CN104019790A - Measurement device and method for long-time-accumulation deformation of underwater pressure-resistant structure - Google Patents

Abstract

A measurement device for long-time-accumulation deformation of an underwater pressure-resistant structure comprises a measurement unit and a correction unit, wherein the measurement unit and the pressure unit are mutually independently arranged. The measurement unit comprises a pressure cylinder. A pressure shell, filled with liquid, to be measured is placed in the pressure cylinder. The pressure shell to be measured is communicated with a volume variation reader located outside the pressure cylinder through a pipeline. A pressure gage is arranged on the pressure cylinder. The correction unit is composed of the other pressure shell be measured, the other volume variation reader and a connection pipeline connected between the other pressure shell and the other volume variation reader. The invention further provides a measurement method for indirectly measuring long-time-accumulation deformation of the pressure-resistant structure by means of measuring the variation of the volume of the pressure-resistant structure along with time accumulation at the hydrostatic pressure, the variation rules of mechanical parameters such as a structure deformation value, stress and strain of the pressure-resistance structure along with time are indirectly measured according to the method and can be used for researching the creep property or the viscoelasticity property of materials applied to the underwater pressure-resistant structure, and the whole measurement device is simple in structure, capable of being used for measurement visually and conveniently, convenient to maintain and high in measurement accuracy.

Description

The measurement mechanism 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 specifically related to for measuring under water pressure-resistance structure long-time accumulated deformation and study under water the resistance to compression creep properties of pressure-resistance structure material or the device and method of viscoelastic property by the measurement result of long-time accumulated deformation under hydrostatic force.

Background technology

Pressure-resistance structure is the important component part that underwater robot, manned underwater vehicle, space station, deep-sea and submarine etc. deliver job platform under water under water, for bearing the safety of the high compressive load in deep-sea support personnel and equipment.At present, the main sensor measurements such as resistance strain gage that adopt of pressure-resistance structure External Hydrostatic Pressure power test under water, by measuring the strain of pressure hull key position under water and being scaled structural stress; The creep measurement of land pressure-resistant pipeline (interior pressure) adopts creep measurement points mensuration and creep measurement mark mensuration conventionally, the former uses milscale between measuring point, to measure distortion, the latter uses special steel band tape to be wrapped on steel pipe or header body measured section outside surface, the increment of measuring this position.For sensor measurements such as resistance strain gages, owing to being immersed in easily make moist aging, the performance generation creep of resistance strain gage in water, cause serviceable life low, be not suitable for the measurement of the long-time distortion of pressure-resistance structure under water, and strain gage testing position is local measurement, and the creep properties of material is a kind of distortion of full structure, therefore, traditional sensor measurements such as resistance strain gage cannot complete long-term observation and the measurement of the creep of pressure-resistance structure under water (or viscoelasticity); For creep measurement points mensuration and creep measurement mark mensuration, because these two kinds of measuring methods can only be for the pressure-resistant pipeline exposing, therefore and the long-term accumulated deformation test of pressure-resistance structure under water need to be carried out in pressure measuring cylinder, the creep measurement method of traditional land pressure-resistant pipeline (interior pressure) also cannot adapt to the measurement of accumulated deformation in pressure-resistance structure process of the test under water.

Summary of the invention

The applicant improves for above-mentioned shortcoming of the prior art, measurement mechanism and the method for the long-time accumulated deformation of a kind of pressure-resistance structure are under water provided, it can realize the volume of the pressure-resistance structure measurement of rule over time under water under hydrostatic force, it is convenient, accurate to measure, and based on volume-variation measurement result, by mathematical conversion, can draw the long-time accumulated deformation of pressure-resistance structure under hydrostatic force, can be used in creep properties or the viscoelastic property of research pressure-resistance structure material.

