that steel-pipe welding is fixing, suppose that the displacement of optical fiber is identical with the displacement of steel pipe, be written as known conditions:

u _x(l ₃)-u _g(l ₃)＝0(31)

Formula (30), formula (31) are substituted in formula (17), calculate and solve constant:

$C_3=\frac{K^2\mathrm{ch}\left({\mathrm{Kl}}_3\right)}{\mathrm{ch}({\mathrm{Kl}}_1+{\mathrm{Kl}}_3)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)}{\mathrm{\ϵ}}_s---\left(32\right)$

Constant C ₃, C ₄, C ₅after having solved, just can write out complete fibre strain representation, to representation integration, derivation fiber lengths variable quantity, calculating formula is such as formula (33):

$\begin{array}{c}{\mathrm{\Δl}}_x={\∫}_{l_3}^{l_1}{\mathrm{\ϵ}}_x\mathrm{dx}\\ =\{\frac{e^{{\mathrm{Kl}}_1}-e^{{\mathrm{Kl}}_3}}{K}-l_1+l_3+\frac{(1-e^{{\mathrm{Kl}}_1})[\mathrm{ch}\left({\mathrm{Kl}}_1\right)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)]}{\mathrm{Ksh}\left({\mathrm{Kl}}_1\right)}\}\frac{\mathrm{ch}\left({\mathrm{Kl}}_3\right)}{\mathrm{ch}({\mathrm{Kl}}_1+{\mathrm{Kl}}_3)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)}{\mathrm{\ϵ}}_s\\ +\frac{\mathrm{ch}\left({\mathrm{Kl}}_1\right)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)}{\mathrm{Ksh}\left({\mathrm{Kl}}_1\right)}{\mathrm{\ϵ}}_s\end{array}---\left(33\right)$

Be welded and fixed a little, supposing that optical fiber and steel pipe, testee do not have relative displacement, write out the resistance strain gauge formula of testee according to this assumed condition:

$\begin{array}{c}{\mathrm{\ϵ}}_t=\frac{\mathrm{\Δ}{l}_2+2\mathrm{\Δ}{l}_x}{l_2+2(l_1-l_3)}\\ =\frac{l_2+\{\frac{e^{{\mathrm{Kl}}_1}-e^{{\mathrm{Kl}}_3}}{K}-l_1+l_3+\frac{(1-e^{{\mathrm{Kl}}_1})[\mathrm{ch}\left({\mathrm{Kl}}_1\right)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)]}{\mathrm{Ksh}\left({\mathrm{Kl}}_1\right)}\}\frac{2\mathrm{ch}\left({\mathrm{Kl}}_3\right)}{\mathrm{ch}({\mathrm{Kl}}_1+{\mathrm{Kl}}_3)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)}}{l_2+2(l_1-l_3)}{\mathrm{\ϵ}}_s\\ +\frac{\frac{2[\mathrm{ch}\left({\mathrm{Kl}}_1\right)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)}{\mathrm{Ksh}\left({\mathrm{Kl}}_1\right)}}{l_2+2(l_1-l_3)}{\mathrm{\ϵ}}_s\end{array}$

(34)

In formula, Δ l ₂represent the length change amount not contacting the fiber section of glue line.

Can see that the strain of testee is relevant with the monitor strain of fiber bragg grating by resistance strain gauge formula, in addition, also with make the material property of sensor, every size, mounting point are relevant, as long as determine parameters just can according to calculating formula solve obtain revise strain, the i.e. strain value of more approaching to reality strain, can also for improvement of the preparation process of sensor and the link such as selection making material.Strain tentative calculation is carried out according to formula (34).

(3) the strain calculation submodule of form sensor is pasted

The strain calculation submodule of stickup form sensor is used for:

Read described sub module stored, find the sub-pipes essential information corresponding with it based on sub-pipes ID; Then by strain value ε that the relevant parameter in the sub-pipes essential information found and the measured point place fiber bragg grating measurement that receives obtain _ssubstitute into following formula, try to achieve the strain value ε at revised measured point place _t:

$\begin{array}{c}{\mathrm{\ϵ}}_t=\frac{l_2{\mathrm{\ϵ}}_s+2\mathrm{\Δ}{l}_x+2[u_{\mathrm{jp}}\left(l_3\right)-u_{\mathrm{mt}}\left(l_3\right)]}{l_2+2(l_1-l_3)}\\ =\frac{l_2+\{\frac{e^{{\mathrm{Kl}}_1}-e^{{\mathrm{Kl}}_3}}{K}-l_1+l_3+\frac{(1-e^{{\mathrm{Kl}}_1})[\mathrm{ch}\left({\mathrm{Kl}}_1\right)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)]}{\mathrm{Ksh}\left({\mathrm{Kl}}_1\right)}\}\frac{2\mathrm{ch}\left({\mathrm{Kl}}_3\right)}{\mathrm{ch}({\mathrm{Kl}}_1+{\mathrm{Kl}}_3)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)}}{l_2+2(l_1-l_3)-\frac{(h_2-h_1)h_1{E}_{\mathrm{jp}}T}{G_{\mathrm{jc}}}[\frac{e^{-T(l_3+l_6)}-e^{{\mathrm{Tl}}_5}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{e}^{{\mathrm{Tl}}_3}-\frac{e^{{-\mathrm{Tl}}_5}-e^{T(l_3+l_6)}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{e}^{-{\mathrm{Tl}}_3}]}{\mathrm{\ϵ}}_s\\ +\frac{\frac{2[\mathrm{ch}\left({\mathrm{Kl}}_1\right)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)]}{\mathrm{Ksh}\left({\mathrm{Kl}}_1\right)}}{l_2+2(l_1-l_3)-\frac{(h_2-h_1)h_1{E}_{\mathrm{jp}}T}{G_{\mathrm{jc}}}[\frac{e^{-T(l_3+l_6)}-e^{T{l}_5}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{e}^{{\mathrm{Tl}}_3}-\frac{e^{-{\mathrm{Tl}}_5}-e^{T(l_3+l_6)}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{e}^{-{\mathrm{Tl}}_3}]}{\mathrm{\ϵ}}_s\end{array}---\left(53\right)$

