Apparatus and method for predicting physical properties of multilayer materials

Abstract

When developing a multilayer material having a laminated structure, the present invention can predict physical properties such as the elastic modulus, shear modulus, and Poisson's ratio of the entire laminate, and can extract not only the homogenized stiffness of the entire laminate of the multilayer material but also the physical properties or thickness of the undefined layers.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0138914, filed October 19, 2021, Korean Patent Application No. 10-2021-0138918, filed October 19, 2021, and Korean Patent Application No. 10-2022-0086160, filed July 13, 2022, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to an apparatus and method for predicting the physical properties of a multilayer material. [Background technology]

[0003] Polymer films are non-fibrous, flat plastic moldings that are lightweight, have good barrier properties, are highly transparent, and are relatively inexpensive, making them widely used in a variety of fields, including packaging, household goods, electronic devices, automobiles, and aircraft.

[0004] For example, synthetic polymers such as polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), and polyethylene terephthalate (PET) are processed into polymer films and are widely used both domestically and internationally, and currently, many synthetic polymers are used alone or in blends as materials for polymer films.

[0005] Multilayer films are composite films made by laminating different types of films to give the film multiple functions. For example, a film that combines the excellent mechanical properties of polyethylene (PE) with the beautiful printing properties of cellophane, and various multilayer films that combine nylon and vinyl alcohol-ethylene copolymers are used as packaging materials.

[0006] When developing such multilayer films as materials, it is necessary to predict the physical properties of the entire laminate, such as elastic modulus, shear modulus, and Poisson's ratio.

[0007] If the elastic modulus is "E", the shear modulus is "G", and the Poisson's ratio is "ν", the relationship between them is as follows:

[0008] G=E / {2(1+ν)}

[0009] Within the elastic range of a material, the lateral deformation (deformation perpendicular to the load) and the longitudinal deformation (deformation in the direction of the load) are mutually proportional, and the ratio of these two deformations has a constant value depending on the material within the elastic limit, and this ratio is called the Poisson's ratio.

[0010] In addition, the elastic modulus indicates the degree of strain that occurs when an elastic material is subjected to stress. If the elastic modulus is "E", stress is "σ", and strain is "ε", the relationship between them is as follows:

[0011] E=σ / ε

[0012] Meanwhile, since multilayer film materials exhibit anisotropy in the machine direction (MD) and transverse direction (TD) during the manufacturing process, in order to design a robust material, not only the homogenized stiffness of the entire laminate of the multilayer film, but also only one of the physical property values and thickness for one undetermined layer must be input as a range value, and the remaining value must be extracted through an algorithm.

[0013] For example, Korean Patent Publication No. 2005-0112788 (published on December 1, 2005) entitled "Method for Evaluating Effective Stiffness of Composite Beam and Optimizing Lamination Angle" (Patent Document 1) discloses a method for evaluating the effective stiffness of a composite beam made by laminating plies composed of a new material, the method comprising the steps of: (a) calculating the stiffness of each ply; (b) calculating the stiffness matrix of the entire laminated composite beam; and (c) applying the stiffness matrix and deformation rate to a stress result component formula to derive the effective stiffness value of the composite beam.

[0014] However, the technique disclosed in Patent Document 1 does not reset the stiffness matrix, and therefore has the problem that it is not suitable for application to the development of multilayer film materials as in the present invention. [Prior art documents] [Patent documents]

[0015] [Patent Document 1] Korean Patent Publication No. 2005-0112788 Summary of the Invention [Problem to be solved by the invention]

[0016] The object of the present invention is to solve the above-mentioned technical problems, and to provide an apparatus and method for predicting physical properties of a multilayer material, which can predict physical properties such as elastic modulus, shear modulus, and Poisson's ratio of the entire laminate when developing a multilayer material having a laminate structure, and can extract not only the homogenized stiffness of the entire laminate of the multilayer material, but also the physical property values or thickness of the undefined layers. [Means for solving the problem]

[0017] As a means for achieving the above object, the present invention provides a device for predicting the physical properties of a multilayer material.

[0018] In one embodiment, the device for predicting physical properties of a multilayer material according to the present invention comprises: (a) an input section for inputting one or more physical properties of each layer excluding the undetermined layer, such as the elastic modulus, Poisson's ratio, shear modulus, thickness, stacking angle, and zone number setting value of each layer, and (b) one or more physical properties of the elastic modulus and thickness of the undetermined layer; a control unit connected to the input unit and including an overall laminate property calculation unit and an undetermined layer property calculation unit; a display coupled to the control unit; a storage unit coupled to the control unit.

[0019] As yet another means for achieving the above object, the present invention provides a method for predicting physical properties of a multilayer material.

[0020] In one embodiment, the method for predicting physical properties of a multilayer material according to the present invention includes: A method for predicting physical properties of a multilayer material in which two or more materials are laminated, comprising: For each layer except for the undetermined layer, one or more physical properties of each layer among an elastic modulus, a Poisson's ratio, a shear modulus, a thickness, a stacking angle, and a set value of the number of regions; and one or more physical properties of the elastic modulus and thickness of the undetermined layer are input as input values; Calculating the physical properties of the entire laminated multilayer material using the input physical properties; and determining whether the calculated physical properties converge to the final target physical properties. [Effects of the Invention]

[0021] When developing a multilayer material having a laminated structure, the present invention can predict physical properties such as the elastic modulus, shear modulus, and Poisson's ratio of the entire laminate, and can extract not only the homogenized stiffness of the entire laminate of the multilayer material but also the physical properties or thickness of the undefined layers. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a configuration diagram of a multilayer material property prediction device according to a first embodiment of the present invention. [Figure 2] 10 is a flowchart of a method for predicting physical properties of a multilayer material according to a second embodiment of the present invention. [Figure 3] 10 is a flowchart of a method for predicting physical properties of a multilayer material according to a third embodiment of the present invention. [Figure 4] 1 is a graph showing the correlation between the elastic modulus E1,2 and the thickness z of the undetermined layer according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] As a means for achieving the above object, the present invention provides a device for predicting physical properties of a multilayer material.

