KR20190103750A - Method for analysing the material data of composite fiber reinforced plastics with finite element method - Google Patents

Abstract

According to one embodiment of the present invention, provided is a method for obtaining static collapse characteristic data of a circular cross-section composite fiber reinforced plastics (CFRP) using a finite element method comprises the steps of: receiving physical properties of a resin and a carbon fiber constituting the CFRP; inputting physical properties of the carbon fiber and resin, design conditions of the CFRP, and collapse conditions for testing the collapse of the CFRP into an orthotropic material model; and operating values inputted to the orthotropic material model and obtaining the characteristic data of the CFRP.

Description

Method for analysing the material data of composite fiber reinforced plastics with finite element method}

The present invention relates to a method for acquiring static collapse characteristic data of a circular cross-section carbon fiber composite material (CFRP) using the finite element method, and more specifically, to apply CFRP to automobile and mechanical parts, stacking of CFRP The present invention relates to a method for acquiring static collapse characteristic data of a circular cross-section CFRP using finite element method to obtain a large number of test data according to the lamination method.

Recently, the results for the weight reduction of the body materials and structure are being promoted in two aspects of the optimum structural design technology and the development of materials and materials. Finite element analysis for structural analysis, impact analysis, etc. for optimal design of parts with various structural shapes is carried out, and metal materials are expanded to lightweight materials through the development of lightweight materials.

Carbon Fiber Reinforced Plastics (CFRP), one of the representative lightweight materials replacing metals as a representative example of recent lightweight technology and material development, is a fiber-reinforced composite material, which is about 1/5 lighter than steel, and has high strength and specific strength. Excellent specific strength and corrosion resistance are also spreading in various fields.

In addition, it has the usefulness to properly select the stack orientation according to the design requirements.

CFRP, which is used in various fields, is an anisotropic material in which the characteristics of two materials, carbon fiber and matrix, coexist. Carbon fiber serves to resist major loads and resin serves as a medium to disperse and reduce the load on the carbon fiber. Due to the characteristics of the carbon fiber, mechanical properties vary according to the stacking angle and the stacking method of CFRP, and show an unstable failure mode unlike metals under load, tension, bending, shear, and the like. Therefore, there is a problem in that it is difficult to predict mechanical property values such as strength and rigidity. In order to design and analyze CFRP for the application of CFRP to automobile and mechanical parts, a large number of test data must be constructed according to the stacking angle or stacking method of CFRP.

In addition, the resin and void amount constituting the CFRP according to the CFRP specimen manufacturing method is not constant, there is a problem that the proficiency and environmental factors of the manufacturer affects the properties of the CFRP a lot. In other words, it takes a lot of time and money to build property data for a consistent CFRP.

Therefore, there is an urgent need for a finite element analysis technique that can secure reliable physical property data for CFRP while reducing the time and cost required for the experiment.

The present invention is based on the properties of the carbon fiber and resin constituting the carbon fiber composite material (CFRP) circular cross-section carbon using the finite element method to obtain the CFRP lamination method and the characteristic data according to the outermost angle through finite element analysis It is an object of the present invention to provide a method for obtaining static collapse characteristic data of a fiber composite material (CFRP).

Method for obtaining static collapse characteristics data of the circular cross-section carbon fiber composite material (CFRP) using the finite element method according to the present invention comprises the steps of receiving the properties of the carbon fibers and resin constituting the carbon fiber composite material (Composite Fiber Reinforced Plastics, CFRP); Inputting physical properties of the carbon fiber and resin, design conditions of the CFRP, and collapse conditions for collapse test of CFRP into an Orthotropic Material model; And calculating characteristic data of CFRP by calculating values input to the orthotropic material model.

Before the step of receiving the properties of the carbon fiber and resin, tensile 0 ° (Longitudinal Tension), tensile 90 ° (Transverse Tension), compression 0 ° (Longitudinal Compression), compression 90 ° (Transverse Compression) and shear (Sheer) Obtaining basic physical properties of the carbon fiber and the resin through basic experiments on respective stresses and modulus for each; And obtaining physical properties of the carbon fiber and the resin through a micro-mechanical formula using the basic physical properties of the carbon fiber and the resin.

The characteristic data of the CFRP may include at least one of Modulus, Possion's Ratio, Stress, and Strain in each direction.

