System and method for reverse engineering of strength of multilayer material

Abstract

The invention relates to a system and method for reverse engineering of the strength of a multilayer material. Conventionally, in order to assess the physical properties of a multilayer material, in particular the strength, a sample of the multilayer material needs to be manufactured for each combination and the manufactured sample is assessed. In the present invention, reverse engineering of the multi-layer material can be performed without manufacturing a sample of the multi-layer material, and in particular, the physical properties required for the layer (p) to be determined to achieve the target strength of the multi-layer material can be derived. Systems or methods are provided that are capable of presenting design directions of certain layers in a simulation step to achieve a target strength of a multi-layer material.

Description

Technical Field

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0085447, filed on July 3, 2023, and the entire contents of the Korean patent application are incorporated herein by reference.

[0002] The present disclosure relates to systems and methods for reverse engineering the strength of multi-layer materials, more specifically multi-layer films. Background Art

[0003] A polymer film refers to a non-fibrous sheet-like plastic molded article having a thickness of 0.25 mm or less. The film is lightweight, exhibits good barrier properties, has excellent transparency, and is relatively inexpensive. Thus, the film is used in almost all fields, including packaging materials, household items, electronic devices, automobiles, aircraft, etc.

[0004] 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. Currently, many synthetic polymers are used, either alone or in mixtures, as materials for polymer films.

[0005] However, there are limitations in that a single film cannot meet the required complex properties. To improve this, multi-layer materials having a structure in which two or more films are stacked together are being developed.

[0006] In the process of developing multi-layer materials, it has been found that the properties of multi-layer materials, especially strength, cannot be calculated by simply adding the properties of individual films. Generally, to evaluate the properties of multi-layer materials, especially strength, samples of each combined multi-layer material are manufactured and then evaluated. This method of manufacturing such multi-layer material samples has limitations in that it not only takes time to manufacture the samples, but also has difficulties in evaluating all the various types and properties of the films.

[0007] Therefore, there is a need for a method capable of predicting the properties of multi-layer materials, especially strength, without directly manufacturing the multi-layer materials. In particular, there is a great need for a new concept system and method that can suggest design directions for certain layers to achieve the target properties of multi-layer materials. Summary of the Invention

[0008] Technical Problem

[0009] As described above, an object of the present disclosure is to provide a system or method capable of suggesting design directions for certain layers during simulation to achieve the target strength of multi-layer materials.

[0010] Technical Solution

[0011] To achieve the above object, the present disclosure provides a system for reverse engineering the strength of a multi-layer material. Specifically, the system for reverse engineering the strength of a multi-layer material according to the present disclosure is a system for reverse engineering the strength of a multi-layer material in which n layers including an amorphous layer (p) are stacked.

[0012] In an exemplary example, the system for reverse engineering the strength of a multi-layer material includes: an input section into which input values including the principal stress direction strength value ([F] k ) for each layer (k) other than the amorphous layer (p) and the target strength value of the multi-layer material are input; a control section that calculates the strength of the multi-layer material by applying the input values input into the input section; a display connected to the control section; and a storage section connected to the control section. Here, n is an integer of 2 or greater, p is an integer from 1 to n, and the sum of k and p is n.

[0013] Specifically, the control section uses the principal stress direction strength value ([F] k ) of each layer (k) and an arbitrarily applied principal stress direction strength value ([F] p ) of the amorphous layer (p) to obtain a calculated strength value of the multi-layer material and determines whether the calculated strength value of the multi-layer material falls within the error range of a predetermined target strength value of the multi-layer material.

[0014] In a specific exemplary example, the input values regarding each layer (k) other than the amorphous layer (p) input into the input section further include any one or more of the following: the elastic modulus (E k ) of each layer (k), the Poisson's ratio (υ k ), the shear modulus (G k ), the thickness (Z k ), and the lamination angle (θ k ) of each layer (k); and any one or more of the total thickness (h) of the multi-layer material.

[0015] In a specific exemplary example, the control section calculates the stress of each layer (k,p). The control section transforms the stress of each layer (k,p) into the principal direction stress ([σ] k,p ) of each layer (k,p) by applying the lamination angle (θ k,p ) of each layer (k,p). The principal stress direction strength ([F] k,pStrength determination parameter [f] configured to determine the strength of a multi-layer material k,p ). The safety factor (S k,p ) of each layer (k, p) is calculated by combining the principal direction stress ([σ] k,p ) of each layer (k, p) and the strength determination parameter [f] k,p ). Then, the calculated strength value of the multi-layer material is obtained from the safety factor (S k,p ) of each layer (k, p) calculated

[0016] Specifically, the control part calculates the force ( / N) and moment ( / M) of the multi-layer material according to the total thickness (h) of the multi-layer material. The control part calculates the mid-plane strain (ε 0 ) and curvature (K) using the force ( / N) and moment ( / M) of the multi-layer material and the inverse matrices ([a], [b], [c], [d]) of the stiffness matrices ([A], [B], [D]) of the multi-layer material. The strain (ε 0 ) of each layer (k, p) is calculated using the mid-plane strain (ε k,p ), curvature (K) and thickness information (Z k,p ) of each layer (k, p). Then, the stress (σ k,p x,y ) of each layer (k, p) is calculated using the strain (ε k,p ) of each layer (k, p) and the stiffness matrix ([Q] k,p ) of each layer (k, p).

[0017] In an exemplary example, the calculated strength value of the multi-layer material obtained from the safety factor (S k,p ) of each layer (k, p) includes: extracting the minimum value ((S k,p ) min ) among the calculated safety factors of each layer (k, p). If the extracted minimum value ((S k,p ) min ) meets the predetermined ULF (ultimate laminate failure) standard, then this minimum value ((S k,p ) min ) is defined as the calculated strength value of the multi-layer material

[0018] In a specific exemplary example, in the process of determining whether the calculated strength value of the multi-layer material falls within the error range of the target strength value of the multi-layer material, if the calculated strength value of the multi-layer material falls within the target strength value Within the error range, the principal stress direction strength value ([F] p ) of the amorphous layer presents an appropriate value.

[0019] In another specific exemplary example, in the process of determining whether the calculated strength value of the multi-layer material falls within the error range of the target strength value of the multi-layer material, if the calculated strength value of the multi-layer material is outside the error range of the target strength value of the multi-layer material, then recalculate the calculated strength value

[0020] For example, if the calculated strength value of the multi-layer material is outside the error range of the target strength value of the multi-layer material and if the calculated strength value of the multi-layer material is less than the target strength value of the multi-layer material, then increase the principal stress direction strength value ([F] p ) of the amorphous layer (p) and recalculate the calculated strength value Alternatively, if the calculated strength value of the multi-layer material is greater than the target strength value of the multi-layer material, then decrease the principal stress direction strength value ([F] p ) of the amorphous layer (p) and recalculate the calculated strength value

[0021] In addition, the present disclosure provides a method for reverse engineering the strength of a multi-layer material. The present disclosure is a method for reverse engineering the strength of a multi-layer material stacked with n layers including an amorphous layer (p).