Wherein: $T=\sqrt{\frac{2G_{\mathrm{jc}}}{(h_2-h_1)h_1{E}_{\mathrm{jp}}}}---\left(46\right)$

$K=\sqrt{\frac{\frac{r_3^2{E}_x+(r_2^2-r_3^2)E_j}{(r_1^2-r_2^2)E_g}+1}{\frac{1}{G_j}[\frac{E_j}{4}(r_2^2-r_3^2)+\frac{r_3^2}{2}(E_x-E_j)\ln \frac{r_2}{r_3}]}}---\left(25\right)$

Introduce the derivation of formula (53) below:

As shown in Figure 5, for adopting the left-half structural representation of stickup form fixation of sensor, 8-substrate; Other figure notation implication is identical with Fig. 3; Holding element and packaged fiber steel pipe used, be cylindrical body so be not suitable for directly being bonded in testee surface due to steel pipe, usually substrate sections is had in the outside of steel pipe, be made up of two orthogonal tinsels, substrate is fixed on steel pipe, another part vertical is with it bonded in testee surface, effectively can increase bond area like this, sensor is installed more firm.After sensor installs, the strain of testee is delivered on optical fiber by glue line, holding element, encapsulation glue-line, part strain can be lost in this process, so need to study strain transfer, determine optical fiber measurement strain and the relation of tested matrix actual strain, obtain strain information accurately.

Sensor is arranged on testee, due to symmetrical configuration, so get half analysis.Fig. 6 is the force analysis schematic diagram of sensor parts and glue line.

Getting length is that the infinitesimal of dx is analyzed, and the correlation derivation of optical fiber, encapsulation glue-line and steel pipe can be analyzed with reference to the strain transducer transmission of Type of Welding, first analyzes substrate sections, the wide and glue line of substrate wide equal, is set to W _d, the force analysis of substrate is such as formula (35):

W _d·(h ₂-h ₁)·σ _jp+(W _d·dx)·τ _jc(x,h ₁)＝W _d·(h ₂-h ₁)·(σ _jp+dσ _jp)(35)

In formula, h ₁for the thickness of glue line;

H ₂for the thickness sum of glue line and substrate;

σ _jpfor the stress of substrate;

τ _jc(x, h ₁) be the shearing stress of glue line.

Arrange above formula, obtain h ₁the shearing stress representation at floor height place:

${\mathrm{\τ}}_{\mathrm{jc}}(x,h_1)=(h_2-h_1)\frac{d{\mathrm{\σ}}_{\mathrm{jp}}}{\mathrm{dx}}---\left(36\right)$

Glue line is analyzed, lists balance differential equation:

(W _d·h)·σ _jc＝(W _d·dx)·τ _jc(x,h)+(W _d·h)·(σ _jc+dσ _jc)(37)

In formula, h is the random layer height of glue line;

σ _jcfor the stress of glue line.

Abbreviation is carried out to formula (37), obtains the representation of shearing stress:

${\mathrm{\τ}}_{\mathrm{jc}}(x,h)=-h\frac{d{\mathrm{\σ}}_{\mathrm{jc}}}{\mathrm{dx}}---\left(38\right)$

Work as h=h ₁time, simultaneous formula (36) and with formula (38), obtain the relation between substrate and glue line stress:

$\frac{{\mathrm{d\σ}}_{\mathrm{jc}}}{\mathrm{dx}}=\frac{h_1-h_2}{h_1}\frac{d{\mathrm{\σ}}_{\mathrm{jp}}}{\mathrm{dx}}---\left(39\right)$

Can write out thus with substrate stress σ _jpthe Calculation Shear formula expressed:

$\begin{array}{c}{\mathrm{\τ}}_{\mathrm{jc}}(x,h)=\frac{(h_2-h_1)h}{h_1}\·\frac{{\mathrm{d\σ}}_{\mathrm{jp}}}{\mathrm{dx}}\\ =\frac{(h_2-h_1)h}{h_1}\·E_{\mathrm{jp}}\·\frac{{\mathrm{d\ϵ}}_{\mathrm{jp}}}{\mathrm{dx}}\end{array}---\left(40\right)$

In formula, E _jpfor the Young's modulus of substrate;

ε _jpfor the strain of substrate.

Because glue line axial length is greater than thickness direction, so ignore the thickness direction displacement of glue-line, the shearing stress representation of glue-line is rewritten as:

${\mathrm{\τ}}_{\mathrm{jc}}(x,h)\≈G_{\mathrm{jc}}\frac{\∂u}{\∂h}=\frac{(h_2-h_1)h}{h_1}\·E_{\mathrm{jp}}\·\frac{{\mathrm{d\ϵ}}_{\mathrm{jp}}}{\mathrm{dx}}---\left(41\right)$

In formula, G _jcfor the shear modulus of glue line.

