Method and device for calculating torsional rigidity of fabric pultrusion composite material product

Abstract

The invention discloses a method and a device for calculating the torsional rigidity of a fabric pultrusion composite material product. The method comprises the following steps: determining product characteristic parameters of a first product; determining the material parameters of each layer of the first product and the fiber layer angle of each layer; according to the product characteristic parameters, the material parameters of all the layers and the fiber layer angles of all the layers, the effective shear modulus of all the layers of the first product is determined; and determining the torsional rigidity of the product based on the effective shear modulus of each layer of the first product. By the adoption of the technical scheme, the torsional rigidity of the product can be accurately calculated under the condition that the calculation efficiency is guaranteed, and therefore the problems that when the torsional rigidity of the product is determined, the determination efficiency is low, and the determination cost is too high are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of torsional stiffness calculation, and particularly relates to a method and device for calculating the torsional stiffness of a fabric pultruded composite product. Background Art

[0002] Due to the characteristics of multi-directional fiber layering, high strength, and light weight, fabric pultruded composite products have been widely used in the fields of aerospace, automotive, construction, and wind power generation.

[0003] However, for some fabric pultruded composite products with insufficient torsional stiffness, it is necessary to determine the torsional stiffness of the fabric pultruded composite products before use. Traditional methods mostly rely on finite element numerical simulation or experimental testing to evaluate the torsional performance, which is difficult to quickly evaluate and has low efficiency. Summary of the Invention

[0004] The present invention provides a method and device for calculating the torsional stiffness of a fabric pultruded composite product to solve the problem that the torsional performance evaluation process cannot be quickly determined.

[0005] According to one aspect of the present invention, a method for calculating the torsional stiffness of a fabric pultruded composite product is provided. The method includes:

[0006] Determine the product characteristic parameters of the first product. The first product is made of a fiber-reinforced composite material manufactured by a pultrusion process. The product characteristic parameters include the cross-sectional area of the first product, the median line length of each ply, and the thickness of each ply;

[0007] Determine the material parameters of each ply of the first product and the fiber ply angle of each ply; the material parameters are determined according to the ply material model; the material parameters include the fiber direction modulus and the equivalent shear modulus; the fiber ply angle is determined with the axial direction of the pultrusion of the first product as zero degrees;

[0008] According to the product characteristic parameters, the material parameters of each ply, and the fiber ply angle of each ply, determine the effective shear modulus of each ply of the first product;

[0009] Based on the effective shear modulus of each ply of the first product, determine the product torsional stiffness; the product torsional stiffness is used to describe the ability of the first product to resist torsional deformation.

[0010] According to another aspect of the present invention, a device for calculating the torsional stiffness of a fabric pultruded composite product is provided. The device includes:

[0011] A characteristic parameter determination module for determining the product characteristic parameters of a first product, where the first product is made of a fiber-reinforced composite material manufactured by a pultrusion process, and the product characteristic parameters include the cross-sectional area of the first product, the center line length of each ply, and the thickness of each ply;

[0012] A material parameter determination module for determining the material parameters of each ply of the first product and the fiber ply angle of each ply; the material parameters are determined according to the ply material type; the material parameters include the fiber direction modulus and the equivalent shear modulus; the fiber ply angle is determined with the axial direction of the pultrusion of the first product as zero degrees;

[0013] A shear modulus determination module for determining the effective shear modulus of each ply of the first product according to the product characteristic parameters, the material parameters of each ply, and the fiber ply angle of each ply;

[0014] A torsional stiffness determination module for determining the product torsional stiffness based on the effective shear modulus of each ply of the first product; the product torsional stiffness is used to describe the ability of the first product to resist torsional deformation.

[0015] According to another aspect of the present invention, there is provided an electronic device, which includes:

[0016] At least one processor; and a memory communicatively connected to the at least one processor; wherein, the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the fabric pultruded composite product torsional stiffness calculation method of any embodiment of the present invention.

[0017] According to another aspect of the present invention, there is provided a computer-readable storage medium storing computer instructions for causing a processor to implement the fabric pultruded composite product torsional stiffness calculation method of any embodiment of the present invention when executed.

