CN113954393A - Method for controlling deformation of composite material component through zone heating and curing - Google Patents
Method for controlling deformation of composite material component through zone heating and curing Download PDFInfo
- Publication number
- CN113954393A CN113954393A CN202111221815.9A CN202111221815A CN113954393A CN 113954393 A CN113954393 A CN 113954393A CN 202111221815 A CN202111221815 A CN 202111221815A CN 113954393 A CN113954393 A CN 113954393A
- Authority
- CN
- China
- Prior art keywords
- curing
- deformation
- thickness direction
- temperature
- composite material
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
- B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
- B29C70/28—Shaping operations therefor
- B29C70/54—Component parts, details or accessories; Auxiliary operations, e.g. feeding or storage of prepregs or SMC after impregnation or during ageing
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/10—Geometric CAD
- G06F30/17—Mechanical parametric or variational design
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Geometry (AREA)
- Theoretical Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- General Engineering & Computer Science (AREA)
- Evolutionary Computation (AREA)
- Mathematical Analysis (AREA)
- Pure & Applied Mathematics (AREA)
- Mathematical Optimization (AREA)
- Computational Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Composite Materials (AREA)
- Mechanical Engineering (AREA)
- Heating, Cooling, Or Curing Plastics Or The Like In General (AREA)
- Moulding By Coating Moulds (AREA)
Abstract
A method for controlling the deformation of a composite material component through zone heating and curing is characterized in that: the composite material member is divided into n regions with independently controllable thickness direction temperature difference, n is more than or equal to 1, and at different stages of the curing process, the thickness direction temperature difference which changes along with time is actively applied to each region according to an off-line or on-line regulation strategy [ D1(t), D2(t), … and Dn (t) ], so that the curing strain corresponding to each region is generated, and the curing deformation of the member is regulated and controlled. The invention actively generates favorable curing deformation in different areas according to the geometric shape, corrects the harmful curing deformation caused by the uneven geometry of the component and realizes the regulation and control of the curing deformation of the component.
Description
Technical Field
The invention relates to a method for controlling the curing deformation of a composite material member, in particular to a method for controlling the curing deformation by regulating and controlling a zone heating temperature field, and specifically relates to a method for controlling the zone heating curing deformation of a composite material member.
Background
The composite material has become a key material for weight reduction and efficiency improvement in the fields of aerospace and the like. During the high-temperature curing process of the composite material member, the curing deformation is inevitably generated due to the mismatching of factors such as thermal expansion, chemical shrinkage and external mechanical force action. The curing deformation directly causes the geometric accuracy of the component to be out of tolerance and the component is scrapped, if the component is forcedly assembled, large and uneven assembly stress is formed, so that structural failures such as layering, cracking and the like occur in the service regulation of the component, and the service safety and the fatigue life are damaged.
At present, mould compensation is an important means for improving curing deformation, and the main principle is to make the member approximate to the theoretical shape after deformation by compensating the mould profile. CN201910089404.5, CN201310628287.8, CN202011003426.4, etc. disclose different mold compensation methods. But the design of the mold surface is finished, and when unmodeled errors such as material batch difference, paving errors and the like are introduced, the stable effect of mold compensation is difficult to ensure.
Homogenizing the temperature field is another technical path to control the solidification distortion. In the traditional autoclave process, parameters such as a mould and the like are optimized, so that the temperature field of the component is uniform, and the curing deformation is improved to a certain extent. Various zone heating and curing technologies have been developed in recent years, patent CN201610821854.5 proposes to provide zone heating and cooling units in the mold, and U.S. Pat. nos. US20150165747a1, US9370877B2 and the like propose zone heating methods, which can significantly improve temperature uniformity and improve curing deformation. However, even if the temperature field is completely uniform, the curved composite member still has curing distortion due to non-uniform thermal expansion and contraction and chemical shrinkage.