Integration is carried out to h in formula (41) both sides simultaneously, obtains the calculating formula of shifted version:

${\∫}_0^{h_1}\left(G_{\mathrm{jc}}\frac{\∂u}{\∂h}\right)\mathrm{dh}={\∫}_0^{h_1}[\frac{(h_2-h_1)h}{h_1}\·E_{\mathrm{jp}}\·\frac{{\mathrm{d\ϵ}}_{\mathrm{jp}}}{\mathrm{dx}}]\mathrm{dh}---\left(42\right)$

Carry out integral and calculating, arrange the relation obtaining displacement and rate of strain:

$G_{\mathrm{jc}}(u_{\mathrm{jp}}-u_{\mathrm{mt}})=\frac{(h_2-h_1)h_1}{2}\·E_{\mathrm{jp}}\·\frac{d{\mathrm{\ϵ}}_{\mathrm{jp}}}{\mathrm{dx}}---\left(43\right)$

In formula, u _jpfor substrate axial displacement;

U _mtfor stick type measures the axial displacement of tested matrix.

Because displacement cannot be obtained by measurement means, so displacement will be converted to strain just can proceed calculating of deriving, namely above formula both sides are to x differentiate, obtain the relation between strain:

$\frac{d^2{\mathrm{\ϵ}}_{\mathrm{jp}}}{{\mathrm{dx}}^2}-\frac{2G_{\mathrm{jc}}}{(h_2-h_1)h_1{E}_{\mathrm{jp}}}{\mathrm{\ϵ}}_{\mathrm{jp}}=-\frac{{2G}_{\mathrm{jc}}}{(h_2-h_1)h_1{E}_{\mathrm{jp}}}{\mathrm{\ϵ}}_{\mathrm{mt}}---\left(44\right)$

With reference to the solution of Second Order with Constant Coefficients nonhomogeneous linear equation, solve formula (44).If a parameter T, so equation can be reduced to:

$\frac{d^2{\mathrm{\ϵ}}_{\mathrm{jp}}}{{\mathrm{dx}}^2}-T^2{\mathrm{\ϵ}}_{\mathrm{jp}}={-T}^2{\mathrm{\ϵ}}_{\mathrm{mt}}---\left(45\right)$

$T=\sqrt{\frac{{2G}_{\mathrm{jc}}}{(h_2-h_1)h_1{E}_{\mathrm{jp}}}}---\left(46\right)$

Select characteristic equation method solving equation, obtain non trivial solution representation:

ε _jp＝C ₆e ^Tx+C ₇e ^-Tx+ε _mt(47)

In formula, C ₆, C ₇for arbitrary constant.

The two ends of substrate are free interface, and substitute into non trivial solution as boundary conditions and calculate, solve parameter, the representation of boundary conditions and parameter is:

$\left\{\begin{array}{cc}{\mathrm{\ϵ}}_{\mathrm{jp}}=0& (x=-l_5)\\ {\mathrm{\ϵ}}_{\mathrm{jp}}=0& (x=l_3+l_6)\end{array}\right.---\left(48\right)$

$\begin{array}{c}{C}_6=\frac{e^{-T(l_3+l_6)}-e^{{\mathrm{Tl}}_5}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{\mathrm{\ϵ}}_{\mathrm{mt}}\\ C_7=\frac{e^{{-\mathrm{Tl}}_5}-e^{T(l_3+l_6)}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{\mathrm{\ϵ}}_{\mathrm{mt}}\end{array}---\left(49\right)$

Representation and the derivative form thereof of substrate strain can be write out after obtaining parameter:

${\mathrm{\ϵ}}_{\mathrm{jp}}=[\frac{e^{-T(l_3+l_6)}-e^{{\mathrm{Tl}}_5}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{e}^{\mathrm{Tx}}+\frac{e^{{-\mathrm{Tl}}_5}-e^{T(l_3+l_6)}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{e}^{-\mathrm{Tx}}+1]{\mathrm{\ϵ}}_{\mathrm{mt}}---\left(50\right)$

$\frac{{\mathrm{d\ϵ}}_{\mathrm{jp}}}{\mathrm{dx}}=T\{\frac{e^{-T(l_3+l_6)}-e^{{\mathrm{Tl}}_5}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{e}^{\mathrm{Tx}}-\frac{e^{{-\mathrm{Tl}}_5}-e^{T(l_3+l_6)}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{e}^{-\mathrm{Tx}}\}{\mathrm{\ϵ}}_{\mathrm{mt}}---\left(51\right)$

L can be obtained thus ₃displacement difference between place's substrate and testee:

$u_{\mathrm{jp}}\left(l_3\right)-u_{\mathrm{mt}}\left(l_3\right)=\frac{(h_2-h_1)h_1{E}_{\mathrm{jp}}T}{{2G}_{\mathrm{jc}}}[\frac{e^{-T(l_3+l_6)}-e^{{\mathrm{Tl}}_5}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{e}^{{\mathrm{Tl}}_3}-\frac{e^{{-\mathrm{Tl}}_5}-e^{T(l_3+l_6)}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{e}^{{-\mathrm{Tl}}_3}]{\mathrm{\ϵ}}_{\mathrm{mt}}---\left(52\right)$