[0018] The technical solution of the embodiments of the present invention, by determining the product characteristic parameters of the first product; determining the material parameters of each ply of the first product and the fiber ply angle of each ply; determining the effective shear modulus of each ply of the first product according to the product characteristic parameters, the material parameters of each ply, and the fiber ply angle of each ply; and finally determining the product torsional stiffness based on the effective shear modulus of each ply of the first product, can accurately calculate the product torsional stiffness of the fabric pultruded composite product while ensuring the calculation efficiency, thereby avoiding the problems of low determination efficiency and high determination cost when determining the product torsional stiffness of the fabric pultruded composite product.

[0019] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0021] Figure 1 is a flowchart of a method for calculating the torsional stiffness of a fabric pultruded composite product according to Embodiment 1 of the present invention;

[0022] Figure 2 This is a flowchart for screening the first product according to the method for calculating the torsional stiffness of a fabric pultruded composite product provided in Embodiment 2 of the present invention;

[0023] Figure 3 is a schematic structural diagram of a device for calculating the torsional stiffness of a fabric pultruded composite product according to Embodiment 3 of the present invention;

[0024] Figure 4 is a schematic structural diagram of an electronic device for implementing the method for calculating the torsional stiffness of a fabric pultruded composite product in the embodiments of the present invention. Detailed Embodiments

[0025] In order to enable those skilled in the art to better understand the solutions of the present invention, the following clearly and completely describes the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, rather than all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present invention shall fall within the protection scope of the present invention.

[0026] It should be noted that the terms "first", "second", etc. in the description, claims and the above-mentioned drawings of the present invention are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0027] Embodiment 1

[0028] Figure 1 FIG. 1 is a flowchart of a method for calculating the torsional stiffness of a fabric pultrusion composite product provided in Embodiment 1 of the present invention. This embodiment is applicable to the case of calculating the torsional stiffness of a fabric pultrusion composite product. This method can be executed by a device for calculating the torsional stiffness of a fabric pultrusion composite product. The device for calculating the torsional stiffness of a fabric pultrusion composite product can be implemented in the form of hardware and / or software, and the device for calculating the torsional stiffness of a fabric pultrusion composite product can be configured in an electronic device with data processing capabilities. As Figure 1 shown, the method includes:

[0029] S110. Determine the product characteristic parameters of the first product. The first product is made of a fiber-reinforced composite material manufactured by a pultrusion process. The product characteristic parameters include the cross-sectional area of the first product, the median line length of each ply, and the thickness of each ply.

[0030] The first product is a fabric pultrusion composite product made of a fiber-reinforced composite material manufactured by a pultrusion process. The first product is made by processing with a reinforcing material and a matrix material. The fiber-reinforced composite material includes at least one of the following: glass fiber, carbon fiber, aramid fiber, etc. The matrix material includes at least one of the following: resin matrix, metal matrix, and ceramic matrix, etc. The resin matrix includes at least one of the following: epoxy resin, polyester resin, vinyl ester resin, etc. The metal matrix includes at least one of the following: aluminum, magnesium, titanium, etc. In the fabric pultrusion composite product, the fiber-reinforced composite material is arranged in a specific direction. During the pultrusion process, due to the high strength and high modulus characteristics of the fiber-reinforced composite material, the fabric pultrusion composite product has strong longitudinal strength and stiffness. The cross-sectional area of the first product refers to the cross-sectional area of the first product in a direction perpendicular to the length direction of the first product. The median line length of the ply refers to the length measured along the center line of the ply shape during the ply laying process of the first product.

[0031] The cross-sectional area of the first product can be determined by at least one of the following calculation methods: direct measurement method, image processing method.

[0032] Among them, by the direct measurement method, to determine the cross-sectional area of the first product, it includes:

[0033] Intercept the first product in a direction perpendicular to the length direction of the first product to obtain the cross-section of the first product;

[0034] Determine the length and width of the cross-section of the first product, and determine the cross-sectional area of the first product according to the length and width.