[0024] In one embodiment, the device for predicting physical properties of a multilayer material according to the present invention comprises: (a) an input section for inputting one or more physical properties of each layer excluding the undetermined layer, such as the elastic modulus, Poisson's ratio, shear modulus, thickness, stacking angle, and zone number setting value of each layer, and (b) one or more physical properties of the elastic modulus and thickness of the undetermined layer; a control unit connected to the input unit and including an overall laminate property calculation unit and an undetermined layer property calculation unit; a display coupled to the control unit; a storage unit coupled to the control unit.

[0025] In a specific example, the control unit sets the input physical properties as an inverse matrix (compliance matrix) for the stiffness matrix of the multilayer material, which is the entire laminate, calculates the physical properties of the multilayer material, which is the entire laminate, using the set inverse matrix value, and determines whether the calculated physical properties converge to the final target physical properties.

[0026] In one specific example, the device for predicting physical properties of a multilayer material according to the present invention comprises: (a) an input section for inputting one or more of the elastic modulus, Poisson's ratio, shear modulus, thickness, stacking angle and zone number setting value of each layer except for the undetermined layer, and (b) the elastic modulus and thickness of the undetermined layer; a control unit connected to the input unit and including an overall laminate property calculation unit and an undetermined layer property calculation unit; a display coupled to the control unit; a storage unit coupled to the control unit.

[0027] In yet another specific example, in a multilayer material in which two or more materials are stacked, the control unit receives (a) for each layer except for an undetermined layer, the elastic modulus, Poisson's ratio, shear modulus, thickness, stacking angle, and zone number setting value of each layer, and (b) any one or more of the elastic modulus and thickness of the undetermined layer.

[0028] Here, the control unit: The stiffness matrix of each layer is calculated using the elastic modulus, Poisson's ratio, and shear modulus of each layer excluding the undetermined layer. The stiffness matrix of each layer is reset by reflecting the lamination angle of each layer in the derived stiffness matrix, and the stiffness matrix of the multilayer material, which is the entire laminate, is calculated using the reset stiffness matrix value after receiving the thickness information of each layer. An inverse matrix (compliance matrix) for the stiffness matrix of the multilayer material, which is the entire laminate, is set, and the elastic modulus / E of the multilayer material, which is the entire laminate, is calculated using the total thickness of the multilayer material, which is the entire laminate, and the set inverse matrix value. x,y , Poisson's ratio / ν x,y and shear modulus / G x,y Calculate one or more of the following: Calculated elastic modulus of multilayer material / E x,y , Poisson's ratio / ν x,y and shear modulus / G x,y One or more of the target elastic modulus (target / E x,y ), target Poisson's ratio (target / ν x,y ) and target shear coefficient (target / G x,y ) and determine whether it converges to one or more of them.

[0029] In the present invention, for an undetermined layer, only one of the physical property value and thickness is input as a range value, and the remaining value can be extracted through an algorithm. In another example, the present invention can simultaneously input the physical property value and thickness as range values for the undetermined layer, and extract or verify values within these ranges. Furthermore, if there are no values that satisfy the physical property value and thickness range for the undetermined layer, each range value can be fixed, and the remaining value can be extracted and presented to the user.

[0030] In one embodiment, the control unit: When the elastic modulus of the undetermined layer and thickness are selected and entered, the calculated elastic modulus / E of the multi-layer material x,y , Poisson's ratio / ν x,y and shear modulus / G x,y One or more of the target elastic modulus (target / E x,y ), target Poisson's ratio (target / νx,y ) and target shear coefficient (target / G x,y ) does not converge to at least one of the values, the elastic coefficients of the undetermined layer can be updated.

[0031] In another embodiment, the control unit When the thickness is selected and entered from the elastic modulus and thickness of the undetermined layer, the calculated elastic modulus / E of the multi-layer material x,y , Poisson's ratio / ν x,y and shear modulus / G x,y One or more of the target elastic modulus (target / E x,y ), target Poisson's ratio (target / ν x,y ) and target shear coefficient (target / G x,y ) does not converge to at least one of the thickness values, the thickness of the undetermined layer can be updated.

[0032] In another embodiment, the control unit Calculated elastic modulus of multilayer material / E x,y , Poisson's ratio / ν x,y and shear modulus / G x,y One or more of the target elastic modulus (target / E x,y ), target Poisson's ratio (target / ν x,y ) and target shear coefficient (target / G x,y ) converges to one or more of the elastic modulus, Poisson's ratio, shear modulus and thickness of the undetermined layer, it can output one or more of them.

[0033] In another embodiment, the controller can plot a correlation between the elastic modulus and thickness of the undetermined layer on a graph.

[0034] As yet another means for achieving the above object, the present invention provides a method for predicting physical properties of a multilayer material.

[0035] In one embodiment, the method for predicting physical properties of a multilayer material according to the present invention includes: A method for predicting physical properties of a multilayer material in which two or more materials are laminated, comprising: For each layer except for the undetermined layer, one or more physical properties of each layer among an elastic modulus, a Poisson's ratio, a shear modulus, a thickness, a stacking angle, and a set value of the number of regions; and one or more physical properties of the elastic modulus and thickness of the undetermined layer are input as input values; Calculating the physical properties of the entire laminated multilayer material using the input physical properties; and determining whether the calculated physical properties converge to the final target physical properties.

[0036] In one specific embodiment, the method for predicting physical properties of a multilayer material according to the present invention includes: For each layer except for the undetermined layer, inputting at least one of the properties of each layer, including elastic modulus, Poisson's ratio, shear modulus, thickness, stacking angle, and number of zones; inputting at least one physical property of an undetermined layer, including an elastic modulus and a thickness; Calculating the physical properties of the entire laminated multilayer material using the input physical properties; and determining whether the calculated physical properties converge to the final target physical properties.

[0037] In a specific example, the step of calculating the physical properties of the multilayer material includes: Setting an inverse matrix (compliance matrix) for the stiffness matrix of the multilayer material that is the entire laminate; and calculating physical properties of the entire laminate, that is, the multi-layer material, using the set inverse matrix value.

[0038] In one embodiment, the step of inputting as an input value is: The first step involves inputting the elastic modulus, Poisson's ratio, shear modulus, thickness, stacking angle and number of zones for each layer except for the undetermined layer. and a second stage in which at least one of the elastic modulus and thickness of the undetermined layer is input.

