CN106066905A - Under solid propellant rocket sealing ring high pressure, residual stress determines method - Google Patents

Abstract

The present invention relates to residual stress under a kind of solid propellant rocket sealing ring high pressure and determine method, belong to solid propellant rocket technical field of sealing technology.Comprise the following steps: 1) determine solid propellant rocket relevant parameter；2) the pretension compress variation of sealing ring is confirmed；3) draught head when determining solid propellant rocket high-pressure work；4) sealing ring deformation rate under Pre strained state is determined；5) sealing ring rate of residual is solved；6) sealing ring residual stress is solved.This method sets up solemn Buddhist nun Rayleigh (Mooney Rivlin) model in rubber seal, on the basis of threaded simplified model gentle differential pressure action model, high pressure effect lower seal residual stress is determined by known sealing ring pretension decrement and solid propellant rocket inner and outer air pressure difference, realizing the solid propellant rocket determination in high pressure effect lower seal slip, the improvement for solid propellant rocket assembly technology provides theory support.

Description

Under solid propellant rocket sealing ring high pressure, residual stress determines method

Technical field

The invention belongs to solid propellant rocket technical field of sealing technology, relate to a kind of solid propellant rocket sealing ring high pressure Lower residual stress determines method, and particularly one determines solid propellant rocket sealing ring indirectly by pre-tight stress and draught head The method of residual stress under elevated pressure conditions.

Background technology

Solid propellant rocket (SRM) is the significant components of guided missile and space rocket, its research work and space safety Closely bound up.Solid-rocket, during assembling, has sealing property requirement.Can its sealing property safe work to solid-rocket Make, significant.During solid-rocket work, if sealing ring leaks, will result in the gas pressure skewness of ejection Even, solid-rocket is by force unbalance；High-temperature gas flows into inside solid-rocket simultaneously, there is serious potential safety hazard.

The index that solid propellant rocket assembling guarantees at present to meet seal request is mainly the compression of sealing ring Rate, typically requires that sealing ring compression deformation rate is 10%～30%.But guarantee solid fire by the compression deformation rate of sealing ring Arrow engine assembly meets seal request and belongs to indirect mode, it is impossible to describe seal request the most accurately.To this end, scientific research personnel carries Go out the assembly technology being sealing property index with sealing ring slip.Describe with sealing ring slip for sealing property index Sealing belongs to direct mode, can describe seal request more accurately.

The rubber seal rings for seal of solid propellant rocket belongs to static seal Intermediate gasket and seals.Real at solid propellant rocket In the engineering of border work, existing boundary leakage, there is again infiltration leakage, leakage path does not only have Laminar Flow and also has molecular flow stream Dynamic, therefore porous media model better describes the leakage situation of gasket seal.

Porous media model is thought that non-metallic pad sheet material can approximate and is regarded isotropic porous media as, and its runner is by many The capillary tube composition that the radius size of individual bending does not waits.Gas can be divided into laminar flow and molecule by the flow regime of porous media Stream, its flow rate is laminar flow flow rate and molecular flow flow rate sum.Research shows the increase with pad residual stress σ of capillary radius r And reduce, there is r=f (σ^-n) relation.Gas by the slip equation of pad is:

$L_{PV}=A_L\frac{1}{b\mathrm{\η}}{\mathrm{\σ}}^{-n_L}{P}_m(P_2-P_1)+A_m\frac{1}{b}\sqrt{\frac{T}{M}}{\mathrm{\σ}}^{-n_m}{P}_m(P_2-P_1)$

In formula, A_L、A_m、n_L、n_mFor constant, its value can be obtained by experiment, L_PVFor PV slip, P_m=(P₂-P₁)/2, M is Molecular weight gas, η is dielectric viscosity, and T is gas absolute temperature.

Slip is with sealing ring residual stress, solid-rocket inner and outer air pressure is poor and gas temperature is relevant.Sealing ring remnants should The determination of power is the essential condition of research solid propellant rocket sealing property, but sealing ring residual stress is difficult to directly detect Arriving, this is a difficult point of solid propellant rocket sealing property research.

