CN104019790B - The measurement apparatus of the long-time accumulated deformation of pressure-resistance structure under water and method - Google Patents

Abstract

The measurement apparatus of the long-time accumulated deformation of pressure-resistance structure under water, measuring unit and amending unit including separate setting, described measuring unit includes pressure measuring cylinder, hydraulically full pressure hull to be measured is placed in pressure measuring cylinder, pressure hull to be measured is connected, equipped with Pressure gauge on pressure measuring cylinder with the volume change reader being positioned at outside pressure measuring cylinder by pipeline；Described amending unit is made up of another set pressure hull to be measured, volume change reader and connecting line therebetween.Present invention also offers the measuring method indirectly measuring the long-time accumulated deformation of pressure-resistance structure by measuring the volume variable quantity that under hydrostatic pressure, pressure-resistance structure is accumulated in time, the mechanics parameter rules over time such as the malformation value of the pressure-resistance structure drawn, stress, strain are indirectly measured by the present invention, can be used in studying creep properties or the viscoelastic property of pressure-resistance structure material therefor under water, whole measurement apparatus simple in construction, it is the most convenient to measure, easy to maintenance, and certainty of measurement is high.

Description

The measurement apparatus of the long-time accumulated deformation of pressure-resistance structure under water and method

Technical field

The present invention relates to pressure-resistance structure External Hydrostatic Pressure experimental technique field under water, be particularly used for measuring the most pressure knot Structure long-time accumulated deformation and the measurement result by long-time accumulated deformation under hydrostatic pressure study the most pressure knot The resistance to compression creep properties of structure material or the device and method of viscoelastic property.

Background technology

Pressure-resistance structure is that underwater robot, manned underwater vehicle, space station, deep-sea and submarine etc. deliver operation horizontal under water under water The important component part of platform, for bearing the safety of Deep-sea high voltage load support personnel and equipment.At present, pressure-resistance structure under water The test of External Hydrostatic Pressure power is main uses the sensor measurements such as resistance strain gage, by measuring pressure hull key position under water Strain and be scaled structural stress；The creep measurement of land pressure-resistant pipeline (intrinsic pressure) the most generally uses creep measurement points Measurement method and creep measurement labelling measurement method, the former uses micrometer to measure deformation between measuring point, and the latter uses special steel Mark is wrapped on steel pipe or header body measured section outer surface, measures the increment at this position.Resistance strain gage etc. is passed Sensor measuring method, easily make moist aging, performance generation creep of the resistance strain gage owing to being immersed in water causes service life Low, it is not suitable for the measurement of the long-time deformation of pressure-resistance structure under water, and strain gage testing position is local measurement, and The creep properties of material is the deformation of a kind of full structure, and therefore, the sensor measurement such as traditional resistance strain gage cannot be complete The long-term observation of the creep (or viscoelasticity) becoming under water pressure-resistance structure and measurement；For creep measurement points measurement method and creep measurement mark Note measurement method, owing to both measuring methods are only used for the pressure-resistant pipeline of exposure, and the long-term accumulated of pressure-resistance structure becomes under water Shape test needs to carry out in pressure measuring cylinder, and the creep measurement method of the most traditional land pressure-resistant pipeline (intrinsic pressure) also cannot be fitted Should the measurement of accumulated deformation in pressure-resistance structure process of the test under water.

Summary of the invention

The applicant improves for disadvantages mentioned above of the prior art, it is provided that one pressure-resistance structure under water tires out for a long time The measurement apparatus of long-pending deformation and method, it is capable of under hydrostatic pressure the volume rule over time of pressure-resistance structure under water Measurement, it is convenient, accurately to measure, and can be derived that under hydrostatic pressure pressure based on volume measure of the change result by mathematical conversion The long-time accumulated deformation of structure, it is possible to for studying creep properties or the viscoelastic property of pressure-resistance structure material.