[0039] In yet another embodiment, calculating the physical properties of the multi-layer material comprises: The third step is to calculate the stiffness matrix of each layer excluding the undetermined layer using the elastic coefficient, Poisson's ratio, and shear coefficient. A fourth step of resetting the stiffness matrix of each layer by reflecting the stacking angle of each layer in the derived stiffness matrix; A fifth step of calculating the stiffness matrix of the multilayer material, which is the entire laminate, using the stiffness matrix value reset by receiving the thickness information of each layer; A sixth step of setting an inverse matrix (compliance matrix) for the stiffness matrix of the multilayer material, which is the entire laminate, calculated in this way; and a seventh step of calculating the elastic modulus, Poisson's ratio, and shear modulus of the multilayer material that is the entire laminate using the total thickness of the multilayer material that is the entire laminate and the set inverse matrix value.

[0040] In yet another embodiment, the step of determining whether the calculated physical properties converge to the final target physical properties comprises: The eighth stage involves inputting the elastic modulus, Poisson's ratio, and shear modulus as the final target properties. Calculated elastic modulus / E x,y , Poisson's ratio / ν x,y and shear modulus / G x,y is the target elastic modulus (target / E x,y ), target Poisson's ratio (target / ν x,y ) and target shear coefficient (target / G x,y ) and a ninth step of determining whether the

[0041] In a specific embodiment, in the third step, the elastic modulus E k 1,2 , Poisson's ratio ν k 1,2 , shear modulus G k 1,2 The stiffness matrix [Q] of each layer k in the machine direction 1 and transverse direction 2 is calculated using k 1,2 can be calculated as follows:

[0042]

number

[0043] In Equation 1, for an isotropic material, G=E / {2(1+ν)}.

[0044] In a specific embodiment, the stiffness matrix [Q] derived in the fourth step is k 1,2 The stacking angle θ of each layer k k Reflecting this, the stiffness matrix [Q] of each layer k k x,y can be redefined as Equation 2 below.

[0045]

number

[0046] In a specific embodiment, in the fifth step, the method of the present invention calculates the stiffness matrix [A] of the multilayer material, which is the entire laminate, using the stiffness matrix value reset by receiving the thickness information of each layer k. x,y , [B] x,y , [D] x,y can be calculated as follows:

[0047]

number

[0048] In formula 3, k represents each layer, and the total number of layers is n, where n is an integer ranging from 2 to 10.

[0049] In Equation 3, k represents each layer, and the total number of layers is n.

[0050] In a specific embodiment, the stiffness matrix [A] of the multilayer material, which is the entire laminate, calculated in the sixth step is x,y , [B] x,y , [D] x,y [a] is the inverse matrix of x,y , [b] x,y , [c] x,y , [d] x,y The compliance matrix can be set as shown in the following equation (4).

[0051]

number

[0052] In a specific embodiment, in the seventh step, the total thickness h of the multilayer material of the entire laminate and the set inverse matrix [a] x,y , [b] x,y , [c] x,y , [d] x,y The elastic modulus / E of the multilayer material, which is the entire laminate, is calculated using the value. x,y , Poisson's ratio / ν x,y , shear modulus / G x,y can be calculated as follows:

[0053]

number

[0054] In one embodiment, the method of the present invention further includes a step of updating the value of the elastic coefficient of the undetermined layer if the elastic coefficient is selected and input from among the elastic coefficient or thickness of the undetermined layer and the calculated elastic coefficient, Poisson's ratio, and shear coefficient do not converge to the elastic coefficient, Poisson's ratio, and shear coefficient input as the final target physical properties.

[0055] In another embodiment, the method of the present invention further includes a step of updating the value of the thickness of the undetermined layer if the calculated elastic modulus, Poisson's ratio, and shear modulus do not converge to the elastic modulus, Poisson's ratio, and shear modulus input as the final target physical properties when the thickness is selected and input from among the elastic modulus and thickness of the undetermined layer.

[0056] In another embodiment, the method of the present invention further comprises the step of outputting the elastic modulus, Poisson's ratio, shear modulus and thickness of the undetermined layer when the calculated elastic modulus, Poisson's ratio and shear modulus converge to the elastic modulus, Poisson's ratio and shear modulus input as the final target properties;

[0057] In another embodiment, the method further comprises the step of plotting the correlation between the elastic modulus and thickness of the undetermined layer on a graph.

[0058] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to provide a detailed description of the present invention so that those skilled in the art can easily carry out the present invention. The objects, functions, effects, and other objects, features, and operational advantages of the present invention will become more apparent from the description of the preferred embodiments.

[0059] For reference, the embodiments disclosed herein have been presented by selecting the most preferred embodiments from among various possible examples to aid in the understanding of those skilled in the art, and the technical ideas of the present invention are not necessarily limited or restricted to only the presented embodiments, and various changes, additions, and modifications, including equivalents or substitutions, are possible within the scope that does not deviate from the technical ideas of the present invention.

[0060] Furthermore, the terms and expressions used in the specification and claims of this application are defined based on the principle that the inventor can appropriately define the concepts of the terms to best describe his or her invention, and should not be interpreted as being limited to their ordinary or dictionary meanings, but as meanings and concepts consistent with the technical spirit of the present invention. For example, singular expressions include plural expressions unless clearly differently understood in the context, directional expressions are based on the positions depicted in the drawings for the convenience of explanation, and the terms "coupled" or "connected" include not only direct coupling or connection but also coupling or connection via other intermediate components. Furthermore, the term "part" includes units implemented using hardware, units implemented using software, and units implemented using both hardware and software, and one unit may be implemented using one or more pieces of hardware or software, and two or more units may be implemented using one piece of hardware or software.

[0061] (First embodiment) FIG. 1 is a configuration diagram of a multilayer material property prediction device according to a first embodiment of the present invention.