[0022] In one exemplary example, the method for reverse engineering the strength of a multi-layer material according to the present disclosure includes: inputting input values including the principal stress direction strength value ([F] k ) for each layer (k) except the amorphous layer (p) and the target strength value of the multi-layer material; using the input values input to the input section and the principal stress direction strength value ([F] p ) for any application of the amorphous layer (p) to calculate the strength value of the multi-layer material and determining whether the calculated strength value of the multi-layer material falls within the error range of the predetermined target strength value of the multi-layer material. Here, n is an integer of 2 or greater, and p is an integer from 1 to n, and the sum of k and p is n.

[0023] In an exemplary example, when inputting an input value, the input value for each layer (p) other than the amorphous layer (p) further includes any one or more of the following: the elastic modulus (E k ) of each layer (k), the Poisson's ratio (υ k ) of each layer (k), the shear modulus (G k ) of each layer (k), the thickness (Z k ) of each layer (k), and the lamination angle (θ k ) of each layer (k); and the total thickness (h) of the multi-layer material.

[0024] In a specific exemplary example, calculating the strength value of the multi-layer material includes: calculating the stress of each layer (k,p); transforming the stress of each layer (k,p) into the principal direction stress ([σ] k,p ) of each layer (k,p) by applying the lamination angle (θ k,p ) of each layer (k,p); configuring the principal stress direction strength ([F] k,p ) of each layer (k,p) as the strength determination parameter ([f] k,p ) for determining the strength of the multi-layer material; calculating the safety factor (S k,p ) of each layer (k,p) by combining the principal direction stress ([σ] k,p ) and the strength determination parameter ([f] k,p ) of each layer (k,p); and obtaining the calculated strength value of the multi-layer material from the calculated safety factor (S k,p ) of each layer (k,p)

[0025] Specifically, calculating the stress of each layer (k,p) includes: calculating the force ( / N) and moment ( / M) of the multi-layer material according to the total thickness (h) of the multi-layer material; calculating the mid-plane strain (ε 0 ) and curvature (K) using the force ( / N) and moment ( / M) of the multi-layer material and the inverse matrices ([a],[b],[c],[d]) of the stiffness matrices ([A],[B],[D]) of the multi-layer material; calculating the strain (ε 0 ) of each layer (k,p) using the mid-plane strain (ε k,p ), curvature (K), and the thickness information (Z k,p ) of each layer (k,p); and calculating the stress (σ k,p x,y ) of each layer (k,p) using the strain (ε k,p ) of each layer (k,p) and the stiffness matrix ([Q] k,p ) of each layer (k,p).

[0026] In an exemplary example, the calculated strength value of the multi-layer material is obtained from the safety factor (S k,p ) of each layer (k, p) including: extracting the minimum value ((S k,p )) in the calculated safety factor (S k,p ) of each layer (k, p); and if the extracted minimum value ((S min )) meets the predetermined ULF (ultimate lamination failure) standard, then defining the minimum value ((S k,p )) as the calculated strength value of the multi-layer material min k,p min p p p

[0027] In a specific example, determining whether the calculated strength value of the multi-layer material falls within the error range of the predetermined target strength value of the multi-layer material includes: if the calculated strength value of the multi-layer material falls within the error range of the target strength value of the multi-layer material then setting the principal stress direction strength value ([F] p ) of the amorphous layer (p) to an appropriate value

[0028] In another specific example, determining whether the calculated strength value of the multi-layer material falls within the error range of the predetermined target strength value of the multi-layer material includes: if the calculated strength value of the multi-layer material is outside the error range of the target strength value of the multi-layer material then recalculating the calculated strength value of the multi-layer material For example, if the calculated strength value of the multi-layer material is less than the target strength value of the multi-layer material then increasing the principal stress direction strength value ([F] p ) of the amorphous layer and recalculating the calculated strength value of the multi-layer material Alternatively, if the calculated strength value of the multi-layer material is greater than the target strength value of the multi-layer material then decreasing the principal stress direction strength value ([F] p ) of the amorphous layer and recalculating the calculated strength value of the multi-layer material Advantageous effects

[0029] The system and method for reverse engineering the strength of a multi-layer material according to the present disclosure can perform reverse engineering on a multi-layer material without the need to fabricate a sample of the multi-layer material. Specifically, the present disclosure can derive the required properties of the amorphous layer (p) to achieve the target strength of the multi-layer material. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a block diagram of a system for predicting the properties of a multi-layer material according to a first embodiment of the present disclosure.

[0031] Figures 2 to 4 is a flowchart of a method for reverse engineering the strength of a multi-layer material according to an embodiment of the present disclosure.

[0032] Figure 5 is a schematic diagram showing the orientation of a multi-layer material. DETAILED DESCRIPTION

[0033] The present disclosure provides a system for reverse engineering the strength of a multi-layer material stacked with n layers (where n is an integer of 2 or greater).

[0034] In an exemplary example, the system for reverse engineering the strength of a multi-layer material according to the present disclosure includes: an input section into which input values are input, the input values including the principal stress direction strength value ([F] k ) for each layer (k) other than the amorphous layer (p) and the target strength value of the multi-layer material a control section for calculating the strength of the multi-layer material by applying the input values input into the input section; a display connected to the control section; and a storage section connected to the control section. Here, n is an integer of 2 or greater, p is an integer from 1 to n, and the sum of k and p is n.

[0035] Specifically, the control section uses the principal stress direction strength value ([F] k ) of each layer (k) and an arbitrarily applied principal stress direction strength value ([F] p ) of the amorphous layer (p) to derive the calculated strength value of the multi-layer material and determines the calculated strength value of the multi-layer material whether it falls within the error range of the predetermined target strength value of the multi-layer material or not.

[0036] In the present disclosure, the amorphous layer (p) refers to any one or more layers whose properties or characteristics are not specified, and may include one or more layers within a multi-layer material. In one example, the present disclosure includes a case where all layers of the multi-layer material are amorphous layers (p). If all layers of the multi-layer material are amorphous layers (p), then the principal stress direction strength value ([F] k ) for each layer (k) other than the amorphous layer (p) is not input.

[0037] In the present disclosure, the multi-layer material includes a case where two or more materials are stacked, for example, a case where two or more planar materials are stacked. Additionally, the planar material can be a plastic molded product or a film, and includes not only non-fibrous materials but also fibrous materials.

[0038] In the present disclosure, an arbitrary value is applied as the principal stress direction strength value ([F] p ) of the amorphous layer (p), and based on this, the calculated strength value of the multi-layer material is obtained. If the calculated strength value of the multi-layer material obtained falls within the error range of the target strength value of the multi-layer material , then the arbitrarily input principal stress direction strength value ([F] p ) of the amorphous layer (p) is presented as an appropriate value. Conversely, if the calculated strength value of the multi-layer material is outside the error range of the target strength value of the multi-layer material , then the principal stress direction strength value ([F] p ) of the amorphous layer (p) is modified and the calculated strength value of the multi-layer material is obtained again

[0039] The system for reverse engineering the strength of a multi-layer material according to the present disclosure extracts the required principal stress direction strength value ([F] p ) of the amorphous layer (p) through the above process to achieve the target strength value of the multi-layer material

[0040] Additionally, for a more detailed description of the present disclosure, refer to Korean Patent Application Nos. 2022-0086176, 2022-0086160, and 2022-0071405. All the content disclosed in these patent application documents is incorporated herein by reference as part of this specification.

