CN101920558B - Process window optimization method of resin-base composite curvature laminate in autoclave molding - Google Patents

Abstract

The invention discloses a process window optimization method applicable to a resin-base composite curvature laminate in autoclave molding, and the method is based on a resin-base composite hot-press molding analogue unit and a process parameter optimization goal setting unit, is combined with a defect property database unit and gives a hot-press molding process window of the curvature laminate, thus preparing the curvature laminate that meets the requirements of the average fiber volume fraction and the probability of defects of the laminate in the optimized process window, and an alarm is given out when a defect occurs in the process of the hot-press molding, thus guiding the resin-base composite curvature laminate to carry out industrial operation of the hot-press molding and enhancing the qualified rate of products.

Description

The process window optimization method of resin-base composite curvature laminate in autoclave molding

Technical field:

The present invention relates to a kind of hot press forming technology that is applicable to polymer matrix composites, specifically, refer to a kind of optimization method that is applicable to the process window of resin-base composite curvature laminate in the autoclave molding process.

Background technology:

Process window refers to satisfy the control range of technological parameter under the target call condition, and process window is wider to show that the manufacturability of material system is better, then easier realization set objective in the actual process.

In September, 2004 publish " a kind of composite autoclave forming process Fig. 8-62 is disclosed in the 233rd page of the polymer matrix composite handbook.The relation (or claiming pressure regime) that exists between the relation that exists between temperature-time as can be seen from the figure (or claiming temperature schedule) and pressure-time.

More be to formulate technological parameter by experience and lot of experiments at present in actual production, it is trial-and-error method, the applicability of the technological parameter that this method optimizes is very poor, only change the geometry of product even raw material are constant, also will again grope new technological specification, this has caused long, the problem such as percent defective is high and reliability is low of lead time undoubtedly.Another kind is that expert system and Sensor monitoring technology are combined, information by being arranged on the machined materials such as sensor Real-time Collection temperature in the curing system, pressure also feeds back to real-time monitoring system in the computer, described real-time monitoring system is according to certain principle technological parameter in time to be adjusted, thereby forming process is control effectively, i.e. online curing monitoring method.The method has been eliminated the blindness of empirical method to a certain extent, improved parts quality stability, but sensor can stay generally that thereby product is inner to affect its performance, and many sensors and monitoring equipment is expensive, so that this method is difficult to rapid popularization.In addition, the quality of expert system on-line monitoring depends on the degree of perfection of its principle, and for complicated situation, it is very difficult formulating rational principle.

In actual applications, the aircraft composite is of a great variety, and version is complicated, and curvature laminate is a kind of typical forms, and namely the two-stage structure by flat plate section and segmental arc forms, referring to three-dimensional structure schematic diagram shown in Figure 1.Curvature laminate is different from equal thick laminate, because segmental arc exists, the arc length of thickness direction diverse location is different, under external force except the distortion of thickness direction, can produce detrusion simultaneously, and the deformation extent of diverse location place laminate is different, the resin bearing pressure is different, resin generation two-dimensional flow, namely the interior direction of thickness direction and face flows; Simultaneously because the anisotropy of composite, the distortion of resin flows and laminate is very complicated in forming process, produce easily various defectives, such as hole, rich resin, bridge formation etc., these process windows that cause being applicable to equal thick laminate no longer satisfy the preparation requirement of curvature laminate, under the condition that breaks away from production line, set up process window optimization method, the evaluating material manufacturability, for reduction manufacturing cost, raising product percent of pass, and the hot-forming industrialization operation of band curvature structure is significant.

Summary of the invention:

The objective of the invention is to propose the process window optimization method of a kind of resin-base composite curvature laminate in autoclave molding, the method is the initial process parameter F with curvature laminate ₇Be the input message source, by the relevant treatment relation that provides in molding technique parameter setting unit 2, characteristic material data library unit 3 and the defect characteristics Database Unit 4, then in conjunction with product configuration and mesh generation unit 1 and process parameter optimizing target setting unit 6 requirements, in hot-forming analogue unit 5, process at last, thereby the average fiber volume fraction of curvature laminate is satisfied in acquisition

Produce probability P with the hole defective ₁The more optimal process window that requires, this more optimal process window is applied to resin-base composite curvature laminate in hot-forming industrialization operation, can improve the qualification rate of product.

The product initial setting up parameter F of product configuration and 1 output of mesh generation unit ₁Include mould-type, suction glue mode, the prepreg overlay number of plies, mould arc part radian, paste die face arc radius, horizontal equal thick laminate length, vertical equal thick laminate length;

The moulding process parameter F of molding technique parameter setting unit 2 outputs ₂Include envionmental humidity, initial temperature, heating rate, temperature-time relationship, add normal pressure, pressure applying moment;

The material parameter F of characteristic material data library unit 3 outputs ₃Include resin kind, kinds of fibers, fabric type, prepreg initial fiber volume fraction and the initial thickness in monolayer of prepreg; Described resin kind is epoxy resin, phenolic resins, cyanate ester resin, bismaleimide resin etc.; Described kinds of fibers is glass fibre, carbon fiber, aramid fiber, basalt fibre etc.; Described fabric type is unidirectional pre-immersion material, one-way fabric, plain cloth, twills, satin fabric etc.;