The strain calculation region of testee be steel pipe between on-chip immovable point, so the resistance strain gauge formula of testee can be written as form below:

$\begin{array}{c}{\mathrm{\ϵ}}_t=\frac{l_2{\mathrm{\ϵ}}_s+2\mathrm{\Δ}{l}_x+2[u_{\mathrm{jp}}\left(l_3\right)-u_{\mathrm{mt}}\left(l_3\right)]}{l_2+2(l_1-l_3)}\\ =\frac{l_2+\{\frac{e^{{\mathrm{Kl}}_1}-e^{{\mathrm{Kl}}_3}}{K}-l_1+l_3+\frac{(1-e^{{\mathrm{Kl}}_1})[\mathrm{ch}\left({\mathrm{Kl}}_1\right)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)]}{\mathrm{Ksh}\left({\mathrm{Kl}}_1\right)}\}\frac{2\mathrm{ch}\left({\mathrm{Kl}}_3\right)}{\mathrm{ch}({\mathrm{Kl}}_1+{\mathrm{Kl}}_3)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)}}{l_2+2(l_1-l_3)-\frac{(h_2-h_1)h_1{E}_{\mathrm{jp}}T}{G_{\mathrm{jc}}}[\frac{e^{-T(l_3+l_6)}-e^{{\mathrm{Tl}}_5}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{e}^{{\mathrm{Tl}}_3}-\frac{e^{{-\mathrm{Tl}}_5}-e^{T(l_3+l_6)}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{e}^{-{\mathrm{Tl}}_3}]}{\mathrm{\ϵ}}_s\\ +\frac{\frac{2[\mathrm{ch}\left({\mathrm{Kl}}_1\right)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)]}{\mathrm{Ksh}\left({\mathrm{Kl}}_1\right)}}{l_2+2(l_1-l_3)-\frac{(h_2-h_1)h_1{E}_{\mathrm{jp}}T}{G_{\mathrm{jc}}}[\frac{e^{-T(l_3+l_6)}-e^{T{l}_5}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{e}^{{\mathrm{Tl}}_3}-\frac{e^{-{\mathrm{Tl}}_5}-e^{T(l_3+l_6)}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{e}^{-{\mathrm{Tl}}_3}]}{\mathrm{\ϵ}}_s\end{array}---\left(53\right)$

Formula (53) is namely the relation calculating formula that the testee strain under stickup means of fixation strains with sensor measurement, although the resistance strain gauge formula more complicated of testee, can see that strain is relevant with parameters.

(4) bending deflection of pipe calculating sub module

Bending deflection of pipe calculating sub module is for calculating the combined deflection of any one monitored sub-pipes, and method is as follows:

(1) for any one monitored sub-pipes, if its total m monitoring cross section, numbering is respectively 1,2 in order ... m; Distance between adjacent monitoring cross section is all equal, is h; The diameter of sub-pipes is D;

Each monitoring Up Highway UHW in cross section, Down Highway, left bus and right bus position arrange a fiber-optic grating sensor respectively, that is: each monitoring cross section arranges 4 monitoring points;

(2) the amount of deflection derivative value of monitoring cross section i is calculated:

For monitoring cross section i, receive the real-time strain value ε in Down Highway place uploaded respectively 4 monitoring points simultaneously _{under is}, the real-time strain value ε in Up Highway UHW place _{on is}, the real-time strain value ε in left bus place _{is is left}strain value ε real-time with right bus place _{is is right};

Then, read sub module stored, judge fiber-optic grating sensor mounting type, if be welded and installed form, then by formula (34) (25), by ε _{under is}be converted into revised Down Highway place strain value ε _{under it}, by ε _{on is}be converted into revised Up Highway UHW place strain value ε _{on it}, ε _{is is left}be converted into revised left bus place strain value ε _{it is left}, ε _{is is right}be converted into revised right bus place strain value ε _{it is right};

Then, to ε _{it is left}and ε _{it is right}carry out COMPREHENSIVE CALCULATING, obtain revised axis place strain value ε _{it axle};

By ε _{it axle}substitute into following formula, try to achieve monitoring cross section i amount of deflection derivative value:

W ' _i=λ _isin θ _i=(ε _{it axle}+ 1) sin θ _i(7)

Wherein, w ' _ifor monitoring cross section i amount of deflection derivative value;

θ _ifor monitoring cross section i is relative to the absolute rotational angle theta of y-axis _i, θ _ifor the algebraic sum of the relative rotation in all monitoring cross sections in this sub-pipes before monitoring cross section i, that is:

${\mathrm{\θ}}_i=\underset{j=1}{\overset{i}{\mathrm{\Σ}}}{\mathrm{\θ}}_j^{*}---\left(5\right)$

Before monitoring cross section i, in this sub-pipes, any one monitors the relative rotation of cross section j, by following formulae discovery:

Wherein, D is the diameter of sub-pipes i; H is the distance between adjacent monitoring cross section;

(3) by step (2) mode, calculate the amount of deflection derivative value in sub-pipes m monitoring cross section respectively, count w ' respectively ₁, w ' ₂w ' _m;

(4) after obtaining discrete m amount of deflection derivative value, adopt numerical computation method to calculate m amount of deflection derivative value, reduction obtains the combined deflection value of sub-pipes.