The invention discloses a harmful solidification deformation regulation and control method, which divides a composite material member into n regions with independently controllable temperature difference in the thickness direction, actively generates different temperature difference in the thickness direction of each region, generates different solidification strain gradients in the thickness direction of each region, further actively generates 'favorable' solidification deformation, and in turn compensates 'harmful' solidification deformation caused by uneven inherent geometric structure of the member, thereby realizing the control of the solidification deformation.
Disclosure of Invention
The invention aims to provide a method for controlling deformation of a composite material member through zone heating and curing, aiming at the problem that the deformation cannot be eliminated in the existing composite material member curing method. The composite material member is divided into n regions with independently controllable temperature difference in the thickness direction, n is more than or equal to 1, the thickness direction temperature difference (D1 (t), D2(t), … and Dn (t)) which changes along with time is actively applied to each region according to an off-line or on-line regulation strategy at different stages of the curing process, different curing strain gradients in the thickness direction of each region are generated, and the whole curing deformation of the regulation member is realized. The invention creatively provides a method for actively generating 'favorable' curing deformation by utilizing the temperature gradient considered harmful in the traditional thought, and compensating the 'harmful' curing deformation caused by the non-uniform inherent geometrical structure of the component in turn, thereby realizing the control of the curing deformation.
The technical scheme of the invention is as follows:
a method for controlling the deformation of a composite material member by zone heating and curing is characterized in that the composite material member is divided into n regions with independently controllable temperature difference in the thickness direction, n is more than or equal to 1, the thickness direction temperature difference [ D1(t), D2(t), …, Dn (t) ] which changes along with time is actively applied to each region according to an off-line or on-line regulation strategy at different stages of the curing process, different curing strain gradients in the thickness direction of each region are generated, including thermal strain gradients, chemical shrinkage strain gradients, mechanical strain gradients and the like, favorable curing deformation is generated, the favorable curing deformation corrects harmful curing deformation caused by the geometric nonuniformity of the member, and finally the regulation and control of the curing deformation after the member is demoulded are realized.
The area dividing method is that the composite material member is divided into a plurality of areas according to the curvature distribution, or the curvature radius distribution, or the curvature change rate distribution of the upper surface or the lower surface of the composite material member, or a certain characteristic attribute distribution of the upper surface or the lower surface, wherein the numerical values of the distribution in each area belong to the same interval, and the range of the interval is determined by the acceptable number n of the partitions in advance.
The value of a certain characteristic attribute, such as the theoretical thickness direction temperature difference Delta T for making the rebound quantity of a certain curved surface infinitesimal be 0 DEGtThe expression is as follows:
wherein r is1，r2Is the radius of the upper and lower surface curved surfaces at that point, Δ TtIs the difference of the temperature of the upper surface minus the temperature of the lower surface, T2Is the temperature of the lower surface alphax、αzIs the glass thermal expansion coefficient, beta, of the material in the horizontal and thickness directionsx、βzIs the rubbery maximum chemical shrinkage strain in the horizontal and thickness directions of the material.
The thickness direction temperature difference is regulated and controlled by heating and cooling units which are distributed on the upper surface and the lower surface of the component and can be controlled in a partition mode, such as an in-situ heating film and a cooling film which are distributed on two sides, or the component can consume external energy to form an internal heat source which can be controlled in a partition mode, such as microwave heating which can be selectively heated and a material self-resistance heating technology.
The method for solving the off-line regulation strategy comprises the steps of firstly calculating the curing deformation of a component under different thickness direction temperature differences [ D1(t), D2(t), … and Dn (t) ] by using an analytical method, a numerical method or a data driving method, then calculating the optimal solution of the thickness direction temperature differences [ D1(t), D2(t), … and Dn (t) ] by taking the target deformation and the optimal solution of the residual stress magnitude in the component smaller than the design allowable range when the target deformation is reached as an optimization target and solving the optimal solution of the thickness direction temperature differences [ D1(t), D2(t), … and Dn (t) ] by using optimization methods such as equation solution or iterative optimization and the like, wherein the optimization method can be a genetic evolution algorithm, a simulated annealing algorithm or other heuristic search and optimization algorithms.