The defect characteristics parameter F of defect characteristics Database Unit 4 outputs ₄Include the various manufacturing defect such as hole that hot press forming technology produces, layering, rich resin, poor glue;

Hot-forming analogue unit 5 is at first according to product initial setting up parameter F ₁, moulding process parameter F ₂, material parameter F ₃With defect characteristics parameter F ₄Carry out the hot press forming technology process simulation, obtain mass parameter

Then according to fitness function

To the average fiber volume fraction

Target average fiber volume fraction

Standard deviation with target average fiber volume fraction

Compare, obtain the fitness parameter; Then produce probability according to the hole defective

To resin pressure P _rWith the resin minimum pressure P that stops air bubble growth _vCompare, obtain the hole defective and produce probability; Produce probability to initial process window parameter F according to fitness parameter and hole defective at last ₇Be optimized processing, the process window after obtaining to optimize;

Process parameter optimizing target setting unit 6 is be used to optimization aim parameter F is provided ₆Give hot-forming analogue unit 5; Can be according to optimization aim parameter F in hot-forming analogue unit 5 ₆The initial process parameter F that further initial process window setting unit (7) is provided ₇Be optimized, thereby embody the average fiber volume fraction of curvature laminate

Produce probability P with the hole defective ₁The preferred process window;

The initial process parameter F of initial process window setting unit 7 outputs ₇Include the lower limit temperature T1 of impressed pressure, the first platform temperature T1 _Min=70～130 ℃, the ceiling temperature T1 of the first platform temperature T1 _Max=100～160 ℃, the minimum of a value PC of the PC that exerts pressure _MinThe maximum PC of≤0.1MPa and the PC that exerts pressure _Max〉=0.6MPa.

The present invention is optimized method to the process window of curvature laminate and has following advantage:

1. with the experimental parameter F in the initial process window 7 ₇Be the basis, utilize Optimization Mechanism automatically to adjust the processing simulation that molding technique parameter (impressed pressure, pressure applying moment) carries out curvature laminate, the process conditions that rejecting porosity content is higher, the discontented foot-eye of average fiber volume fraction requires, process window can offer with reference to person's use or for hot-forming industrialization operation with data file and graphic form after the optimization that simulation obtains.

2. the present invention utilizes computer technology to realize optimization to the curvature laminate process window, has simple to operately, and simulation precision is high, real-time characteristics.

3. the Optimization Technology window that adopts the present invention to obtain can prepare and satisfy the low curvature laminate that requires of average fiber volume fraction, porosity content.

4. resin base composite material hot-pressed formation analogy method and defect characteristics database combination among the present invention can be estimated defective and produce probability, and report to the police when defective occurring in the hot-forming process.

Description of drawings:

Fig. 1 is curvature laminate two-dimension plane structure schematic diagram.

Fig. 2 is the structural representation block diagram of the hot-forming polymer matrix composites curvature laminate of the present invention process window optimization system.

Fig. 3 arranges the interface for the mesh generation to curvature laminate.

Fig. 4 is the interface of molding technique parameter setting unit of the present invention.

Fig. 4 A is the graph of a relation of temperature, pressure and time three in the existing autoclave forming process.

Fig. 5 is the interface that initial process window of the present invention arranges.

Fig. 6 is the interface that optimization aim of the present invention arranges.

Fig. 7 is the cross-sectional view of carbon fiber/epoxy resin curvature laminate.

Fig. 7 A is the network subdivision schematic diagram of carbon fiber/epoxy resin curvature laminate.

Fig. 7 B is the computer interface of carbon fiber/epoxy resin curvature laminate.

Fig. 7 C is the process window after the carbon fiber/epoxy resin curvature laminate is optimized.

The specific embodiment:

The present invention is described in further detail below in conjunction with drawings and Examples.

The present invention is a kind of hot-forming process of utilizing computer technology to come analog tree resin-based composite curvature laminate, is the initial process parameter F with curvature laminate ₇Be the input message source, by the relevant treatment relation that provides in molding technique parameter setting unit 2, characteristic material data library unit 3 and the defect characteristics Database Unit 4, then in conjunction with product configuration and mesh generation unit 1 and process parameter optimizing target setting unit 6 requirements, in hot-forming analogue unit 5, process at last, thereby the average fiber volume fraction of curvature laminate is satisfied in acquisition Produce probability P with the hole defective ₁The more optimal process window that requires, this more optimal process window is applied to resin-base composite curvature laminate in hot-forming industrialization operation, can improve the qualification rate of product.

Referring to shown in Figure 2, a kind of resin-base composite curvature laminate, process window optimization method in autoclave molding of being applicable to of the present invention includes product configuration and mesh generation unit 1, molding technique parameter setting unit 2, characteristic material data library unit 3, defect characteristics Database Unit 4, hot-forming analogue unit 5, process parameter optimizing target setting unit 6 and initial process window setting unit 7 in this process window optimization process.

In the present invention, the product initial setting up parameter F of product configuration and 1 output of mesh generation unit ₁Include mould-type, suction glue mode, the prepreg overlay number of plies, mould arc part radian, paste die face arc radius, horizontal equal thick laminate length, vertical equal thick laminate length, these parameters can carry out the desired parameters typing of simulation process by interface (referring to shown in Figure 3) mode, also can read by data file.