Technical scheme is as follows:

The measurement apparatus of the long-time accumulated deformation of pressure-resistance structure under water of the present invention, including the measurement list of separate setting Unit and amending unit, described measuring unit includes the pressure measuring cylinder for simulating deep sea pressure environment, and pressure hull to be measured is placed in pressure In power cylinder, hydraulically full in pressure hull to be measured, and pressure hull to be measured is by pipeline one and the volume being positioned at outside pressure measuring cylinder Change reader one connects, and pressure measuring cylinder connects has water injecting pipeline and discharge pipe line, described water injecting pipeline to be provided with force (forcing) pump and control Valve one processed, equipped with Pressure gauge on pressure measuring cylinder, described discharge pipe line is provided with control valve two；Described amending unit includes contrasting pressure Housing, contrast pressure hull in hydraulically full, and contrast pressure hull by pipeline two and be positioned at contrast pressure hull outside Volume change reader two connects；Contrast pressure hull, pipeline two and volume change reader two in described amending unit Structure is identical with the pressure hull to be measured in described measuring unit, pipeline one and volume change reader one respectively.

The measuring method of the long-time accumulated deformation of pressure-resistance structure under water of the present invention, comprises the steps of

The first step, described water injecting pipeline and described discharge pipe line are in closed mode, are not subject at pressure hull to be measured In the case of hydrostatic pressure, record scale value H at free surface place in volume change reader one₀；

Second step, opens described water injecting pipeline, and described discharge pipe line is still in closed mode, by described water injecting pipeline pair Pressure measuring cylinder water filling applies hydrostatic pressure, observes pressure gauge reading, when pressure cylinder pressure reaches goal pressure P₁Time, close described Water injecting pipeline, records scale value H at free surface place in now volume changes reader one₁；Revise described in adjusted in concert In unit, the free surface of volume change reader two is in scale value H₁Position；

3rd step, keeps the pressure of pressure measuring cylinder to be in goal pressure P₁Lower t₁After time, record now volume change reading Scale value H at free surface place in device one₂With scale value H at free surface place in volume change reader two₃；

4th step, calculates pressure hull to be measured and is in constant hydrostatic pressure P₁Lower t₁Volume changing value △ V after time₁': Scale value H obtained with the 3rd pacing₂Scale value H recorded with second step₁Difference be multiplied by volume change reader one cross section Long-pending；

5th step, the volume changing value △ V that four-step calculation is obtained₁' it is modified: calculate contrast pressure hull not Bear in the case of External Hydrostatic Pressure through t₁The volume changing value △ V caused by variations in temperature after time₁", i.e. use scale value H₃With Scale value H₁Difference be multiplied by volume change reader two sectional area；△V₁' and △ V₁" difference be completely by hydrostatic pressing Power P₁The t in time caused₁The volume changing value △ V of accumulation₁；

6th step, the most at regular intervals t_iRepeat above-mentioned third step to the 5th step, obtain one group of hydrostatic pressure P₁Under By volume changing value △ V_iWith corresponding time t_iThe data of composition；

7th step, to one group of data (the △ V recorded in the 6th step_i, t_i) use mathematical method to be fitted, draw to be measured Pressure hull is in hydrostatic pressure P₁Under the volume change accumulated in time and the relation function of time, tie according to pressure hull to be measured The geometrical relationship of structure parameter and volume and the material constitutive relation of pressure hull to be measured, can converse corresponding t_iTreat during the time Survey the malformation value of pressure hull, strain, stress, thus obtain the malformation value of pressure hull to be measured, strain, stress exist Hydrostatic pressure P₁Under rule over time.

Its further technical scheme is:

Change described hydrostatic pressure P₁To P₂、P₃... Pn, repeats described second to the 7th step, obtains different hydrostatic pressing The volume of pressure hull to be measured, malformation value, strain, stress rule over time under power.