The method for solving the online regulation strategy comprises the steps of firstly, taking online monitoring data of strain, stress, curing degree, pressure and other quantities related to curing deformation as state quantities, taking a final curing deformation result as an evaluation standard, establishing an association relation between a [ D1(t), D2(t), …, Dn (t) strategy and the state quantities along with time on line, predicting the contribution of the current thickness direction temperature difference strategy to the final curing deformation in real time, and dynamically calculating the optimal solution of [ D1(t), D2(t), …, Dn (t) ] by taking the highest strategy contribution value as a target.
The strain can be obtained by using a multi-point strain gauge or a Fiber Bragg Grating (FBG) which is embedded in the member for on-line monitoring. The curing degree can be obtained by fitting in advance to obtain a composite material reaction kinetic equation or a composite material reaction kinetic equation provided by a manufacturer, and the curing degree is obtained by calculation according to an online monitored temperature field, and the temperature is obtained by measuring through a sensor such as an infrared thermal imaging thermometer or a thermocouple. The degree of cure can also be monitored on-line by a monitoring sensor, such as an optical fiber sensor for monitoring the refractive index change of the composite material during curing or a dielectric sensor for monitoring the curing process.
The thickness direction temperature difference Dn (t) is obtained by subtracting the temperature of the low temperature side of the nth region from the temperature of the high temperature side at the time t, the maximum value of the temperature of the high temperature side does not exceed the glass transition temperature of the cured resin, and the maximum value of the temperature of the low temperature side is not lower than the lowest curing temperature of the resin. On the basis, the value range of the temperature difference Dn (t) in the thickness direction of each area is further determined by combining the thickness of the component in the area and the constraint condition of external heating and cooling.
The external heating and cooling constraint conditions adopt different heating methods such as a mold partition heating method, a microwave partition heating method, an in-situ heating film method, an electric loss partition heating method and the like, comprehensively consider the heat transfer results of heat generated by a part heat source in a component and a mold system, and determine the value range which can be realized in the thickness direction Dn (t) of each area by combining the cooling conditions in the heating system, such as mold water cooling, convection cooling and the like.
The invention has the following effective effects:
the obvious advantages of the invention for controlling the curing deformation of the composite material member are as follows: in the conventional thought, the zone heating method is used for realizing uniform curing, and deformation caused by nonuniform temperature field is reduced to a certain extent, however, due to nonuniform geometrical structure, curing deformation still exists even if the completely uniform curing temperature field exists. The invention provides a method for actively controlling a subarea temperature field to generate 'favorable' curing deformation, and in turn correcting 'harmful' curing deformation caused by uneven inherent geometric structure of a component, so that the curing deformation of a composite material can be further controlled on the basis of the traditional method, and the high-precision curing of the composite material is realized.
Drawings
FIG. 1 is a schematic diagram showing the temperature application manner of the temperature gradient Dn (t) in the thickness direction of different regions of the member according to the present invention.
FIG. 2 is a graph illustrating the variation of different regions Dn (t) with time according to an embodiment of the present invention.
FIG. 3 is a schematic view of the sectional heating deformation control of the leading edge type member of the airfoil according to the embodiment of the invention.
Detailed description of the preferred embodiments
The invention is further illustrated with reference to the following figures and examples. It should be noted that the following examples are only intended to illustrate some specific examples of the process and are not intended to limit the scope of the invention. In addition, after the present invention is disclosed, any modification and variation of the present invention based on the principle of the composite material zone heating curing deformation regulating method will fall within the scope of the present invention as defined in the appended claims.
As shown in fig. 1-3.