Summary of the invention

In view of this, it is an object of the invention to provide residual stress under a kind of solid propellant rocket sealing ring high pressure true Determining method, the method sets up solemn Buddhist nun Rayleigh (Mooney-Rivlin) model in rubber seal, threaded simplified model On the basis of gentle differential pressure action model, true by known sealing ring pretension decrement and solid propellant rocket inner and outer air pressure difference Make high pressure effect lower seal residual stress, it is achieved solid propellant rocket is in high pressure effect lower seal slip really Fixed, the improvement for solid propellant rocket assembly technology provides theory support.

For reaching above-mentioned purpose, the present invention provides following technical scheme:

Under a kind of solid propellant rocket sealing ring high pressure, residual stress determines that method, the method comprise the following steps:

1) rubber seal Buddhist nun Mu Rayleigh (Mooney-Rivlin) model, housing used by solid propellant rocket are determined The relevant parameter of differential pressure action model gentle with spout threads link model；

2) with solid propellant rocket tightening machine, solid propellant rocket is assembled, determine that tightening assembling completes After, the compress variation of sealing ring；

3) when determining solid propellant rocket high-pressure work, solid propellant rocket inner and outer air pressure is poor；

4) by step 2) in the sealing ring compress variation that obtains bring deformation rate computing formula into, obtain solid propellant rocket Sealing ring deformation rate under Pre strained state；

5) by step 1) in model parameter, step 3) in inner and outer air pressure difference and step 4) in sealing ring pretension deformation rate bring into Sealing ring rate of residual, pretension deformation rate and draught head relational expression；Solve relational expression, can deform at known seal circle pretension Sealing ring rate of residual in the case of rate and solid propellant rocket draught head；

6) with step 5) gained sealing ring rate of residual as known conditions, bring rubber Buddhist nun Mu Rayleigh (Mooney-into Rivlin) model, can obtain the sealing ring residual stress corresponding to sealing ring rate of residual.

Further, in step 1) in, described rubber seal Buddhist nun Mu Rayleigh (Mooney-Rivlin) model is:

Wherein: σ is residual stress, e is the compression deformation rate of sealing ring, C₁, C₂For rubber Mechanical constant in glue Buddhist nun Mu Rayleigh (Mooney-Rivlin) model.

Further, in step 1) in, solid rocket motor case is connected simplified model and is with spout threads:

$F=C\mathrm{\δ}=\frac{C_a{C}_b\mathrm{\δ}}{C_a+C_b}$

Wherein: δ is housing deformed threads amount when being connected stress with spout threads；

C is threaded simplified model rigidity, and has relational expression:

$C=\frac{C_a{C}_b}{C_a+C_b}$

Housing rigidity C_aComputing formula be:

$\frac{1}{C_a}=\frac{L_1}{E_a{A}_1}$

Jet pipe rigidity C_bComputing formula be:

$\frac{1}{C_b}=\frac{L_2}{E_b{A}_1^{\′}}$

Housing screw thread nominal stress sectional area A₁:

$A_1=\frac{\mathrm{\π}}{4}{d}_4^2-\frac{\mathrm{\π}}{4}{\left(\frac{d_2+d_3}{2}\right)}^2$

Spout threads nominal stress sectional area A '₁:

$A_1^{\′}=\frac{\mathrm{\π}}{4}{\left(\frac{d_2+d_3}{2}\right)}^2-\frac{\mathrm{\π}}{4}{d}_5^2$

$d_3=d_1-\frac{H}{6};$

Wherein: E_aElastic modelling quantity for case material；E_bElastic modelling quantity for jet pipe material；L₁Long for housing threaded portion Degree；L₂For spout threads partial-length；d₁For major diameter of external thread；d₂For pitch diameter of external thread；d₄For housing outer diameter；d₅For in jet pipe Footpath；H is the triangle height that screw thread is original.