Take the group data that the pressure hull to be measured volume under at least two hydrostatic pressure is constituted with the time, by mathematics side Method simulates the Creep Rule of pressure hull material therefor to be measured.

The technique effect of the present invention:

The present invention is by being converted to pressure-resistance structure at hydrostatic by measuring target by the deflection of traditional pressure-resistance structure under water The volume variable quantity of the long-time accumulation under pressure, is exaggerated measurement target, thus can not only be by the appearance recorded By mathematical conversion and Mathematical Fitting, long-pending variable quantity show that the collecting structure deformation of pressure-resistance structure, stress, strain are in time Changing Pattern, and can further by mathematical conversion and matching draw pressure-resistance structure material therefor resistance to compression creep properties or Viscoelastic property, on the other hand, overcomes the sensor measurements such as traditional resistance strain gage because of resistance strain gage and uses the longevity Order short and measurement and the local of strain gage testing position of the long-time accumulated deformation of pressure-resistance structure under water cannot be applicable to The defect of property；Measurement apparatus simple in construction of the present invention, measure the most convenient, experimentation cost is low, easy to maintenance, and test can be held Continuous strong, solve traditional external pressure test of pressure-resistance structure under water and cannot measure the technology of the long-time accumulated deformation of pressure-resistance structure under water Problem；The present invention setting by correcting device, it is possible to eliminate the measurement error caused by variations in temperature, improves measurement essence Degree.

Accompanying drawing explanation

Fig. 1 is the structural representation of measuring unit of the present invention.

Fig. 2 is the structural representation of amending unit of the present invention.

Fig. 3 is the pressure hull to be measured strain time plot under two kinds of hydrostatic pressures.

Wherein: 1, pressure measuring cylinder；2, pressure hull to be measured；3, pipeline one；4, volume change reader one；5, force (forcing) pump；6、 Control valve one；7, Pressure gauge；8, valve two processed；9, contrast pressure hull；10, pipeline two；11, volume change reader two.

Detailed description of the invention

Below in conjunction with the accompanying drawings, the detailed description of the invention of the present invention is described.

Seeing Fig. 1, Fig. 2, the measurement apparatus of the long-time accumulated deformation of pressure-resistance structure under water of the present invention includes separate setting The measuring unit put and amending unit, described measuring unit includes the pressure measuring cylinder 1 for simulating deep sea pressure environment, to be measured pressure Housing 2 is placed in pressure measuring cylinder 1, is full of incompressible liquid in pressure hull 2 to be measured, and pressure hull to be measured 2 passes through pipeline One 3 connect with the volume change reader 1 being positioned at outside pressure measuring cylinder 1, and pressure measuring cylinder 1 connects water injecting pipeline and discharge pipe line, Described water injecting pipeline is provided with force (forcing) pump 5 and control valve 1, and equipped with Pressure gauge 7 on pressure measuring cylinder 1, described discharge pipe line is provided with Control valve 28, control valve 1 and control valve 28 are respectively used to control described water injecting pipeline, the open and close of described discharge pipe line；Institute State amending unit and include contrasting pressure hull 9, in contrast pressure hull 9, be full of incompressible liquid, and contrast pressure hull 9 Connected with the volume change reader 2 11 being positioned at outside contrast pressure hull 9 by pipeline 2 10；In described amending unit Contrast pressure hull 9, pipeline 2 10 and volume change reader 2 11 structure respectively with the pneumatic shell to be measured in measuring unit Body 2, pipeline 1 and volume change reader 1 are identical, and volume change reader 1 and volume change reader 2 11 are mark Graduated container, is preferably shaped to cylindrical elongate container.