Design conditions of the CFRP may include the outermost angle and the number of interfaces.

The outermost angle of the CFRP is 0 or 90 °, the interfacial number of the CFRP may be 2, 3, 6 or 7.

The collapse condition may restrict the degrees of freedom of the lower end of the CFRP and the displacement of the upper end of the CFRP to be controlled.

The CFRP may be a circular member.

According to the present invention, the characteristic data of CFRP manufactured according to the method of manufacturing CFRP based on the basic physical properties of the material constituting CFRP can be obtained similarly to the actual experimental value through finite element analysis.

Therefore, it is possible to obtain the characteristic data for CFRP through finite element analysis without the need for a separate experiment according to the method of manufacturing CFRP, it is possible to reduce the cost and time required to analyze the characteristics of CFRP.

1 is a flowchart illustrating a method of obtaining static collapse characteristic data of a circular cross-section carbon fiber composite material (CFRP) using the finite element method according to the present invention.
2 is a graph showing a stress-strain curve for carbon fiber.
3 is a graph showing stress-strain curves for resins.
4 is an image of an element having four nodes through a hypermesh for a sketched specimen model.
Figure 5 is an image showing the physical properties for the carbon fiber and resin input to GENOA.
Figure 6 is an image showing the conditions set in the upper and lower parts of the specimen model in the collapse finite element analysis.
FIG. 7 is a graph showing a load-displacement curve for a CFRP circular structure having an outermost angle of 90 ° and 2, 3, 6, or 7 surfaces analyzed through the collapse finite element analysis.
FIG. 8 is a graph showing a load-displacement curve for a CFRP circular structure having an outermost angle of 0 ° and an interface number of 2, 3, 6, or 7 analyzed through the collapse finite element analysis.
FIG. 9 is a graph showing load-displacement curves for CFRP circular structures having 90 ° or 0 ° outermost surfaces and 2, 3, 6 or 7 surfaces analyzed through collapse finite element analysis.
10 is an image showing carbon CFRP prepared according to an embodiment of the present invention.
FIG. 11 is a graph showing load-displacement curves for a CFRP circular structural member having an outermost layer angle of 90 ° and an interfacial number of two, four, six, or seven analyzed through actual collapse experiments.
12 is a graph showing a load-displacement curve for a CFRP circular structural member having an outermost layer angle of 0 ° and an interfacial number of 2, 4, 6, or 7 analyzed through actual collapse experiments.
FIG. 13 is a graph showing load-displacement curves for CFRP circular structural members having an outermost layer angle of 90 ° or 0 ° and having 2, 4, 6, or 7 interface numbers analyzed through actual collapse experiments.
FIG. 14 is a graph showing load-displacement curves for CFRP circular structural members having an outermost layer angle of 90 ° analyzed by actual collapse test and collapse finite element analysis.
FIG. 15 is a graph showing load-displacement curves for CFRP circular structural members having different outer surface angles of 0 ° and analyzed by actual collapse test and collapse finite element analysis.

Hereinafter, with reference to the accompanying drawings will be described in detail a method of obtaining static collapse characteristics data of a circular cross-section carbon fiber composite material (CFRP) using the finite element method according to an embodiment of the present invention. As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosed form, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the drawings, similar reference numerals are used for similar elements. In the accompanying drawings, the dimensions of the structures are shown in an enlarged scale than actual for clarity of the invention.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described on the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Hereinafter, embodiments of the present invention will be described in detail. However, this is presented as an example, by which the present invention is not limited and the present invention is defined only by the scope of the claims to be described later.

1 is a flowchart illustrating a method of obtaining static collapse characteristic data of a circular cross-section carbon fiber composite material (CFRP) using the finite element method according to the present invention.

Hereinafter, an embodiment of the present invention will be described with reference to FIG. 1.

The method for acquiring static collapse characteristics data of a circular cross-section carbon fiber composite material (CFRP) using the finite element method according to an embodiment of the present invention is to input the physical properties of the carbon fiber and resin constituting the carbon fiber composite material (Composite Fiber Reinforced Plastics, CFRP) Receiving step 110, inputting the physical properties of the carbon fiber and resin, design conditions of the CFRP and collapse conditions for collapse test CFRP into an Orthotropic Material model (120), calculating the values entered in the Orthotropic Material model To obtain the characteristic data of the CFRP (130).