[0062] As shown in FIG. 1, the configuration of the physical property prediction device for a multilayer material according to the first embodiment of the present invention is such that a user calculates the elastic modulus E of each layer k in the machine direction 1 and the transverse direction 2 for each layer k, excluding the undetermined layer. k 1,2 , Poisson's ratio ν in the machine direction 1 and transverse axis 2 of each layer k k 1,2 , shear modulus G in the machine direction 1 and transverse direction 2 of each layer k k 1,2 , the thickness Z of each layer k k , the number of zones set value N, the elastic modulus of the undetermined layer E 1,2Alternatively, the apparatus includes an input unit 10 for inputting a thickness z, a control unit 20 connected to the input unit 10 and including an overall laminate property calculation unit 21 and an undetermined layer property calculation unit 22, a display 30 connected to the control unit 20, and a storage unit 40 connected to the control unit 20.

[0063] In the present invention, the term "multilayer material" refers to a laminate having a structure in which two or more materials are laminated, and may refer to a multilayer film of a polymer or the like, or a composite material made of different materials such as FRP (fiber reinforced plastic) and an aluminum pouch, etc. For example, the multilayer material may refer to a multilayer film.

[0064] Meanwhile, the input unit 10 is for a user to input actual physical property values, but is not necessarily limited thereto. For example, the input unit 10 may be connected to a database (DB) in which information to be input to the input unit 10 is stored.

[0065] In addition, the Poisson's ratio ν in the machine direction 1 and the transverse axis 2 of each layer k k 1,2 In this case, ν 1,2 is the Poisson's ratio associated with the deformation in the transverse direction 2 when a material is loaded in the machine direction 1, and ν 2,1 means the Poisson's ratio associated with deformation in the machine direction 1 when the material is loaded in the transverse direction 2. On the other hand, if the material is an isotropic material, then ν 1,2 =ν 2,1 =ν.

[0066] On the other hand, the angle θ k may refer to the counterclockwise angle of each layer relative to the x-direction of the multilayer material.

[0067] In addition, the thickness Z of each layer k k This may mean coordinate information from the center of thickness of the entire laminate in a multi-layer material.

[0068] The display 30 may provide an input screen including a name input field, a thickness input field, an angle input field, a machine direction (MD) elastic modulus input field, a transverse direction (TD) elastic modulus input field, a Poisson's ratio input field, a thermal expansion coefficient input field, a sample length input field, an X-axis tensile force input field, a Y-axis tensile force input field, a shear force input field, a temperature change input field, and the like.

[0069] The display 30 can provide an output screen on which the x-direction elastic modulus, y-direction elastic modulus, Poisson's ratio, shear modulus, bulk modulus, thermal expansion coefficient, etc. are arranged.

[0070] (Second embodiment) FIG. 2 is a flowchart of a method for predicting physical properties of a multilayer material according to a second embodiment of the present invention.

[0071] As shown in FIG. 2, the method for predicting physical properties of a multilayer material according to the second embodiment of the present invention is a method for predicting physical properties of a multilayer material in which two or more materials are stacked, For each layer k remaining except for the undetermined layer, the elastic modulus E in the machine direction 1 and transverse axis direction 2 of each layer k k 1,2 , Poisson's ratio ν in the machine direction 1 and transverse axis 2 of each layer k k 1,2 , shear modulus G in the machine direction 1 and transverse direction 2 of each layer k k 1,2 , the thickness Z of each layer k k Step S11, in which a set value N of the number of zones is input; Step S12: setting a region number variable i to 1; Elastic modulus of the undetermined layer E 1,2 and a step S13 in which the following is input: The above elastic modulus E k 1,2 , Poisson's ratio ν k 1,2 , shear modulus G k 1,2 The stiffness matrix [Q] of each layer k in the machine direction 1 and transverse direction 2 is calculated using k 1,2and step S14 of calculating the following equation 1:

[0072]

number

[0073] In Equation 1, for an isotropic material, G=E / {2(1+ν)}.

[0074] The stiffness matrix [Q] of each layer k in the machine direction 1 and transverse direction 2 calculated in this way k 1,2 The inverse matrix for [S] k 1,2 Step S15 of setting a compliance matrix; Stacking angle θ of each layer in the machine direction 1 k and a step S16 in which the following is input: The stiffness matrix [Q] derived above k 1,2 The stacking angle θ of each layer k k Reflecting this, the stiffness matrix [Q] of each layer k k x,y and step S17 of resetting it as in the following equation 2.

[0075]

number

[0076] Also, the thickness Z of each layer k k and a step S18 in which the following is input: The stiffness matrix [A] of the entire laminated multilayer material is calculated using the stiffness matrix value reset by transmitting the thickness information of each layer k. x,y , [B] x,y , [D] x,y Step S19 is performed to calculate the following equation 3:

[0077]

number

[0078] In formula 3, k represents each layer, and the total number of layers is n, where n is an integer ranging from 2 to 10.

[0079] The stiffness matrix [A] of the multilayer material, which is the entire laminate, calculated in this way x,y , [B] x,y , [D] x,y [a] is the inverse matrix of x,y , [b] x,y , [c] x,y , [d] x,y Step S20 is performed to set the compliance matrix as shown in Equation 4 below.

[0080]

number

[0081] Step S21: calculating and inputting the total thickness h of the multilayer material, which is the entire laminate; The total thickness h of the multilayer material that is the entire laminate and the inverse matrix [a] set above x,y , [b] x,y , [c] x,y , [d] x,y The elastic modulus / E of the multilayer material, which is the entire laminate, is calculated using the value. x,y , Poisson's ratio / ν x,y , shear modulus / G x,y is calculated as in the following equation 5.

[0082]

number

[0083] Next, the final target property is the elastic modulus / E x,y , Poisson's ratio / ν x,y , shear modulus / G x,y and a step S23 in which the following is input: Calculated elastic modulus / E x,y , Poisson's ratio / ν x,y , shear modulus / G x,y is the elastic modulus / E entered as the final target propertyx,y , Poisson's ratio / ν x,y , shear modulus / G x,y a step S24 of determining whether Calculated elastic modulus / E x,y , Poisson's ratio / ν x,y , shear modulus / G x,y is the elastic modulus / E entered as the final target property x,y , Poisson's ratio / ν x,y , shear modulus / G x,y If the elastic coefficient of the undetermined layer E 1,2 Step S25 of updating the value of , and then jumping to step S13; Calculated elastic modulus / E x,y , Poisson's ratio / ν x,y , shear modulus / G x,y is the elastic modulus / E entered as the final target property x,y , Poisson's ratio / ν x,y , shear modulus / G x,y When the value converges to , the physical property value of the undetermined layer (elastic modulus E 1,2 , Poisson's ratio ν k x,y , shear modulus G k x,y ) and thickness Z k and a step S26 of outputting Step S27 of incrementing the area number variable i by 1; Elastic modulus of the undetermined layer E 1,2 and a step S28 of plotting the correlation between the thickness z and the thickness z. Step S29: determining whether the zone number variable i is equal to or less than the zone number setting value N, and if it is equal to or less than the zone number setting value N, jumping to step S13; and step S30 of terminating the operation when the zone number variable i exceeds the zone number setting value N.