The present embodiment is described by taking a process of regulating and controlling the deformation of a leading edge component of a typical aeronautical variable camber airfoil by zone heating curing. The components are laid by adopting carbon fiber reinforced high-temperature epoxy resin based prepreg T800/3900, and the laying method is
The thickness of the single-layer prepreg is 0.125mm, the size of the single-layer prepreg of the component is 2000mm multiplied by 2000mm, and the variation range of the curvature radius of the R corner area of the component is 50-150 mm. The specific embodiment comprises the following steps:
the method comprises the following steps: dividing the three-dimensional digital-analog of the part into 27 areas as shown in figure 1;
step two: heating the component by using a 27-partition closed die heating die, wherein the temperature of the upper surface and the lower surface of each area of the component can be independently monitored and controlled, the control dimension is 54, and 27 fiber bragg grating strain sensors are embedded in the upper surface and the lower surface of the corresponding area in the material and used for monitoring curing strain;
step three: determining the lowest heat preservation temperature of the T800/3900 material system and the highest temperature which can be reached in the whole curing process according to the principle that the high temperature does not exceed the glass transition temperature of the cured material and the low temperature ensures that the material can be completely cured within the required time; as shown in fig. 3.
Step four: determining the maximum temperature difference Dn (t) -max of the 16 layers of materials in the thickness direction according to the heating and cooling conditions of the closed mould;
step five: determining the gel point and the glass transition point of the material according to the material parameters and a curing kinetic equation given by a manufacturer, and dividing the temperature gradient Dn (t) in the thickness direction of each region into three stages, namely before the gel point, between the gel point and the glass transition point and after the glass transition point; as shown in fig. 2.
Step six: combining a curing deformation simulation model and a genetic algorithm optimization model, aiming at the minimum curing deformation, iteratively calculating an expression of thickness direction temperature difference Dn (t) of each of 27 regions between a gel point and a glass transition point by taking the minimum temperature keeping temperature, the maximum temperature reachable in the whole curing process and the maximum temperature difference Dn (t) -max as constraint conditions, so that each region forms a chemical shrinkage strain gradient in the thickness direction, and forms a temperature gradient in the thickness direction at the glass transition point (thermal expansion coefficient mutation point), further forms an unrecoverable residual chemical shrinkage strain gradient in the thickness direction under the action of viscoelasticity after the material is cooled, forms an unrecoverable thermal strain gradient in the thickness direction due to uneven cold shrinkage (different cooling temperatures), and finally reaches the position between the gel point and the glass transition point, the residual thermal strain gradient and the residual chemical shrinkage gradient formed by the temperature difference Dn (t) in the thickness direction of each region are combined to ensure that the curing deformation is minimum and the magnitude of the residual stress of the component reaching the deformation is smaller than the design allowable range.
Step seven: applying the obtained initial Dn (t) of each region to the material, starting curing, establishing the correlation between the [ D1(t), D2(t), …, D27(t) ] strategy and the curing strain state quantity which change along with time on line according to 27 sets of measured strain data, predicting the contribution value of the current thickness direction temperature difference strategy to the final curing deformation in real time, dynamically calculating the latest [ D1(t), D2(t), …, D27(t) ] by taking the highest contribution value of each strategy as a target, and finally realizing the regulation and control of the curing deformation.
The comprehensive curing deformation of the wing leading edge part realized by the steps can be reduced by more than 50 percent.
The embodiment finally realizes the high-precision active temperature control partition heating and curing process on the premise of meeting the requirement of material curing degree and ensuring the material performance, and can accurately regulate and control the curing deformation of the composite material component.
The present invention is not concerned with parts which are the same as or can be implemented using prior art techniques.
Claims (6)
1. A method for controlling the deformation of a composite material component through zone heating and curing is characterized in that: the composite material member is divided into n regions with independently controllable thickness direction temperature difference, n is more than or equal to 1, at different stages of the curing process, the thickness direction temperature difference which changes along with time is actively applied to each region according to an off-line or on-line regulation strategy [ D1(t), D2(t), …, Dn (t) ], the corresponding curing strain of each region is generated, and then the favorable curing deformation is actively generated, and the harmful curing deformation caused by the uneven inherent geometric structure of the member is compensated, so that the control of the curing deformation is realized.