The characteristic data of CFRP obtained through the finite element method, which is one of the simulations, is compared with the characteristic data of CFRP obtained through actual experiments.

In order to derive the properties of the carbon fibers and the resin before the step 110 of inputting the properties of the carbon fibers and the resin constituting the carbon fiber composite material (CFRP), the tension 0 ° (Longitudinal Tension), tension Through the basic experiments on the stress and modulus of 90 ° (Transverse Tension), 0 ° (Longitudinal Compression), 90 ° (Transverse Compression) and Shear, the carbon fiber and Obtaining the physical properties of the resin and the physical properties of the carbon fiber and the resin through the micro-mechanical formula using the basic physical properties of the carbon fiber and the resin can be performed first.

Here, the micro-mechanical equation is as follows.

The magnitude of the stress is determined by a clear failure criterion. In the 12 failure modes, fly failure is related to six local stresses along the direction of the material, as in condition (1), and resin failure is as in condition (2). Progressive damage and failure assessments are performed according to the entered failure criteria.

S is strength, σ is stress, l is longitudinal direction, 11 is x axis, 22 is y axis, 33 is z axis, 12 is xy shear, 23 is yz shear, 13 is xz shear, C is compression And m represents resin.

The basic physical properties obtained through five basic tests such as tensile, compression, and shear are shown in the table below.

Basic Properties for Carbon Fibers and Resins Description Initial Value Units Manufacturing data Fiber Volume Ratio 5.380 × 10 ^-1 Void Volume Ratio 3.950 × 10 ^-2 Manufacturing Fiber Properties (Ef11) Longitudinal Modulus 2.352 × 10 ² GPa Manufacturing Matrix Properties (NUm) Poisson's Ratio 3.400 × 10 ^-1 Unidirectional Test Ply Properties (E11) Longitudinal Modulus 1.234 × 10 ² GPa (E22) Transverse Modulus 7.938 GPa (G12) Shear Modulus 6.280 GPa (NU12) Poisson's Ratio 3.100 × 10 ^-1 (S11T) Tension Strength 1.786 × 10 ³ MPa (S11C) Compressive Strength 2.620 × 10 ¹ MPa (S22T) Tension Strength 5.204 × 10 ² MPa (S22C) Compressive Strength 1.867 × 10 ² MPa (S12S) Shear Strength in 12 Direction 8.639 × 10 ¹ MPa

Manufacturing Data, Manufacturing Fiber Properties, Manufacturing Matrix Properties and Unidirectional Ply Test Property data can be used to obtain the properties of carbon fiber and resin constituting CFRP prepreg sheet (USN125) produced by SK Chemicals used in the present invention. have.

Here, Unidirectional Ply Test Property data is used for the tension 0 ° (Longitudinal Tension), tension 90 ° (Transverse Tension), compression 0 ° (Longitudinal Compression), compression 90 ° (Transverse Compression) and Shear It is the basic properties of carbon fiber and resin for each stress and modulus.

The basic properties of carbon fiber and resin can be used to obtain the properties of carbon fiber and resin through micro-mechanical equations. The physical properties of the carbon fiber and the resin obtained by the micro-mechanical theory can be shown in the tables below and FIGS. 2 and 3.

Properties of Carbon Fiber Property Value (E11) Longitudinal Modulus 2.352 × 102 GPa (E22) Transverse Modulus 1.435 × 101 GPa (G12) Shear Modulus in 12 Direction 1.636 × 101 GPa (G23) Shear Modulus in 23 Direction 4.999 GPa (S11T) Longitudinal Tension Strength 3.414 × 103 MPa (S11C) Longitudinal Compressive Strength 7.750 × 102 MPa (NU12) Poisson's Ratio in 12 Direction 2.821 × 10-1 MPa (NU23) Poisson's Ratio in 23 Direction 4.513 × 10-1 MPa

Properties of Resin Property Value (E) Modulus 3.697 GPa (SC) Compressive Strength 3.096 × 10 ² MPa (ST) Tension Strength 4.345 × 10 ¹ MPa (SS) Shear Strength 1.559 × 10 ² MPa (NU) Poisson's Ratio 3.400 × 10 ^-1

The properties of a single CFRP can be calculated as shown in the table below through the properties of carbon fiber and resin obtained by micro-mechanical theory.

