Method for determining winding parameters of a pressure vessel, readable storage medium, electronic device

Abstract

A method for determining winding parameters of a pressure vessel, comprising: obtaining stress functions, strain functions and displacement functions of all plies based on a pressure vessel mechanics model and boundary conditions; obtaining a relationship between a failure factor, a radial deformation amount, a number of layers and a fiber angle of each layer based on the stress functions, the strain functions, the displacement functions of the plies and a strength failure criterion of the pressure vessel; and determining the fiber angle of each layer by an optimization algorithm based on the relationship between the failure factor, the radial deformation amount, the number of layers and the fiber angle of each layer. The present disclosure obtains one or more groups of optimal fiber angles through the optimization algorithm, and can obtain corresponding fiber angles under the minimum number of layers by adjusting the given number of layers while keeping the failure factor and the radial deformation amount meeting the requirements. The direction of carbon fibers is no longer limited by 0° / ±45° / 90° or other given angles, and the optimal plating scheme in theory can be found after breaking free from the constraints, which is more beneficial to the lightweight and strength and stiffness design of the pressure vessel.

Description

TECHNICAL FIELD

[0001] The present disclosure belongs to the technical field of pressure vessels, and particularly relates to a pressure vessel winding parameter determination method, a readable storage medium and an electronic device. BACKGROUND

[0002] At present, the design method of fiber ply of carbon fiber hydraulic cylinder is relatively scarce. The ply scheme designed by the traditional grid theory is based on the equal strength limit, that is, the stress of each layer is completely the same, and as long as one layer is damaged in strength, other layers will also be damaged, which is still deviated from the actual situation to some extent, but at the time when the composite material mechanics is not perfect.

[0003] The ply design method of traditional fiber material or composite material mostly adopts fixed angle 0° / ±45° / 90° or other given angle combination for ply combination optimization design, which will shield the optimal combination of other angles, which is not conducive to further weight reduction and strength, stiffness enhancement, etc. SUMMARY

[0004] In order to solve at least one of the above technical problems, the purpose of the present disclosure is to provide a pressure vessel winding parameter determination method for the current situation of stipulating ply angle during ply, taking ply angle as design variable, and variable interval being not limited to 0° / ±45° / 90° or other given angle combination.

[0005] In order to achieve the first purpose of the present disclosure, the technical solution adopted by the present disclosure is as follows:

[0006] A pressure vessel winding parameter determination method, the pressure vessel is made of fiber material or composite material ply winding, comprising:

[0007] Based on the stress function, the strain function and the displacement function of all plies are obtained based on the mechanical model and the boundary condition of the pressure vessel;

[0008] The relationship among the failure factor, the radial deformation amount, the number of layers and the fiber angle of each layer is composed based on the stress function, the strain function and the displacement function of the ply and the strength failure criterion of the pressure vessel;

[0009] The fiber angle of each layer is determined by an optimization algorithm based on the relationship among the failure factor, the radial deformation amount, the number of layers and the fiber angle of each layer.

[0010] Optionally, the fiber angle of each layer is determined by an optimization algorithm based on the relationship among the failure factor, the radial deformation amount, the number of layers and the fiber angle of each layer, comprising:

[0011] The algorithm steps are performed on the given initial number of layers;

[0012] Algorithm steps: The angle of each fiber layer is used as a variable. Through optimization algorithm, the angle of each fiber layer is determined with the failure factor and radial deformation as the optimization objectives to be minimized.

[0013] If the failure factor meets the strength requirements, the angle of each fiber layer is the fiber winding angle of the corresponding layer;

[0014] If the failure factor does not meet the strength requirements, adjust the number of layers and re-execute the algorithm steps.

[0015] Optionally, the initial number of layers is obtained by determining the total number of layers based on the structural parameters, load index, and material parameters of the pressure vessel, with the total number of layers serving as the preset number of layers.

[0016] Optionally, the step of determining that if the failure factor meets the strength requirement, the fiber angle of each layer is the fiber winding angle of the corresponding layer specifically includes:

[0017] If the failure factor meets the strength requirement, decrease the current layer number by one and re-execute the algorithm steps; continue until the algorithm factor no longer meets the strength requirement.

[0018] The current layer number plus one is the number of fiber winding layers in the pressure vessel.

[0019] Optionally, the fiber angle of each layer in the algorithm step corresponding to the number of fiber winding layers in the pressure vessel is the fiber winding angle of the corresponding layer.

[0020] Optionally, in the step of adjusting the number of layers and re-executing the algorithm if the failure factor does not meet the strength requirements,

[0021] If the failure factor does not meet the strength requirements, the number of layers before adjustment should be less than the number of layers the fiber needs to be wound.