In the present invention, the moulding process parameter F of molding technique parameter setting unit 2 outputs ₂Include envionmental humidity, initial temperature, heating rate, temperature-time relationship, add normal pressure, pressure applying moment, these parameters can carry out the parameter typing by interface (referring to shown in Figure 4) mode, be stored in the computer after also can obtaining by Analysis on Mathematic Model, wait for that extracting corresponding file when using gets final product.In September, 2004 publish " a kind of composite autoclave forming process Fig. 8-62 (being shown in Fig. 4 A) is disclosed in the 233rd page of the polymer matrix composite handbook, temperature in insulation 30～60min section is called the first platform temperature T1, the temperature of insulation 120 ± 10min section is called the second platform temperature T2, as can be seen from the figure, the relation between temperature-time and pressure-time.Because the present invention is will be to the initial process parameter F of curvature laminate ₇Be optimized, the temperature that therefore arranges has difference.

In the present invention, the material parameter F of characteristic material data library unit 3 outputs ₃Include resin kind, kinds of fibers, fabric type, prepreg initial fiber volume fraction and the initial thickness in monolayer of prepreg; Described resin kind is epoxy resin, phenolic resins, cyanate ester resin, bismaleimide resin etc.; Described kinds of fibers is glass fibre, carbon fiber, aramid fiber, basalt fibre etc.; Described fabric type is unidirectional pre-immersion material, one-way fabric, plain cloth, twills, satin fabric etc.; Resin kind, kinds of fibers, form of fabric difference, its thermal conductivity factor, specific heat capacity, density value and different from the functional relation of temperature adopt the testing arrangement of laboratory designed, designed to measure; The difference of resin kind, the value that relates to parameter in its Viscosity Model and the model is different, can adopt rheometer test to obtain; Kinds of fibers, fabric type, ply sequence affect fibrage permeability, fibrolaminar compression property, adopt the testing arrangement of laboratory designed, designed to measure; The characteristic material data storehouse has comprised the parameter in the described Viscosity Model relevant with the resin kind, to be BJ University of Aeronautics ﹠ Astronautics's Materials Academy obtain through for many years the polymer matrix composites system being carried out experimental study, test, measurement the parameters such as described and kinds of fibers, fabric type, permeability, the parameter in the compression property model and thermal conductivity factor that ply sequence is relevant, specific heat capacity, density, have accuracy, reliability, once be used as one of industrial analysis data source by polymer matrix composite technology experiment chamber, Beijing.

In the present invention, the defect characteristics parameter F of defect characteristics Database Unit 4 outputs ₄Include the various manufacturing defect such as hole that hot press forming technology produces, layering, rich resin, poor glue, the present invention is for to (the initial process parameter F of curvature laminate of the process window in the moulding ₇) be optimized, only for the hole defect analysis, and hole is the cavity that forms in the composite material shaping process, generally characterizes with porosity.Described porosity refers to that volume that exist in the resin between fibrage, the microcosmic aperture accounts for the ratio of total composite volume, represents with percentage, and be one of major defect of composite.

Referring to shown in Figure 5, in the present invention, the initial process parameter F of initial process window setting unit 7 outputs ₇Include the lower limit temperature T1 of impressed pressure, the first platform temperature T1 _MinThe ceiling temperature T1 of (being set to 70～130 ℃), the first platform temperature T1 _MaxThe minimum of a value PC of (being set to 100～160 ℃), the PC that exerts pressure _MinThe maximum PC of (less than or equal to 0.1MPa) and the PC that exerts pressure _Max(more than or equal to 0.6MPa); The mathematical expression mode is initial process parameter F ₇={ T1 _Min, T1 _Max, PC _Min, PC _Max.In the present invention, T1 _MinAnd T1 _MaxThe material parameter F according to characteristic material data library unit 3 ₃Choose; PC _MinAnd PC _MaxTo decide with thermosetting resin base composite material process planning pressure basic demand according to aerospace structure.

In the present invention, process parameter optimizing target setting unit 6 is be used to optimization aim parameter F is provided ₆Give hot-forming analogue unit 5; Can be according to optimization aim parameter F in hot-forming analogue unit 5 ₆The initial process parameter F that further initial process window setting unit 7 is provided ₇Be optimized, thereby embody the average fiber volume fraction of curvature laminate

Produce probability P with the hole defective ₁The preferred process window.Referring to shown in Figure 6, the optimization aim parameter F in the process parameter optimizing target setting unit 6 ₆Include target average fiber volume fraction

The standard deviation of target average fiber volume fraction

Produce probability P with the hole defective ₁Target average fiber volume fraction

The standard deviation of target average fiber volume fraction

Be in using with the thermosetting resin based composites according to aerospace structure the fiber volume fraction basic demand to be decided, the hole defective produces probability P ₁Characterize the possibility that hole produces, probability is 0 o'clock, and the expression porosity is lower than and equals 1%, and probability is 1 o'clock, and the expression porosity is higher than 1%, and the structural composite material application requirements has been satisfied in the definition that among the present invention the hole defective is produced probability.Process window after the optimization is on initial process window basis, by in hot-forming analogue unit 5, processing, acquisition satisfy optimization aim parameter F ₆Process window after the optimization that requires, the process window after the optimization has increased the regulation to impressed pressure and pressure applying moment span on the basis of initial process window.