Bending deflection of pipe calculating sub module working principle is as follows:

The present invention, according to the needs of computational analysis, selects the euler beam of Large Deflection Deformation to study the large elastic deformation of pipeline as mechanical model.Euler beam is typical element type in the mechanics of materials, and the assumed condition of its theory is:

(1) perpendicular to the cross section of beam axis, after beam distortion, plane is remained;

(2), before and after distortion, cross section is all the time perpendicular to beam axis.

If the diameter of pipeline is D, length is L, in order to obtain boundary conditions more easily, select the object of reference comparison deformation that fixing simultaneously, the two ends of pipeline are selected in outside texturing zone, think that two ends are fixed, consider the time requirement of monitoring, the used time of post-processed data is unsuitable long, pipeline is evenly divided into N section vertically, the length of every section is h=L/N, thus be convenient to calculate, save the time analyzed, suppose that the distortion of pipeline occurs in xy plane, xy plane is by axis and perpendicular to the plane of horizontal plane, as shown in Figure 7, for conduit axis bends schematic diagram.

Point p on conduit axis, its coordinate is (x, 0), bending deflection along with pipeline moves to a p ' position, namely puts p and moves u (x) in x-axis direction, move w (x) in the y-axis direction, the coordinate then putting p ' is (x+u, w).Beam Large Deflection Deformation geometrical relationship formula is:

$\frac{\mathrm{du}}{\mathrm{dx}}=\mathrm{\λ}\cos \mathrm{\θ}-1---\left(1\right)$

$\frac{\mathrm{dw}}{\mathrm{dx}}=\mathrm{\λ}\sin \mathrm{\θ}---\left(2\right)$

$\frac{\mathrm{ds}}{\mathrm{dx}}=\mathrm{\λ}=\mathrm{\ϵ}+1---\left(3\right)$

$k_{\mathrm{ql}}=\frac{\mathrm{d\θ}}{\mathrm{\λdx}}---\left(4\right)$

In formula, u (x) is a p displacement in the direction of the x axis;

The axis elongation rate that λ (x) is beam;

The angle that θ (x) is line of deflection tangent line and x-axis forward;

W (x) is the displacement of p in y-axis, i.e. the deflection value of beam;

The arc length coordinate that s (x) is line of deflection;

The strain that ε (x) is axis;

K _qlx () is flexure curvature of a curve.

As can be seen from large deformation geometrical relationship formula, the angle theta of the axis elongation rate λ of amount of deflection and beam, line of deflection tangent line and x-axis forward has direct correlation, is therefore evolved into solving for axis elongation rate and angle for solving of amount of deflection.

Selective light fiber grating sensor is as the monitoring means of pipeline strain, and the computational analysis determining the later stage all will be carried out using the real-time strain value of pipeline as known conditions.As can be seen from Large Deflection Deformation geometrical relationship formula, axis elongation rate λ and strain stress have direct relation, directly carrying out corrected Calculation by measuring the axis strain value obtained, being substituted into by the axis strain value after the corrected Calculation obtained and can obtain elongation percentage λ.

Because known conditions only comprises the strain value of pipeline, utilize geometrical relationship formula to solve angle theta, when supposing that pipe bending is out of shape, sectional shape does not change, and arbitrary section i is relative to the corner θ of y-axis _irepresent, be called absolute corner, arbitrary section i is relative to the corner θ in previous cross section ^* _irepresent, be called relative rotation, then the absolute rotational angle theta of arbitrary section i _ifor the algebraic sum of the relative rotation in all cross sections before this cross section, calculating formula is:

${\mathrm{\θ}}_i=\underset{j=1}{\overset{i}{\mathrm{\Σ}}}{\mathrm{\θ}}_j^{*}---\left(5\right)$

Pipeline Up Highway UHW, cross section i and y-axis form a triangle, if section length is reasonable, can be similar to and thinks that this triangle is right-angled triangle, can obtain the calculation expression of the relative rotation in cross section:

The correction strain value at Down Highway place of pipeline section i place is expressed as ε _{under it}, the correction strain value at Up Highway UHW place of pipeline section i place is expressed as ε _{on it}these two strain values can after obtaining on-the-spot actual measured value, calculated by correction formula, the diameter of pipeline and the length of every section are known conditions, relative rotation value is obtained so can solve, it be updated in the calculating formula of absolute corner, pipeline arbitrary section i is relative to the absolute rotational angle theta of y-axis again _ijust can obtain.Due to the assumed condition of beam theory, the cross section of pipeline before being deformed after all the time perpendicular to axis, so pipeline arbitrary section i is relative to the absolute rotational angle theta of y-axis _ibe the line of deflection tangent line at arbitrary section i place and the angle of x-axis forward.

According to large deformation geometrical relationship formula, axis elongation rate and angle are substituted into, obtain the amount of deflection calculation expression after being out of shape:

W ' _i=λ _isin θ _i=(ε _{it axle}+ 1) sin θ _i(7)

The strain value of each Nodes can be obtained by monitoring means, therefore solve and obtain w ' (x _i), (i=0,1 ..., N).

So far, the derivative value of conduit axis amount of deflection has solved complete, because calculate after duct segments, so be the numerical value of series of discrete.According to infinitesimal calculus theory, calculating research is carried out to continuous print curve, to divide, the accuracy of the less calculating in region divided is higher, the present invention also follows this calculating thinking, and pipeline is divided into N section in the axial direction, in order to simplify the work of post-processed data, adopt the way of dividing equally, the length of every section is

After obtaining one group of discrete amount of deflection derivative value, solving of bending deflection of pipe is summed up as a mathematical problem, and namely how known discrete derivative value, solve its original, and the present invention adopts numerical computation method to carry out analysis and solution to this problem.