[0084] Elastic modulus E of each layer k k 1,2 , Poisson's ratio ν k 1,2 , shear modulus G k 1,2 In step S11, the shear coefficient G of each layer k is input. k 1,2Since it is generally very difficult to measure the elastic modulus E, the shear modulus G, and the Poisson's ratio ν of an isotropic material are assumed to be isotropic, and the control unit 20 measures the elastic modulus E by using the relation G=E / {2(1+ν)} between the elastic modulus E, shear modulus G, and Poisson's ratio ν of the isotropic material. k 1,2 and Poisson's ratio ν k 1,2 to shear modulus G k 1,2 Calculate.

[0085] (Third embodiment) FIG. 3 is a flowchart of a method for predicting physical properties of a multilayer material according to a third embodiment of the present invention.

[0086] As shown in FIG. 3, the method for predicting physical properties of a multilayer material according to the third embodiment of the present invention includes: A method for predicting physical properties of a multilayer material in which two or more materials are laminated, comprising: For each layer k remaining after excluding the undetermined layer, the elastic modulus e in the machine direction 1 and transverse axis 2 of each layer k k 1,2 , Poisson's ratio ν in the machine direction 1 and transverse direction 2 of each layer k k 1,2 , the shear modulus G in the machine direction 1 and transverse direction 2 of each layer k k 1,2 , the thickness Z of each layer k k Step S41: inputting a set value N of the number of zones; Step S42: setting a region number variable i to 1; Step S43: inputting the thickness z of the undetermined layer; The above elastic modulus E k 1,2 , Poisson's ratio ν k 1,2 , shear modulus G k 1,2 The stiffness matrix [Q] of each layer k in the machine direction 1 and transverse direction 2 is calculated using k 1,2 and step S44 of calculating the following equation 1:

[0087]

number

[0088] In Equation 1, for an isotropic material, G=E / 2(1+ν).

[0089] The stiffness matrix [Q] of each layer k in the machine direction 1 and transverse direction 2 calculated in this way k 1,2 The inverse matrix for [S] k 1,2 a step S45 of resetting the compliance matrix; Stacking angle θ of each layer in the machine direction 1 k and a step S46 in which the above is input. The stiffness matrix [Q] derived above k 1,2 The stacking angle θ of each layer k k Reflecting this, the stiffness matrix [Q] of each layer k k x,y is reset to the following equation 2:

[0090]

number

[0091] The thickness Z of each layer k k and a step S48 in which the above is input. The stiffness matrix [A] of the entire laminated multilayer material is calculated using the stiffness matrix value reset by transmitting the thickness information of each layer k. x,y , [B] x,y , [D] x,y Step S49 is performed to calculate the following equation 3:

[0092]

number

[0093] In formula 3, k represents each layer, and the total number of layers is n. For example, n is an integer in the range of 2 to 10, specifically, an integer in the range of 3 to 5.

[0094] The stiffness matrix [A] of the multilayer material, which is the entire laminate, calculated in this way x,y , [B] x,y , [D] x,y [a] is the inverse matrix of x,y , [b] x,y , [c] x,y , [d] x,y Step S50 is performed to set the compliance matrix as shown in the following equation (4).

[0095]

number

[0096] Also, a step S51 of calculating and inputting the total thickness h of the multilayer material which is the entire laminate; The total thickness h of the multilayer material that is the entire laminate and the inverse matrix [a] set above x,y , [b] x,y , [c] x,y , [d] x,y The elastic modulus / E of the multilayer material, which is the entire laminate, is calculated using the value. x,y , Poisson's ratio / ν x,y , shear modulus / G x,y Step S52 is performed to calculate the following equation 5:

[0097]

number

[0098] Next, the final target property is the elastic modulus / E x,y , Poisson's ratio / ν x,y , shear modulus / G x,y and a step S53 in which the above is input. Calculated elastic modulus / E x,y , Poisson's ratio / ν x,y , shear modulus / G x,y is the elastic modulus / E entered as the final target property x,y , Poisson's ratio / ν x,y , shear modulus / G x,ya step S54 of determining whether Calculated elastic modulus / E x,y , Poisson's ratio / ν x,y , shear modulus / G x,y is the elastic modulus / E entered as the final target property x,y , Poisson's ratio / ν x,y , shear modulus / G x,y If the value of the thickness z of the undetermined layer is not converged to, a step S55 is performed in which the value of the thickness z of the undetermined layer is updated and then the step S13 is jumped to; Calculated elastic modulus / E x,y , Poisson's ratio / ν x,y , shear modulus / G x,y is the elastic modulus / E entered as the final target property x,y , Poisson's ratio / ν x,y , shear modulus / G x,y When the value converges to , the physical property value of the undetermined layer (elastic modulus E 1,2 , Poisson's ratio ν k x,y , shear modulus G k x,y ) and thickness z, and step S56 Step S57 of incrementing the area number variable i by 1; Elastic modulus of the undetermined layer E 1,2 and a step S58 of plotting the correlation between the thickness z and the thickness z. Step S59: determining whether the zone number variable i is equal to or less than the zone number setting value N, and if it is equal to or less than the zone number setting value N, jumping to step S13; and step S60 of terminating the operation when the zone number variable i exceeds the zone number setting value N.

[0099] Elastic modulus E of each layer k k 1,2 , Poisson's ratio ν k 1,2 , shear modulus G k 1,2 In step S41, the shear coefficient G of each layer k is input. k 1,2Since it is generally very difficult to measure the elastic modulus E, the shear modulus G, and the Poisson's ratio ν of an isotropic material are used to assume that the material is isotropic. The elastic modulus E is calculated by the control unit 20 using the relation G=E / 2(1+ν) between the elastic modulus E, shear modulus G, and Poisson's ratio ν of the isotropic material. k 1,2 and Poisson's ratio ν k 1,2 to shear modulus G k 1,2 Calculate.