[0035] Among them, the measurement of the length and width of the cross-section of the first product can be carried out by at least one of the following tools: calipers, micrometers, etc.

[0036] The determination of the center line length of the ply can be classified and calculated according to different ply shapes. The ply shapes include but are not limited to at least one of the following: rectangular ply, circular ply, and irregularly shaped ply.

[0037] Optionally, the determination of the center line length of the ply includes:

[0038] If the ply is a rectangular ply, then determine the length and width of the ply;

[0039] According to the length and width of the ply, determine the center line length; among them, the center line length is equal to half of the sum of the length and the width.

[0040] Optionally, the determination of the center line length of the ply includes:

[0041] If the ply is a circular ply, then determine the radius of the ply;

[0042] According to the radius of the ply, determine the center line length;

[0043] Among them, the center line length of the ply π2.

[0044] Optionally, the determination of the center line length of the ply includes:

[0045] If the ply is an irregularly shaped ply, then determine the coordinates of a preset number of boundary points on the ply;

[0046] Determine the distance between adjacent boundary points;

[0047] Sum up the distances between each adjacent boundary point to obtain the center line length of the ply.

[0048] S120. Determine the material parameters of each ply of the first product and the fiber ply angle of each ply; the material parameters are determined according to the ply material model; the material parameters include the fiber-direction modulus and the equivalent shear modulus; the fiber ply angle is determined with the axis of pultrusion of the first product as zero degrees.

[0049] The material parameters are determined according to the material quality of the ply. The material parameters include the fiber-direction modulus and the equivalent shear modulus. The fiber-direction modulus refers to the ratio of the stress to the strain of the fiber in the fiber axial direction. The higher the fiber-direction modulus, the smaller the deformation of the fiber under the same external force.

[0050] The axial direction refers to the direction in which the fiber length extends. The equivalent shear modulus can be the ratio of the stress to the strain when the fiber is subjected to a shear force. The larger the equivalent shear modulus, the smaller the shear strain of the fiber under the same shear force.

[0051] The fiber ply angle is the angle between the fiber and the axis of pultrusion of the first product.

[0052] S130. Determine the effective shear modulus of each ply of the first product according to the product characteristic parameters, the material parameters of each ply, and the fiber ply angle of each ply.

[0053] The effective shear modulus is the ratio of the shear stress to the shear strain when the material is subjected to a shear force.

[0054] Since the cross-sectional area of the first product of the first product, the center line length of the ply, the thickness of the ply, the material parameters of the ply, and the fiber ply angle of the ply will all have a greater impact on the effective shear modulus of the ply, the influence coefficients of the cross-sectional area of the first product of the first product, the center line length of the ply, the thickness of the ply, the material parameters of the ply, and the fiber ply angle of the ply on the effective shear modulus of the ply can be determined through experiments, and the effective shear modulus of the ply of the first product can be determined according to the influence coefficients.

[0055] In an alternative solution, determining the effective shear modulus of each ply of the first product according to the product characteristic parameters, the material parameters of each ply, and the fiber ply angle of each ply includes:

[0056] Based on the approximate conversion formula of composite material mechanics, convert the product characteristic parameters, the material parameters of each ply, and the fiber ply angle of each ply to obtain the effective shear modulus of each ply of the first product.

[0057] The approximate conversion formula of composite material mechanics is used to calculate various mechanical properties of composite materials under different conditions.

[0058] For the i-th layer, the effective shear modulus can be calculated using the approximate transformation formula of composite mechanics based on its fiber lay-up angle θi and material parameters (modulus E along the fiber direction and matrix or equivalent shear modulus G).

[0059] Among them, the expression of the effective shear modulus is:

[0060] ;

[0061] Among them, represents the effective shear modulus of the i-th layer; E represents the modulus along the fiber direction; G represents the equivalent shear modulus; represents the fiber lay-up angle; i represents the i-th layer.

[0062] In an alternative solution, based on the approximate transformation formula of composite mechanics, the product characteristic parameters, the material parameters of each ply, and the fiber lay-up angles of each ply are transformed to obtain the effective shear modulus of each ply of the first product, including steps A1 - A2:

[0063] Step A1: Determine the stress-strain relationship of the ply.

[0064] Step A2: Based on the approximate transformation formula of composite mechanics, adjust the stress-strain relationship, product characteristic parameters, the material parameters of each ply, and the fiber lay-up angles of each ply to obtain the effective shear modulus of the ply.

[0065] Assume that the composite single layer is an orthotropic material, and its principal axis directions are the fiber direction 1 and the perpendicular direction 2. Under its constitutive relationship, the stress-strain relationship in the local coordinate system is:

[0066] ;

[0067] Among them:

[0068] E is the modulus along the fiber direction; E2 is the modulus in the matrix direction; G is the shear modulus; represents the Poisson's ratio of the fiber direction (direction 1) with respect to the perpendicular direction (direction 2); represents the strain in the 1 direction; represents the strain in the 2 direction; represents the shear strain in the 1 - 2 plane; represents the stress in the 1 direction; represents the stress in the 2 direction; represents the shear stress in the 1 - 2 plane.

[0069] When the ply is pulled at an angle θ, the deformation direction deviates from the material principal axis. It is equivalent to a shear response with uniform stiffness and equivalent isotropy.

[0070] According to the transformation rules of material stiffness in the rotating coordinate system, the following expressions can be obtained:

[0071] ;

[0072] By adjusting the above formula, the expression of the effective shear modulus can be obtained.

[0073] S140. Determine the torsional stiffness of the product based on the effective shear modulus of each ply of the first product; the torsional stiffness of the product is used to describe the ability of the first product to resist torsional deformation.

[0074] After obtaining the effective shear modulus of each ply of the first product, the effective shear moduli of each ply can be superimposed, and the torsional stiffness of the product can be determined according to the superimposed result.

[0075] In an alternative solution, determine the torsional stiffness of the product based on the effective shear modulus of each ply of the first product; the torsional stiffness of the product is used to describe the ability of the first product to resist torsional deformation, including:

[0076] Based on the thin-walled member torsion theory, superimpose the effective shear moduli of each ply to obtain the torsional stiffness of the product.

[0077] The thin-walled member torsion theory is a theory for analyzing the mechanical behavior of thin-walled members under torsion.

[0078] For a closed thin-walled cross-section structure, the torsional angle stiffness per unit length Kt is given by the following formula:

[0079] ;

[0080] where, Am represents the area enclosed by the closed neutral axis (the neutral axis is a closed curve formed by the centerlines of the wall thickness); s represents the coordinate of the wall length along the circumferential direction (path integral); t represents the wall thickness; G represents the shear modulus; T represents the torque; represents the fiber ply angle.

[0081] For the cross-section of the first product, it is often composed of multiple plies (each ply has different angles, thicknesses, and materials). Divide its thin-walled structure into at least one section according to the ply direction, and each section is numbered i, with a length of si, a thickness of ti, and an equivalent shear modulus of Geff,i.

[0082] Thus, the integral term can be transformed into the form of a discrete sum:

[0083] ;

[0084] Based on the thin-walled member torsion theory, by superimposing each layer, the overall torsional stiffness Kt can be approximately expressed as:

[0085] ;

[0086] Among them, the denominator part is the superposition effect of the equivalent shear deformation of each ply under torsional load.

[0087] According to the technical solution of the embodiment of the present invention, by determining the product characteristic parameters of the first product; determining the material parameters of each ply of the first product and the fiber ply angle of each ply; according to the product characteristic parameters, the material parameters of each ply, and the fiber ply angle of each ply, determining the effective shear modulus of each ply of the first product; and finally, based on the effective shear modulus of each ply of the first product, determining the torsional stiffness of the product, it is possible to accurately calculate the torsional stiffness of the fabric pultrusion composite product while ensuring the calculation efficiency, thereby avoiding the problems of low determination efficiency and high determination cost when determining the torsional stiffness of the fabric pultrusion composite product.

[0088] Embodiment Two

[0089] Figure 2 This is a flowchart for screening the first product according to the method for calculating the torsional stiffness of a fabric pultrusion composite product provided by the embodiment of the present invention. As Figure 2 shown, it may include the following steps:

[0090] S210. Determine at least one first product.

[0091] S220. Determine the torsional stiffness of each first product.

[0092] S230. Determine a second product according to the torsional stiffness of each first product; the torsional stiffness of the second product is within a preset torsional stiffness range.

[0093] For different application scenarios, the required torsional stiffness of the first product is different. Therefore, for different application scenarios, determine the preset torsional stiffness range. According to the torsional stiffness of each first product, determine the first product whose torsional stiffness is within the preset torsional stiffness range as the second product.

[0094] According to the technical solution of the embodiment of the present invention, by determining at least one first product; determining the torsional stiffness of each first product; determining a second product according to the torsional stiffness of each first product; and the torsional stiffness of the second product is within a preset torsional stiffness range, it is possible to achieve a preliminary screening of the fabric pultrusion composite product, thereby reducing the test time of the fabric pultrusion composite product required for this application scenario and reducing the waste of test resources.

[0095] Embodiment Three

[0096] Figure 3 This embodiment of the present invention provides a structural block diagram of a device for calculating the torsional stiffness of a fabric pultruded composite material product. This embodiment is applicable to the situation of calculating the torsional stiffness of the product. The device for calculating the torsional stiffness of the fabric pultruded composite material product can be implemented in the form of hardware and / or software, and the device for calculating the torsional stiffness of the fabric pultruded composite material product can be configured in an electronic device with data processing capabilities. As Figure 3 shown, the device for calculating the torsional stiffness of the fabric pultruded composite material product in this embodiment may include: a characteristic parameter determination module 310, a material parameter determination module 320, a shear modulus determination module 330, and a torsional stiffness determination module 340. Among them:

[0097] The characteristic parameter determination module 310 is used to determine the product characteristic parameters of the first product. The first product is made of a fiber-reinforced composite material manufactured by a pultrusion process. The product characteristic parameters include the cross-sectional area of the first product, the median line length of each ply, and the thickness of each ply;

[0098] The material parameter determination module 320 is used to determine the material parameters of each ply of the first product and the fiber ply angles of each ply; the material parameters are determined according to the ply material type; the material parameters include the fiber direction modulus and the equivalent shear modulus; the fiber ply angles are determined with the axial direction of the first product pultrusion as zero degrees;

[0099] The shear modulus determination module 330 is used to determine the effective shear modulus of each ply of the first product according to the product characteristic parameters, the material parameters of each ply, and the fiber ply angles of each ply;

[0100] The torsional stiffness determination module 340 is used to determine the product torsional stiffness based on the effective shear modulus of each ply of the first product; the product torsional stiffness is used to describe the ability of the first product to resist torsional deformation.

[0101] Based on the above embodiment, optionally, the shear modulus determination module 330 is specifically used for:

[0102] Based on the approximate conversion formula of composite material mechanics, convert the product characteristic parameters, the material parameters of each ply, and the fiber ply angles of each ply to obtain the effective shear modulus of each ply of the first product.

[0103] Based on the above embodiment, optionally, based on the approximate conversion formula of composite material mechanics, convert the product characteristic parameters, the material parameters of each ply, and the fiber ply angles of each ply to obtain the effective shear modulus of each ply of the first product, including:

[0104] Determine the stress-strain relationship of the ply;

[0105] Based on the approximate conversion formula of composite material mechanics, the stress-strain relationship, product characteristic parameters, material parameters of each ply, and fiber ply angles of each ply are adjusted to obtain the effective shear modulus of the ply.

[0106] Based on the above embodiments, optionally, the torsional stiffness determination module 340 is specifically configured to:

[0107] Based on the thin-walled bar torsion theory, the effective shear moduli of each ply are superimposed to obtain the product torsional stiffness.

[0108] Based on the above embodiments, optionally, the expression of the effective shear modulus is:

[0109] ;

[0110] Wherein, represents the effective shear modulus of the i-th ply; E represents the modulus in the fiber direction; G represents the equivalent shear modulus; θ represents the fiber ply angle; i represents the i-th ply.

[0111] Based on the above embodiments, optionally, the expression of the product torsional stiffness is:

[0112] ;

[0113] Wherein, Am is the cross-sectional area of the first product; is the median length of the i-th ply of the first product; is the thickness of the i-th ply of the first product; Kt is the product torsional stiffness; n is the total number of plies of the first product.

[0114] The fabric pultruded composite product torsional stiffness calculation device provided by the embodiments of the present invention can execute the fabric pultruded composite product torsional stiffness calculation method provided by any embodiment of the present invention, and has the corresponding functional modules and beneficial effects for executing the method.

[0115] Embodiment 4

[0116] Figure 4The schematic structural diagram of the electronic device 10 that can be used to implement the embodiments of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or claimed herein.

[0117] As Figure 4 shown, the electronic device 10 includes at least one processor 11 and a memory communicatively connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc. The memory stores a computer program executable by the at least one processor. The processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 into the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other via a bus 14. The input / output (I / O) interface 15 is also connected to the bus 14.

[0118] A plurality of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a magnetic disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0119] The processor 11 can be various general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as the method for calculating the torsional stiffness of a fabric pultrusion composite product.

[0120] In some embodiments, the method for calculating the torsional stiffness of a fabric pultrusion composite product can be implemented as a computer program tangibly embodied in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed onto the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the method for calculating the torsional stiffness of the fabric pultrusion composite product described above can be performed. Alternatively, in other embodiments, the processor 11 can be configured to perform the method for calculating the torsional stiffness of the fabric pultrusion composite product by any other suitable means (e.g., by means of firmware).

[0121] The various embodiments of the systems and techniques described above in this document can be implemented in digital electronic circuitry, integrated circuit systems, field programmable gate arrays (FPGA), application specific integrated circuits (ASIC), application specific standard products (ASSP), systems on a chip (SOC), complex programmable logic devices (CPLD), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special-purpose or general-purpose programmable processor that receives data and instructions from a storage system, at least one input device, and at least one output device, and transmits the data and instructions to the storage system, the at least one input device, and the at least one output device.

[0122] The computer programs for implementing the methods of the present invention can be written in any combination of one or more programming languages. These computer programs can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when the computer programs are executed by the processor, the functions / operations specified in the flowchart and / or block diagram are implemented. The computer programs can be executed entirely on the machine, partially on the machine, as a stand-alone software package partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0123] In the context of the present invention, a computer-readable storage medium can be a tangible medium that can contain or store a computer program for use by or in connection with an instruction execution system, apparatus, or device. The computer-readable storage medium can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. Alternatively, the computer-readable storage medium can be a machine-readable signal medium. More specific examples of the machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0124] For providing interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the electronic device. Other kinds of devices can also be used for providing interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and the input received from the user can be in any form (including acoustic input, voice input, or tactile input).

[0125] The systems and techniques described herein can be implemented in a computing system including backend components (e.g., as a data server), or a computing system including middleware components (e.g., an application server), or a computing system including frontend components (e.g., a user computer having a graphical user interface or a web browser through which the user can interact with an implementation of the systems and techniques described herein), or a computing system including any combination of such backend components, middleware components, or frontend components. The components of the system can be interconnected to each other by any form or medium of digital data communication (e.g., a communication network). Examples of the communication network include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0126] A computing system may include a client and a server. The client and the server are generally far from each other and usually interact via a communication network. The client-server relationship is created by computer programs running on respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or a cloud host, which is a host product in the cloud computing service system, solving the defects of difficult management and weak business scalability existing in traditional physical hosts and VPS services.

[0127] It should be understood that various forms of processes shown above can be used, with steps reordered, added or deleted. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and no limitation is made herein.

[0128] The above specific embodiments do not constitute a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for calculating the torsional stiffness of a fabric pultrusion composite material product, characterized in that, Including: Determine the product characteristic parameters of the first product, where the first product is made of fiber-reinforced composite material manufactured by pultrusion process, and the product characteristic parameters include the cross-sectional area of the first product, the median line length of each ply, and the thickness of each ply; Determine the material parameters of each ply of the first product and the fiber ply angle of each ply; the material parameters are determined according to the ply material model; the material parameters include the fiber-direction modulus and the equivalent shear modulus; the fiber ply angle is determined with the axial direction of the pultrusion of the first product as zero degree; According to the product characteristic parameters, the material parameters of each ply, and the fiber ply angle of each ply, determine the effective shear modulus of each ply of the first product; Based on the effective shear modulus of each ply of the first product, determine the product torsional stiffness; the product torsional stiffness is used to describe the ability of the first product to resist torsional deformation.

2. The method according to claim 1, wherein According to the product characteristic parameters, the material parameters of each ply, and the fiber ply angle of each ply, to determine the effective shear modulus of each ply of the first product, including: Based on the approximate conversion formula of composite material mechanics, convert the product characteristic parameters, the material parameters of each ply, and the fiber ply angle of each ply, to obtain the effective shear modulus of each ply of the first product.

3. The method according to claim 2, wherein Based on the approximate conversion formula of composite material mechanics, convert the product characteristic parameters, the material parameters of each ply, and the fiber ply angle of each ply, to obtain the effective shear modulus of each ply of the first product, including: Determine the stress-strain relationship of the ply; Based on the approximate conversion formula of composite material mechanics, adjust the stress-strain relationship, the product characteristic parameters, the material parameters of each ply, and the fiber ply angle of each ply, to obtain the effective shear modulus of the ply.

4. The method according to claim 1, characterized in that, Based on the effective shear modulus of each ply of the first product, determine the product torsional stiffness, including: Based on the thin-walled bar torsion theory, superimpose the effective shear moduli of each ply to obtain the product torsional stiffness.

5. The method according to claim 1, wherein The expression of the effective shear modulus is: ； Among them, represents the effective shear modulus of the i-th layer; E represents the fiber direction modulus; G represents the equivalent shear modulus; represents the fiber ply angle; i represents the i-th layer.

6. The method according to claim 5, characterized in that The expression of the product torsional stiffness is: ； where, Am is the cross-sectional area of the first product; is the center line length of the i-th ply of the first product; is the thickness of the i-th ply of the first product; Kt is the torsional stiffness of the product; n is the total number of plies of the first product.

7. A torsional stiffness calculation device for a fabric pultrusion composite material product, characterized in that, Including: A characteristic parameter determination module, configured to determine the product characteristic parameters of the first product, where the first product is made of fiber-reinforced composite material manufactured by pultrusion process, and the product characteristic parameters include the cross-sectional area of the first product, the median line length of each ply, and the thickness of each ply; A material parameter determination module, configured to determine the material parameters of each ply of the first product and the fiber ply angle of each ply; the material parameters are determined according to the ply material model; the material parameters include the fiber-direction modulus and the equivalent shear modulus; the fiber ply angle is determined with the axial direction of the pultrusion of the first product as zero degree; A shear modulus determination module, configured to determine the effective shear modulus of each ply of the first product according to the product characteristic parameters, the material parameters of each ply, and the fiber ply angle of each ply; A torsional stiffness determination module, configured to determine the product torsional stiffness based on the effective shear modulus of each ply of the first product; the product torsional stiffness is used to describe the ability of the first product to resist torsional deformation.

8. The device according to claim 7, characterized in that, The shear modulus determination module is specifically configured to: Based on the approximate conversion formula of composite material mechanics, convert the product characteristic parameters, material parameters of each ply, and fiber ply angles of each ply to obtain the effective shear modulus of each ply of the first product.

9. An electronic device, characterized in that, The electronic device includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein, the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to execute the method for calculating the torsional stiffness of the fabric pultruded composite material product according to any one of claims 1-6.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for implementing the method for calculating the torsional stiffness of the fabric pultruded composite material product according to any one of claims 1-6 when executed by a processor.

Images