Technical scheme of the present invention is as follows:

The measurement mechanism of the present invention's the long-time accumulated deformation of pressure-resistance structure under water, the measuring unit and the amending unit that comprise separate setting, described measuring unit comprises for simulating the pressure measuring cylinder of deep sea pressure environment, pressure hull to be measured is placed in pressure measuring cylinder, in pressure hull to be measured, be full of liquid, and pressure hull to be measured is communicated with the volume-variation reader one that is positioned at pressure measuring cylinder outside by pipeline one, pressure measuring cylinder is connected with water injecting pipeline and discharge pipe line, described water injecting pipeline is provided with force (forcing) pump and operation valve one, tensimeter is housed on pressure measuring cylinder, described discharge pipe line is provided with operation valve two, described amending unit comprises contrast pressure hull, in contrast pressure hull, is full of liquid, and contrast pressure hull is communicated with the volume-variation reader two that is positioned at contrast pressure hull outside by pipeline two, the structure of the contrast pressure hull in described amending unit, pipeline two and volume-variation reader two is identical with pressure hull to be measured, pipeline one and volume-variation reader one in described measuring unit respectively.

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

The first step, described water injecting pipeline and described discharge pipe line, all in closed condition, in the situation that pressure hull to be measured does not bear hydrostatic force, are recorded the scale value H at the interior free surface of volume-variation reader one place ₀;

Second step, opens described water injecting pipeline, and described discharge pipe line is still in closed condition, and by described water injecting pipeline, to pressure measuring cylinder, water filling applies hydrostatic force, observes pressure gauge reading, when pressure measuring cylinder internal pressure reaches goal pressure P ₁time, close described water injecting pipeline, record the now scale value H at the interior free surface of volume-variation reader one place ₁; Described in adjusted in concert in amending unit the free surface of volume-variation reader two in scale value H ₁position;

The 3rd step, keeps the pressure of pressure measuring cylinder in goal pressure P ₁lower t ₁after time, record the now scale value H at the interior free surface of volume-variation reader one place ₂scale value H with the interior free surface of volume-variation reader two place ₃;

The 4th step, calculates pressure hull to be measured in constant hydrostatic force P ₁lower t ₁volume-variation value △ V after time ₁': the scale value H obtaining with the 3rd pacing ₂the scale value H recording with second step ₁difference be multiplied by the sectional area of volume-variation reader one;

The 5th step, the volume-variation value △ V that four-step calculation is obtained ₁' revise: calculate contrast pressure hull process t in the situation that not bearing External Hydrostatic Pressure ₁the volume-variation value △ V being caused by temperature variation after time ₁", use scale value H ₃with scale value H ₁difference be multiplied by the sectional area of volume-variation reader two; △ V ₁' with △ V ₁" difference be completely by hydrostatic force P ₁the t in time causing ₁the volume-variation value △ V of accumulation ₁;

The 6th step, often t at regular intervals _irepeat above-mentioned third step to the five steps, obtain one group of hydrostatic force P ₁under by volume-variation value △ V _iwith corresponding time t _ithe data that form;

The 7th step, to one group of data (the △ V recording in the 6th step _i, t _i) adopt mathematical method to carry out matching, show that pressure hull to be measured is at hydrostatic force P ₁under in time accumulation volume-variation and the relation function of time, the material constitutive relation according to the geometric relationship of pressure hull structural parameters to be measured and volume and pressure hull to be measured, can converse corresponding t _imalformation value, strain, the stress of pressure hull to be measured during the time, obtain the malformation value, strain, stress of pressure hull to be measured thus at hydrostatic force P ₁under rule over time.

Its further technical scheme is:

Change described hydrostatic force P ₁to P ₂, P ₃pn, repeats the described second to the 7th step, and the volume, malformation value, strain, stress that obtains pressure hull to be measured under different hydrostatic forces be rule over time.

Get the volume of pressure hull to be measured under at least two kinds of hydrostatic forces and the group data of time formation, by mathematical method, simulate the Creep Rule of pressure hull material therefor to be measured.