Properties of CFRP Prepreg Sheet Property Value (E11) Longitudinal Modulus 1.235 × 10 ² GPa (E22) Transverse Modulus 7.938 GPa (E33) Thickness Modulus 7.938 GPa (G12) Shear Modulus in 12 Direction 6.280 GPa (G13) Shear Modulus in 13 Direction 6.280 GPa (G23) Shear Modulus in 23 Direction 2.202 (S11T) Longitudinal Tension Strength 1.786 × 10 ³ MPa (S11C) Longitudinal Compressive Strength 5.300 × 10 ² MPa (S22T) Transverse Tension Strength 2.612 × 10 ¹ MPa (S22C) Transverse Compressive Strength 1.862 × 10 ² MPa (S33T) Thickness Tension Strength 2.612 × 10 ¹ MPa (S33C) Thickness Compressive Strength 1.862 × 10 ² MPa (S12S) Shear Strength in 12 Direction 8.637 × 10 ¹ MPa (S23S) Shear Strength in 23 Direction 8.427 × 10 ¹ MPa (S12S) Shear Strength in 13 Direction 8.637 × 10 ¹ MPa (NU12) Poisson's Ratio in 12 Direction 3.100 × 10 ^-1 (NU13) Poisson's Ratio in 13 Direction 3.100 × 10 ^-1 (NU23) Poisson's Ratio in 23 Direction 5.308 × 10 ^-1

CFRP according to the invention has the properties of anisotropic materials. Carbon fiber constituting CFRP is an anisotropic material having a direction, the physical properties may vary depending on the carbon fiber composition method (stacking direction) and thickness. In addition, the properties of the resin may vary depending on the type, curing time and temperature of the resin.

Therefore, Orthotropic Material Properties of Outlinerow Density, Orthotropic Secant Coefficient of Thermal Expansion, Orthotropic Elasticity, Orthotropic Strain Limits, Substitute in Orthotropic Stress Limits, Tsai-Wu Constants, etc.

The basic theory of Orthotropic Material model used in this study is as follows.

Where σ is stress and D is elastic or elastic force constant of resin or stress-strain amount of resin, and ε ^el is elastic deformation vector.

Example 1 Characteristic Data of CFRP Obtained by Finite Element Analysis

CFRP specimens for collapse finite element analysis in the same shape as the actual experimental model for CFRP sketch the shape with 3D CAD SurfaceModel. The sketched model is converted into a step file, and an element having four nodes is created as shown in FIG. 4 using hypermesh, which is a mesh software. After generating urea, using GENOA, an analysis tool dedicated to composite materials, input the physical properties of the carbon fiber and the resin properties obtained through basic theory and basic experiment as shown in FIG. For the collapse test conditions of the same simulation as the actual model, as shown in FIG. The node at the top of the specimen is constrained to control the displacement. The displacement in which the upper end of the specimen is controlled can be adjusted according to the collapse test. Specifically, it may be 10 mm / min. The displacement of the lower part of the specimen can also be controlled without restraining the degree of freedom depending on the conditions of the actual experiment.

After setting CFRP specimen condition and collapse test condition to a predetermined value for simulation, finite element analysis is performed by using ansys, which is one of problem solvers.

FIG. 7 is a graph showing a load-displacement curve for a CFRP circular structure having an outermost angle of 90 ° and an interface number of 2, 3, 6 or 7, calculated by the collapse finite element method.

FIG. 8 is a graph showing a load-displacement curve for a CFRP circular structure having an outermost angle of 0 ° and an interfacial number of 2, 3, 6 or 7 calculated by the collapse finite element method.

Each specimen as shown in Fig. _{9 [90 2/0 2]} S, [0 2/90 2] 2, [90/0] 2S, [0/90] 4, [0 2/90 2] S, [90 2 / 0 ₂ ] ₂ , [0/90] _2S and [90/0] ₄ are initially linear. However, after a certain load, the load suddenly increases and then breaks at maximum strength, resulting in a sharp decrease in strength. The maximum load of the outermost specimens of the 90 ° [90 _{2/0 2] S} is _{30.457kN, [0 2/90 2} ] The maximum load is a maximum load of 27.388kN, [90/0] _{2S 2} is 38.467kN, The maximum load of [0/90] ₄ is calculated at 27.02 kN. Further, the outermost specimens of the 0 ° - _{02/90 2] S} is the maximum load 30.1074kN, [90 _{2/0 2]} is a maximum load of ₂ 27.387kN, the maximum load of [0/90] _2S is 35.7369 kN, [90/0] _{4 The} maximum load is calculated to be 27.512 kN.