[0022] Optionally, in the step of adjusting the number of layers and re-executing the algorithm if the failure factor does not meet the strength requirements,

[0023] If the failure factor meets the strength requirements, the number of layers before adjustment should be greater than or equal to the number of layers the fiber needs to be wound.

[0024] Optionally, the angle of each fiber layer can be in the range of -90° to 90°.

[0025] To achieve the second objective of this disclosure, the technical solution adopted in this disclosure is as follows:

[0026] A readable storage medium having executable instructions thereon, which, when executed, cause a computer to perform the steps of the method for determining the fiber winding parameters of a pressure vessel as described above.

[0027] To achieve the third objective of this disclosure, the technical solution adopted in this disclosure is as follows:

[0028] An electronic device, the device comprising a processor and a memory having stored therein computer program instructions adapted to be executed by the processor, the computer program instructions being executed by the processor to perform the steps of the method for determining the winding parameters of a pressure vessel as described above.

[0029] In the present disclosure, by combining the strength failure criterion of the pressure vessel with the stress function, the strain function and the displacement function, a function group of the failure factor, the radial deformation amount, the number of layers and the fiber angle of each layer can be formed, and in a given number of layers, the fiber angle of each layer is adjusted to minimize the failure factor and the radial deformation amount as the optimization target, and through an optimization algorithm, one or more groups of preferred fiber angles are obtained, and by adjusting the given number of layers, the failure factor and the radial deformation amount can also be obtained to meet the requirements, and the corresponding fiber angle under the minimum number of layers can also be obtained, the direction of the carbon fiber is no longer limited by 0° / ±45° / 90° or other given angles, and after being freed from the constraints, the optimal layering scheme in theory can be found, which is more advantageous for the lightweight and strength and stiffness design of the pressure vessel. BRIEF DESCRIPTION OF DRAWINGS

[0030] The accompanying drawings illustrate exemplary embodiments of the present disclosure, and together with the general description given above, and the detailed description given below, serve to explain the principles of the present disclosure. These drawings are included herewith and constitute a part of this specification.

[0031] Figure 1 is a method principle diagram of the method for determining the winding parameters of a pressure vessel in the present disclosure;

[0032] Figure 2 is a structural schematic diagram of a pressure vessel in the present disclosure;

[0033] Figure 3 is a method principle diagram of the method for determining the winding parameters of a pressure vessel in the preferred embodiment of the present disclosure;

[0034] Figure 4 is a structural block diagram of a readable storage medium in the present disclosure;

[0035] Figure 5 is a structural block diagram of an electronic device in the present disclosure. DETAILED DESCRIPTION

[0036] The present disclosure will be further described below in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related content, and not to limit the present disclosure. In addition, it should be noted that only parts related to the present disclosure are shown in the drawings for ease of description.

[0037] It should be noted that the embodiments in the present disclosure and the features in the embodiments can be combined with each other without conflict. The present disclosure will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0038] Referring to Figure 1 The present embodiment provides a method for determining winding parameters of a pressure vessel, the pressure vessel being wound by fiber material or composite material layers, the pressure vessel can be a cylinder, an oxygen cylinder, a hydrogen cylinder, or a reaction kettle, a sulfurization tank, a cooking pot, etc.; the fiber material can be carbon fiber material, nylon material, aromatic polyamide fiber material, polyimide fiber material, etc., and the composite material can be high-silicon glass fiber material, thermosetting resin-based composite material, etc.

[0039] The method for determining winding parameters of the pressure vessel comprises:

[0040] S101, based on a mechanical model of the pressure vessel and boundary conditions, obtaining stress functions, strain functions and displacement functions of all layers;

[0041] This embodiment takes a hydraulic cylinder wound by carbon fiber composite material as an example to analyze the mechanical model and boundary conditions, and other shapes of pressure vessels and composite materials, combined with the method of the present disclosure and the mechanical model and boundary conditions in the prior art, do not affect the implementation of the present disclosure;

[0042] 1) The mechanical model is analyzed as follows:

[0043] First, a cylindrical coordinate system of the carbon fiber laminate cylinder is established, as shown in Figure 1 z is the axial direction of the laminate cylinder, r is the radial direction of the laminate cylinder, and θ is the circumferential direction of the laminate cylinder.

[0044] The displacement relationship is established as follows:

[0045] u z = u z (r,z)

[0046] u θ = u θ (r,z)

[0047] u r = u r (r)

[0048] In the formula, u z is the axial deformation, u θ is the circumferential deformation, and u r is the radial deformation.