[0041] In one exemplary example, the input values input to the input section may include, in addition to the principal stress direction strength value ([F] kVarious values other than k ). Specifically, the input value for each layer (k) other than the amorphous layer (p) input to the input section may also include any one or more of the following: the elastic modulus (E k ) of each layer (k), the Poisson's ratio (υ k ), the shear modulus (G k ), the thickness (Z k ), and the lamination angle (θ

[0042] ); and any one or more of the total thickness (h) of the multilayer material.

[0043] In one exemplary example, when the multilayer material includes one or more layers (k) that are not the amorphous layer (p), k and p are each independently an integer between 1 and n, and the sum of k and p satisfies n. p ), the Poisson's ratio (υ p ), the shear modulus (G p ), the thickness (Z p ), and the lamination angle (θ p ); and the total thickness (h) of the multilayer material. For these input values for the amorphous layer (p), any value can be input. Alternatively, if some of the input values for the amorphous layer (p) are known, the known values can be input, and any value can be input for the other input values. In another example, the input value input to the input section may be the principal stress direction strength value ([F] p ) of any application of the amorphous layer (p).

[0044] Using the above input values, the control section calculates the stress of each layer (k, p) and further obtains the calculated strength value of the multilayer material

[0045] Specifically, the control section calculates the stress of each layer (k, p). The control section converts the calculated stress of each layer (k, p) into the principal direction stress ([σ] k,p ) of each layer (k, p) by applying the lamination angle (θ k,p ) of each layer (k, p). Then, the control section configures the principal stress direction strength ([F] k,p ) of each layer (k, p) as the strength determination parameter ([f] k,p), and calculating the safety factor (S k,p ) of each layer (k, p) by combining the principal directional stress ([σ] k,p ) and the strength determination parameter ([f] k,p ) of each layer (k, p). The calculated strength value of the multi-layer material is obtained from the safety factor (S k ,p ) of each layer (k, p)

[0046] In an exemplary example, the control part can calculate the stress of each layer (k, p) through the following process. For example, the control part calculates the force ( / N) and moment ( / M) of the multi-layer material from the total thickness (h) of the multi-layer material. The control part calculates the mid-plane strain (ε 0 ) and curvature (K) using the calculated force ( / N) and moment ( / M) of the multi-layer material and the inverse matrices ([a], [b], [c], [d]) of the stiffness matrices ([A], [B], [D]) of the multi-layer material. Using the calculated mid-plane strain (ε 0 ), curvature (K) and the thickness information (Z k,p ) of each layer (k, p), calculate the strain (ε k,p ) of each layer (k, p). Then, using the strain (ε k,p x,y ) of each layer (k, p) and the stiffness matrix ([Q] k,p ) of each layer (k, p), calculate the stress (σ k,p ) of each layer (k, p).

[0047] In another exemplary example, the control part can obtain the calculated strength value of the multi-layer material from the safety factor (S k ,p ) of each layer (k, p) through the following process For example, the control part extracts the minimum value ((S k,p )) from the calculated safety factors of each layer (k, p) min . If the extracted minimum value ((S k,p )) min meets the predetermined ULF (ultimate laminate failure) standard, then this minimum value ((S k,p )) min is defined as the calculated strength value of the multi-layer material

[0048] In an exemplary example, the process of determining whether the calculated strength value of the multi-layer material falls within the error range of the predetermined target strength value of the multi-layer material can be performed as follows.

[0049] For example, if the calculated strength value of the multi-layer material falls within the error range of the target strength value of the multi-layer material , then the principal stress direction strength value ([F] p ) of the amorphous layer is presented as an appropriate value.

[0050] In another example, if the calculated strength value of the multi-layer material is outside the error range of the target strength value of the multi-layer material , then the following steps are taken: If the calculated strength value of the multi-layer material is less than the target strength value of the multi-layer material , then increase the principal stress direction strength value ([F] p ) of the amorphous layer (p) and recalculate the calculated strength value of the multi-layer material Conversely, if the calculated strength value of the multi-layer material is greater than the target strength value of the multi-layer material , then decrease the principal stress direction strength value ([F] p ) of the amorphous layer (p) and recalculate the calculated strength value of the multi-layer material

[0051] In addition, the present disclosure provides a method for reverse engineering the strength of a multi-layer material, the multi-layer material including n layers containing an amorphous layer (p).

[0052] In one exemplary example, the method for reverse engineering the strength of a multi-layer material according to the present disclosure includes:

[0053] Inputting input values including the principal stress direction strength value ([F] k ) for each layer (k) other than the amorphous layer (p) and the target strength value of the multi-layer material ;

[0054] Using the input values input to the input section and the principal stress direction strength value ([F] p ) for any application of the amorphous layer (p) to calculate the strength value of the multi-layer material and

[0055] Determining whether the calculated strength value of the multi-layer material falls within the error range of a predetermined target strength value of the multi-layer material .

[0056] Here, n is an integer of 2 or greater, and p is an integer from 1 to n, and the sum of k and p is n.

[0057] In one example, the present disclosure includes a case where all layers of a multi-layer material are amorphous layers (p). In the case where all layers of the multi-layer material are amorphous layers (p), the principal stress direction strength values ([F] are not input for each layer (k) other than the amorphous layer (p). k )

[0058] In a specific example, when inputting input values, the input values for each layer (k) other than the amorphous layer (p) may further include any one or more of the following: the elastic modulus (E k ) of each layer (k), the Poisson's ratio (υ k ), the shear modulus (G k ), the thickness (Z k ), and the lamination angle (θ k ); and the total thickness (h) of the multi-layer material.

[0059] In another exemplary example, all layers of the multi-layer material may be amorphous layers (p). In this case, the input values for each layer (p) as an amorphous layer input to the input section may further include any one or more of the following: the elastic modulus (E p ) of each layer (p), the Poisson's ratio (υ p ), the shear modulus (G p ), the thickness (Z p ), and the lamination angle (θ p ); and the total thickness (h) of the multi-layer material. For these input values for the amorphous layer (p), any values may be input. Alternatively, if some of the input values for the amorphous layer (p) are known, the known values may be input, and any values may be input for the other input values. In another example, the input value input to the input section may be the principal stress direction strength value ([F] p ) of any application of the amorphous layer (p).

[0060] In one exemplary example, the steps of calculating the strength value of the multi-layer material include:

[0061] Calculating the stress of each layer (k, p);

[0062] By applying the lamination angle (θ k,p ) of each layer (k, p), transforming the stress of each layer (k, p) into the principal direction stress ([σ] k,p ) of each layer (k, p);

[0063] Configuring the principal stress direction strength ([F] k,p ) of each layer (k, p) as a strength determination parameter ([f] for determining the strength of the multi-layer material.k,p );

[0064] By combining the principal directional stress ([σ] k,p ) and the strength determination parameter ([f] k,p ) of each layer (k,p), the safety factor (S k,p ) of each layer (k,p) is calculated; and

[0065] The calculated strength value of the multi-layer material is obtained from the safety factor (S k,p ) of each layer (k,p) calculated

[0066] In a specific example, the steps of calculating the stress of each layer (k,p) include:

[0067] Calculating the force ( / N) and moment ( / M) of the multi-layer material from the total thickness (h) of the multi-layer material;

[0068] Using the force ( / N) and moment ( / M) of the multi-layer material and the inverse matrices ([a], [b], [c], [d]) of the stiffness matrices ([A], [B], [D]) of the multi-layer material to calculate the mid-plane strain (ε 0 ) and curvature (K);

[0069] Using the mid-plane strain (ε 0 ), curvature (K) and the thickness information (Z k,p ) of each layer (k,p) to calculate the strain (ε k,p ) of each layer (k,p); and

[0070] Using the strain (ε k,p x,y ) of each layer (k,p) and the stiffness matrix ([Q] k,p ) of each layer (k,p) to calculate the stress (σ k,p ) of each layer (k,p).