Comparative Example 1. Mechanical Properties of CFRP Prepreg Sheets Obtained by Actual Experiments

The specimen used in the experimental example of the present invention is a CFRP circular member in the form of a structural member for a vehicle. The CFRP circular member is formed by laminating the USN125A prepreg sheet produced by SK Chemicals by vacuum forming process using Autoclave which is a typical process.

Mechanical properties for the CFRP prepreg sheet are shown in the table below.

Condition of manufactured specimen Carbon / Epoxy Prepreg Sheet thickness
(mm) Total watt
(h / m ² ) Fiber ArealWt
(g / m ² ) Resin Content
(%) USN125A 0.129 195 125 36

Properties of CFRP Prepreg Sheet Type
Characteristics Fiber
(Carbon) Resin
(Epoxy # 2500) Prepreg Sheet
(CU125NS) Denstiy
[kg / m3] 1.83 × 10 ³ 1.24 × 1 ^-3 - Tensile strength
[GPa] - - 2.53 Elastic Modulus [GPa] 240 3.6 132.7 Breaking Elongation [%] 21 3 1.3 Poisson's ratio - - 0.3 Resin Content [% Wt] - - 33

In addition, the thermosetting cycle used in the Autoclave vacuum forming process is heated to 130 ° C. for 50 minutes at 20 ° C. at 3 × 10 ⁵ Pa pressure and then maintained at 130 ° C. for 100 minutes. Thereafter, the mixture is cooled to 20 ° C. for 50 minutes and subjected to thermosetting.

In order to investigate the collapse mode of CFRP circular members according to design variables, the stacking angle and the number of interfacial numbers are changed. A specimen is prepared by varying the lamination angle and the number of interfaces in a laminated configuration in the form of [A ° N / B ° N] with the axial direction of the CFRP prepreg sheet at 0 °.

Specifically, the lamination angles A ° and B ° vary in lamination angle in the form of 90 ° / 0 ° or 0 ° / 90 °, and the lamination number N is made of 2, 3, 6 or 7 interfacial water according to the change of interfacial number. . In addition, in the general collapse mode test, one end is intentionally given a defect to induce sequential and local collapse so as to have high energy absorption characteristics. The specimen according to the present invention manufactures a specimen in which a trigger exists by chamfering the surface on which load is applied at 45 °. In addition, the length of the specimen shall be 120 mm, which is long enough for the crush to repeatedly appear in the experiment without causing Euler Buckling.

Static collapse tests are conducted to investigate the energy absorption characteristics of CFRP structural members. Static crush test uses a universal testing machine (UTM) and installs two compression jigs in parallel between the load cell and the actuator. The test is carried out so that a uniform load is applied through a displacement control of 10 mm / min. Several tests are carried out to ensure reproducibility during the experiment, and successive crush tests are performed while controlling the length of the entire specimen to 60 mm so that sequential crush occurs. The average collapse stress is obtained by dividing the average collapse load by the cross-sectional area of the specimen as shown below.

는 평균 압궤 응력,

는 평균 압궤 하중

,

는 흡수에너지이며, A는 단면적이다.

Is the average collapse stress,

Is the average crush load

,

Is the absorbed energy and A is the cross-sectional area.

FIG. 11 is a graph showing a load-displacement curve obtained through a collapse test on a CFRP circular structural member having an outermost layer angle of 90 ° and having an interfacial number of 2, 4, 6, or 7, respectively.

12 is an outermost layer angle of 0 ° and two interfacial water. This is a graph showing the load-displacement curve obtained through the collapse test of four, six or seven CFRP circular structural members.

11 and 12, when the outermost layer angle is 0 °, the outermost sheet shows no expansion and fracture to the carbon fiber.