[0049] The strain-displacement relationship is established as follows:

[0050]

[0051]

[0052] In the formula, k is the layer number. Let be the axial strain of the k-th layer. For the circumferential strain of the k-th layer, For the radial strain of the k-th layer, The shear strain in the θr direction of the k-th layer is... The shear strain in the zr direction of the k-th layer is... Let θz be the shear strain in the k-th layer. Let be the axial deformation of the k-th layer. Let K be the radial deformation of the k-th layer. Let be the circumferential deformation of the k-th layer.

[0053] Establish the equilibrium equation:

[0054]

[0055]

[0056]

[0057] In the formula, For the radial stress of the k-th layer, For the circumferential stress of the k-th layer, For the axial stress of the kth layer, The shear stress in the θr direction of the kth layer is... Let be the shear stress in the zr direction of the k-th layer.

[0058] Establish the constitutive equation:

[0059] Because of the engineering constant E of carbon fiber composites x E y E z ,v xy ,v zx ,v zy G xx G yy G zz Since it can be measured experimentally, the positive axis stiffness coefficient C is calculated using engineering constants. ij Where i and j represent the rows and columns of the matrix, as shown in the following formula:

[0060]

[0061] Then calculate the off-axis stiffness coefficient in cylindrical coordinates. As shown in the following formula.

[0062]

[0063] In the formula, is the angle between the principal axis of the material along the fiber direction and the z-axis of the cylindrical coordinate system,

[0064]

[0065] The stress-strain relationship of the kth layer of anisotropic material is

[0066]

[0067] The mechanical model of the carbon fiber hydraulic cylinder fiber layer is completed.

[0068] 2) The boundary condition analysis is as follows:

[0069] The innermost radial stress of the layer is:

[0070]

[0071] In the formula, p is the inner cavity pressure, R I is the inner layer radius of the layer.

[0072] The outermost radial stress of the layer is:

[0073]

[0074] In the formula, R O is the outer layer radius of the layer.

[0075] The axial force balance condition is:

[0076]

[0077] The torque balance condition is:

[0078]

[0079] The force traction and displacement continuity condition is:

[0080]

[0081] In the formula, r k is the outer layer radius of the kth layer.

[0082] So far, the boundary condition example is completed.

[0083] 3) The mechanical model and the boundary condition are combined, and the stress, strain, displacement, etc. of each place of the layer can be obtained to provide the objective function for the next step optimization.

[0084] The deformation function of each place of the layer is:

[0085]

[0086]

[0087]

[0088] The stress function of each place of the ply is:

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095] The stress function of each place of the ply is:

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102] In the formula, and are process parameters when solving the equation;

[0103] S102, based on the stress function, strain function, displacement function of the ply, the strength failure criterion of the pressure vessel is combined to form a failure factor, the relationship between the radial deformation amount, the number of layers and the fiber angle of each layer;

[0104] Wherein, the strength failure criterion can be Tsai-Wu strength criterion, Tsai-Hill strength criterion, etc., to give the strength failure factor analytical expression of the weakest position in the carbon fiber reinforced layer;

[0105] Taking Tsai-Wu strength criterion as an example:

[0106]

[0107] In the formula, X t is the tensile strength of the unidirectional plate fiber direction, Y tis the tensile strength of the unidirectional plate in the vertical fiber direction, S is the in-plane shear strength of the unidirectional plate, THFC is a failure factor of the Tsai-Wu strength criterion; σ1 is a fiber longitudinal stress, σ2 is a fiber transverse stress, τ 12 is the limiting in-plane shear stress, which can be obtained according to σ z , σ θ , τ zθ in the previous step.

[0108] The strength criterion can be combined with the stress function, the strain function and the displacement function in the previous step to form the relationship between the failure factor THFC, the radial deformation amount u r , the number of layers n and the fiber angle θ1, θ2Lθ n of each layer. The smaller the radial deformation amount u r , the greater the stiffness of the pressure vessel.

[0109] S103, based on the relationship between the failure factor THFC, the radial deformation amount u r , the number of layers n and the fiber angle θ1, θ2Lθ n of each layer, the fiber angle of each layer is determined by an optimization algorithm.

[0110] The optimization algorithm can be a particle swarm optimization algorithm or a genetic algorithm. Since the number of design variables n is too large and the relationship between the design variables and the design target is very complex, a heuristic algorithm is preferably used.

[0111] If the failure factor THFC does not meet the strength requirement, the number of previous layers is adjusted to be less than the number of layers in which the fiber needs to be wound.

[0112] If the failure factor THFC meets the strength requirement, the number of previous layers is adjusted to be greater than or equal to the number of layers in which the fiber needs to be wound.