[0071] In another specific example, the steps of obtaining the calculated strength value of the multi-layer material from the safety factor (S k,p ) of each layer (k,p) include: Extracting the minimum value ((S

[0072] ) in the calculated safety factor (S k,p ) of each layer (k,p); and k,p ); and min If the extracted minimum value ((S

[0073] ) k,p ) min ) meets the predetermined ULF (Ultimate Laminated Failure) standard, then the minimum value ((S k,p) min )is defined as the calculated strength value of the multi-layer material

[0074] In an exemplary example, determining the calculated strength value of the multi-layer material whether it falls within the error range of the predetermined target strength value of the multi-layer material The steps include: if the calculated strength value of the multi-layer material falls within the error range of the target strength value of the multi-layer material then set the principal stress direction strength value ([F] of the amorphous layer (p) p ) to an appropriate value.

[0075] In another exemplary example, determining the calculated strength value of the multi-layer material whether it falls within the error range of the predetermined target strength value of the multi-layer material The steps include: if the calculated strength value of the multi-layer material is outside the error range of the target strength value of the multi-layer material and if the calculated strength value of the multi-layer material is less than the target strength value of the multi-layer material then increase the principal stress direction strength value ([F] of the amorphous layer p ) and recalculate the calculated strength value of the multi-layer material

[0076] Conversely, if the calculated strength value of the multi-layer material is greater than the target strength value of the multi-layer material then decrease the principal stress direction strength value ([F] of the amorphous layer p ) and recalculate the calculated strength value of the multi-layer material

[0077] For example, the method for calculating the strength of the multi-layer material can be performed as follows:

[0078] By inputting any one or more of the elastic modulus (E k,p ), Poisson's ratio (υ k,p ), shear modulus (G k,p ), thickness (Z k ,p ), lamination angle (θ k,p ) of each layer (k, p) and the total thickness (h) of the multi-layer material to calculate the stress of each layer (k, p) (step a);

[0079] By applying the lamination angle (θ k,p) to transform the stress of each layer (k, p) calculated into the principal direction stress of each layer (k, p) ([σ] k,p )(step b);

[0080] Configure the individually input principal stress direction strength ([F] k,p ) of each layer (k, p) as a strength determination parameter ([f] k,p )(step c);

[0081] By combining the principal direction stress ([σ] k,p ) and the strength determination parameter ([f] k,p ) of each layer (k, p) to calculate the safety factor of each layer (k, p) (step d); and

[0082] Define the strength value of the multi-layer material by extracting the minimum value among the calculated safety factors of each layer (k, p) (step e).

[0083] As an example, the process of predicting the strength of a multi-layer material according to the present disclosure is as follows:

[0084] The input information includes any one or more of the following: the elastic modulus (E k,p 1,2 ) in the machine direction (MD, 1) and the transverse direction (TD, 2) of each layer (k, p), the Poisson's ratio (υ k,p 1,2 ) in the machine direction (1) and the transverse direction (2) of each layer (k, p), the shear modulus (G k,p 1,2 ) in the machine direction (1) and the transverse direction (2) of each layer (k, p), the angle (θ k,p ) of the machine direction (1) of each layer relative to the x-direction of the multi-layer material, the thickness (Z k,p ) of each layer (k, p), and the total thickness (h) of the multi-layer material.

[0085] First, using the input information, calculate the stress (σ k,p x,y ) of each layer (k, p). Then, the stress (σ k,p x,y ) of each layer (k, p) calculated is transformed into the principal direction stress ([σ] k,p ) of each layer (k, p) by applying the lamination angle (θ k,p 1,2 ) of each layer (k, p). Additionally, optionally apply the principal stress direction strength ([F] p ) of the amorphous layer (p).

[0086] The principal stress direction strength ([F] of each layer (k, p) k,p 1,2 ) is a strength determination parameter ([f] configured to determine the strength of a multi-layer material k,p 1,2 ). Here, it is noted that the principal stress direction strength ([F] of each layer (k, p) k,p 1,2 ) includes the principal stress direction strength ([F] of the amorphous layer (p) p 1,2 ). By combining the principal direction stress ([σ] of each layer (k, p) k,p 1,2 ) and the strength determination parameter ([f] k,p 1,2 ), the safety factor (S of each layer (k, p) k,p f ) is calculated. For example, in order to calculate the safety factor (S of each layer (k, p) k,p f ), the Tsai-Wu criterion can be applied, or alternatively, the maximum stress criterion, the maximum strain criterion, or the Tsai-Hill criterion can be appropriately applied.

[0087] The minimum value ((S in the calculated safety factor (S of each layer (k, p) k,p f ) k,p f ) min ) is extracted and defined as the strength value of the multi-layer material In this case, the minimum value ((S in the calculated safety factor of each layer (k, p) k,p f ) min ) is defined as the strength value of the multi-layer material And if this value meets the predetermined ULF (ultimate laminate failure) standard, this value is designated as the final calculated strength value of the multi-layer material Here, if the calculated strength value of the multi-layer material falls within the error range of the target strength value of the multi-layer material , the principal stress direction strength value ([F] of the amorphous layer (p) p ) presents an appropriate value.

[0088] According to the method of applying the ULF standard, the minimum value ((S in the calculated safety factor (S of each layer (k, p) k,p f ) k,p f ) min) and take this minimum value ((S k,p f ) min ) as the strength value of the multi-layer material The process can be divided into the following three methods.

[0089] The first method involves repeating once from calculating the stress of each layer (k,p) (step a) to calculating the safety factor of each layer (k,p) (step d), extracting the minimum value ((S k,p f ) in the safety factors (S k,p f ) calculated for each layer (k,p) min ) and take this minimum value ((S k,p f ) min ) as the strength value of the multi-layer material And if this defined strength value of the multi-layer material meets the predetermined ULF (ultimate lamination failure) standard, then this strength value is designated as the final strength value of the multi-layer material In this case, if any one of the layers constituting the multi-layer material fails, the final strength value of the multi-layer material is determined based on this.

[0090] The second method involves repeating n times from calculating the stress of each layer (k,p) (step a) to calculating the safety factor of each layer (k,p) (step d), where the values calculated in the i-th cycle are reflected in the input values for performing the (i + 1)-th cycle. The strength at which all n layers forming the multi-layer material fail is defined as the strength value of the multi-layer material And if this value meets the predetermined ULF (ultimate lamination failure) standard, then this value is designated as the calculated strength value of the multi-layer material Here, i is an integer between 1 and n - 1, and n represents the number of layers (k,p) constituting the multi-layer material. For each cycle, the minimum value ((S k,p f ) in the safety factors (S k,p f ) calculated for each layer (k,p) min ) is extracted and defined as the strength value of the multi-layer material for this cycle In this case, the strength reflecting the failure of all layers constituting the multi-layer material is selected as the final strength value of the multi-layer material.