In addition, in practical application, remote monitoring center can also arrange relevant function module according to the actual requirements, includes but not limited to: sub-pipes monitoring modular, system function module and analysis report module;

Wherein, the real-time stress value uploaded for the fiber-optic grating sensor receiving each monitoring point of described Monitoring Pinpelines module;

Described system function module comprises systems management submodule, server resource management submodule, network connection management submodule and system log management submodule;

Described analysis report module comprises: every day, assessment report generated submodule, healthy trend report generation submodule, emergent report generation submodule and instant report generation submodule;

Wherein, described assessment report generation every day submodule is used for: according to the combined deflection value of the sub-pipes that described bending deflection of pipe calculating sub module calculates, the health status of assessment this sub-pipes on the same day;

Described healthy trend report generates submodule and is used for: the result generated according to described assessment report generation every day submodule, sums up sub-pipes history health status situation, generates the healthy trend of this sub-pipes in following certain hour;

Described emergent report generation submodule is used for: the healthy trend generating the sub-pipes that submodule generates according to described healthy trend report, judge whether this sub-pipes is dangerous in future certain hour, if had, then generate the emergent report of measure scheme characterizing this sub-pipe risk factor and can take;

Described instant report generation submodule is used for: according to the combined deflection value of the sub-pipes that described bending deflection of pipe calculating sub module calculates, and generates the report of this sub-pipes current health state in real time.

The normal work of long distance oil-gas conveyance conduit and productive life closely related, if due to natural disaster, human users are improper or the reason such as damage from third-party that conveyance conduit is out of shape is serious, there is the oil gas leakage that pipeline damage causes carrying, physical environment can be polluted, affect the normal life of the normal production of relevant enterprise and resident, more serious situation is even blasted accident, threaten human life safely, cause huge economic loss.

And the present invention proposes a kind of distributed monitoring method for the strain of long distance pipeline Crossover phase first, the optical fiber sensing technology of employing, can avoid the interference of electromagnetic signal.By theory analysis, calculating with contrast, to realizing the monitoring and evaluation to pipe deforming.By analysis conduit strain data, pipe deforming state can be grasped, judge its whether be moved bending deflection and distortion whether be in safety range.According to monitoring system result of calculation, staff can intuitively understand pipeline present situation.In addition, extrapolate the deformation of pipeline according to the strain value measured in real time, also have real-time stress phase warning function, avoid pipeline actual generation security incident, improve the Security of conduit running.

The above is only the preferred embodiment of the present invention; it should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention; can also make some improvements and modifications, these improvements and modifications also should look protection scope of the present invention.

Claims (4)

1. a distributed monitoring system for long distance pipeline Crossover phase strain, it is characterized in that, comprising: remote monitoring center and several distributed nodes, distributed node described in each carries out information interaction by signal transmission system and described remote monitoring center;

Each distributed node is arranged in the following ways:

Monitored long distance pipeline is divided in the axial direction n sub-pipes; For any one sub-pipes i, equidistant in the axial direction w the monitoring cross section perpendicular to axis is set, 4 monitoring points are arranged in each monitoring cross section, that is: a fiber-optic grating sensor is respectively installed at the Up Highway UHW in described monitoring cross section, Down Highway, left bus and right bus place; The all fiber-optic grating sensors be arranged on sub-pipes i form a distributed node with the data capture and pre-treater being arranged on sub-pipes i this locality.

2. the distributed monitoring system of long distance pipeline Crossover phase strain according to claim 1, it is characterized in that, the outer surface of tube wall of described fiber-optic grating sensor and monitored sub-pipes fits tightly installation, for gathering the original strain information fitting tightly tube wall with it;

The original strain information that described data capture and pre-treater send for receiving each fiber-optic grating sensor, and data prediction is carried out to described original strain information, obtain the real-time strain information in monitoring point be applicable to after the process of transmission and analysis further;

Described signal transmission system is used for: real-time for described monitoring point strain information is stored in this locality; Meanwhile, real-time for described monitoring point strain information is sent to described remote monitoring center in real time.

3. the distributed monitoring system of long distance pipeline Crossover phase strain according to claim 1, it is characterized in that, described remote monitoring center comprises pipe deforming computing module; Described pipe deforming computing module comprises sub module stored, the strain calculation submodule of Type of Welding sensor, the strain calculation submodule pasting form sensor and bending deflection of pipe calculating sub module;

Described sub module stored is for storing the corresponding relation between sub-pipes ID and sub-pipes attribute; Wherein, described sub-pipes attribute comprises fiber-optic grating sensor mounting type and sub-pipes essential information on the geographical position at sub-pipes place, sub-pipes; Wherein, described mounting type comprises two kinds: fiber-optic grating sensor is arranged on sub-pipes by Type of Welding, and fiber-optic grating sensor is arranged on sub-pipes by stickup form;

Wherein, for the sub-pipes of erecting and welding form sensor, the essential information of described sub-pipes comprises:

L ₁: optical fiber adhesive layer partial-length;

L ₂: optical fiber is without adhesive tape sections length;

L ₃: immovable point distance tip lengths:

R ₁: the outer radius of encapsulation steel pipe;