Produce reason in hot-forming process mesopore and mainly be that air entrainment in the fiber laying is not got rid of thoroughly or the volatile matters such as the solvent that contains in the resin, aqueous vapor are not dissolved in the resin fully, exist and finally be fixed up along with the curing of resin with the form of bubble, the formation of hole defective and temperature, resin pressure are relevant, adopt the resin minimum pressure P that stops air bubble growth among the present invention _rAs hole defect characteristics characterization parameter, by the mass parameter F that obtains with hot-forming analogue unit 5 ₅Middle resin pressure P _rRelatively, obtain the hole defective and produce probability P ₁, and with it as one of foundation of process window optimization.Described mass parameter F ₅Comprise resin pressure P _rWith average fiber volume fraction

Its mathematical expression mode is mass parameter

In the present invention, hot-forming analogue unit 5 is at first according to product initial setting up parameter F ₁, moulding process parameter F ₂, material parameter F ₃With defect characteristics parameter F ₄Carry out the hot press forming technology process simulation, obtain mass parameter

Then according to fitness function

To the average fiber volume fraction

Target average fiber volume fraction

Standard deviation with target average fiber volume fraction

Compare, obtain the fitness parameter; Then produce probability according to the hole defective

Resin minimum pressure P to resin pressure P and prevention air bubble growth compares, and obtains the hole defective and produces probability; Produce probability to initial process window parameter F according to fitness parameter and hole defective at last ₇Be optimized processing, the process window after obtaining to optimize.

In the present invention, the minimum requirements of known computer is more than the CPU PIV 1.8G, more than the internal memory 512M, more than the hard disk 40G.Use the intrinsic computation performance of computer, hot-forming polymer matrix composites product mesopore genetic analysis method is easy to operate, analysis result is reliable.Use the method to instruct resin base composite material hot-pressed formation industrialization operation, reduce manufacturing cost and improve product percent of pass.

In the present invention, the implementation step of polymer matrix composites curvature laminate hot press forming technology window has:

The first step: in described product configuration and mesh generation unit 1, extract product initial setting up parameter F ₁In the present invention, according to product initial setting up parameter F ₁Mean curvature laminate original dimension, adopt computer technology that curvature laminate is carried out three-dimensional configuration, and the three-dimensional laminate figure of setting up acquisition is carried out mesh generation process, acquisition is with the laminate model (referring to shown in Figure 3) of node, and described node layer Slab is saved as a text formatting file (* .TXT); The extraction of simulation desired parameters after described text formatting file can make things convenient for.

Second step: in described molding technique parameter setting unit 2, extract moulding experimental parameter F ₂

The 3rd step: in described characteristic material data library unit 3, extract material parameter F ₃

The 4th step: in described defect characteristics Database Unit 4, extract defect characteristics parameter F ₄

The 5th step: the target parameter F that extraction process is optimized in described process optimization target setting unit 6 ₆

The 6th step: in described initial process windows units 7, extract initial process window F7={T1 _Min, T1 _Max, PC _Min, PC _Max;

The 7th step: at first set T1=T1 _Min, Pc=Pc _Min, to pressure applying moment t _CjiaBe optimized;

The 8th the step: in described hot-forming analogue unit 5 with initial setting up parameter F ₁, moulding process parameter F ₂, material parameter F ₃At resin flows and laminate deformation relationship formula W ₁Middle processing is resolved and is obtained product pressure inside the resin P _rWith product average fiber volume fraction Then with the average fiber volume fraction

Substitution fitness function F _iMiddle parsing obtains the fitness parameter; Then with product pressure inside the resin P _rWith defect characteristics parameter F ₄In the resin minimum pressure P of prevention air bubble growth _vRelatively, obtain the hole defective and produce probability P ₁In the present invention, the fitness parameter of acquisition and hole defective produce probability P ₁Size can be used for estimating hot-forming process, the reasonability of the current set technological parameter of curvature laminate.

The 9th step: adopt Optimization Technology window considerations F ₀The 8th step was carried out iteration process, and will pick up result's (curvature laminate process window after the optimization) and be stored in the hot-forming analogue unit 5.In the present invention, the result who obtains can export to and carry out actual making curvature laminate usefulness in the autoclave; The analysis that also can be used as the polymer matrix composites process is used.