[0091] The third method involves repeatedly performing the steps from calculating the stress of each layer (k,p) (step a) to calculating the safety factor of each layer (k,p) (step d), where the value calculated in the i-th cycle is reflected in the input values for performing the (i + 1)-th cycle, and the value calculated in the i-th cycle is compared with the value calculated in the (i + 1)-th cycle. When the defined strength of the multi-layer material no longer increases, the value calculated in the i-th cycle is defined as the strength of the multi-layer material. Here, i is an integer between 1 and n - 1, and n represents the number of layers (k,p) that make up the multi-layer material. For each cycle, the minimum value among the calculated safety factors (S k,p f ) of each layer (k,p) ((S k,p f ) min ) is extracted and defined as the strength value of the multi-layer material for that cycle In this case, the strength of the layer that bears the maximum load among the layers constituting the multi-layer material is selected as the calculated strength value of the multi-layer material

[0092] In yet another exemplary example, the minimum value among the calculated safety factors (S k,p f ) of each layer (k,p) ((S k ,p f ) min ) is extracted and defined as the strength value of the multi-layer material In this case, the minimum value among the calculated safety factors of each layer (k,p) ((S k,p f ) min ) is defined as the strength value of the multi-layer material And it can be checked whether this value meets the predetermined ULF (Ultimate Laminated Failure) criteria.

[0093] If the value defined as the strength value of the multi-layer material meets the predetermined ULF (Ultimate Laminated Failure) criteria, then this value is designated as the calculated strength value of the multi-layer material

[0094] Conversely, if the value defined as the strength value of the multi-layer material If the value does not meet the predetermined ULF (ultimate lamination failure) standard, then adjust and recalculate the elastic modulus of the failed layer determined in this cycle. Specifically, apply the coefficient r to adjust the elastic modulus of the failed layer. For example, when r = 0, it is assumed that the failed layer in this cycle has lost its stress-bearing capacity for the next loading cycle in the corresponding direction. When 0 < r < 1, it is assumed that the failed layer in this cycle has partially lost its stress-bearing capacity for the next loading cycle. At the same time, the strength of the failed layer is changed to infinity to ensure that the same layer will not fail in the next loading cycle.

[0095] In yet another exemplary example, by inputting any one or more of the elastic modulus (E k,p )), Poisson's ratio (υ k,p ), shear modulus (G k,p ), thickness (Z k,p ), lamination angle (θ k,p ), and the total thickness (h) of the multi-layer material for each layer (k, p), calculating the stress of each layer (k, p) (step a) can be performed as follows.

[0096] First, the input information includes: the elastic modulus (E k,p 1,2 ) in the machine direction (MD, 1) and the transverse direction (TD, 2) of each layer (k, p), the Poisson's ratio (υ k,p 1,2 ) in the machine direction (1) and the transverse direction (2) of each layer (k, p), the shear modulus (G k,p 1,2 ) in the machine direction (1) and the transverse direction (2) of each layer (k, p), the angle (θ k,p ) of the machine direction (1) of each layer relative to the x-direction of the multi-layer material, the thickness (Z k,p ) of each layer (k, p), and the total thickness (h) of the multi-layer material.

[0097] Using the elastic modulus (E k,p 1,2 ), Poisson's ratio (υ k,p 1,2 ), and shear modulus (G k,p 1,2 ), calculate the stiffness matrix ([Q] k,p 1,2 ) in the machine direction (1) and the transverse direction (2) of each layer (k, p). Then establish the compliance matrix ([S] k,p 1,2 ) which is the inverse of the stiffness matrix ([Q] k,p 1,2)。By applying the lamination angle (θ of each layer (k,p) to the stiffness matrix ([Q] k,p ), the stiffness matrix ([Q] k,p 1,2 ) of each layer (k,p) is redefined. Using the thickness (Z of each layer (k,p) k,p x,y ) information and the redefined stiffness matrix values, the stiffness matrix ([A] k,p ), [B] x,y , [D] x,y ) of the multi-layer material is calculated. Finally, the flexibility matrix ([a] x,y ), [b] x,y , [c] x,y , [d] x,y ), which is the inverse of the stiffness matrix ([A] x,y ), [B] x,y , [D] x,y ) of the multi-layer material, is established. x,y )。

[0098] Next, using the flexibility matrix for arbitrary forces ( / F) and moments ( / M), the mid-plane strain and curvature are calculated. Then, using the calculated mid-plane strain and curvature and the thickness (Z of each layer (k,p) k,p ), the strain of each layer (k,p) is calculated.

[0099] Specifically, the arbitrary forces ( / F) and moments ( / M) are assumed virtual external forces, which can be defined using the total thickness value to virtually apply a unit normal stress to the multi-layer material.

[0100] Using the forces ( / F) and moments ( / M) and the flexibility matrix ([a] x,y ), [b] x,y , [c] x,y ), [d] x,y ), which is the inverse of the stiffness matrix ([A] x,y ), [B] x,y ), [D] x,y ) of the multi-layer material, the mid-plane strain (ε 0 x,y ) and curvature (k,p x,y,s ) are calculated. Then, using the mid-plane strain (ε 0 x,y ) and curvature (k,p x,y,s ) and the thickness (Z of each layer (k,p) k,p ), the strain (ε of each layer (k,p) k,p x,y)。Subsequently, using the strain of each layer (k,p) and the stiffness matrix ([Q] of each layer (k,p) k,p x,y ), the stress (σ of each layer (k,p) is calculated k,p x,y ). Finally, the calculated stress (σ of each layer (k,p) k,p x,y ) is transformed into the principal direction stress ([σ] of each layer (k,p) by applying the lamination angle (θ of each layer (k,p) k,p ). k,p 1,2 )

[0101] Detailed description

[0102] The present disclosure will be described more specifically by the following drawings and exemplary examples; however, the scope of the present disclosure is not limited thereto.

[0103] (First Embodiment)

[0104] Figure 1 is a configuration diagram of a system for reverse engineering the strength of a multi-layer material according to the first embodiment of the present disclosure.

[0105] As Figure 1 illustrated in, a system for reverse engineering the strength of a multi-layer material according to the first embodiment of the present disclosure includes an input part 10 for inputting input values, a control part 20 connected to the input part 10, a display 30 connected to the control part 20, and a storage part 40 connected to the control part 20.

[0106] The input values input into the input part 10 regarding each layer (k) except for the amorphous layer (p) include the principal stress direction strength value ([F] of the multi-layer material k ) and the target strength value

[0107] In some cases, the input values may further include additional input values. For example, the additional input values may include: the elastic modulus (E in the machine direction (MD, hereinafter set as "1" and referring to the principal direction) and the transverse direction (TD, hereinafter set as "2") of each layer (k) k 1,2 ), the Poisson's ratio (υ in the machine direction (1) and the transverse direction (2) of each layer (k) k 1,2 ), the shear modulus (G in the machine direction (1) and the transverse direction (2) of each layer (k) k 1,2 ), the angle (θ of the machine direction (1) of each layer relative to the x-direction of the multi-layer materialk ) and the thickness (Z) of each layer (k) k ). Additionally, the additional input value includes the total thickness (h) of the multi-layer material.