[0100] The operation of the apparatus and method for predicting physical properties of a multilayer material according to the embodiment of the present invention having the above configuration is as follows.

[0101] To predict the physical properties of a multilayer material, the user uses the input unit 10 while viewing the input screen displayed on the display 30 to input the elastic modulus E in the machine direction 1 and the transverse direction 2 of each layer k (k=1, 2, 3). k 1,2 , Poisson's ratio ν in the machine direction 1 and transverse axis 2 of each layer k (k=1, 2, 3) k 1,2 , shear modulus G in the machine direction 1 and transverse direction 2 of each layer k (k=1, 2, 3) k 1,2 , the thickness Z of each layer k k , the set value N of the number of zones is input (S11, S41).

[0102] The input screen provided on the display 30 has a name input field, a thickness input field, an angle input field, a machine direction (MD) elastic modulus input field, a transverse direction (TD) elastic modulus input field, a Poisson's ratio input field, a thermal expansion coefficient input field, a sample length and width input field, an X-axis tensile force input field, a Y-axis tensile force input field, a shear force input field, a temperature change input field, and the like, for each layer. Information not shown on the input screen is automatically calculated by the control unit 20 from the information input through the input unit 10 and stored in the storage unit 40. For example, the machine direction (MD) elastic modulus E for each layer can be input through the input unit 10 and the input screen of the display 30. k 1. Transverse axis (TD) elastic modulus E k 2. Poisson's ratio ν k 1,2When the input is made, the overall laminate physical property calculation unit 21 of the control unit 20 automatically calculates the shear modulus G using the relational expression between the elastic modulus E, shear modulus G, and Poisson's ratio ν of the following isotropic material: k 1,2 After being calculated, it is stored in the storage unit 40.

[0103] G=E / {2(1+ν)}

[0104] Next, the undetermined layer property calculation unit 22 of the control unit 20 sets the zone number variable i to 1 (S12, S42).

[0105] Next, the undetermined layer property calculation unit 22 of the control unit 20 calculates the elastic modulus E of the undetermined layer. 1,2 is input (S13), and the thickness z of the undetermined layer is input (S43).

[0106] Next, the overall laminate property calculation unit 21 of the control unit 20 calculates the elastic modulus E k 1,2 , Poisson's ratio ν k 1,2 , shear modulus G k 1,2 The stiffness matrix [Q] of each layer k in the machine direction 1 and transverse direction 2 is calculated using k 1,2 is calculated using the following formula 1 (S14, S44).

[0107]

number

[0108] In Equation 1, the relation G=E / {2(1+ν)} for isotropic materials is used.

[0109] Next, the overall laminate physical property calculation unit 21 of the control unit 20 calculates the stiffness matrix [Q] of each layer k in the machine direction 1 and the transverse direction 2 calculated above. k 1,2 Inverse matrix [S] k 1,2is calculated and set as the compliance matrix (S15, S45). This is to convert the singular stiffness matrix into an invertible matrix whose inverse matrix exists.

[0110] Next, the overall laminate property calculation unit 21 of the control unit 20 calculates the lamination angle θ of each layer in the machine direction 1. k is input (S16, S46).

[0111] Next, the overall laminated body physical property calculation unit 21 of the control unit 20 calculates the stiffness matrix [Q] of each layer k derived above. k 1,2 The layering angle θ of the multilayer material k Reflecting this, the stiffness matrix [Q] of each layer k k x,y is reset in the x or y direction as shown in the following equation 2 (S17, S47).

[0112]

number

[0113] Next, the overall laminate property calculation unit 21 of the control unit 20 calculates the thickness Z of each layer k. k is input (S18, S48).

[0114] Next, the overall laminate physical property calculation unit 21 of the control unit 20 calculates the stiffness matrix [A] of the multilayer material, which is the overall laminate, using the stiffness matrix value reset by receiving the thickness information of each layer k. x,y , [B] x,y , [D] x,y is calculated using the following formula 3 (S19, S49).

[0115]

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[0116] In formula 3, k represents each layer, and the total number of layers is n, where n is an integer ranging from 2 to 10.

[0117] Next, the overall laminate physical property calculation unit 21 of the control unit 20 calculates the stiffness matrix [A] of the multilayer material that is the calculated overall laminate. x,y , [B] x,y , [D] x,y [a] is the inverse matrix of x,y , [b] x,y , [c] x,y , [d] x,y (compliance matrix) is set as shown in the following equation 4 (S20, S40).

[0118]

number

[0119] Next, the total laminate physical property calculation unit 21 of the control unit 20 calculates and inputs the total thickness h of the multilayer material, which is the total laminate, from the thickness information of each layer k (S21, S51).

[0120] Next, the overall laminate physical property calculation unit 21 of the control unit 20 calculates the total thickness h of the multilayer material that is the overall laminate and the inverse matrix [a] set above. x,y , [b] x,y , [c] x,y , [d] x,y The elastic modulus / E of the multilayer material, which is the entire laminate, is calculated using the value. x,y , shear modulus / G x,y , Poisson's ratio / ν x,y is calculated as in the following equation 5 (S22, S52).

[0121]

number

[0122] Next, the user inputs the elastic modulus / E as the final target physical property using the input unit 10 while looking at the input screen of the display 30. x,y , Poisson's ratio / ν x,y , shear modulus / Gx,y is input, and the undetermined layer property calculation unit 22 of the control unit 20 reads this (S23, S53).

[0123] Next, the undetermined layer property calculation unit 22 of the control unit 20 calculates the calculated elastic modulus / E x,y , Poisson's ratio / ν x,y , shear modulus / G x,y is the elastic modulus / E entered as the final target property x,y , Poisson's ratio / ν x,y , shear modulus / G x,y It is determined whether the equation converges to (S24, S54).