R ₂: the inside radius of encapsulation steel pipe, i.e. glue-line outer radius;

R ₃: fiber radius;

E _x: the Young's modulus of optical fiber;

E _g: the Young's modulus of sensor steel pipe;

E _j: the Young's modulus in mesosphere;

ε _s: the real-time strain value that fiber bragg grating measurement obtains;

G _jfor the shear modulus of glue line;

Wherein, for the sub-pipes installing stickup form sensor, the essential information of described sub-pipes comprises:

L ₁: optical fiber adhesive layer partial-length;

L ₂: optical fiber is without adhesive tape sections length;

L ₃: immovable point distance tip lengths:

R ₁: the outer radius of encapsulation steel pipe;

R ₂: the inside radius of encapsulation steel pipe, i.e. glue-line outer radius;

R ₃: fiber radius;

E _x: the Young's modulus of optical fiber;

E _g: the Young's modulus of sensor steel pipe;

E _j: the Young's modulus in mesosphere;

G _jfor the shear modulus of glue line;

ε _s: the real-time strain value that fiber bragg grating measurement obtains;

H ₁for the thickness of glue line;

H ₂for the thickness sum of glue line and substrate;

E _jpfor the Young's modulus of substrate;

G _jcfor the shear modulus of glue line;

L ₅for substrate end and steel tube end part distance;

L ₆for immovable point and the other end steel tube end part distance;

The strain calculation submodule of described Type of Welding sensor is used for: read described sub module stored, finds the sub-pipes essential information corresponding with it based on sub-pipes ID; Then by strain value ε that the relevant parameter in the sub-pipes essential information found and the measured point place fiber bragg grating measurement that receives obtain _ssubstitute into following formula, try to achieve the strain value ε at revised measured point place _t:

$\begin{array}{c}{\mathrm{\ϵ}}_t=\frac{\mathrm{\Δ}{l}_2+2\mathrm{\Δ}{l}_x}{l_2+2(l_1-l_3)}\\ =\frac{l_2+\{\frac{e^{{\mathrm{Kl}}_1}-e^{{\mathrm{Kl}}_3}}{K}-l_1+l_3+\frac{(1-e^{{\mathrm{kl}}_1})[\mathrm{ch}\left({\mathrm{Kl}}_1\right)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)]}{\mathrm{Ksh}\left({\mathrm{Kl}}_1\right)}\}\frac{2\mathrm{ch}\left({\mathrm{Kl}}_3\right)}{\mathrm{ch}({\mathrm{Kl}}_1+{\mathrm{Kl}}_3)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)}}{l_2+2(l_1-l_3)}{\mathrm{\ϵ}}_s\\ +\frac{\frac{2[\mathrm{ch}\left({\mathrm{Kl}}_1\right)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)]}{\mathrm{Ksh}\left({\mathrm{Kl}}_1\right)}}{l_2+2(l_1-l_3)}{\mathrm{\ϵ}}_s\end{array}---\left(34\right)$

Wherein:

$K=\sqrt{\frac{\frac{r_3^2{E}_x+(r_2^2-r_3^2)E_j}{(r_1^2-r_2^2)E_g}+1}{\frac{1}{G_j}[\frac{E_j}{4}(r_2^2-r_3^2)+\frac{r_3^2}{2}(E_x-E_j)\ln \frac{r_2}{r_3}]}}---\left(25\right)$

The strain calculation submodule of described stickup form sensor is used for: read described sub module stored, finds the sub-pipes essential information corresponding with it based on sub-pipes ID; Then by strain value ε that the relevant parameter in the sub-pipes essential information found and the measured point place fiber bragg grating measurement that receives obtain _ssubstitute into following formula, try to achieve the strain value ε at revised measured point place _t:

$\begin{array}{c}{\mathrm{\ϵ}}_t=\frac{l_2{\mathrm{\ϵ}}_s+2\mathrm{\Δ}{l}_x+2[u_{\mathrm{jp}}\left(l_3\right)-u_{\mathrm{mt}}\left(l_3\right)]}{l_2+2(l_1-l_3)}\\ =\frac{l_2+\{\frac{e^{{\mathrm{Kl}}_1}-e^{{\mathrm{Kl}}_3}}{K}-l_1+l_3+\frac{(1-e^{{\mathrm{Kl}}_1})[\mathrm{ch}\left({\mathrm{Kl}}_1\right)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)]}{\mathrm{Ksh}\left({\mathrm{Kl}}_1\right)}\}\frac{2\mathrm{ch}\left({\mathrm{Kl}}_3\right)}{\mathrm{ch}({\mathrm{Kl}}_1+{\mathrm{Kl}}_3)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)}}{l_2+2(l_1-l_3)-\frac{(h_2-h_1)h_1{E}_{\mathrm{jp}}T}{G_{\mathrm{jc}}}[\frac{e^{-T(l_3+l_6)}-e^{{\mathrm{Tl}}_5}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{e}^{{\mathrm{Tl}}_3}-\frac{e^{{-\mathrm{Tl}}_5}-e^{T(l_3+l_6)}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{e}^{-{\mathrm{Tl}}_3}]}{\mathrm{\ϵ}}_s\\ +\frac{\frac{2[\mathrm{ch}\left({\mathrm{Kl}}_1\right)-\mathrm{ch}\left({\mathrm{Kl}}_3\right)]}{\mathrm{Ksh}\left({\mathrm{Kl}}_1\right)}}{l_2+2(l_1-l_3)-\frac{(h_2-h_1)h_1{E}_{\mathrm{jp}}T}{G_{\mathrm{jc}}}[\frac{e^{-T(l_3+l_6)}-e^{T{l}_5}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{e}^{{\mathrm{Tl}}_3}-\frac{e^{-{\mathrm{Tl}}_5}-e^{T(l_3+l_6)}}{2\mathrm{sh}({\mathrm{Tl}}_5+{\mathrm{Tl}}_3+{\mathrm{Tl}}_6)}{e}^{-{\mathrm{Tl}}_3}]}{\mathrm{\ϵ}}_s\end{array}---\left(53\right)$