The measurement apparatus utilizing the long-time accumulated deformation of pressure-resistance structure under water of the present invention is long-time to pressure hull under water The method that accumulated deformation measures comprises the steps of

The first step, described water injecting pipeline and described discharge pipe line are in closed mode, are not subject at pressure hull 2 to be measured In the case of hydrostatic pressure, record scale value H at free surface place in volume change reader 1₀；

Second step, opens described water injecting pipeline, and described discharge pipe line is still in closed mode, by described water injecting pipeline pair Pressure measuring cylinder 1 water filling applies hydrostatic pressure, observes Pressure gauge 7 reading, when in pressure measuring cylinder 1, pressure reaches goal pressure P₁Time, close Described water injecting pipeline, records scale value H at free surface place in now volume changes reader 1₁；Meanwhile, same to step Save the free surface of volume change reader 2 11 in described amending unit and be in scale value H₁Position；

3rd step, keeps the pressure of pressure measuring cylinder 1 to be in goal pressure P₁Lower t₁After time, record now volume change and read Scale value H at free surface place in number device 1₂With scale value H at free surface place in volume change reader 2 11₃；

4th step, calculates pressure hull 2 to be measured and is in constant hydrostatic pressure P₁Lower t₁Volume changing value △ V after time₁': Scale value H obtained with the 3rd pacing₂Scale value H recorded with second step₁Difference be multiplied by volume change reader 1 cross section Long-pending, described product value is △ V₁′；

5th step, the volume changing value △ V that four-step calculation is obtained₁' it is modified: calculate contrast pressure hull 9 and exist It is not subject in the case of External Hydrostatic Pressure through t₁The volume changing value △ V caused by variations in temperature after time₁", i.e. use scale value H₃ With scale value H₁Difference be multiplied by volume change reader 2 11 sectional area, described product value is △ V₁″；△V₁' and △ V₁" difference be completely by hydrostatic pressure P₁Pressure hull to be measured 2 t in time caused₁The volume changing value △ V of accumulation₁；

6th step, the most at regular intervals t_iRepeat above-mentioned third step to the 5th step, thus obtain one group of hydrostatic pressing Power P₁Under by volume changing value △ V_iWith corresponding time t_iData (the △ V of composition_i, t_i), wherein, i=1,2 ..., n；

7th step, to one group of data (the △ V recorded in the 6th step_i, t_i) use mathematical method to be fitted, draw to be measured Pressure hull 2 is in hydrostatic pressure P₁Under the volume change accumulated in time and the relation function of time, according to pressure hull 2 to be measured The geometrical relationship of structural parameters and volume and the material constitutive relation of pressure hull to be measured 2, can converse corresponding t_iTime Time the malformation value of pressure hull 2 to be measured, strain, stress, thus obtain the malformation value of pressure hull 2 to be measured, strain, Stress is in hydrostatic pressure P₁Under rule over time.

Specifically, to one group of data (the △ V recorded in the 6th step_i, t_i) use mathematical method to be fitted, draw to be measured Pressure hull 2 is in hydrostatic pressure P₁Under the volume change accumulated in time and the Changing Pattern of time, according in first step Pressure hull 2 original volume V to be measured₀, can convert and obtain pressure hull to be measured 2 in hydrostatic pressure P₁Under the appearance accumulated in time The long-pending Changing Pattern with the time:

V=f (t) is 1.

According to material used by the geometrical structure parameter of pressure hull 2 to be measured and the geometrical relationship of volume and pressure hull to be measured The constitutive relation of material, can converse the mechanics parameters such as the malformation value of pressure-resistance structure body 2 to be measured, strain, stress in time Changing Pattern, such as:

R=f ' (f (t)) is 2.

ε=f is " (f (t)) 3.

In formula: r represents one of geometric parameter of pressure hull 2 structure to be measured, the radius of pressurized spherical shell the most under water；ε table Showing pressure hull 2 particular location to be measured strain value in particular directions, f ', f are " for corresponding functional relationship.

Further, by changing described hydrostatic pressure P₁To P₂、P₃... Pn, repeats described second to the 7th step, energy Access the volume of pressure hull 2 to be measured, malformation value, strain, stress rule over time under different hydrostatic pressure, Creep properties or viscoelastic property research for pressure hull 2 structural material to be measured.