[0108] The control section 20 may include, for example, a multi-layer material property calculation unit 21 and a layer-by-layer strain and stress calculation unit 22. The control section 20 uses the principal stress direction strength value ([F] of each layer (k) k ) and the arbitrarily applied principal stress direction strength value ([F] of the amorphous layer (p) p ) to obtain the calculated strength value of the multi-layer material

[0109] In the present disclosure, the term "multi-layer material" refers to a laminated structure including two or more materials stacked together. For example, the multi-layer material may refer to a multi-layer film of a polymer or the like, or a composite material of heterogeneous materials such as FRP (fiber reinforced plastic) and an aluminum bag. For example, the multi-layer material may refer to a multi-layer film.

[0110] (Second Embodiment)

[0111] Figure 2 is a flowchart of a method for reverse engineering the strength of a multi-layer material according to an embodiment of the present disclosure.

[0112] Specifically, Figure 2 illustrates a process of calculating the stress of each layer in a multi-layer material including two or more stacked materials.

[0113] Input (S11) the following parameters: the elastic modulus (E) in the machine direction (1) and the transverse direction (2) of each layer (k) k 1,2 , the Poisson's ratio (υ) in the machine direction (1) and the transverse direction (2) of each layer (k) k 1,2 , the shear modulus (G) in the machine direction (1) and the transverse direction (2) of each layer (k) k 1,2 , the angle (θ) of the machine direction (1) of each layer relative to the x direction of the multi-layer material k and the thickness (Z) of each layer (k) k .

[0114] Using the elastic modulus (E k 1,2 ), the Poisson's ratio (υ k 1,2 ), and the shear modulus (G k 1,2 ), calculate the stiffness matrix ([Q] in the machine direction (1) and the transverse direction (2) of each layer (k)k 1,2 ) as shown in the following equation (1) (S12).

[0115]

[0116] Q 66 = G 12' (1)

[0117] (For isotropic materials, G = E / 2(1 + υ))

[0118] Establish the flexibility matrix ([S] k 1,2 ) which is the inverse of the stiffness matrix ([Q] k 1,2 ) for each layer (k) calculated in the machine direction (1) and the transverse direction (2) (S13).

[0119] Redefine the stiffness matrix ([Q] k ) of each layer (k) by applying the lamination angle (θ k 1,2 ) to the obtained stiffness matrix ([Q] k x,y ) as shown in the following equation (2) (S14).

[0120]

[0121] Using the thickness information of each layer (k) and the redefined stiffness matrix values, calculate the stiffness matrix ([A] x,y , [B] x,y , [D] x,y ) of the entire laminate structure of the multi-layer material as shown in the following equation (3) (S15).

[0122]

[0123] Establish the flexibility matrix ([a] x,y , [b] x,y , [c] x,y ) which is the inverse of the stiffness matrix ([A] x,y , [B] x,y , [C] x,y , [D] x,y ) of the calculated entire laminate structure (i.e., multi-layer material) as shown in the following equation (4) (S16).

[0124]

[0125] In the present disclosure, to virtually apply a unit normal stress to the entire multi-layer material, which can be defined using the total thickness value as shown in the following equation (5) or equation (6) (S17). Here, equation (5) is applied when calculating the strength in the x-direction of the multi-layer material, and equation (6) is applied when calculating the strength in the y-direction of the multi-layer material.

[0126]

[0127] Using the input total force ( / N) and total moment ( / M) and the flexibility matrix ([a] x,y ,[B] x,y ,[D] x,y ) which is the inverse of the stiffness matrix ([A] x,y ,[b] x,y ,[c] x,y ,[d] x,y ) of the entire laminated structure (i.e., the multi-layer material), the mid-plane strain (ε 0 x,y ) and curvature (k,p x,y,s ) are calculated as shown in the following equation (7) (S18).

[0128]

[0129] Using the mid-plane strain (ε 0 x,y ) and curvature (k,p x,y,s ) and the thickness (Z k ) information of each layer (k) input through the input section, the strain (ε k x,y ) of each layer (k) is calculated as shown in the following equation (8) (S19).

[0130]

[0131] Using the strain of each layer (k) and the stiffness matrix ([Q] k x,y ) of each layer (k), the stress (σ k x,y ) of each layer (k) is calculated as shown in the following equation (9) (S20).

[0132]

[0133] The second embodiment illustrates the process of calculating the stress of each layer (k) other than the amorphous layer (p) using input values. The second embodiment can be similarly applied to the amorphous layer (p). As an example, the input values for the amorphous layer (p) can be arbitrarily applied. As another example, if some of the input values for the amorphous layer (p) are known, the known values can be input, and arbitrary values can be input for the other input values.

[0134] (Third Embodiment)

[0135] Figure 3 is a flowchart of a method for reverse engineering the strength of a multi-layer material according to an embodiment of the present disclosure. Figure 3 Illustrates the process of calculating the calculated strength value of a multi-layer material using input values and the principal stress direction strength value ([F] p ) of the amorphous layer (p) of the process.

[0136] Referring to Figure 3 , the stress (σ k,p x,y ) of each layer (k, p) in the x and y directions calculated using the lamination angle (θ k,p ) information of each layer is transformed into the principal direction stress ([σ] k,p 1,2 ) in the machine direction (MD) and the transverse direction (TD) of each layer (S21). Here, the following equation (10) is used.

[0137]

[0138] Individually, for example, the principal stress direction strength ([F] k 1,2 ) of each layer (k) other than the amorphous layer (p) is input as follows (S22):

[0139] Tensile strength in the 1 direction of each layer (k): F k 1t , compressive strength in the 1 direction: F k 1c Tensile strength in the 2 direction of each layer (k): F k 2t , compressive strength in the 2 direction: F k 2c

[0140] Tensile strength in the 6 direction of each layer (k): F k 6, biaxial tensile strength in the 1-2 direction: F k 12

[0141] Here, for the amorphous layer (p), the strength value of the arbitrarily applied principal stress direction ([F] p 1,2 ) is input.

[0142] Here, the direction of each layer (k, p) is as Figure 5 shown. Referring to Figure 5 , the horizontal direction of the multi-layer material is set to the 1 direction or the x direction, and the vertical direction is set to the 2 direction or the y direction. Additionally, the diagonal direction is set to the 6 direction or the s direction.

[0143] Using the input strength of each layer (k, p), parameters for determining the strength of the entire multi-layer material are configured as shown in the following equation (11) (S23). The following equation (11) is an example of applying the Tsai-Wu criterion.

[0144] [f] k = [f1 f2 f 11 f 22 f 66 f 12 k

[0145]

[0146] Here, if the experimental value of the biaxial tensile strength cannot be obtained, it can be assumed as shown in the following equation (12).

[0147]

[0148] Using the principal direction stress ([σ] k,p 1,2 ) and the strength determination parameter ([f] k,p 1,2 ), the safety factor (S k,p f ) of each layer (k, p) is calculated (S24). For example, when applying the Tsai-Wu criterion, the safety factor is calculated as shown in the following equation (13).

[0149]

[0150] b = f1σ1 + f2σ2 (13)

[0151] Solving the quadratic equation in equation (12) gives two solutions for the safety factor (S k,p f ) of each layer (k, p), where the positive value (S k,p fa ) represents the tensile strength, and the negative value (S k,p ​fr ) represents the compressive strength. The layer (k,p) with the minimum safety factor among all layers (k,p i ) can be defined as the failure layer (S25).