Technique effect of the present invention:

The present invention is by being converted to measurement target the volume-variation amount of the long-time accumulation of pressure-resistance structure under hydrostatic force by the deflection of traditional pressure-resistance structure under water, measurement target is amplified, not only can by mathematical conversion and Mathematical Fitting, show that the collecting structure of pressure-resistance structure is out of shape by the volume-variation amount that records thus, stress, strain is rule over time, and can further by mathematical conversion and matching, draw resistance to compression creep properties or the viscoelastic property of pressure-resistance structure material therefor, on the other hand, traditional sensor measurements such as resistance strain gage have been overcome because of the resistance strain gage short defect that cannot be applicable to the measurement of the long-time accumulated deformation of pressure-resistance structure under water and the locality of strain gage testing position in serviceable life, measurement mechanism of the present invention is simple in structure, it is intuitively convenient to measure, and experimentation cost is low, easy to maintenance, tests sustainable by force, solved traditional external pressure test of pressure-resistance structure under water and cannot measure the technical matters of the long-time accumulated deformation of pressure-resistance structure under water, the present invention, by the setting of correcting device, can eliminate the measuring error being caused by temperature variation, has improved measuring accuracy.

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 strain---the time plot of pressure hull to be measured under two kinds of hydrostatic forces.

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

Embodiment

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described.

See Fig. 1, Fig. 2, the measurement mechanism of the present invention's the long-time accumulated deformation of pressure-resistance structure under water comprises measuring unit and the amending unit of separate setting, described measuring unit comprises for simulating the pressure measuring cylinder 1 of deep sea pressure environment, pressure hull 2 to be measured is placed in pressure measuring cylinder 1, in pressure hull 2 to be measured, be full of incompressible liquid, and pressure hull 2 to be measured is communicated with the volume-variation reader 1 that is positioned at pressure measuring cylinder 1 outside by pipeline 1, pressure measuring cylinder 1 is connected with water injecting pipeline and discharge pipe line, described water injecting pipeline is provided with force (forcing) pump 5 and operation valve 1, tensimeter 7 is housed on pressure measuring cylinder 1, described discharge pipe line is provided with operation valve 28, operation valve 1 and operation valve 28 are respectively used to control described water injecting pipeline, opening of described discharge pipe line, close, described amending unit comprises contrast pressure hull 9, in contrast pressure hull 9, is full of incompressible liquid, and contrast pressure hull 9 is communicated with the volume-variation reader 2 11 that is positioned at contrast pressure hull 9 outsides by pipeline 2 10, the structure of the contrast pressure hull 9 in described amending unit, pipeline 2 10 and volume-variation reader 2 11 is identical with pressure hull to be measured 2, pipeline 1 and volume-variation reader 1 in measuring unit respectively, volume-variation reader 1 and volume-variation reader 2 11 are the graduated container of mark, and shape is preferably cylindrical elongate container.

Utilize the method that the measurement mechanism of the present invention's the long-time accumulated deformation of pressure-resistance structure is under water measured the long-time accumulated deformation of pressure hull under water to comprise following steps:

The first step, described water injecting pipeline and described discharge pipe line, all in closed condition, in the situation that pressure hull 2 to be measured does not bear hydrostatic force, are recorded the scale value H at the interior free surface of volume-variation reader 1 place ₀;

Second step, opens described water injecting pipeline, and described discharge pipe line is still in closed condition, and by described water injecting pipeline, to pressure measuring cylinder, 1 water filling applies hydrostatic force, observes tensimeter 7 readings, when pressure measuring cylinder 1 internal pressure reaches goal pressure P ₁time, close described water injecting pipeline, record the now scale value H at the interior free surface of volume-variation reader 1 place ₁; Meanwhile, described in adjusted in concert in amending unit the free surface of volume-variation reader 2 11 in scale value H ₁position;

The 3rd step, keeps the pressure of pressure measuring cylinder 1 in goal pressure P ₁lower t ₁after time, record the now scale value H at the interior free surface of volume-variation reader 1 place ₂scale value H with the interior free surface of volume-variation reader 2 11 place ₃;

The 4th step, calculates pressure hull 2 to be measured in constant hydrostatic force P ₁lower t ₁volume-variation value △ V after time ₁': the scale value H obtaining with the 3rd pacing ₂the scale value H recording with second step ₁difference be multiplied by the sectional area of volume-variation reader 1, described product value is △ V ₁';