Take two groups of the pressure hull 2 to be measured malformation value under at least two hydrostatic pressure, strain, stress and time Data, simulate the Creep Rule of pressure hull 2 material therefor to be measured by mathematical method.

Two kinds of typical structures with pressure hull under water: metal refines spherical shell and ring stiffened shell as example, illustrates how The long-time accumulated deformation of pressure hull under hydrostatic pressure is drawn by measurement apparatus of the present invention and measuring method, and by This creep properties drawing pressure-resistance structure material or viscoelastic property.

Take the Creep Rule such as following formula of the metal material of pressure hull 2 to be measured:

ε^c=A₁σⁿt^mPrimary creep behavior is 4.

ε^c=A₂σⁿT creep second stage is 5.

In formula: A, n, m are the coefficient needing to be fitted calculating by measurement result, ε^cFor creep strain, σ is corresponding The stress of pressure hull under water under hydrostatic pressure.

According to the first step described in the measuring method of the long-time accumulated deformation of pressure-resistance structure under water of the present invention to the 6th step, Obtain one group of hydrostatic pressure P₁Under by volume changing value △ V_iWith corresponding time t_iData (the △ V of composition_i, t_i), according to Pressure hull to be measured 2 original volume V in one step₀, can convert and obtain pressure hull to be measured 2 in hydrostatic pressure P₁Under by holding Product value V_iWith corresponding time t_iData (the V of composition_i, t_i), carry out test enough for a long time and guarantee that pressure hull 2 to be measured enters Enter creep second stage；Then, described hydrostatic pressure P is changed₁To P₂, in hydrostatic pressure P₂Under repeat described second step to Six steps, obtain pressure hull to be measured 2 in hydrostatic pressure P₂Under by volumetric values V_i' and the time t of correspondence_iData (the V of composition_i', t_i), same, the data of the volume under other hydrostatic pressures and time can be measured by test, in order to briefly illustrate, select Two kinds of hydrostatic pressures P₁、P₂Explain.

When pressure hull 2 to be measured is spherical shell, in constant hydrostatic pressure P₁And P₂Lower elapsed-time standards t respectively_kAfter, now, ball Shell is in hydrostatic pressure P₁And P₂Volumetric values be respectively V_kAnd V_k', spherical shell hydrostatic pressure P₁And P₂Radius r_kAnd r_k', strain respectively For:

$r_k={\left(\frac{3}{4\mathrm{\π}}{V}_k\right)}^{1/3}$

${r_k}^{\′}={\left(\frac{3}{4\mathrm{\π}}{V_k}^{\′}\right)}^{1/3}$

${\mathrm{\ϵ}}_k^{c_1}=\frac{r_k-r_0}{r_0}$

${\mathrm{\ϵ}}_k^{c_1}=\frac{r_k-r_0}{r_0}$

In formula:WithRepresent hydrostatic pressure P respectively₁And P₂Corresponding time t_kTime spherical shell in arbitrfary point, face caused by creep Strain value, r₀For pressure hull 2 original volume V to be measured₀Time radius.According to above-mentioned mathematical relationship, then can obtain hydrostatic Pressure P₁And P₂Corresponding time t_kTime spherical shell strain data point: The most same acting by external hydrostatic pressure Under, in different time points, it is possible to obtain corresponding dependent variable, with dependent variable as vertical coordinate, with the time as abscissa, pass through hydrostatic Pressure P₁And P₂Two groups of strains of lower spherical shell and the data of time:Then can draw out spherical shell Two of material therefor strain time graphs, Fig. 3 show the material that the titanium alloy spherical shell obtained by measurement is used Titanium alloy is in constant hydrostatic pressure P₁Under strain time graph, the creep that creep rate is successively decreased as we can see from the figure First stage and the almost unchanged second stage of creep rate, another is in hydrostatic pressure P₂Under strain time graph also Be not given, but drawn by test data, its strain time graph and hydrostatic pressure P₁Under the strain time bent Line approximates, and the most similarly discloses primary creep behavior that creep rate successively decreases and the almost unchanged second stage of creep rate.