Further, in step 1) in, solid propellant rocket draught head action model is:

q₃A₃=Δ PA₃=(P₂-P₁)A₃

Wherein: P₁For solid-rocket external pressure；P₂For solid-rocket air pressure inside；A₃For the draught head effect to housing Area.

Further, in step 2) in, when solid propellant rocket has assembled the pretension decrement of rubber seal based on The physical dimension variation relation of solid propellant rocket utilizes slide gauge directly to measure to obtain.

Further, in step 4) in, the compression deformation rate formula of sealing ring is:

$e=1-\frac{\mathrm{\Δ}L}{L}=1-\frac{\mathrm{\ϵ}}{L}$

In formula: L is sealing ring thickness；ε is the axial strain amount that sealing ring is subject to when compressing；E is that the compression of sealing ring becomes Form quotient.

Further, in step 5) in, sealing ring rate of residual, pretension deformation rate and draught head relational expression be:

${\mathrm{CLe}}^{\′}-2C_1{A}_2(e^{\′}-\frac{1}{e^{\′2}})+\frac{2C_2{A}_2}{e^{\′3}}=CLe-2C_1{A}_2(e-\frac{1}{e^2})+\frac{2C_2{A}_2}{e^3}+{\mathrm{\ΔPA}}_3$

Wherein, e ' is sealing ring rate of residual.

Further, in step 6) in, with sealing ring rate of residual as known conditions, the rubber Buddhist nun Mu Rayleigh brought into (Mooney-Rivlin) model is:

${\mathrm{\σ}}^{\′}=2(e^{\′}-\frac{1}{e^{\′2}})(C_1+\frac{C_2}{e^{\′}})$

Wherein: σ ' is residual stress.

The beneficial effects of the present invention is: 1) solve solid propellant rocket sealing ring residual stress under elevated pressure conditions It is difficult to the problem determined, it is provided that one determines close by sealing ring pretension decrement and solid propellant rocket draught head indirectly The method of seal residual stress；2) sealing ring rate of residual, pretension deformation rate and draught head relational expression are established；3) establish The method being controlled residual stress by pretension decrement under certain draught head；4) the simplification mould of threaded stress is established Type, can conveniently research and analyse.

Accompanying drawing explanation

In order to make the purpose of the present invention, technical scheme and beneficial effect clearer, the present invention provides drawings described below to carry out Illustrate:

Fig. 1 is rubber Buddhist nun Mu Rayleigh (Mooney-Rivlin) model curve figure；

Fig. 2 is sealing ring rate of residual, pretension deformation rate and draught head relation surface chart；

Fig. 3 is the schematic flow sheet of the method for the invention.

Detailed description of the invention

Below in conjunction with accompanying drawing, the preferred embodiments of the present invention are described in detail.

Fig. 3 is the schematic flow sheet of the method for the invention, as it can be seen, the implementation process of this method includes: (1) determines Solid propellant rocket relevant parameter；(2) the pretension compress variation of sealing ring is confirmed；(3) solid propellant rocket is determined Draught head during high-pressure work；(4) sealing ring deformation rate under Pre strained state is determined；(5) sealing ring rate of residual is solved； (6) sealing ring residual stress is solved.

(1) solid propellant rocket relevant parameter is determined

The model parameter determined required in the present invention is more, mainly the structural material parameter of solid propellant rocket with And the structural material parameter of rubber seal.In the present embodiment, the solid propellant rocket of a certain model and corresponding rubber are selected Glue sealing ring, design parameter is as follows:

(2) the pretension compress variation of sealing ring is confirmed

During with pretension compress variation for sealing property index, it is desirable to pretension compress variation is sealing ring nature thickness 10%～30%, in this example, sealing ring nature thickness is 1.5mm.Therefore solid propellant rocket is when tightening assembling, it is screwed to close The pretension compress variation of seal is 0.2mm.