Wherein, $T=\sqrt{\frac{2G_{\mathrm{jc}}}{(h_2-h_1)h_1{E}_{\mathrm{jp}}}}---\left(46\right)$

$K=\sqrt{\frac{\frac{r_3^2{E}_x+(r_2^2-r_3^2)E_j}{(r_1^2-r_2^2)E_g}+1}{\frac{1}{G_j}[\frac{E_j}{4}(r_2^2-r_3^2)+\frac{r_3^2}{2}(E_x-E_j)\ln \frac{r_2}{r_3}]}}---\left(25\right)$

Described bending deflection of pipe calculating sub module is for calculating the combined deflection of any one monitored sub-pipes, and method is as follows:

(1) for any one monitored sub-pipes, if its total m monitoring cross section, numbering is respectively 1,2 in order ... m; Distance between adjacent monitoring cross section is all equal, is h; The diameter of sub-pipes is D;

Each monitoring Up Highway UHW in cross section, Down Highway, left bus and right bus position arrange a fiber-optic grating sensor respectively, that is: each monitoring cross section arranges 4 monitoring points;

(2) the amount of deflection derivative value of monitoring cross section i is calculated:

For monitoring cross section i, receive the real-time strain value ε in Down Highway place uploaded respectively 4 monitoring points simultaneously _{under is}, the real-time strain value ε in Up Highway UHW place _{on is}, the real-time strain value ε in left bus place _{is is left}strain value ε real-time with right bus place _{is is right};

Then, read sub module stored, judge fiber-optic grating sensor mounting type, if be welded and installed form, then by formula (34) (25), by ε _{under is}be converted into revised Down Highway place strain value ε _{under it}, by ε _{on is}be converted into revised Up Highway UHW place strain value ε _{on it}, ε _{is is left}be converted into revised left bus place strain value ε _{it is left}, ε _{is is right}be converted into revised right bus place strain value ε _{it is right};

Then, to ε _{it is left}and ε _{it is right}carry out COMPREHENSIVE CALCULATING, obtain revised axis place strain value ε _{it axle};

By ε _{it axle}substitute into following formula, try to achieve monitoring cross section i amount of deflection derivative value:

W ' _i=λ _isin θ _i=(ε _{it axle}+ 1) sin θ _i(7)

Wherein, w ' _ifor monitoring cross section i amount of deflection derivative value;

θ _ifor monitoring cross section i is relative to the absolute rotational angle theta of y-axis _i, θ _ifor the algebraic sum of the relative rotation in all monitoring cross sections in this sub-pipes before monitoring cross section i, that is:

${\mathrm{\θ}}_i=\underset{j=1}{\overset{i}{\mathrm{\Σ}}}{\mathrm{\θ}}_j^{*}---\left(5\right)$

Before monitoring cross section i, in this sub-pipes, any one monitors the relative rotation of cross section j, by following formulae discovery:

Wherein, D is the diameter of sub-pipes i; H is the distance between adjacent monitoring cross section;

(3) by step (2) mode, calculate the amount of deflection derivative value in sub-pipes m monitoring cross section respectively, count w ' respectively ₁, w ' ₂w ' _m;

(4) after obtaining discrete m amount of deflection derivative value, adopt numerical computation method to calculate m amount of deflection derivative value, reduction obtains the combined deflection value of sub-pipes.

4. the distributed monitoring system of long distance pipeline Crossover phase strain according to claim 3, it is characterized in that, described remote monitoring center also comprises sub-pipes monitoring modular, system function module and analysis report module;

Wherein, the real-time stress value uploaded for the fiber-optic grating sensor receiving each monitoring point of described Monitoring Pinpelines module;

Described system function module comprises systems management submodule, server resource management submodule, network connection management submodule and system log management submodule;

Described analysis report module comprises: every day, assessment report generated submodule, healthy trend report generation submodule, emergent report generation submodule and instant report generation submodule;

Wherein, described assessment report generation every day submodule is used for: according to the combined deflection value of the sub-pipes that described bending deflection of pipe calculating sub module calculates, the health status of assessment this sub-pipes on the same day;

Described healthy trend report generates submodule and is used for: the result generated according to described assessment report generation every day submodule, sums up sub-pipes history health status situation, generates the healthy trend of this sub-pipes in following certain hour;

Described emergent report generation submodule is used for: the healthy trend generating the sub-pipes that submodule generates according to described healthy trend report, judge whether this sub-pipes is dangerous in future certain hour, if had, then generate the emergent report of measure scheme characterizing this sub-pipe risk factor and can take;

Described instant report generation submodule is used for: according to the combined deflection value of the sub-pipes that described bending deflection of pipe calculating sub module calculates, and generates the report of this sub-pipes current health state in real time.