The 5th step, the volume-variation value △ V that four-step calculation is obtained ₁' revise: calculate contrast pressure hull 9 process t in the situation that not bearing External Hydrostatic Pressure ₁the volume-variation value △ V being caused by temperature variation after time ₁", use scale value H ₃with scale value H ₁difference be multiplied by the sectional area of volume-variation reader 2 11, described product value is △ V ₁"; △ V ₁' with △ V ₁" difference be completely by hydrostatic force P ₁the pressure hull to be measured 2 causing is t in time ₁the volume-variation value △ V of accumulation ₁;

The 6th step, often t at regular intervals _irepeat above-mentioned third step to the five steps, obtain thus one group of hydrostatic force P ₁under by volume-variation value △ V _iwith corresponding time t _idata (the △ V forming _i, t _i), wherein, i=1,2 ..., n;

The 7th step, to one group of data (the △ V recording in the 6th step _i, t _i) adopt mathematical method to carry out matching, show that pressure hull 2 to be measured is at hydrostatic force P ₁under in time accumulation volume-variation and the relation function of time, according to pressure hull 2 structural parameters to be measured and the geometric relationship of volume and the material constitutive relation of pressure hull to be measured 2, can converse corresponding t _imalformation value, strain, the stress of pressure hull 2 to be measured during the time, obtain the malformation value, strain, stress of pressure hull 2 to be measured thus at hydrostatic force P ₁under rule over time.

Particularly, to one group of data (the △ V recording in the 6th step _i, t _i) adopt mathematical method to carry out matching, show that pressure hull 2 to be measured is at hydrostatic force P ₁under in time accumulation volume-variation and the Changing Pattern of time, according to the pressure hull to be measured 2 original volume V in first step ₀, can transform and obtain pressure hull 2 to be measured at hydrostatic force P ₁under in time accumulation volume and the Changing Pattern of time:

V＝f(t) ①

According to the constitutive relation of the geometric relationship of the geometrical structure parameter of pressure hull 2 to be measured and volume and withstand voltage object material therefor to be measured, the mechanics parameter such as malformation value, strain, stress that can converse pressure-resistance structure body 2 to be measured is rule over time, as:

r＝f′(f(t)) ②

ε＝f″(f(t)) ③

In formula: r represents one of geometric parameter of pressure hull 2 structures to be measured, the radius of withstand voltage spherical shell under water for example; ε represents the strain value of pressure hull 2 particular locations to be measured on specific direction, and f ', f " are corresponding funtcional relationship.

Further, by changing described hydrostatic force P ₁to P ₂, P ₃pn, repeat the described second to the 7th step, the volume, malformation value, strain, stress that can access pressure hull 2 to be measured under different hydrostatic forces be rule over time, for creep properties or the viscoelastic property research of pressure hull 2 structured materials to be measured.

Get two groups of data of malformation value, strain, stress and the time of pressure hull 2 to be measured under at least two kinds of hydrostatic forces, by mathematical method, simulate the Creep Rule of pressure hull 2 material therefors to be measured.

Take two kinds of typical structures of pressure hull under water: the refining spherical shell of metal and ring rib cylindrical shell are example, illustrate and how by measurement mechanism of the present invention and measuring method, to draw the long-time accumulated deformation of pressure hull under hydrostatic force, and draw thus creep properties or the viscoelastic property of pressure-resistance structure material.

Get pressure hull 2 to be measured metal material Creep Rule as shown in the formula:

ε ^c=A ₁σ ⁿt ^mprimary creep behavior 4.

ε ^c=A ₂σ ⁿt creep subordinate phase 5.

In formula: A, n, m are and need to carry out by measurement result the coefficient of the Fitting Calculation, ε ^cfor creep strain, σ is the stress of pressure hull under water under corresponding hydrostatic force.