2. The method of claim 1, wherein: the dividing method comprises the following steps: dividing the composite material member into a plurality of regions according to the curvature distribution, the curvature radius distribution, the curvature change rate distribution or the distribution of a certain characteristic attribute of the surface of the upper surface or the lower surface of the composite material member, wherein the numerical value of the distribution in each region belongs to the same interval, and the range of the interval is determined by the acceptable number n of the partitions in advance.
3. The method of claim 1, wherein: the thickness direction temperature difference is regulated and controlled by heating or cooling units which are distributed on the upper surface and the lower surface of the component and can be controlled in a partition mode, or the component loses external energy to form internal heat source regulation and control which can be controlled in a partition mode.
4. The method of claim 1, wherein: the solving method of the off-line regulation strategy comprises the following steps: firstly, the curing deformation of the component under different thickness direction temperature differences [ D1(t), D2(t), …, Dn (t) ] is calculated by an analytical method, a numerical method or a data driving method, and then the optimal solution of the thickness direction temperature differences [ D1(t), D2(t), …, Dn (t) ] is obtained by solving an equation or an iterative optimization method by taking the target deformation and the order of magnitude of residual stress in the component when the target deformation is reached to be smaller than a design allowable range as an optimization target.
5. The method of claim 1, wherein: the solving method of the online regulation and control strategy comprises the following steps: firstly, on-line monitoring data of strain, stress, curing degree, pressure and curing deformation related quantity is used as state quantity, the final result of curing deformation is used as evaluation standard, the correlation relation between the [ D1(t), D2(t), …, Dn (t) ] strategy and the state quantity which change along with time is established on line, then the contribution value of the current thickness direction temperature difference strategy to the final curing deformation is predicted in real time, and the optimal solution of [ D1(t), D2(t), …, Dn (t) ] is dynamically obtained by taking the highest contribution value of each strategy as a target.
6. The method of claim 1, wherein: the thickness direction temperature difference Dn (t) is obtained by subtracting the temperature of the low temperature side of the nth region from the temperature of the high temperature side at the time t, the maximum value of the temperature of the high temperature side does not exceed the glass transition temperature of the cured resin, and the maximum value of the temperature of the low temperature side is not lower than the lowest curing temperature of the resin.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111221815.9A CN113954393B (en) | 2021-10-20 | 2021-10-20 | Method for controlling deformation of composite material component through zone heating and curing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111221815.9A CN113954393B (en) | 2021-10-20 | 2021-10-20 | Method for controlling deformation of composite material component through zone heating and curing |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113954393A true CN113954393A (en) | 2022-01-21 |
| CN113954393B CN113954393B (en) | 2022-08-05 |
Family
ID=79465040
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111221815.9A Active CN113954393B (en) | 2021-10-20 | 2021-10-20 | Method for controlling deformation of composite material component through zone heating and curing |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113954393B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101786328A (en) * | 2010-02-11 | 2010-07-28 | 力仓风力设备(上海)有限公司 | Intelligent segmental temperature control system of wind power blade die |
| EP2490875A1 (en) * | 2009-10-20 | 2012-08-29 | Surface Generation Limited | Zone control of tool temperature |
| CN107538771A (en) * | 2017-03-08 | 2018-01-05 | 青岛东正浩机电科技有限公司 | Monitoring repair method is glued in a kind of composite solidification |
| CN108081518A (en) * | 2017-12-20 | 2018-05-29 | 南京航空航天大学 | A kind of carbon fibre reinforced composite electrical loss heating temperature field Active Control Method |