See Fig. 3, cast out first stage and second stage transitional regionData, according to two kinds of hydrostatic pressings Power P₁And P₂The strain drawn and the data of time, it is possible to by Mathematical Fitting go out creep formula 4. and 5. in coefficient A, n, m:

$\left\{\begin{array}{c}{A}_1={\mathrm{\σ}}_1^{-n}(\stackrel{\‾}{\ln {\mathrm{\ϵ}}_g^{c_1}}-m\stackrel{\‾}{\ln t_g}),g=(\mathrm{1,2},...,k_1)\\ A_2={\mathrm{\σ}}_1^{-n}{\stackrel{.}{\mathrm{\ϵ}}}_h^{c_1},h=(i-k_2+1,i-k_2+2,...,i)\\ n=\frac{\ln {\stackrel{.}{\mathrm{\ϵ}}}_h^{c_2}-\ln {\stackrel{.}{\mathrm{\ϵ}}}_h^{c_1}}{\ln P_2/P_1}\\ m=\frac{\underset{g=1}{\overset{k_1}{\mathrm{\Σ}}}\ln t_g\ln {\mathrm{\ϵ}}_g^{c_1}-k_1\stackrel{\‾}{\ln t_g}\stackrel{\‾}{\ln {\mathrm{\ϵ}}_g^{c_1}}}{\underset{g=1}{\overset{k_1}{\mathrm{\Σ}}}{\left(\ln t_g\right)}^2-k_1{\left(\stackrel{\‾}{{\ln t}_g}\right)}^2}\end{array}\right.$

In formula, σ₁It is P for hydrostatic pressure₁Time spherical shell axial/circumferential stress, by hydrostatic pressure, spherical shell radius and spherical shell Thickness carries out mathematical calculation can calculate this stress；WithIt is respectively hydrostatic pressure P₁And P₂Time in creep second stage Creep rate, this creep rate can pass through P₁And P₂Under two groups of strains and the data of time be fitted calculating, in formula Upper horizontal line all represents that taking time subscript is averaging.Thus, the Creep Rule formula of spherical shell material has i.e. been drawn, it is possible to be used for studying The resistance to compression creep properties of spherical shell material therefor, when material therefor is lucite, then can be used in studying pmma material Viscoelastic property under hydrostatic pressure.

Similarly, when pressure hull 2 to be measured is ring stiffened shell structure, equally according at least two hydrostatic pressure Under strain and the group data of time, by mathematical method simulate creep formula corresponding under this structure 4. and 5. in coefficient A, n, m, it follows that the resistance to compression Creep Rule of respective material, the process that herein calculates no longer describes in detail.

Above description is explanation of the invention, is not the restriction to invention, and limited range of the present invention sees right Requirement, within protection scope of the present invention, can make any type of amendment.

Claims (4)

1. The measurement apparatus of the long-time accumulated deformation of pressure-resistance structure the most under water, it is characterised in that: include the measurement of separate setting Unit and amending unit, described measuring unit includes the pressure measuring cylinder (1) for simulating deep sea pressure environment, pressure hull to be measured (2) in being placed in pressure measuring cylinder (1), hydraulically full in pressure hull to be measured (2), and pressure hull to be measured (2) by pipeline one (3) with Being positioned at volume change reader one (4) connection that pressure measuring cylinder (1) is outside, pressure measuring cylinder (1) connects water injecting pipeline and discharge pipe line, Described water injecting pipeline is provided with force (forcing) pump (5) and control valve one (6), equipped with Pressure gauge (7), described drain pipe on pressure measuring cylinder (1) Road is provided with control valve two (8)；Described amending unit includes contrasting pressure hull (9), is full of liquid in contrast pressure hull (9) Body, and contrast pressure hull (9) is by pipeline two (10) and the volume change reader two being positioned at contrast pressure hull (9) outside (11) connection；Contrast pressure hull (9), pipeline two (10) and the knot of volume change reader two (11) in described amending unit Structure is identical with the pressure hull to be measured (2) in described measuring unit, pipeline one (3) and volume change reader one (4) respectively.
2. 2. the measurement apparatus utilizing the long-time accumulated deformation of pressure-resistance structure under water described in claim 1 carries out pressure-resistance structure under water The method that long-time accumulated deformation is measured, it is characterised in that comprise the steps of