According to the first step to the six steps described in the measuring method of the present invention's the long-time accumulated deformation of pressure-resistance structure under water, obtain one group of hydrostatic force P ₁under by volume-variation value △ V _iwith corresponding time t _idata (the △ V forming _i, t _i), according to the pressure hull to be measured 2 original volume V in first step ₀, can transform and obtain pressure hull 2 to be measured at hydrostatic force P ₁under by volumetric values V _iwith corresponding time t _idata (the V forming _i, t _i), carry out enough test for a long time and guarantee that pressure hull 2 to be measured has entered creep subordinate phase; Then, change described hydrostatic force P ₁to P ₂, at hydrostatic force P ₂under repeat described second step to the six steps, obtain pressure hull 2 to be measured at hydrostatic force P ₂under by volumetric values V _i' and corresponding time t _idata (the V forming _i', t _i), same, can, by the volume under other hydrostatic forces of experimental measurement and the data of time, for concise and to the point elaboration, select two kinds of hydrostatic force P ₁, P ₂explain.

When pressure hull 2 to be measured is spherical shell, at constant hydrostatic force P ₁and P ₂lower elapsed-time standards t respectively _kafter, now, spherical shell is at hydrostatic force P ₁and P ₂volumetric values be respectively V _kand V _k', spherical shell hydrostatic force P ₁and P ₂radius r _kand r _k', strain is respectively:

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

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

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

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

In formula: with represent respectively hydrostatic force P ₁and P ₂corresponding time t _ktime spherical shell in the strain value that caused by creep of face arbitrfary point, r ₀for pressure hull 2 original volume V to be measured ₀time radius.According to above-mentioned mathematical relation, can obtain hydrostatic force P ₁and P ₂corresponding time t _ktime spherical shell strain data point: , under same acting by external hydrostatic pressure, in different time points, can access corresponding dependent variable, take dependent variable as ordinate, take the time as horizontal ordinate, by hydrostatic force P ₁and P ₂two groups of strains of lower spherical shell and the data of time: can draw out two strains---the time curve of spherical shell material therefor, Figure 3 shows that material titanium alloy that the titanium alloy spherical shell by measuring uses is at constant hydrostatic force P ₁under strain---time curve, the primary creep behavior that creep rate is successively decreased as we can see from the figure and creep rate be constant subordinate phase almost, another is at hydrostatic force P ₂under strain---time curve does not provide, but by test figure, draw, its strain---time curve and hydrostatic force P ₁under strain---time curve is approximate, similarly disclosed almost constant subordinate phase of primary creep behavior that creep rate successively decreases and creep rate.

See Fig. 3, cast out first stage and subordinate phase transitional region data, according to two kinds of hydrostatic force P ₁and P ₂the strain drawing and the data of time, can go out coefficient A, n, the m of creep formula 4. and 5. by Mathematical Fitting:

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

In formula, σ ₁for hydrostatic force is P ₁time spherical shell axially/circumferential stress, by hydrostatic force, spherical shell radius and shell thickness, carry out mathematical computations and can calculate this stress; with be respectively hydrostatic force P ₁and P ₂time in the creep rate of creep subordinate phase, this creep rate can be passed through P ₁and P ₂under two groups of strains and the data of time carry out the Fitting Calculation, the upper horizontal line in formula all represents to get all over subscript and is averaging.Thus, draw the Creep Rule formula of spherical shell material, can be used in the resistance to compression creep properties of research spherical shell material therefor, when material therefor is organic glass, can be used in the viscoelastic property of research pmma material under hydrostatic force.

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

More than describing is explanation of the invention, is not the restriction to invention, and limited range of the present invention, referring to claim, within protection scope of the present invention, can be done any type of modification.

Claims (4)

1. the measurement mechanism of the long-time accumulated deformation of pressure-resistance structure under water, it is characterized in that: the measuring unit and the amending unit that comprise separate setting, described measuring unit comprises the pressure measuring cylinder (1) for simulating deep sea pressure environment, pressure hull to be measured (2) is placed in pressure measuring cylinder (1), pressure hull to be measured is full of liquid in (2), and pressure hull to be measured (2) is communicated with by pipeline one (3) the volume-variation reader one (4) outside with being positioned at pressure measuring cylinder (1), pressure measuring cylinder (1) is connected with water injecting pipeline and discharge pipe line, described water injecting pipeline is provided with force (forcing) pump (5) and operation valve one (6), tensimeter (7) is housed on pressure measuring cylinder (1), described discharge pipe line is provided with operation valve two (8), described amending unit comprises contrast pressure hull (9), in contrast pressure hull (9), be full of liquid, and contrast pressure hull (9) is communicated with by pipeline two (10) the volume-variation reader two (11) outside with being positioned at contrast pressure hull (9), the structure of the contrast pressure hull (9) in described amending unit, pipeline two (10) and volume-variation reader two (11) is identical with pressure hull to be measured (2), pipeline one (3) and volume-variation reader one (4) in described measuring unit respectively.