[0152] In this case, the safety factor of the failure layer can be defined as the strength value for the corresponding loading cycle (i) (S26). In this case, if a unit normal stress is applied according to Equation (5) in the previous S17, the strength in the x - direction of the multi - layer material is obtained through Equation (14).

[0153]

[0154] In addition, if a unit normal stress is applied according to Equation (6) in the previous S17, the strength in the y - direction of the multi - layer material is obtained through Equation (15).

[0155]

[0156] If the result of the corresponding loading cycle meets the predetermined ULF (Ultimate Laminar Failure) criterion (S27), the defined strength value is determined as the calculated strength value of the multi - layer material (S28).

[0157] If the ULF criterion has not been met, S29 and S30 are executed to re - apply the entire algorithm loop.

[0158] Here, the ULF criterion (S27) can be applied by selecting one of the following Examples 1 to 3:[[]]

[0159] (Example 1) Loading cycle (i = 1): When any one of the layers constituting the multi - layer material reaches failure, select the corresponding strength as the final strength of the multi - layer material.

[0160] (Example 2) Loading cycle (n cycles): When all layers (n layers) forming the multi - layer material have completed failure, select the corresponding strength as the final strength of the multi - layer material.

[0161] (Example 3) When comparing the results of the i - th loading cycle and the (i + 1)-th loading cycle, if the corresponding strength does not increase, select the strength selected in the i - th loading cycle as the final strength.

[0162] If the strength value of the multi - layer material defined in S26 If the ULF standard is not satisfied, the elastic modulus of the failed layer identified in the corresponding cycle (i) is adjusted and recalculated (S29). In this case, the elastic modulus of the failed layer is adjusted by applying a coefficient r. For example, when r = 0, it is assumed that the failed layer in this cycle has lost its stress-bearing capacity for the next loading cycle in the corresponding direction. When 0 < r < 1, it is assumed that the failed layer in this cycle has partially lost its stress-bearing capacity for the next loading cycle.

[0163] (Fourth Embodiment)

[0164] Figure 4 is a flowchart of a method for reverse engineering the strength of a multi-layer material according to another embodiment of the present disclosure.

[0165] If the calculated strength value of the multi-layer material is calculated then the calculated strength value is determined whether it falls within the error range of the predetermined target strength value of the multi-layer material (S30).

[0166] If the calculated strength value of the multi-layer material is outside the error range of the target strength value of the multi-layer material then the calculated strength value is compared with the target strength value of the multi-layer material .

[0167] If the calculated strength value of the multi-layer material is less than the target strength value of the multi-layer material then the principal stress direction strength value of the amorphous layer ([F] p 1,2 ) is increased, and the calculated strength value of the multi-layer material is recalculated (S31).

[0168] Conversely, if the calculated strength value of the multi-layer material is greater than the target strength value of the multi-layer material then the principal stress direction strength value of the amorphous layer ([F] p 1,2 ) is decreased, and the calculated strength value of the multi-layer material is recalculated (S32). However, if further decreasing the principal stress direction strength value of the amorphous layer ([F] p 1,2 ) would result in a negative value, the calculated strength value of the multi-layer material is not recalculated and instead, the minimum value set in the program is specified as the principal stress direction strength value of the amorphous layer ([F] p 1,2 ) and output.

[0169] In the process of determining whether the calculated strength value of the multi-layer material falls within the error range of the predetermined target strength value of the multi-layer material S30, if the calculated strength value of the multi-layer material falls within the error range of the target strength value of the multi-layer material , the principal stress direction strength value ([F] of the input amorphous layer (p) p 1,2 ) is presented as an appropriate value (S33).

[0170] (Fifth Embodiment)

[0171] In another exemplary example of the present disclosure, when the input value to be input into the input section cannot be directly obtained, the input value can be obtained through a conversion process using other material property values.

[0172] In an exemplary example, during the process of inputting the elastic modulus (E k ) and Poisson's ratio (υ k ) of each layer (k), these can be calculated using one or more material property values among the first Lamé parameter (λ k ), shear modulus (G k ) and bulk modulus (K k ). For example, they can be converted into the elastic modulus (E k ) and Poisson's ratio (υ k ) using the following Mathematical Equation 1 to Mathematical Equation 9.

[0173] When the available combination is (λ k , G k ), it follows the following Mathematical Equation 1.

[0174] [Mathematical Equation 1]

[0175]

[0176] When the available combination is (λ k , E k ), it follows the following Mathematical Equation 2.

[0177] [Mathematical Equation 2]

[0178]

[0179] When the available combination is (λ k , υ k ), it follows the following Mathematical Equation 3.

[0180] [Mathematical Equation 3]

[0181]

[0182] When the available combination is (λ k , K k ), it follows the following mathematical equation 4.

[0183] [Mathematical Equation 4]

[0184]

[0185] When the available combination is (G k , E k ), it follows the following mathematical equation 5.

[0186] [Mathematical Equation 5]

[0187]

[0188] When the available combination is (G k , υ k ), it follows the following mathematical equation 6.

[0189] [Mathematical Equation 6]

[0190] E k = 2G k (1 + υ k ), υ k

[0191] When the available combination is (G k , K k ), it follows the following mathematical equation 7.

[0192] [Mathematical Equation 7]

[0193]

[0194] When the available combination is (K k , E k ), it follows the following mathematical equation 8.

[0195] [Mathematical Equation 8]

[0196]

[0197] When the available combination is (K k , υ k ), it follows the following mathematical equation 9.

[0198] [Mathematical Equation 9]

[0199] E k = 3K k(1 - 2υ k ), v k

[0200] The above mathematical equations 1 to 9 are examples, and two or more mathematical equations can be combined as needed.

[0201] Description of the reference numerals

[0202] 10: Input section

[0203] 20: Control section

[0204] 21: Multilayer material property calculation unit

[0205] 22: Coefficient of expansion and stress calculation unit

[0206] 30: Display

[0207] 40: Storage section

[0208] 100: Multilayer material

Claims

1. A system for reverse engineering the strength of a multilayer material, wherein n layers including an amorphous layer (p) are stacked, the system comprising: An input section comprising the principal stress direction strength values ​​([F]) for each layer (k) except the amorphous layer (p) k ) and the target strength value of the multilayer material The input value of is input into the input part; a control section for calculating the strength of the multi-layer material by applying the input value input into the input section; a display connected to the control section; as well as a storage section connected to the control section, Wherein, the control part, Using the principal stress direction strength value ([F]) of each layer (k) k ) and the strength value of the principal stress direction of the amorphous layer (p) in any application ([F] p ) to obtain the calculated strength value of the multilayer material and Determining the calculated strength value of the multilayer material Whether it falls within the predetermined target strength value of the multilayer material Within the error range, wherein n is an integer of 2 or more, and p is an integer from 1 to n, and the sum of k and p is n.

2. The system for reverse engineering the strength of a multi-layer material according to claim 1, wherein: The input value for each layer (k) other than the amorphous layer (p) input into the input section further includes any one or more of the following: The elastic modulus (E) of each layer (k) k ), Poisson's ratio (υ k ), shear modulus (G k ), thickness (Z k ) and lamination angle (θ k );as well as The total thickness (h) of the multilayer material.