[0124] If the calculated elastic modulus / E x,y , Poisson's ratio / ν x,y , shear modulus / G x,y is the elastic modulus / E entered as the final target property x,y , Poisson's ratio / ν x,y , shear modulus / G x,y If it does not converge to (i) When the elastic coefficient is selected and input from the elastic coefficient or thickness of the undetermined layer, the undetermined layer property calculation unit 22 of the control unit 20 calculates the elastic coefficient E of the undetermined layer. 1,2 After updating the value of , jump to step S13 (S25) and repeat the above process again. (ii) If the thickness is selected and input from the elastic modulus or thickness of the undetermined layer, the value of the thickness z of the undetermined layer is updated, and then the process jumps to step S13 (S55), and the above process is repeated.

[0125] In contrast, the calculated elastic modulus / E x,y , Poisson's ratio / ν x,y , shear modulus / G x,y is the elastic modulus / E entered as the final target property x,y , Poisson's ratio / ν x,y , shear modulus / G x,y When the value converges to , the undetermined layer property calculation unit 22 of the control unit 20 calculates the property value (elastic modulus E 1,2 , Poisson's ratio ν k x,y , shear modulus G kx,y ) and thickness Z k is output (S26, S56).

[0126] Next, the undetermined layer physical property calculation unit 22 of the control unit 20 increments the zone number variable i by 1 (S27, S57), and then calculates the elastic coefficient E of the undetermined layer. 1,2 The correlation between the elastic modulus E of the undetermined layer according to the present invention is plotted on a graph (S28, S58). 1,2 10 is a graph showing the correlation between the thickness z and the thickness of the film.

[0127] Next, the undetermined layer property calculation unit 22 of the control unit 20 determines whether the zone number variable i is equal to or less than the zone number setting value N, and if it is equal to or less than the zone number setting value N, jumps to step S13 and repeats the above process until the zone number variable i exceeds the zone number setting value N (S29, S59).

[0128] When the zone number variable i exceeds the zone number setting value N, the control unit 20 ends the operation (S30, S60).

[0129] (Fourth embodiment) In an embodiment of the present invention, if an input value to be input to an input unit is not readily available, it can be derived through a conversion process using other physical property values.

[0130] Elastic modulus E of each layer k k and Poisson's ratio ν of each layer k k In the process of inputting, the first Lamé coefficient λ k , shear modulus G k and bulk modulus K k For example, the elastic modulus E can be calculated using the following formulas 1 to 9. k and Poisson's ratio ν k It is possible to convert it into

[0131] The available combinations are (λ k ,G k ) is determined by the following formula 1.

[0132]

number

[0133] The available combinations are (λ k ,E k ) is determined by the following formula 2.

[0134]

number

[0135] The available combinations are (λ k ,ν k ), then, according to the following formula 3:

[0136]

number

[0137] The available combinations are (λ k ,K k ), then, according to the following formula 4:

[0138]

number

[0139] The available combinations are (G k ,E k ), then, according to the following formula 5:

[0140]

number

[0141] The available combinations are (G k ,ν k ), then, according to the following formula 6:

[0142]

number

[0143] The available combinations are (G k ,K k ), then, according to the following formula 7:

[0144]

number

[0145] The available combinations are (K k ,E k ), then, according to the following formula 8.

[0146]

number

[0147] The available combinations are (K k ,ν k ), then, according to the following formula 9.

[0148]

number

[0149] The above formulas 1 to 9 are examples, and two or more formulas can be combined as needed. [Explanation of symbols]

[0150] 10 Input section 20 Control Unit 21 Overall laminate property calculation section 22 Undetermined layer physical property calculation section 30 Display 40 Preservation Department

Claims

1. (a) an input section for inputting, for each layer excluding the undetermined layer, one or more physical properties of each layer among the elastic modulus, Poisson's ratio, shear modulus, thickness, and stacking angle, and (b) one or more physical properties of the elastic modulus and thickness of the undetermined layer; a control unit connected to the input unit and including an overall laminate property calculation unit and an undetermined layer property calculation unit; a display coupled to the control unit; a storage unit coupled to the control unit, The control unit For multi-layer materials in which two or more materials are laminated, (a) The elastic modulus, Poisson's ratio, shear modulus, thickness and stacking angle of each layer excluding the undetermined layer are input, (b) any one or more of the elastic modulus and thickness of the undetermined layer are input, The stiffness matrix of each layer is calculated using the elastic modulus, Poisson's ratio, and shear modulus of each layer excluding the undetermined layer. The stiffness matrix of each layer is reset by reflecting the lamination angle of each layer in the calculated stiffness matrix, and the stiffness matrix of the multilayer material that is the entire laminate is calculated using the stiffness matrix value reset after receiving the thickness information of each layer. An inverse matrix is set for the stiffness matrix of the multilayer material that is the entire laminate, and one or more of the elastic modulus ( / E x,y ), Poisson's ratio ( / ν x,y ), and shear modulus ( / G x,y ) of the multilayer material that is the entire laminate are calculated using the total thickness of the multilayer material that is the entire laminate and the set inverse matrix value. A physical property prediction device for a multilayer material that determines whether one or more of the calculated elastic modulus ( / E x,y ), Poisson's ratio ( / ν x,y ), and shear modulus ( / G x,y ) of the multilayer material converge to one or more of the target elastic modulus (target / E x,y ), target Poisson's ratio (target / ν x,y ), and target shear modulus (target / G x,y ) input as final target physical properties.

2. The control unit Using the input physical properties, the inverse matrix for the stiffness matrix of the multilayer material, which is the entire laminate, is set. The physical properties of the entire laminated multilayer material are calculated using the set inverse matrix value. The device for predicting physical properties of a multilayer material according to claim 1, further comprising a step of determining whether the calculated physical properties converge to final target physical properties.

3. The input unit includes: (a) For each layer excluding the undetermined layer, the elastic modulus, Poisson's ratio, shear modulus, thickness and stacking angle of each layer, and 2. The device for predicting physical properties of a multilayer material according to claim 1, wherein (b) at least one of the elastic modulus and thickness of the undetermined layer is input.

4. The control unit When the elastic modulus is selected and entered among the elastic modulus and thickness of the undetermined layer, The calculated elastic modulus of the multilayer material ( / E ｘ，ｙ ), Poisson's ratio ( / ν ｘ，ｙ ) and shear modulus ( / G ｘ，ｙ ) is the target elastic modulus (target / E ｘ，ｙ ), target Poisson's ratio (target / ν ｘ，ｙ ) and target shear coefficient (target / G ｘ，ｙ ) does not converge to at least one of The device for predicting physical properties of a multilayer material according to claim 1 , wherein the elastic modulus values of undetermined layers are updated.