2. utilize the measurement mechanism of the long-time accumulated deformation of pressure-resistance structure under water described in claim 1 to carry out the method that the long-time accumulated deformation of pressure-resistance structure is under water measured, it is characterized in that, comprise following steps:

The first step, described water injecting pipeline and described discharge pipe line, all in closed condition, in the situation that pressure hull to be measured (2) does not bear hydrostatic force, are recorded the scale value H at volume-variation reader one (4) interior free surface place ₀;

Second step, opens described water injecting pipeline, and described discharge pipe line is still in closed condition, and by described water injecting pipeline, to pressure measuring cylinder (1), water filling applies hydrostatic force, observes tensimeter (7) reading, when pressure measuring cylinder (1) internal pressure reaches goal pressure P ₁time, close described water injecting pipeline, record the now scale value H at volume-variation reader one (4) interior free surface place ₁; Described in adjusted in concert in amending unit the free surface of volume-variation reader two (11) in scale value H ₁position;

The 3rd step, keeps the pressure of pressure measuring cylinder (1) in goal pressure P ₁lower t ₁after time, record the now scale value H at volume-variation reader one (4) interior free surface place ₂scale value H with volume-variation reader two (11) interior free surface places ₃;

The 4th step, calculates pressure hull to be measured (2) in constant hydrostatic force P ₁lower t ₁volume-variation value △ V after time ₁': the scale value H obtaining with the 3rd pacing ₂the scale value H recording with second step ₁difference be multiplied by the sectional area of volume-variation reader one (4);

The 5th step, the volume-variation value △ V that four-step calculation is obtained ₁' revise: calculate contrast pressure hull (9) process t in the situation that not bearing External Hydrostatic Pressure ₁the volume-variation value △ V being caused by temperature variation after time ₁", use scale value H ₃with scale value H ₁difference be multiplied by the sectional area of volume-variation reader two (11); △ V ₁' with △ V ₁" difference be completely by hydrostatic force P ₁the t in time causing ₁the volume-variation value △ V of accumulation ₁;

The 6th step, often t at regular intervals _irepeat above-mentioned third step to the five steps, obtain one group of hydrostatic force P ₁under by volume-variation value △ V _iwith corresponding time t _ithe data that form;

The 7th step, to one group of data (the △ V recording in the 6th step _i, t _i) adopt mathematical method to carry out matching, show that pressure hull to be measured (2) is at hydrostatic force P ₁under in time accumulation volume-variation and the relation function of time, the material constitutive relation according to the geometric relationship of pressure hull to be measured (2) structural parameters and volume and pressure hull to be measured (2), can converse corresponding t _imalformation value, strain, the stress of pressure hull to be measured (2) during the time, obtain the malformation value, strain, stress of pressure hull to be measured (2) thus at hydrostatic force P ₁under rule over time.

3. by the measuring method of the long-time accumulated deformation of pressure-resistance structure under water claimed in claim 2, it is characterized in that: change described hydrostatic force P ₁to P ₂, P ₃pn, repeats the described second to the 7th step, and the volume, malformation value, strain, stress that obtains pressure hull to be measured (2) under different hydrostatic forces be rule over time.

4. by the measurement mechanism of the long-time accumulated deformation of pressure-resistance structure under water claimed in claim 3, it is characterized in that: get the volume of pressure hull to be measured (2) under at least two kinds of hydrostatic forces and the group data of time formation, by mathematical method, simulate the Creep Rule of pressure hull to be measured (2) material therefor.