(3) draught head when determining solid propellant rocket high-pressure work

Solid propellant rocket is operationally the environment of high pressure, the cylinder in the present embodiment, when working with reference to electromotor Pressure, draught head during solid propellant rocket high-pressure work elects 10MPa as.

(4) sealing ring deformation rate under Pre strained state is determined

The pretension compress variation 0.2mm of sealing ring is brought into deformation rate computing formula:

$e=1-\frac{\mathrm{\Δ}L}{L}=1-\frac{\mathrm{\ϵ}}{L}$

Obtaining pretension compression deformation rate now is 86.67%.

(5) sealing ring rate of residual is solved

By pretension compression deformation rate, draught head and relevant parameter, bring sealing ring rate of residual, pretension deformation rate into gentle Pressure reduction relational expression:

${\mathrm{CLe}}^{\′}-2C_1{A}_2(e^{\′}-\frac{1}{e^{\′2}})+\frac{2C_2{A}_2}{e^{\′3}}=CLe-2C_1{A}_2(e-\frac{1}{e^2})+\frac{2C_2{A}_2}{e^3}+{\mathrm{\ΔPA}}_3$

In relational expression, only one of which unknown number e ', solves equation, and can obtain e '=88.91%.

(6) sealing ring residual stress is solved.

Compressive permanent set rate e ' is brought into rubber Buddhist nun Mu Rayleigh (Mooney-Rivlin) model:

${\mathrm{\σ}}^{\′}=2(e^{\′}-\frac{1}{e^{\′2}})(C_1+\frac{C_2}{e^{\′}})$

Can obtain sealing ring residual stress σ ' is: 1.3859MPa.

Fig. 1 is rubber Buddhist nun Mu Rayleigh (Mooney-Rivlin) model curve figure in the present embodiment；Fig. 2 is the present embodiment Middle sealing ring rate of residual, pretension deformation rate and draught head relation surface chart.

Finally illustrate, preferred embodiment above only in order to technical scheme to be described and unrestricted, although logical Cross above preferred embodiment the present invention to be described in detail, it is to be understood by those skilled in the art that can be In form and it is made various change, without departing from claims of the present invention limited range in details.

Claims (8)

1. under a solid propellant rocket sealing ring high pressure, residual stress determines method, it is characterised in that: the method include with Lower step:

1) rubber seal Buddhist nun Mu Rayleigh (Mooney-Rivlin) model, housing and spray used by solid propellant rocket are determined Manage the relevant parameter of threaded model gentle differential pressure action model；

2) with solid propellant rocket tightening machine, solid propellant rocket is assembled, after determining that tightening assembling completes, close The compress variation of seal；

3) when determining solid propellant rocket high-pressure work, solid propellant rocket inner and outer air pressure is poor；

4) by step 2) in the sealing ring compress variation that obtains bring deformation rate computing formula into, obtain solid propellant rocket and seal Circle deformation rate under Pre strained state；

5) by step 1) in model parameter, step 3) in inner and outer air pressure difference and step 4) in sealing ring pretension deformation rate bring sealing into Circle rate of residual, pretension deformation rate and draught head relational expression；Solve relational expression, can in known seal circle pretension deformation rate and Sealing ring rate of residual in the case of solid propellant rocket draught head；

6) with step 5) gained sealing ring rate of residual as known conditions, bring rubber Buddhist nun Mu Rayleigh (Mooney-into Rivlin) model, can obtain the sealing ring residual stress corresponding to sealing ring rate of residual.

Under a kind of solid propellant rocket sealing ring high pressure the most according to claim 1, residual stress determines method, and it is special Levy and be: in step 1) in, described rubber seal Buddhist nun Mu Rayleigh (Mooney-Rivlin) model is:

Wherein: σ is residual stress, e is the compression deformation rate of sealing ring, C₁, C₂Solemn for rubber Mechanical constant in Buddhist nun Rayleigh (Mooney-Rivlin) model.