3. The system for reverse engineering the strength of a multi-layer material according to claim 1, wherein: The control part: Calculate the stress in each layer (k,p), By applying the lamination angle (θ k,p ) to transform the stress of each layer (k, p) into the principal direction stress ([σ] k,p ), The principal stress direction strength ([F]) of each layer (k, p) is calculated. k,p ) is configured to determine a strength determination parameter ([f]) for determining the strength of the multilayer material k,p ), By combining the principal stresses ([σ] k,p ) and the intensity determination parameter ([f] k,p ) to calculate the safety factor (S) of each layer (k,p) k,p ),as well as The safety factor (S) of each layer (k, p) is calculated k,p ) to obtain the calculated strength value of the multilayer material 4. The system for reverse engineering the strength of a multi-layer material according to claim 3, wherein: The control part: Calculate the force ( / N) and moment ( / M) of the multilayer material based on the total thickness (h) of the multilayer material, The midplane strain (ε ) is calculated using the force ( / N) and the moment ( / M) of the multilayer material and the inverse matrix ([a], [b], [c], [d]) of the stiffness matrix ([A], [B], [D]) of the multilayer material. 0 ) and curvature (K), Using the midplane strain (ε 0 ), the curvature (K) and the thickness information (Z) of each layer (k, p) k,p ) calculates the strain (ε) of each layer (k,p) k,p ),and Using the strain (ε) of each layer (k,p) k,p x,y ) and the stiffness matrix ([Q]) of each layer (k,p) k,p ) calculates the stress (σ) of each layer (k,p) k,p ).

5. The system for reverse engineering the strength of a multi-layer material according to claim 3, wherein: The safety factor (S k,p ) to obtain the calculated strength value of the multilayer material include: Extract the minimum value (S) of the safety factor calculated for each layer (k, p) k,p ) min ), Among them, if the minimum value ((S k,p ) min ) satisfies the predetermined ULF (Ultimate Laminate Failure) standard, then the minimum value ((S k,p ) min ) is defined as the calculated strength value of the multilayer material 6. The system for reverse engineering the strength of a multi-layer material according to claim 1, wherein: In determining the calculated strength value of the multilayer material Whether it falls within the target strength value of the multilayer material Within the error range of the process, If the calculated strength value of the multilayer material The target strength value falling within the multilayer material Within the error range of , the principal stress direction strength value ([F] p ) is rendered as an appropriate value.

7. The system for reverse engineering the strength of a multi-layer material according to claim 1, wherein: In determining the calculated strength value of the multilayer material Whether it falls within the target strength value of the multilayer material Within the error range of the process, When the calculated strength value of the multilayer material The target strength value of the multilayer material When the error is outside the range, If the calculated strength value of the multilayer material Less than the target strength value of the multilayer material Then the principal stress direction strength value ([F]) of the amorphous layer (p) is increased p ) and recalculate the calculated strength value of the multilayer material and If the calculated strength value of the multilayer material Greater than the target strength value of the multilayer material Then the principal stress direction strength value ([F]) of the amorphous layer (p) is reduced. p ) and recalculate the calculated strength value of the multilayer material 8. A method for reverse engineering the strength of a multilayer material, the multilayer material being a stack of n layers including an amorphous layer (p), the method comprising: The input includes the principal stress direction strength values ​​([F]) for each layer (k) except the amorphous layer (p) k ) and the target strength value of the multilayer material The input value of Using the input values ​​entered into the input section and any applicable principal stress direction strength values ​​([F]) for the amorphous layer (p), p ) Calculate the strength value of the multilayer material as well as Determine the calculated strength value of the multilayer material Whether it falls within the predetermined target strength value of the multilayer material Within the error range, wherein n is an integer of 2 or more, and p is an integer from 1 to n, and the sum of k and p is n.

9. The method for reverse engineering the strength of a multi-layer material according to claim 8, wherein: When the input value is input, The input value for each layer (k) other than the amorphous layer (p) includes any one or more of the following: The elastic modulus (E) of each layer (k) k ), Poisson's ratio (υ k ), shear modulus (G k ), thickness (Z k ) and lamination angle (θ k );as well as The total thickness (h) of the multilayer material.

10. The method for reverse engineering the strength of a multi-layer material according to claim 8, wherein: Calculate the strength value of the multi-layer material include: Calculate the stress in each layer (k,p); By applying the lamination angle (θ k,p ) to transform the stress of each layer (k, p) into the principal direction stress ([σ] k,p ); The principal stress direction strength ([F]) of each layer (k, p) is calculated. k,p ) is configured to determine a strength determination parameter ([f]) for determining the strength of the multilayer material k,p ); By combining the principal stresses ([σ] k,p ) and the intensity determination parameter ([f] k,p ) to calculate the safety factor (S) of each layer (k,p) k,p );as well as The safety factor (S) of each layer (k, p) is calculated k,p ) to obtain the calculated strength value of the multilayer material 11. The method for reverse engineering the strength of a multi-layer material according to claim 10, wherein: Calculating the stress for each layer (k,p) includes: Calculating the force ( / N) and moment ( / M) of the multilayer material based on the total thickness (h) of the multilayer material; The midplane strain (ε ) is calculated using the force ( / N) and the moment ( / M) of the multilayer material and the inverse matrix ([a], [b], [c], [d]) of the stiffness matrix ([A], [B], [D]) of the multilayer material. 0 ) and curvature (K); Using the midplane strain (ε 0 ), the curvature (K) and the thickness information (Z) of each layer (k, p) k,p ) calculates the strain (ε) of each layer (k,p) k,p );as well as Using the strain (ε) of each layer (k,p) k,p x,y ) and the stiffness matrix ([Q]) of each layer (k,p) k,p ) calculates the stress (σ) of each layer (k,p) k,p ).

12. The method for reverse engineering the strength of a multi-layer material according to claim 10, wherein: The safety factor (S k,p ) to obtain the calculated strength value of the multilayer material include: Extract the calculated safety factor (S) for each layer (k, p) k,p ) in the minimum value ((S k,p ) min );as well as If the minimum value ((S k,p ) min ) meets the predetermined ULF (Ultimate Laminate Failure) standard, then the minimum value ((S k,p ) min ) is defined as the calculated strength value of the multilayer material 13. The method for reverse engineering the strength of a multi-layer material according to claim 8, wherein: Determining the calculated strength value of the multilayer material Whether it falls within the predetermined target strength value of the multilayer material The error range includes: If the calculated strength value of the multilayer material The target strength value falling within the multilayer material If the error range is within the range of , the principal stress direction strength value ([F]) of the amorphous layer (p) is p ) to an appropriate value.

14. The method for reverse engineering the strength of a multi-layer material according to claim 8, wherein: Determining the calculated strength value of the multilayer material Whether it falls within the predetermined target strength value of the multilayer material The error range includes: When the calculated strength value of the multilayer material The target strength value of the multilayer material When the error is outside the range, If the calculated strength value of the multilayer material Less than the target strength value of the multilayer material Then the principal stress direction strength value of the amorphous layer is increased ([F] p ) and recalculate the calculated strength value of the multilayer material and If the calculated strength value of the multilayer material Greater than the target strength value of the multilayer material Then the principal stress direction strength value of the amorphous layer is reduced ([F] p ) and recalculate the calculated strength value of the multilayer material

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