In contrast to 0 ° when the outermost layer angle is 90 °, the outermost sheet shows a somewhat high collapse characteristic due to expansion and fracture of the carbon fiber.

In order to predict the physical properties of CFRP according to the present invention, first, physical properties of carbon fiber and resin may be obtained using basic physical data and carbon-mechanical formula for carbon fiber and resin. Basic properties data for carbon fiber and resin are available for Longitudinal Tension, Transverse Tension, Longitudinal Compression, Transverse Compression, and Shear. It can be obtained through basic experiments on stress and modulus.

Physical properties of carbon fiber and resin can be calculated by substituting basic physical data about carbon fiber and resin obtained through basic experiments into Micro-Mechanical theory. Based on the calculated properties of carbon fiber and resin, finite element analysis by Orthotropic Material theory can be performed to obtain the properties of CFRP including carbon fiber and resin. The physical properties of CFRP for static collapse may be a load-displacement curve, numerical data on load-displacement, and the like. In order to confirm the reliability of the prediction data through the simulation, the collapsed finite element analysis is performed under the same experimental conditions as the actual model, and the data obtained through the collapsed finite element analysis are compared with the actual experimental data.

The results of the actual collapse test and collapse finite element analysis of CFRP specimens with the outermost 90 ° are shown in FIG. 14 and the table below.

Collapse test results and collapse finite element analysis results for CFRP specimens with 90 ° outermost layer Characteristics
Type Real test Simulation Deviation [90 _{2/0 2] S} 27.4855 kN 30.09945 kN -8.6% _{[02/90 2 2} 31.3784 kN 27.38737 kN 14% [90/0] _2S 36.5169 kN 36.13652 kN 1.04% [0/90] ₄ 31.3456 kN 27.51257 kN 12%

[90 _{2/0 2]} In the case of the specimen _S, by comparing the actual results with the finite element analysis results, it shows about 8.6% error rate. Furthermore, [0, _2/2 90] For the _second specimen, the 14% error rate, in the case of a [90/0] _2S specimen, in the case of the error rate of about 1.04%, [0/90] ₄ specimens, approximately 12% Show error rate.

For specimens with 90 ° outermost layer, the error rate is approximately 10%.

The results of the finite element analysis were compared with the actual test results of the specimen having the outermost layer of 0 ° and are shown in FIG. 15 and the table below.

Collapse test results and collapse finite element analysis results for CFRP specimens with 0 ° outermost layer Characteristics
Type Real test Simulation Deviation [0 _{2/90 2] S} 27.2512 kN 30.10749 kN -10.48% [90 _{2/0 2] 2} 31.4572 kN 27.38757 kN 12.93% [0/90] _2S 36.7385 kN 35.73693 kN 2.72% [90/0] ₄ 29.378 kN 27.51283 kN 6.34%

[0, _2/2 90] In the case of the specimen _S, the actual result and the FEM analysis result of 10.48% error rate, in the case of [90 _{2/0 2] 2} samples, show that the error rate of 12.93%. In addition, the error rate of 2.72% for the [0/90] _2S specimen and the error rate of 6.34% for the [90/0] ₄ specimen.

Specimens with an outermost layer of 0 ° generally have an error rate of about 10%.

When applying the finite element analysis to the CFRP static collapse, it is found that the CFRP properties can be predicted through the finite element analysis because the error rate is about 10% when compared with the results from the actual experiments.

The description of the presented embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the scope of the invention. Thus, the present invention should not be limited to the embodiments set forth herein but should be construed in the broadest scope consistent with the principles and novel features set forth herein.