Under a kind of solid propellant rocket sealing ring high pressure the most according to claim 1, residual stress determines method, and it is special Levy and be: in step 1) in, solid rocket motor case is connected simplified model and is with spout threads:

$F=C\mathrm{\δ}=\frac{C_a{C}_b\mathrm{\δ}}{C_a+C_b}$

Wherein: δ is housing deformed threads amount when being connected stress with spout threads；

C is threaded simplified model rigidity, and has relational expression:

$C=\frac{C_a{C}_b}{C_a+C_b}$

Housing rigidity C_aComputing formula be:

$\frac{1}{C_a}=\frac{L_1}{E_a{A}_1}$

Jet pipe rigidity C_bComputing formula be:

$\frac{1}{C_b}=\frac{L_2}{E_b{A}_1^{\′}}$

Housing screw thread nominal stress sectional area A₁:

$A_1=\frac{\mathrm{\π}}{4}{d}_4^2-\frac{\mathrm{\π}}{4}{\left(\frac{d_2+d_3}{2}\right)}^2$

Spout threads nominal stress sectional area A '₁:

$A_1^{\′}=\frac{\mathrm{\π}}{4}{\left(\frac{d_2+d_3}{2}\right)}^2-\frac{\mathrm{\π}}{4}{d}_5^2$

$d_3=d_1-\frac{H}{6};$

Wherein: E_aElastic modelling quantity for case material；E_bElastic modelling quantity for jet pipe material；L₁For housing threaded portion length；L₂ For spout threads partial-length；d₁For major diameter of external thread；d₂For pitch diameter of external thread；d₄For housing outer diameter；d₅For jet pipe internal diameter；H is The triangle height that screw thread is original.

Under a kind of solid propellant rocket sealing ring high pressure the most according to claim 1, residual stress determines method, and it is special Levy and be: in step 1) in, solid propellant rocket draught head action model is:

q₃A₃=Δ PA₃=(P₂-P₁)A₃

Wherein: P₁For solid-rocket external pressure；P₂For solid-rocket air pressure inside；A₃For the draught head active area to housing.

Under a kind of solid propellant rocket sealing ring high pressure the most according to claim 1, residual stress determines method, and it is special Levy and be: in step 2) in, when solid propellant rocket has assembled, the pretension decrement of rubber seal is based on solid-rocket The physical dimension variation relation of electromotor utilizes slide gauge directly to measure to obtain.

Under a kind of solid propellant rocket sealing ring high pressure the most according to claim 1, residual stress determines method, and it is special Levy and be: in step 4) in, the compression deformation rate formula of sealing ring is:

$e=1-\frac{\mathrm{\Δ}L}{L}=1-\frac{\mathrm{\ϵ}}{L}$

In formula: L is sealing ring thickness；ε is the axial strain amount that sealing ring is subject to when compressing；E is the compression deformation rate of sealing ring.

Under a kind of solid propellant rocket sealing ring high pressure the most according to claim 1, residual stress determines method, and it is special Levy and be: in step 5) in, sealing ring rate of residual, pretension deformation rate and draught head relational expression be:

${\mathrm{CLe}}^{\′}-2C_1{A}_2(e^{\′}-\frac{1}{e^{\′2}})+\frac{2C_2{A}_2}{e^{\′3}}=CLe-2C_1{A}_2(e-\frac{1}{e^2})+\frac{2C_2{A}_2}{e^3}+{\mathrm{\ΔPA}}_3$

Wherein, e ' is sealing ring rate of residual.

Under a kind of solid propellant rocket sealing ring high pressure the most according to claim 1, residual stress determines method, and it is special Levy and be: in step 6) in, with sealing ring rate of residual as known conditions, the rubber Buddhist nun Mu Rayleigh (Mooney-brought into Rivlin) model is:

${\mathrm{\σ}}^{\′}=2(e^{\′}-\frac{1}{e^{\′2}})(C_1+\frac{C_2}{e^{\′}})$

Wherein: σ ' is residual stress.