5. The control unit When the thickness is selected and entered from the elastic modulus and thickness of the undetermined layer, The calculated elastic modulus of the multilayer material ( / E ｘ，ｙ ), Poisson's ratio ( / ν ｘ，ｙ ) and shear modulus ( / G ｘ，ｙ ) is the target elastic modulus (target / E ｘ，ｙ ), target Poisson's ratio (target / ν ｘ，ｙ ) and target shear coefficient (target / G ｘ，ｙ ) does not converge to at least one of The device for predicting physical properties of a multilayer material according to claim 1 , further comprising updating thickness values of undetermined layers.

6. The control unit The calculated elastic modulus of the multilayer material ( / E ｘ，ｙ ), Poisson's ratio ( / ν ｘ，ｙ ) and shear modulus ( / G ｘ，ｙ ) is the target elastic modulus (target / E ｘ，ｙ ), target Poisson's ratio (target / ν ｘ，ｙ ) and target shear coefficient (target / G ｘ，ｙ 2. The physical property prediction device for a multilayer material according to claim 1, wherein when the calculated values converge to one or more of the elastic modulus, Poisson's ratio, shear modulus, and thickness of the undetermined layer, the device outputs one or more of the elastic modulus, Poisson's ratio, shear modulus, and thickness of the undetermined layer.

7. A method for predicting physical properties of a multilayer material in which two or more materials are laminated, comprising: inputting, as input values, at least one of physical properties of the elastic modulus, Poisson's ratio, shear modulus, thickness, and stacking angle of each layer, and at least one of physical properties of the elastic modulus and thickness of the undetermined layer, for each layer excluding the undetermined layer; Calculating the physical properties of the entire laminated multilayer material using the input physical properties; and determining whether the calculated physical properties converge to the final target physical properties; The step of inputting the input value includes: The first stage involves inputting the elastic modulus, Poisson's ratio, shear modulus, thickness and stacking angle of each layer, excluding undetermined layers; a second step in which at least one of the elastic modulus and thickness of the undetermined layer is input; The step of calculating the physical properties of the multilayer material includes: a third step of calculating a stiffness matrix of each layer excluding an undetermined layer using the elastic coefficient, Poisson's ratio, and shear coefficient; a fourth step of resetting the stiffness matrix of each layer by reflecting the stacking angle of each layer in the calculated stiffness matrix; A fifth step of calculating a stiffness matrix of the multilayer material, which is the entire laminate, using the stiffness matrix values reset by receiving the thickness information of each layer; A sixth step of setting an inverse matrix for the calculated stiffness matrix of the multilayer material that is the entire laminate; and a seventh step of calculating the elastic modulus, Poisson's ratio, and shear modulus of the multilayer material that is the entire laminate using the total thickness of the multilayer material that is the entire laminate and the value of the set inverse matrix.

8. The step of calculating the physical properties of the multilayer material includes: Setting an inverse matrix for the stiffness matrix of the multilayer material that is the entire laminate; 10. The method of claim 7, further comprising: calculating the physical properties of the entire multilayer material using the set inverse matrix value.

9. The step of determining whether the calculated physical property converges to a final target physical property includes: The eighth stage involves inputting the elastic modulus, Poisson's ratio, and shear modulus as the final target properties; The calculated elastic modulus ( / E ｘ，ｙ ), Poisson's ratio ( / ν ｘ，ｙ ) and shear modulus ( / G ｘ，ｙ ) is the target elastic modulus (target / E ｘ，ｙ ), target Poisson's ratio (target / ν ｘ，ｙ ) and target shear coefficient (target / G ｘ，ｙ and a ninth step of determining whether the multi-layer material converges to the formula (1) above.

10. The third stage is Elastic modulus (E ｋ １，２ ), Poisson's ratio (ν ｋ １，２ ), shear modulus (G ｋ １，２ ) to calculate the stiffness matrix ([Q]) in the machine direction (1) and transverse direction (2) of each layer (k). ｋ １，２ ) is calculated so as to satisfy the following relational expression 1: [Equation 1] 8. The method for predicting physical properties of a multilayer material according to claim 7, wherein in Equation 1, for an isotropic material, G = E / {2(1 + v)}.

11. The fourth stage is The calculated stiffness matrix ([Q] ｋ １，２ ) and the lamination angle (θ ｋ ) and the stiffness matrix ([Q] ｋ ｘ，ｙ ) is reset to satisfy the following relational expression 2: [Equation 2] The method for predicting physical properties of a multilayer material according to claim 7, wherein

12. The fifth stage is The stiffness matrix ([A]) of the multilayer material, which is the entire laminate, is calculated using the stiffness matrix value reset by transmitting the thickness information of each layer (k). ｘ，ｙ , [B] ｘ，ｙ , [D] ｘ，ｙ ) is calculated by the following formula 3, [Equation 3] In Formula 3, k represents each layer, and the total number of layers is n, where n is an integer ranging from 2 to 10, and z ｋ The method for predicting physical properties of a multilayer material according to claim 7, wherein x is the thickness of each layer.

13. The sixth step is The calculated stiffness matrix of the multilayer material, which is the entire laminate ([A] ｘ，ｙ , [B] ｘ，ｙ , [D] ｘ，ｙ ) is the inverse matrix ([a] ｘ，ｙ , [b] ｘ，ｙ , [c] ｘ，ｙ , [d] ｘ，ｙ ) is set by the following formula 4: [Equation 4] The method for predicting physical properties of a multilayer material according to claim 7, wherein

14. The seventh step is The inverse matrix ([a]) is set to the total thickness (h) of the multilayer material that is the entire laminate. ｘ，ｙ [b] ｘ，ｙ , [c] ｘ，ｙ , [d] ｘ，ｙ ) to determine the elastic modulus ( / E ｘ，ｙ ), Poisson's ratio ( / v ｘ，ｙ ), shear modulus ( / G ｘ，ｙ ) is calculated by the following formula 5, [Equation 5] The method for predicting physical properties of a multilayer material according to claim 7, wherein

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