| CN109878106A (en) * | 2019-01-30 | 2019-06-14 | 南京航空航天大学 | A kind of polymer matrix composites based on dynamic thermodynamic barrier are heating and curing method |
| CN112793057A (en) * | 2020-11-24 | 2021-05-14 | 南京航空航天大学 | Microwave multi-frequency zone heating method for carbon fiber reinforced composite material |
-
2021
- 2021-10-20 CN CN202111221815.9A patent/CN113954393B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2490875A1 (en) * | 2009-10-20 | 2012-08-29 | Surface Generation Limited | Zone control of tool temperature |
| CN101786328A (en) * | 2010-02-11 | 2010-07-28 | 力仓风力设备(上海)有限公司 | Intelligent segmental temperature control system of wind power blade die |
| CN107538771A (en) * | 2017-03-08 | 2018-01-05 | 青岛东正浩机电科技有限公司 | Monitoring repair method is glued in a kind of composite solidification |
| CN108081518A (en) * | 2017-12-20 | 2018-05-29 | 南京航空航天大学 | A kind of carbon fibre reinforced composite electrical loss heating temperature field Active Control Method |
| CN109878106A (en) * | 2019-01-30 | 2019-06-14 | 南京航空航天大学 | A kind of polymer matrix composites based on dynamic thermodynamic barrier are heating and curing method |
| CN112793057A (en) * | 2020-11-24 | 2021-05-14 | 南京航空航天大学 | Microwave multi-frequency zone heating method for carbon fiber reinforced composite material |
Non-Patent Citations (1)
| Title |
|---|
| 程文礼等: "热压罐成型复合材料固化变形机理及控制研究", 《材料导报》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113954393B (en) | 2022-08-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Oh et al. | Cure cycle for thick glass/epoxy composite laminates | |
| Kuo et al. | Minimizing warpage of ABS prototypes built with low-cost fused deposition modeling machine using developed closed-chamber and optimal process parameters | |
| Wang et al. | A review on prediction and control of curing process-induced deformation of continuous fiber-reinforced thermosetting composite structures | |
| Kim et al. | Development of an autoclave cure cycle with cooling and reheating steps for thick thermoset composite laminates | |
| CN109746444B (en) | Method for reducing additive manufacturing residual stress and unstable state by optimizing substrate | |
| Sorrentino et al. | A method for cure process design of thick composite components manufactured by closed die technology | |
| EP3168021A1 (en) | Advanced multiple grid heat sources to achieve optimized cure structure and method of making the same | |
| US5345799A (en) | Method and device for forming various workpieces | |
| GB2507080A (en) | Composite Product Manufacturing System and Method | |
| CN113954393B (en) | Method for controlling deformation of composite material component through zone heating and curing | |
| Zhendong et al. | An alternative method to reduce process-induced deformation of CFRP by introducing prestresses | |
| Vu et al. | Numerical and experimental determinations of contact heat transfer coefficients in nonisothermal glass molding | |
| Shen et al. | Self-resistance electric heating of shaped CFRP laminates: temperature distribution optimization and validation | |
| CN110826269A (en) | Temperature-structure field coupling topology optimization design method based on irregular cells | |
| Su et al. | Modeling of truck tire curing process by an experimental and numerical method | |
| US11623418B2 (en) | Multi-cell heating blankets that facilitate composite fabrication and repair | |
| CN109435271B (en) | Forming method suitable for main bearing frame body of satellite laser radar frame | |
| Sonmez et al. | Optimal post-manufacturing cooling paths for thermoplastic composites | |
| Duarte et al. | IR sheet heating in roll fed thermoforming: Part 1-Solving direct and inverse heating problems | |
| CN110625861A (en) | Method for screening surface forming performance of carbon fiber composite mold | |
| Lee et al. | Smart cure of thick composite filament wound structures to minimize the development of residual stresses | |
| CN107187074A (en) | Reduce the method for the U-shaped product deformation of composite | |
| Stringer et al. | Curing stresses in thick polymer composite components Part II: Management of residual stresses | |
| EP3069842A1 (en) | Object production | |
| CN114347505B (en) | Method for controlling curing temperature of composite material workpiece with super thickness ratio in split mode |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |