CN114880807A - Design method of fixed-frequency composite blade structure facing propeller scaling similar model - Google Patents

Design method of fixed-frequency composite blade structure facing propeller scaling similar model Download PDF

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CN114880807A
CN114880807A CN202210579462.8A CN202210579462A CN114880807A CN 114880807 A CN114880807 A CN 114880807A CN 202210579462 A CN202210579462 A CN 202210579462A CN 114880807 A CN114880807 A CN 114880807A
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blade
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skin
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牛斌
孙振华
杨睿
孙士勇
于浩俣
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Dalian University of Technology
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Abstract

The invention belongs to the technical field of composite material structures, and provides a fixed-frequency composite material blade structure design method for a propeller scaling similarity model. The blade structure of the scaled fixed-frequency composite propeller comprises a blade root rib, a composite skin on the surface, an internal composite core and a core prepared by an additive manufacturing technology. The structure design method combines the design of skin materials, subareas and layers with the design of core materials and structure forms, and simultaneously combines manufacturing constraints to change the local or integral rigidity and mass distribution of the structure, so that the fixed-frequency optimization of the blade structure with the scaling similarity considering the manufacturability is completed through the optimization of the skin and the core.

Description

Design method of fixed-frequency composite blade structure facing propeller scaling similar model
Technical Field
The invention relates to the field of composite material structures, in particular to a fixed-frequency composite material blade structure design method for a propeller scaling similarity model.
Background
The composite material has high specific strength and specific stiffness and good damping and vibration attenuation performance, and is widely applied to the fields of aerospace, large-scale wind power blades and the like. The good corrosion resistance and the light weight and high strength of the composite material lead the application of the composite material in the field of navigation to be increased continuously. For the underwater propeller blade power structure, compared with the traditional metal material, the composite material has the advantages of low vibration noise, corrosion resistance, cavitation reduction and the like, so that the underwater composite material propeller is paid more and more attention.
When the propeller blade structure works, the vibration of the structure can greatly affect the performance of the structure, but the propeller blade is taken as a large-size structure, and the related dynamics test is difficult to develop on the large-size structure. Therefore, based on the original-size propeller, it is necessary to develop a scale similarity model design of the propeller blades of the composite material, which satisfies a certain dynamics similarity relation, and reflect the characteristics of the reference model by exploring the vibration characteristics and hydrodynamic performance of the scale model.
At present, structural design of specified frequency oriented to scaling similar models has been researched a lot and is applied to structures such as wings, rockets and the like in the field of aerospace. For example, in the literature, "beijing university of aerospace, proceedings 2019,45(4), 743-. In the literature, "national defense science and technology university report, 2017,39(2), and 27-31" a certain type of carrier rocket is taken as a prototype object, and the design of a rocket scaling model is completed according to the similar relation of structural components and the constraint of the transverse rigidity and mass similarity coefficient. The patent "a manufacturing method of wing composite material scaled model, CN 103342167B" provides a manufacturing method of wing composite material scaled model. Selecting proper material parameters and processing technological parameters, manufacturing wing spars and wing ribs, filling foam on the skeleton, and modifying. The scheme obtains larger rigidity and strength with smaller weight, and can adjust the bending rigidity and the torsional rigidity of the wing composite material scaling model according to different requirements. The patent 'airship scale model design method based on similar theory, CN 111680361A' provides an airship scale model design method based on similar theory, which takes a set airship structural member as a prototype object and designs a scale model with corresponding statics and dynamic characteristics based on similar theory.
The design of propeller blade structures still presents the following problems:
(1) at present, most propeller blades made of composite materials are of solid structures, fixed-frequency design of the structures is completed by changing materials and laying schemes, design variables are few, and the problem that frequency adjusting amplitude is limited exists in multi-stage fixed-frequency design. The appropriate skin and core materials are selected, and the composite material laying design of the skin is combined with the structural design of the core, so that a larger design space can be obtained, including consideration of damping performance and weight reduction effect.
(2) The scale optimization design of the asymmetric blade is lacked. Most of design objects of the composite propeller blade have uniform thickness change, the layering design of the upper skin and the lower skin is symmetrical, and the asymmetrical design of the large-side-inclination large-torsion blade is lacked, namely the design variables of each skin partition are independent.
(3) There are no manufacturing constraints in the design and no experimental verification of the design results. The shape of each layer of the laminate of the variable-thickness composite material blade from outside to inside is necessarily gradually reduced, particularly the position of the neutral plane of the blade, and the calculation can be simplified only through skin partition. The core body part with extremely uneven thickness variation is manufactured by adopting an additive manufacturing technology, so that the error caused by gradual change of the shape of the layering can be reduced during manufacturing.
The design of the structure is optimized by combining the design of skin materials, partitions and layers with the design of core materials and structural forms by taking the constant-frequency optimization of the scaled similar blades considering the manufacturability as a design target. According to the thickness distribution and the manufacturing realizability of the blade with the similar scaling, the skin of the blade is divided into a plurality of subareas, a single material or a plurality of materials are selected and mixed, the thickness of each subarea is optimized by combining with the manufacturing constraint, and then the layering angle and the layering sequence of each subarea are determined, so that the designability of the composite material can be utilized to the maximum extent, and the local or integral rigidity and mass distribution of the structure can be changed. And then optimizing a core structure to change the mass distribution of the structure, wherein the core structure is one of a beam rib structure, a topological structure and a periodic hole array structure. Therefore, through optimization of the skin and the core, fixed frequency optimization of the scaled similar blade structure considering manufacturability is completed, meanwhile, manufacturing and experimental verification of a fixed frequency structure design of a certain large-side inclined blade are realized based on the design method, and the dynamic characteristic of an original structure can be effectively presented by the composite material blade structure fixed frequency design method for the propeller scaled similar model, and the method can be used for follow-up more complex dynamic problem research.
Disclosure of Invention
The invention aims to provide a fixed-frequency composite material blade structure design method facing a propeller scaling similarity model.
The technical scheme of the invention is as follows:
a design method for a fixed-frequency composite blade structure facing a propeller scaling similar model is characterized in that the design method combines the design of skin materials, partitions and layers with the design of core materials and structural forms to carry out optimization design, and fixed-frequency optimization of the scaling similar blade structure is completed by combining manufacturability constraint.
The composite material scaled propeller structure is formed by connecting and assembling a propeller hub 1 and composite material blades 2; the composite material blade 2 structurally comprises a blade skin 3, a blade core 4 and a root rib 5; the blade skin 3 comprises an upper skin and a lower skin which are mainly made of composite materials, the interior of the skin is connected with a blade core body 4, the blade core body 4 is divided into two parts, the thick part of a blade root is of a solid structure 6 made of the composite materials, and the thin part of a blade tip is connected with a sandwich structure 7 of the solid structure 6. The sandwich structure 7 is manufactured by an additive manufacturing technology, and the root rib 5 is connected to the root part of the blade; the fixed-frequency structure optimization design of the composite material blade of the propeller scaling similar model can be realized by optimizing the manufacturing partitioned laying angle of the blade skin 2, and determining and optimizing the blade sandwich structure form.
Firstly, obtaining the target natural frequency of the blade structure of the scaled similar composite material according to the natural frequency of the blade with the original size and combining the frequency ratio derived from the similarity criterion. And establishing a multistage frequency optimization model according to the target natural frequency and the structural form of the blade (the partitioned position and the partitioned thickness of the skin, the partitioned layering angle and the layering sequence, the material schemes of the skin and the sandwich, the structural form and the size of the sandwich structure and the like).
Figure BDA0003663264910000041
s.t.Ω 1 b ≤Ω 1 ≤Ω 1 t ,
m b ≤m≤m t ,
p m ＝c 1 ,
p d ≤c 2 ,
p s ≤c 3 ,
θ w ＝c 4 .
x n b ≤x n ≤x n t (n＝1,2,···,q)
In the above formula, omega i a Target frequency of ith order for designing model; omega i s For designing the ith order frequency, W, of the model i Is the weight of the ith order frequency difference, has
Figure BDA0003663264910000042
Therefore, the optimization goal is to minimize the sum of the frequency difference values of the p orders before the structure, and the frequency of the important order can be highlighted by changing the weight value; omega 1 To design the first order natural frequency of the model; m is the mass of the structure; while adding manufacturability considerations, p, in the skin optimization process m Is a single thickness of the ply, p d Thickness of throw layer between adjacent zone-laminated plates, p s To maximize the number of consecutive identical plies allowed, θ w Is the angle constraint of the structural surface layer. c. C 1 、c 2 、c 3 Is a constant number c 4 A certain designated ply angle or ply angle combination; x is the number of n For designing a design variable in the model, the design variable is the thickness, the layering angle and the layering sequence of each partition unit of the skin when the skin is optimized, wherein the layering thickness is a discrete variable, and the value is p m Or a multiple thereof; the spreading angle is a continuous variable and the value range is 0-180 degrees; the layering sequence is the laying sequence for optimizing layering at different angles. When the core sandwich structure is optimized, the design variables can be the thickness of the beam rib, the unit volume ratio and the position or the size of the hole according to the structure form; the variable superscripts b and t in the constraint represent the lower limit and the upper limit of each variable; q is the number of design variables.
The blade skin 3 is divided into an upper skin and a lower skin which are independently changed and are asymmetrically distributed in thickness; the blade skin is divided into a plurality of partitions, the partition division rules are that each partition is regular in shape, has no narrow long edge and no excessive round angle, and the thickness difference of the blade in each partition is within a given threshold value. Selecting a proper layering form and material, optimally designing the layering angle and the layering sequence of each partition, and considering manufacturing constraints such as composite material layer loss constraint, surface layering angle limitation, continuous identical layering quantity limitation and the like during optimization.
The thickness change of the blade at the position of the sandwich structure 4 is extremely uneven, the shape of each layer of layering of the variable-thickness composite material blade from outside to inside is necessarily gradually reduced, and particularly the position of a neutral plane of the blade can be simply processed only through skin zoning during calculation. The sandwich structure 4 is prepared by adopting an additive manufacturing technology, so that errors caused by gradual change of the shape of the layering can be reduced during manufacturing. The sandwich structure can be in one of a beam rib structure, a topological structure and a periodic hole array structure.
The blade skin 3 and the solid structure 6 are variable thickness composite material laminated shells; the composite material laminated shell is composed of a reinforcement and a matrix, wherein one or more of carbon fiber, glass fiber, aramid fiber, surface felt and reinforcing felt is/are used as the reinforcement, and one of epoxy resin, polyester resin, vinyl ester, bismaleimide, thermosetting polyimide and cyanate is used as the matrix.
The ply form of the reinforcement of the composite material laminated shell can be one or more of unidirectional fiber cloth, plain weave fiber cloth and fiber felt. The layering angle of the unidirectional fiber cloth and the plain weave fiber cloth is selected from one or more of 0-180 degrees.
The material used for the root rib 5 is one of No. 45 steel, A3 steel, 40Cr, HT150 and composite material.
The sandwich structure 7 is manufactured by an additive manufacturing technology, and the used material is one of resin, composite material, nylon, stainless steel and aluminum alloy.
The propeller hub 1 is made of one of aluminum alloy, copper alloy and composite materials.
According to the composite material blade structure design method, on the premise that manufacturing constraints and process realizability are fully considered, a proper material scheme is adopted, the rigidity and mass distribution of the structure are changed from local or overall through adjusting the partition position, partition thickness, partition layering angle and layering sequence of the skin and combining core optimization in different structural forms, and fixed-frequency optimization design of the scaling similar model aiming at the original size model is achieved.
The blade skin 3 in the composite material blade structure provided by the invention is a main part for providing structural rigidity, and the structural rigidity can be greatly changed when the thickness of the skin is changed. The solid structure 6 in the blade core 4 is intended to ensure the attachment of the root rib and to prevent the root rib from coming off the blade. The sandwich structure 7 is formed by changing the material, structural form and size of the core body so as to change the mass distribution.
The skin of the blade structure of the scaled fixed-frequency composite propeller provided by the invention is divided into areas according to thickness distribution and manufacturability, and a sandwich structure adopts a proper structural form and materials. On the premise of fully considering manufacturing constraints and process realizability, the rigidity and mass distribution of the structure are locally or integrally changed by changing the partition position, partition thickness, partition layering angle and layering sequence of the skin, the material schemes of the skin and the sandwich, and the structural form and size of the sandwich structure, so that the fixed-frequency optimal design of the blade structure similar to the composite material shrinkage ratio is realized.
The invention has the beneficial effects that: the composite material laying design of the skin is combined with the structural design of the core, the partition position, the partition thickness, the partition laying angle and the laying sequence of the skin, the material schemes of the skin and the sandwich, and the structural form and the size of the sandwich structure can be changed, a larger design space can be obtained when multi-stage constant frequency design is carried out, the consideration of damping performance and weight reduction effect is included, and therefore constant frequency optimization of the blade structure with the similar scaling in consideration of manufacturability is completed. Design variables of each skin subarea are independent, the method is suitable for scale optimization design of an asymmetric blade structure, and the application range is wider. The manufacturing constraint and the process realizability are fully considered, and the feasibility of the design scheme is verified through the design, the manufacture and the test of the large-side-inclined composite propeller blade.
Drawings
Fig. 1 is a schematic overall structure diagram of a scaled fixed-frequency composite propeller structure according to the present invention.
Fig. 2 is a schematic structural diagram of a scaled, fixed-frequency composite propeller blade according to the present invention.
FIG. 3 is a schematic diagram of a solid structure and a sandwich structure in a blade core of a scaled, fixed-frequency composite propeller blade according to the present invention.
FIG. 4 is a schematic representation of a specific design of a scaled, fixed frequency composite propeller blade configuration of the present invention.
In the figure, 1-propeller hub, 2-composite material blade, 3-blade skin, 4-blade core, 5-root rib, 6-core solid structure, 7-core sandwich structure, 8-core sandwich beam rib structure and 9-core sandwich solid structure.
Detailed Description
The following further describes a specific embodiment of the present invention with reference to the drawings and technical solutions.
The scaling fixed-frequency composite propeller is formed by connecting and assembling a propeller hub 1 and composite blades 2 by combining and explaining with the figure 1.
As explained in connection with fig. 1 and 2, the scaled, fixed frequency composite propeller blade structure includes a blade skin 3, a blade core 4, and a root rib 5. The single blade is made by curing a composite material through a mold by a low-pressure contact molding process. The upper and lower skins of the blade skin 3 are divided into a plurality of areas according to the thickness distribution and the manufacturing realizability, the skins are subjected to layering optimization according to the areas, and the layering scheme of each area is different.
The blade core 4 in the scaled and fixed-frequency composite propeller blade structure comprises a solid structure 6 at the root of the blade and a sandwich structure 7 connected to the thinner part of the blade tip, and the sandwich structure has various structural forms, which is explained by combining with figures 1 and 3. The solid structure 6 and the sandwich structure 7 are connected by a mould in a gluing way.
A specific design scheme of the blade structure of the scaled and fixed-frequency composite propeller is described with reference to fig. 4. The sandwich structure 7 consists of a middle beam rib structure 8 and a solid structure 9 at the blade tip part; the transverse beams are named Liang1, Liang2 from top to bottom, and the chordwise ribs are named Lei1, Lei2, Lei3 from left to right, wherein Lei1 is connected with the solid structure 6, and Lei3 is connected with the blade tip solid structure 9. The solid structure 9 is adopted at the blade tip part to prevent resin from flowing out to influence the blade forming during manufacturing. The blade skin 3 is divided into an upper skin and a lower skin, and the thicknesses of the upper skin and the lower skin are asymmetrically distributed; the upper skin and the lower skin are divided into four subareas; the section 1 is arranged between the Lei1 and the Lei2, the section 2 is arranged between the Lei2 and the Lei3, and the section 3 is arranged between the Lei3 and the blade tip surface.
The blade skin 3 and the solid structure 6 at the root of the blade are made of the variable thickness woven composite material laminated shell by taking glass fiber as a reinforcement and epoxy resin as a matrix. The sandwich structure 7 is formed by taking photosensitive resin as a material and performing photocuring printing.
The working principle of the invention is as follows: the invention provides a method for designing a blade structure of a scaled constant-frequency composite propeller, which combines the design of skin materials, subareas and layers with the design of core materials and structural forms to carry out optimization design and completes the fixed-frequency optimization of a scaled similar blade structure by combining manufacturability constraint. The composite material blade comprises a variable-thickness blade skin 3 made of composite materials, a blade core 4 made of a composite material solid structure 6 and a photosensitive resin material sandwich structure 7, and a root rib 5 connected with a hub. And obtaining the target natural frequency of the scaled fixed-frequency composite propeller blade structure according to the natural frequency-frequency ratio of the reference model. And establishing an optimization model by combining the target natural frequency and the structural form of the blade.
Figure BDA0003663264910000081
s.t.Ω 1 b ≤Ω 1 ≤Ω 1 t ,
m b ≤m≤m t ,
p m ＝c 1 ,
p d ≤c 2 ,
p s ≤c 3 ,
θ w ＝c 4 .
x n b ≤x n ≤x n t (n＝1,2,···,q)
In the above formula, omega i a Target frequency of ith order for designing model; omega i s To design the ith order frequency of the model, the optimization objective is to minimize the sum of the differences of the first 3 orders of the frequency; omega 1 To design the first order natural frequency of the model; m is the mass of the structure; x is the number of n For designing the design variables in the model, the design variables are the thickness, the layering angle and the layering sequence of each partition unit of the skin during optimization of the skin, and the beam rib joint is selected for the core sandwich structureThe form, and therefore the design variable, is the thickness of the beam rib; the constraint variable superscripts b and t represent the lower limit and the upper limit of each variable; q is the number of design variables, and the upper skin and the lower skin have 6 partitions in total, so that the thickness of the upper skin and the lower skin has 6 skin thickness variables. The beam rib part has two beams and three ribs, so that the thickness of the beam rib part has 5 beam rib thickness variations.
The first three-order frequencies of the reference model of the carbon fiber composite material blade structure to be designed in the example are 43.63Hz, 87.29Hz and 185.55Hz respectively, and the frequency ratio is 1:6, so that the target frequencies of the first three-order frequencies of the design model are 261.78Hz, 523.74Hz and 1113.30Hz respectively, and the target structure mass is 77.6 g.
The optimization comprises two steps of skin optimization and beam rib thickness optimization, the optimization targets of the two optimization processes are the same as the constraint of the first-order frequency, namely, 256 is more than or equal to omega 1 ≤266。
The optimized mass constraint of the skin is that m is more than or equal to 72 and less than or equal to 77.6, and the initial value and the upper and lower limits of each partition design variable are shown in table 1. Setting the thickness p of a single ply of a ply during optimization m 0.24mm, upper limit p of variation of thickness of missing layer of adjacent skin sections d 0.72mm, and the surface layers theta of the upper skin and the lower skin w At 45 deg., the number of layers of successive identical layer angles does not exceed 3, i.e. p s 3. The optimized thicknesses of the partitions are shown in table 2.
The optimized mass constraint of the beam ribs is set to be m more than or equal to 77 and less than or equal to 77.6, and the initial values and the upper and lower limits of the design variables of the beam ribs are shown in Table 3. The optimized rib thickness is shown in table 4. Table 5 shows the frequency results and design errors after skin optimization and after two-step optimization.
TABLE 1
Shang1 Shang2 Shang3 Xia1 Xia2 Xia3
Initial value 1.00 1.00 1.00 1.00 1.00 1.00
Lower limit of 0.96 0.96 0.96 0.96 0.96 0.96
Upper limit of 3.84 3.84 3.84 3.84 3.84 3.84
TABLE 2
Shang1 Shang2 Shang3 Xia1 Xia2 Xia3
Optimized thickness 1.92 1.92 1.44 1.44 1.44 1.44
TABLE 3
Liang1 Liang2 Lei1 Lei2 Lei3
Initial value 2.00 2.00 2.00 2.00 2.00
Lower limit of 1.00 1.00 1.00 1.00 1.00
Upper limit of 5.00 5.00 5.00 5.00 5.00
TABLE 4
Liang1 Liang2 Lei1 Lei2 Lei3
Optimized thickness 1.62 1.77 3.00 3.00 2.66
TABLE 5
Target frequency/(Hz) Skin optimized frequency/(Hz) Final design frequency/(Hz) Error of the measurement
First order frequency 261.78 265.89 265.16 1.29％
Second order frequency 523.74 535.80 533.94 1.94％
Third order frequency 1113.30 1079.68 1080.66 2.93％
The final optimized structure first third order frequency results are 265.16Hz, 533.94Hz and 1080.66 Hz. The frequency error of each order is 1.29%, 1.94% and 2.93%. Therefore, the fixed-frequency optimization design of the blade structure similar to the composite material shrinkage ratio is realized.

Claims (8)

1. A design method for a fixed-frequency composite blade structure facing a propeller scaling similar model is characterized in that the composite scaling propeller structure is formed by connecting a propeller hub (1) and a composite blade (2); the composite material blade (2) structure comprises a blade skin (3), a blade core body (4) and a root rib (5); the blade skin (3) comprises an upper skin and a lower skin and mainly comprises composite materials, the interior of the skin is connected with the blade core (4), the blade core (4) is divided into two parts, the thick part of the blade root is of a solid structure (6) consisting of the composite materials, and the thin part of the blade tip is connected with a sandwich structure (7) of the solid structure (6); the sandwich structure (7) is prepared by an additive manufacturing technology, and the root rib (5) is connected to the root part of the blade; by selecting proper materials, the blade skin (2) is optimized by considering the manufacturability of the layer spreading angle in a subarea mode, and the blade sandwich structure (7) is determined and optimally designed in the structural form, so that the fixed-frequency structure optimal design of the composite material blade of the propeller scaling similar model is realized.
2. The method for designing a blade structure of a scaled and fixed-frequency composite propeller as recited in claim 1, wherein the target natural frequency of the scaled and fixed-frequency composite propeller blade structure is obtained by combining a frequency ratio derived from a similarity criterion according to the natural frequency of the blade with the original size; establishing a multi-order frequency optimization model according to the target natural frequency and the structural characteristics of the skin core of the blade:
Figure FDA0003663264900000011
s.t.Ω 1 b ≤Ω 1 ≤Ω 1 t ，
m b ≤m≤m t ，
p m ＝c 1 ，
p d ≤c 2 ，
p s ≤c 3 ,
θ w ＝c 4 .
x n b ≤x n ≤x n t (n＝1,2,···,q)
in the above formula, omega i a Target frequency of ith order for designing model; omega i s For designing the ith order frequency, W, of the model i Is the weight of the ith order frequency difference, has
Figure FDA0003663264900000012
Therefore, the optimization goal is to minimize the sum of the frequency difference values of the p orders before the structure, and the frequency of the important order can be highlighted by changing the weight value; omega 1 To design the first order natural frequency of the model; m is the mass of the structure; while adding manufacturability considerations, p, in the skin optimization process m Is a single thickness of the ply, p d Thickness of throw layer between adjacent zone-laminated plates, p s To maximize the number of consecutive identical plies allowed, θ w Angle constraint for structural surface layering; c. C 1 、c 2 、c 3 Is a constant number c 4 A certain designated ply angle or ply angle combination;x n for designing a design variable in the model, the design variable is the thickness, the layering angle and the layering sequence of each partition unit of the skin when the skin is optimized, wherein the layering thickness is a discrete variable, and the value is p m Or a multiple thereof; the spreading angle is a continuous variable and the value range is 0-180 degrees; the laying sequence is the laying sequence for optimizing the laying at different angles; when the core sandwich structure is optimized, the design variables can be the thickness of the beam rib, the unit volume ratio and the position or the size of the hole according to the structure form; the variable superscripts b and t in the constraint represent the lower limit and the upper limit of each variable; q is the number of design variables.
3. The method for designing the scaled fixed-frequency composite propeller blade structure according to claim 1, wherein the blade skin (3) is divided into a plurality of partitions, the partition division rules are that each partition is regular in shape and has no narrow long side and fillet, and the thickness difference of the blade in each partition is within a given threshold value; selecting a layering form and a material, and optimally designing the layering thickness, the layering angle and the layering sequence of each partition.
4. The design method of the scaled fixed-frequency composite propeller blade structure as recited in claim 1, wherein the structural form of the sandwich structure (4) is one of a beam rib structure, a topological structure and a periodic hole array structure.
5. The method for designing a scaled, fixed-frequency composite propeller blade structure according to claim 1, wherein the blade skin (3) and the solid structure (6) are a variable thickness composite laminated shell; the composite material laminated shell is composed of a reinforcement and a matrix, wherein one or more of carbon fiber, glass fiber, aramid fiber, surface felt and reinforcing felt is/are used as the reinforcement, and one of epoxy resin, polyester resin, vinyl ester, bismaleimide, thermosetting polyimide and cyanate is used as the matrix.
6. The method for designing a scaled fixed-frequency composite propeller blade according to claim 1, wherein the root rib (5) is made of one of 45 steel, A3 steel, 40Cr, HT150 and composite material.
7. The design method of the scaled fixed-frequency composite propeller blade structure as recited in claim 1, wherein the material used for the sandwich structure (7) is one of resin, composite material, nylon, stainless steel and aluminum alloy.
8. The method for designing a scaled, fixed-frequency composite propeller blade according to claim 1, wherein the hub (1) is one of an aluminum alloy, a copper alloy and a composite material.
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117690532A (en) * 2023-12-22 2024-03-12 华中科技大学 Topology optimization design method and system for fiber reinforced composite structure with variable thickness skin
CN117690532B (en) * 2023-12-22 2024-07-16 华中科技大学 Topology optimization design method and system for fiber reinforced composite structure with variable thickness skin

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117690532A (en) * 2023-12-22 2024-03-12 华中科技大学 Topology optimization design method and system for fiber reinforced composite structure with variable thickness skin
CN117690532B (en) * 2023-12-22 2024-07-16 华中科技大学 Topology optimization design method and system for fiber reinforced composite structure with variable thickness skin

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