In the present invention described resin flows and laminate deformation relationship formula W ₁For:

$W_1\⇒\left\{\begin{array}{c}\frac{{\∂\mathrm{\σ}}_{\mathrm{xx}}}{\∂x}+\frac{{\∂\mathrm{\σ}}_{\mathrm{xz}}}{\∂z}+\frac{{\∂P}_r}{\∂x}=0\\ \frac{{\∂\mathrm{\τ}}_{\mathrm{xz}}}{\∂x}+\frac{{\∂\mathrm{\σ}}_{\mathrm{zz}}}{\∂z}+\frac{{\∂P}_r}{\∂z}=0\\ \frac{{\∂\mathrm{\ϵ}}_v}{\∂t}+[\frac{\∂}{\∂x}\left(\frac{S_{\mathrm{xx}}}{\mathrm{\μ}}\frac{\∂P_r}{\∂x}\right)+\frac{\∂}{\∂z}\left(\frac{S_{\mathrm{zz}}}{\mathrm{\μ}}\frac{\∂P_r}{\∂z}\right)]=0\end{array}\right.---\left(1\right)$

In the formula, x is illustrated in the local coordinate system along 0 ° of direction of laying, and z is illustrated in vertical thickness direction in the local coordinate system, σ _XxX direction stress under the expression local coordinate system, τ _XzExpression local coordinate system down cut stress, P _rExpression resin bearing pressure, ε _vThe expression body strain, S _XxX directional permeability under the expression local coordinate system, S _ZzZ directional permeability under the expression local coordinate system, μ represents resin viscosity, t represents simulated time.

Stress and strain satisfies relational expression W in the formula (1) ₂For:

$W_2\⇒\left\{\begin{array}{c}{\mathrm{\σ}}_{\mathrm{xx}}=V_{f}E{\mathrm{\ϵ}}_{\mathrm{xx}}\\ {\mathrm{\σ}}_{\mathrm{zz}}=\frac{3\mathrm{\πE}}{{\mathrm{\β}}^4}\·\frac{\sqrt{1+{\mathrm{\ϵ}}_{\mathrm{zz}}}-1}{\sqrt{1+{\mathrm{\ϵ}}_{\mathrm{zz}}}{(\sqrt{V_a/V_0({\mathrm{\ϵ}}_{\mathrm{zz}}+1)}-1)}^4}\\ {\mathrm{\τ}}_{\mathrm{xz}}=G_{\mathrm{xz}}{\mathrm{\γ}}_{\mathrm{xz}}\end{array}\right.---\left(2\right)$

In the formula, σ _XxX direction stress under the expression local coordinate system, τ _XzExpression local coordinate system down cut stress, ε _XxX direction strain under the expression local coordinate system, σ _ZzZ direction stress under the expression local coordinate system, ε _ZzZ direction strain under the expression local coordinate system, γ _XzThe strain of expression local coordinate system down cut, G _XzExpression material modulus of shearing, E represents the bending modulus of fiber, β represents fibrage compression property coefficient, V ₀Expression prepreg initial fiber volume fraction, V _fThe expression fiber volume fraction, V _aExpression dense packing fiber volume fraction.

Strain and displacement satisfies relational expression W in the formula (2) ₃For:

$W_3\⇒\left\{\begin{array}{c}{\mathrm{\ϵ}}_{\mathrm{xx}}=\frac{\∂u}{\∂x}\\ {\mathrm{\ϵ}}_{\mathrm{zz}}=\frac{\∂v}{\∂z}\\ {\mathrm{\γ}}_{\mathrm{xz}}=\frac{\∂u}{\∂z}+\frac{\∂v}{\∂x}\end{array}\right.---\left(3\right)$

In the formula, ε _XxX direction strain under the expression local coordinate system, ε _ZzZ direction strain under the expression local coordinate system, γ _XzThe strain of expression local coordinate system down cut, u represents x direction displacement under the local coordinate system, v represents z direction displacement under the local coordinate system.

The mean curvature laminate diverse location fiber volume fraction V of place of the present invention _fWith z direction strain stress under the local coordinate system _ZzThe pass be:

$V_f=\frac{V_0}{1+{\mathrm{\ϵ}}_{\mathrm{zz}}}---\left(4\right)$

In the formula, V ₀Expression prepreg initial fiber volume fraction, ε _ZzZ direction strain under the expression local coordinate system; Through type (4) is resolved and is obtained the fiber volume fraction V of curvature laminate diverse location place _f

The average fiber volume fraction of curvature laminate of the present invention

With fiber volume fraction V _fThe pass is:

$\stackrel{\‾}{V_f}=\frac{\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{V}_f^i}{N}---\left(5\right)$

In the formula, N represents the prepreg overlay number of plies, and i represents the i fibrage,

Represent i fibrage fiber volume fraction,

Expression average fiber volume fraction; Through type (8) obtains laminate average fiber volume fraction

The resin minimum pressure of described prevention air bubble growth in the present invention

T is illustrated in the hot-forming temperature in effective process time in the formula; (RH) ₀Relative humidity when reaching balance for hot-forming front resin water absorption.

Described fitness function in the present invention

Expression target average fiber volume fraction,

The standard deviation of expression target average fiber volume fraction.

Described Optimization Technology window considerations in the present invention In, the k increase step number that represents to exert pressure, value is integer, scope is

M represents that pressure applying moment increases step number, and value is integer, and scope is t _C3The concluding time that represented for the 3rd segment process time; t _C1The time started of expression second segment process time; t _CjiaExpression pressurization is (claiming again pressure applying moment) constantly, take zero point of process time as benchmark.Shown in Fig. 4 A, abscissa refers to process time (min of unit), 0～t _C1The expression first paragraph process time, t _C1～t _C2The expression second segment process time, t _C2～t _C3Represented for the 3rd segment process time; Left side ordinate refers to the hot-forming temperature within effective process time; The right ordinate refers to hot press molding pressure (being read by Pressure gauge) within effective process time.

Described Optimization Technology window considerations F ₀Implementation step be:

The first step: T1=T1 _Min, making k=0, m=0 then has Pc=Pc _Min, t _Cjia=t _C1

Second step: according to T1, Pc, t _CjiaValue, in hot-forming analogue unit 5, resolve and obtain product pressure inside the resin P _rWith product average fiber volume fraction

Then with the average fiber volume fraction

Substitution fitness function F _iMiddle parsing obtains the fitness parameter; Then with product pressure inside the resin P _rWith the resin minimum pressure P that stops air bubble growth _vRelatively, obtain the hole defective and produce probability P ₁

The 3rd step: if P ₁=1, then pressure applying moment is not optimized, make k=k+1, increase the Pc that exerts pressure, repeat second step;

The 4th step: if P ₁=0, fitness parameter＜0 is then no longer to pressure applying moment t _CjiaBe optimized;

The 5th step: if P ₁=0, second step is then repeated, from t in fitness parameter＞0 _Cjia=t _C1Begin pressure applying moment is optimized, record is also preserved and is satisfied P ₁=0 and the pressure applying moment t of fitness parameter=0 _Cjia

The 6th the step: repeat second and third, four, five steps, until Pc=Pc _Max, record is also preserved and is satisfied fitness parameter=0 and P ₁=0 exert pressure and corresponding pressure applying moment;

The 7th step: make T1=T1, repeat second and third, four, five, six steps, record is also preserved and is satisfied fitness parameter=0 and P ₁=0 exert pressure and corresponding pressure applying moment.

Embodiment 1: the carbon fiber/epoxy resin curvature laminate that unidirectional shop is 30 layers

The laying structure of embodiment 1 expression has A layer fiber 101, A layer prepreg 101, B layer prepreg 102 referring to shown in Figure 7 in from bottom to up order discharging ... N layer prepreg 130 inhaled gummed paper 31.This is the laying system of a kind of common " the prepreg overlay number of plies ", and prepreg has referred to for the manufacture of the dipping of composite a kind of intermediate materials of the carbon fiber of epoxy resin, is a kind of commercial goods.

The first step: in described product configuration and mesh generation unit 1, pick up product initial setting up parameter F ₁, described product initial setting up parameter F ₁Middle mould-type is former, and inhaling the glue mode is that single face is inhaled glue, and prepreg initial fiber volume fraction is 55%, 30 layers of the prepreg overlay numbers of plies, laminate original depth h ₀Be 4.3mm, female mould forming, 90 ° of mould arc part radians, pasting the die face arc radius is 4mm, horizontal and vertical equal thick laminate length is 25mm.In Patran software, create out laminate profile graphics (referring to shown in Figure 1), then described three-dimensional laminate figure is carried out 30 * 100 mesh generations and process (shown in Fig. 7 A), acquisition is with the laminate model (having the color three dimension Image Display on the display screen) of node, and described node layer Slab saved as text formatting file, i.e. a CurveL.TXT;

Second step: extraction process parameter F in described molding technique parameter setting unit 2 ₂, temperature-time relationship is for being raised to 130 ℃ with the heating rate of 1.5 ℃/min from 25 ℃ of room temperatures, is raised to 180 ℃ and constant temperature 1 hour with the heating rate of 1.5 ℃/min from 130 ℃ behind 130 ℃ of lower constant temperature 20min, then naturally cools off., on computers by resolving rise time and temperature data it is kept in the temperatedata.txt file according to temperature-time relationship, adds normal pressure P _aBe 0.3MPa, vacuum is 0.1MPa, and pressure applying moment is 4600s.At the computer visualization interface (referring to shown in Figure 4) simulation is set is 1200s, time step Δ t=10s total time.

The 3rd step: in described characteristic material data library unit 3, extract material parameter F ₃, the resin kind: epoxy resin, kinds of fibers: carbon fiber, fabric type: unidirectional pre-immersion material, ply sequence: unidirectional laying, fiber is along 0 ° of direction lay.According to described material parameter, can from the characteristic material data storehouse, extract and calculate required and fiber and resin associated arguments and comprise parameter in Viscosity Model, penetration rate model, the compact model.

The 4th step: in described defect characteristics Database Unit 4, extract defect characteristics parameter F ₄, described defect characteristics parameter F ₄For stoping the resin minimum pressure P of air bubble growth _v, namely

Relative humidity (RH) when hot-forming front resin water absorption reaches balance ₀Be 50%; The experimental parameter F that hot-forming temperature T is extracted by molding technique parameter setting unit 2 ₂Middle temperature and time relation curve obtains.

The 5th step: the target parameter F that extraction process is optimized in described process optimization target setting unit 6 ₆Target average fiber volume fraction Be 63%, the standard deviation of target average fiber volume fraction

Be 5%, the hole defective produces probability P ₁Be 0.

The 6th step: in described initial process windows units 7, extract initial process window F ₇={ T1 _Min, T1 _Max, Pc _Min, Pc _Max, T1 _MinBe 120 ℃, T1 _MaxBe 130 ℃, Pc _MinBe 0.1MPa, Pc _MaxBe 0.6MPa.

The 7th step: at first set T1=120 ℃, Pc=0.1MPa is to pressure applying moment t _CjiaBe optimized;

The 8th the step: in described resin base composite material hot-pressed formation analogue unit 5 with initial setting up parameter F ₁, moulding process parameter F ₂, material parameter F ₃At resin flows and laminate deformation relationship formula W ₁Middle processing is resolved and is obtained product pressure inside the resin P _r, fiber volume fraction V _fAnd product average fiber volume fraction

Then with the average fiber volume fraction

Substitution fitness function F _iMiddle parsing obtains the fitness parameter; Then with product pressure inside the resin P _rWith defect characteristics parameter F ₄In the resin minimum pressure P of prevention air bubble growth _vRelatively, obtain the hole defective and produce probability P ₁

The 9th step: pick up the optimized algorithm function F ₀, and repeated for the 8th step, until fitness parameter and hole defective produce probability P ₁Satisfy simultaneously stopping rule, calculate to finish, export the result to autoclave or store in the computer (interface during simulation such as Fig. 7 B); Process window after the carbon fiber/epoxy resin curvature laminate optimization that the unidirectional shop of parsing acquisition is 30 layers, referring to Fig. 7 C, a point, b point are illustrated under certain temperature and pressure condition among the figure, satisfy target average fiber volume fraction Be 63 ± 5%, the hole defective produces probability P ₁Be 0 pressure applying moment value lower limit and the upper limit.

Simultaneously, select process conditions in the process window after optimization, namely the first platform temperature is 130 ℃, exert pressure and be 0.5MPa, pressure applying moment is 3800s, has prepared the carbon fiber/epoxy resin curvature laminate of 30 layers of unidirectional shops, and making laminate average fiber content is 64%, porosity is 0.8%, has satisfied the optimization aim requirement.

The present invention is a kind of polymer matrix composites curvature laminate that is applicable to, process window optimization method in hot-forming process, the method is with the resin base composite material hot-pressed formation analogue unit, process parameter optimizing target setting unit is the basis, binding deficient performance data library unit, provide curvature laminate hot press forming technology window, in the process window of optimizing, can prepare the curvature laminate that satisfies laminate average fiber volume fraction and defective generation probability demands, report to the police when in hot-forming process, defective occurring, instruct the hot-forming industrialization operation of polymer matrix composites curvature laminate, improve product percent of pass.

Claims (6)

1. the process window optimization method of a resin-base composite curvature laminate in autoclave molding, this optimization method utilizes computer technology to come the hot-forming process of analog tree resin-based composite curvature laminate, is the initial process parameter F with curvature laminate ₇Be the input message source, by the relevant treatment relation that provides in molding technique parameter setting unit (2), characteristic material data library unit (3) and the defect characteristics Database Unit (4), then in conjunction with product configuration and mesh generation unit (1) and process parameter optimizing target setting unit (6) requirement, in hot-forming analogue unit (5), process at last, thereby the average fiber volume fraction of curvature laminate is satisfied in acquisition

Produce probability P with the hole defective ₁The more optimal process window that requires is characterized in that:

The product initial setting up parameter F of product configuration and mesh generation unit (1) output ₁Include mould-type, suction glue mode, the prepreg overlay number of plies, mould arc part radian, paste die face arc radius, transverse thick laminate length, vertical thick laminate length;

The moulding process parameter F of molding technique parameter setting unit (2) output ₂Include envionmental humidity, initial temperature, heating rate, temperature-time relationship, add normal pressure, pressure applying moment;

The material parameter F of characteristic material data library unit (3) output ₃Include resin kind, kinds of fibers, fabric type, prepreg initial fiber volume fraction and the initial thickness in monolayer of prepreg; Described resin kind is epoxy resin, phenolic resins, cyanate ester resin, bismaleimide resin; Described kinds of fibers is glass fibre, carbon fiber, aramid fiber, basalt fibre; Described fabric type is unidirectional pre-immersion material, one-way fabric, plain cloth, twills, satin fabric;

The defect characteristics parameter F of defect characteristics Database Unit (4) output ₄Include hole, layering, rich resin, the various manufacturing defect of poor glue that hot press forming technology produces;

Hot-forming analogue unit (5) is at first according to product initial setting up parameter F ₁, moulding process parameter F ₂, material parameter F ₃With defect characteristics parameter F ₄Carry out the hot press forming technology process simulation, obtain mass parameter $F_5=\left\{\begin{array}{cc}P,& \stackrel{\&OverBar;}{V}\\ r& f\end{array}\right\};$ Then according to fitness function $F_i=\left\{\begin{array}{ccc}-1& \mathrm{if}& \stackrel{\&OverBar;}{V_f}<\stackrel{\&OverBar;}{V_{\mathrm{fg}}}-\mathrm{\&Delta;}\stackrel{\&OverBar;}{V_f}\\ 0& \mathrm{if}& \stackrel{\&OverBar;}{V_{\mathrm{fg}}}-\mathrm{\&Delta;}\stackrel{\&OverBar;}{V_f}<\stackrel{\&OverBar;}{V_f}\\ 1& \mathrm{if}& \stackrel{\&OverBar;}{V_f}>\stackrel{\&OverBar;}{V_{\mathrm{fg}}}+\mathrm{\&Delta;}\stackrel{\&OverBar;}{V_f}\end{array},<\stackrel{\&OverBar;}{V_{\mathrm{fg}}}+\mathrm{\&Delta;}\stackrel{\&OverBar;}{V_f}\right.$ To the average fiber volume fraction

Target average fiber volume fraction

Standard deviation with target average fiber volume fraction

Compare, obtain the fitness parameter; Then produce probability according to the hole defective $P_1=\left\{\begin{array}{cc}0,& P_r>P_v\\ 1,& P_r<P_v\end{array}\right.$ To resin pressure P _rWith the resin minimum pressure P that stops air bubble growth _vCompare, obtain the hole defective and produce probability; Produce probability to initial process window parameter F according to fitness parameter and hole defective at last ₇Be optimized processing, the process window after obtaining to optimize;

Process parameter optimizing target setting unit (6) is be used to optimization aim parameter F is provided ₆Give hot-forming analogue unit (5); Can be according to optimization aim parameter F in hot-forming analogue unit (5) ₆The initial process parameter F that further initial process window setting unit (7) is provided ₇Be optimized, thereby embody the average fiber volume fraction of curvature laminate

Produce probability P with the hole defective ₁The preferred process window;

The initial process parameter F of initial process window setting unit (7) output ₇Include the lower limit temperature T1 of impressed pressure, the first platform temperature T1 _Min=70～130 ℃, the ceiling temperature T1 of the first platform temperature T1 _Max=100～160 ℃, the minimum of a value PC of the PC that exerts pressure _MinThe maximum PC of≤0.1MPa and the PC that exerts pressure _Max〉=0.6MPa.

2. the process window optimization method of resin-base composite curvature laminate according to claim 1 in autoclave molding is characterized in that: the fiber volume fraction V of curvature laminate diverse location place _fWith z direction strain stress under the local coordinate system _ZzThe pass be

V ₀Expression prepreg initial fiber volume fraction, ε _ZzZ direction strain under the expression local coordinate system.

3. the process window optimization method of resin-base composite curvature laminate according to claim 1 in autoclave molding is characterized in that: the average fiber volume fraction of curvature laminate

With fiber volume fraction V _fThe pass is

N represents the prepreg overlay number of plies, and i represents the i fibrage,

Represent i fibrage fiber volume fraction,

Expression average fiber volume fraction.

4. the process window optimization method of resin-base composite curvature laminate according to claim 1 in autoclave molding is characterized in that: the resin minimum pressure that stops air bubble growth $P_v=4.69\&times;{10}^4\exp (-\frac{4892}{T}){\left(\mathrm{RH}\right)}_0+3.41\&times;{10}^{-4}T-0.10,$ T is illustrated in the hot-forming temperature in effective process time in the formula; (RH) ₀Relative humidity when reaching balance for hot-forming front resin water absorption.

5. the process window optimization method of resin-base composite curvature laminate according to claim 1 in autoclave molding is characterized in that: the Optimization Technology window considerations $F_0\&DoubleRightArrow;\left\{\begin{array}{c}T1={T1}_{\min }\mathrm{or}{T1}_{\max }\\ \mathrm{Pc}={\mathrm{Pc}}_{\min }+0.1k\\ t_{\mathrm{cjia}}=t_{c1}+60m\end{array}\right.$ In, the k increase step number that represents to exert pressure, value is integer, scope is

M represents that pressure applying moment increases step number, and value is integer, and scope is

t _C3The concluding time that represented for the 3rd segment process time; t _C1The time started of expression second segment process time; t _CjiaExpression pressurization constantly, take zero point of process time as benchmark.

6. the process window optimization method of resin-base composite curvature laminate according to claim 5 in autoclave molding is characterized in that Optimization Technology window considerations F ₀Implementation step be:

The first step: T1=T1 _Min, making k=0, m=0 then has Pc=Pc _Min, t _Cjia=t _C1

Second step: according to T1, Pc, t _CjiaValue, in hot-forming analogue unit 5, resolve and obtain product pressure inside the resin P _rWith product average fiber volume fraction

Then with the average fiber volume fraction

Substitution fitness function F _iMiddle parsing obtains the fitness parameter; Then with product pressure inside the resin P _rWith the resin minimum pressure P that stops air bubble growth _vRelatively, obtain the hole defective and produce probability P ₁

The 3rd step: if P ₁=1, then pressure applying moment is not optimized, make k=k+1, increase the Pc that exerts pressure, repeat second step;

The 4th step: if P ₁=0, fitness parameter＜0 is then no longer to pressure applying moment t _CjiaBe optimized;

The 5th step: if P ₁=0, second step is then repeated, from t in fitness parameter＞0 _Cjia=t _C1Begin pressure applying moment is optimized, record is also preserved and is satisfied P ₁=0 and the pressure applying moment t of fitness parameter=0 _Cjia

The 6th the step: repeat second and third, four, five steps, until Pc=Pc _Max, record is also preserved and is satisfied fitness parameter=0 and P ₁=0 exert pressure and corresponding pressure applying moment;

The 7th step: make T1=T1 _Max, repeat second and third, four, five, six steps, record is also preserved and is satisfied fitness parameter=0 and P ₁=0 exert pressure and corresponding pressure applying moment.

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