510: physical properties of carbon fibers input to GENOA
520: physical properties of the fiber entered into GENOA
610, 620: Image showing the conditions set in the upper and lower parts of the specimen model in collapse analysis
710: the analysis through the crushing finite element analysis [90 _{2/0 2]} load on the _S CFRP circular structure - a graph showing the displacement curve
Graph illustrating the displacement curve - crushing a finite element method analysis through the _{[02/90 2 2} load on the CFRP circular structure: 720
730: Graph showing load-displacement curves for [90/0] _2S CFRP circular structures analyzed by collapse finite element analysis
Graph illustrating the displacement curve - crushing a finite element analysis through analysis [0/90] ₄ load on the CFRP circular structure: 740
810: the analysis by the finite element method crushing [0, _2/2 90] load on the _S CFRP circular structure - a graph showing the displacement curve
Graph illustrating the displacement curve - the finite element method analysis through the crushing [90 _{2/0 2] 2} load on the CFRP circular structure: 820
830: Graph showing the load-displacement curves for the _2S CFRP circular structure analyzed by the collapse finite element method.
840: Graph showing load-displacement curves for [90/0] ₄ CFRP circular structures analyzed by the collapse finite element method
910: [90 _{2/0 2] S,} [0 _2/2 90] _2, [90/0] _2S and [0/90] ₄ load on the CFRP circular structure - graph comparing displacement curve
_{920: [0 2/90 2} ] S, [90 2/0 2] 2, [0/90] 2S and [90/0] ₄ load on the CFRP circular structure - graph comparing displacement curve
1010: Image showing a CFRP circular structure
1020: Image showing manufacturing conditions of specimens for CFRP circular structures.
1110 to 1140: Graph showing load-displacement curves for CFRP circular structural members having an outermost layer angle of 90 ° and 2 or 4, 6 or 7, respectively, which were analyzed by actual collapse test
1220 to 1240: The outermost layer angle analyzed by actual collapse test was 0 ° and two interfacial water. Graph showing load-displacement curves for four, six, or seven CFRP circular structural members
1310: Graph comparing load-displacement curves for CFRP circular structural members with the outermost layer angle of 90 ° and the number of interfaces, respectively, analyzed by actual collapse test
1320: The outermost layer angle analyzed by the actual collapse test is 0 ° and two interfacial water. Graph comparing load-displacement curves for four, six or seven CFRP circular structural members
1410 to 1440: Graphs comparing load-displacement curves for CFRP circular structural members with 90 ° outermost layer angles analyzed by actual collapse test and collapse finite element analysis
1510 to 1540: Graphs comparing load-displacement curves of CFRP circular structural members with different outer surface angles of 0 ° and analyzed by actual collapse test and collapse finite element analysis

Claims (7)

Receiving physical property data of the carbon fibers and the resin constituting the carbon fiber composite material (CFRP);
Inputting the received physical properties data of the carbon fiber and resin, design conditions of the CFRP, and collapse conditions for collapse tests of CFRP into an Orthotropic Material model; And
Calculating characteristic data of CFRP by calculating values input to the orthotropic material model;
Method for obtaining static collapse characteristics data of circular cross-section carbon fiber composite material (CFRP) using finite element method. The method of claim 1,
Before the step of receiving the properties of the carbon fiber and resin,
For each stress and modulus for Longitudinal Tension, Tension 90 ° (Transverse Tension), Compression 0 ° (Longitudinal Compression), Compression 90 ° (Transverse Compression), and Shear Obtaining basic properties of the carbon fiber and the resin through a basic experiment; And
Including the basic properties of the carbon fiber and the resin to obtain the physical properties of the carbon fiber and the resin through a micro-mechanical formula; comprising,
Method for obtaining static collapse characteristics data of circular cross-section carbon fiber composite material (CFRP) using finite element method. The method of claim 1,
The characteristic data of the CFRP,
At least one of a coefficient, a Poisson's ratio, and a stress-strain in each direction,
Method for obtaining static collapse characteristics data of circular cross-section carbon fiber composite material (CFRP) using finite element method. The method of claim 1,
The design conditions of the CFRP,
Including the outermost angle and interfacial number of CFRP,
Method for obtaining static collapse characteristics data of circular cross-section carbon fiber composite material (CFRP) using finite element method. The method of claim 4, wherein
The outermost angle of the CFRP is 0 or 90 degrees,
Interfacial number of the CFRP is 2, 3, 6 or 7,
Method for obtaining static collapse characteristics data of circular cross-section carbon fiber composite material (CFRP) using finite element method. The method of claim 1,
The collapse condition is,
The degree of freedom at the bottom of the CFRP is constrained,
The displacement of the top of the CFRP to be controlled to be controlled,
Method for obtaining static collapse characteristics data of circular cross-section carbon fiber composite material (CFRP) using finite element method. The method of claim 1,
The CFRP is a member in the form of a circle,
Method for obtaining static collapse characteristics data of circular cross-section carbon fiber composite material (CFRP) using finite element method.

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