   The first step, described water injecting pipeline and described discharge pipe line are in closed mode, are not subject to quiet at pressure hull to be measured (2) In the case of water pressure, record scale value H at the volume change interior free surface place of reader one (4)₀；

   Second step, opens described water injecting pipeline, and described discharge pipe line is still in closed mode, by described water injecting pipeline to pressure Cylinder (1) water filling applies hydrostatic pressure, observes Pressure gauge (7) reading, when in pressure measuring cylinder (1), pressure reaches goal pressure P₁Time, close Close described water injecting pipeline, record scale value H at the now volume change interior free surface place of reader one (4)₁；Adjusted in concert In described amending unit, the free surface of volume change reader two (11) is in scale value H₁Position；

   3rd step, keeps the pressure of pressure measuring cylinder (1) to be in goal pressure P₁Lower t₁After time, record now volume change reading Scale value H at the interior free surface place of device one (4)₂Scale value H with the volume change interior free surface place of reader two (11)₃；

   4th step, calculates pressure hull to be measured (2) and is in constant hydrostatic pressure P₁Lower t₁Volume changing value △ V after time₁': use Scale value H that 3rd pacing obtains₂Scale value H recorded with second step₁Difference be multiplied by volume change reader one (4) cross section Long-pending；

   5th step, the volume changing value △ V that four-step calculation is obtained₁' it is modified: calculate contrast pressure hull (9) and do not holding By in the case of External Hydrostatic Pressure through t₁The volume changing value △ V caused by variations in temperature after time₁", i.e. use scale value H₃With quarter Angle value H₁Difference be multiplied by volume change reader two (11) sectional area；△V₁' and △ V₁" difference be completely by hydrostatic Pressure P₁The t in time caused₁The volume changing value △ V of accumulation₁；

   6th step, the most at regular intervals t_iRepeat above-mentioned third step to the 5th step, obtain one group of hydrostatic pressure P₁Under by Volume changing value △ V_iWith corresponding time t_iThe data of composition；

   7th step, to one group of data (the △ V recorded in the 6th step_i, t_i) use mathematical method to be fitted, draw to be measured pressure Housing (2) is in hydrostatic pressure P₁Under the volume change accumulated in time and the relation function of time, according to pressure hull to be measured (2) The geometrical relationship of structural parameters and volume and the material constitutive relation of pressure hull to be measured (2), can converse corresponding t_iTime Between time pressure hull to be measured (2) malformation value, strain, stress, thus obtain the malformation of pressure hull to be measured (2) Value, strain, stress are in hydrostatic pressure P₁Under rule over time.
3. 3. the measuring method of the long-time accumulated deformation of pressure-resistance structure under water as described in claim 2, it is characterised in that: change institute State hydrostatic pressure P₁To P₂、P₃... Pn, repeats described second to the 7th step, obtains pneumatic shell to be measured under different hydrostatic pressure The volume of body (2), malformation value, strain, stress rule over time.
4. 4. the measurement apparatus of the long-time accumulated deformation of pressure-resistance structure under water as described in claim 3, it is characterised in that: take to be measured The group data that the pressure hull (2) volume under at least two hydrostatic pressure was constituted with the time, are simulated by mathematical method and treat Survey the Creep Rule of pressure hull (2) material therefor.