[0113] In the optimization algorithm, the fiber angles θ1, θ2Lθ n of the n layers are used as design variables, and the variable interval is -90° to 90°. The optimization targets are selected as follows:

[0114] f1 = min (u r )

[0115] f2 = min (THFC)

[0116] Where f1 is the minimum radial deformation amount, which is constrained by the radial stiffness of the hydraulic cylinder u r , and should not be too large, i.e. is determined by the hydraulic cylinder, and f2 is the minimum failure factor, which is less than the preset value when the strength of the reinforcing layer is qualified. In this embodiment, the preset value is generally set to 1. The number of particles and the number of iterations in the optimization algorithm are given by the designer according to the actual situation.

[0117] By optimizing the algorithm, the fiber angles θ1, θ2, and Lθ of each layer are determined. n .

[0118] In another embodiment, the failure factor THFC and the radial deformation amount u r The number of layers n and the fiber angles θ1, θ2, and Lθ in each layer n The angle of each fiber layer is determined through an optimization algorithm, including:

[0119] Execute the algorithm steps on a given initial layer number n;

[0120] Algorithm steps: For each fiber layer, the angles θ1, θ2, and Lθ are... n As variables, the angle of each fiber layer is determined by using an optimization algorithm to minimize the failure factor THFC and radial deformation.

[0121] If the failure factor THFC meets the strength requirements, the fiber angles θ1, θ2Lθ of each layer are... n That is, the fiber winding angle of the corresponding layer;

[0122] If the failure factor THFC does not meet the strength requirements, adjust the number of layers n and re-execute the algorithm steps.

[0123] This method allows us to adjust the number of layers n until the strength requirements are met when the initial number of layers n does not meet the requirements.

[0124] In another embodiment, the initial number of layers n is obtained by determining the total number of layers based on the structural parameters, load index, and material parameters of the pressure vessel, and the total number of layers is used as the preset number of layers.

[0125] The total number of layers is expressed as follows:

[0126]

[0127] In the formula, N is the total number of carbon fiber layers required, p is the internal pressure on the hydraulic cylinder, R is the radius of the inner wall of the hydraulic cylinder, σ is the longitudinal allowable stress value of the unidirectional carbon fiber material, and a is the thickness of each layer of carbon fiber material.

[0128] In another embodiment, combined Figure 3 As shown, in order to obtain the minimum number of layers that meet the strength requirements, if the failure factor THFC meets the strength requirements, the fiber angles θ1, θ2, and Lθ of each layer are... n The steps for determining the fiber winding angle of the corresponding layer specifically include:

[0129] If the failure factor THFC meets the strength requirement, the algorithm steps are re-executed after the current layer number n = n-1; until the algorithm factor THFC no longer meets the strength requirement, then the previous layer number is the minimum number of layers that can guarantee the strength.

[0130] i.e. the current layer number n = n + 1 is the fiber winding layer number of the pressure vessel.

[0131] In fact, the design requirements are met between the layer number N and the minimum layer number; the designer can integrate the weight (total layer number n), the strength (THFC), the stiffness (related value u r ), select appropriate decision-making techniques to select appropriate layering schemes.

[0132] In another preferred embodiment, the layering scheme that meets the design requirements is also checked from a plurality of groups in finite element analysis software such as ANSYS, ABAQUS, etc., and finally the optimal layering scheme obtained by the design method is obtained.

[0133] Figure 3 The readable storage medium 1 provided by the exemplary embodiment of the present disclosure is exemplified, and the executable instructions 2 are stored thereon, when the executable instructions 2 are executed, the computer executes the steps of the pulse noise processing method described above. The computer readable storage medium 1 can be: electronic medium, magnetic medium, optical medium, electromagnetic medium, infrared medium or semiconductor system or propagation medium. The computer readable storage medium 1 can also include a semiconductor or solid state memory, a magnetic tape, a removable computer disk, a random access memory (RAM), a read-only memory (ROM), a hard disk and an optical disk. The optical disk can include a compact disk-read only memory (CD-ROM), a compact disk-read / write (CD-RW) and a DVD.

[0134] Referring to Figure 4An electronic device provided by an example embodiment of the present disclosure includes a processor 3 and a memory 4, the memory storing computer program instructions suitable for execution by the processor, the computer program instructions being executed by the processor to perform the steps of the impulse noise processing method described above. The processor 3 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, for example, the processor 3 uses a multi-core digital signal processor 3713 with multiple 500 MHz DSP cores built-in and uses an interrupt-based approach to control time precision; the memory 4 can include a random access memory (RAM) and can also include a non-volatile memory (NVM), such as at least one disk memory. The memory 4 can also be an internal memory of the random access memory (RAM) type, and the processor 3 and the memory 4 can be integrated into one or more independent circuits or hardware, such as an application-specific integrated circuit (ASIC). It should be noted that the computer program in the memory 4 described above can be implemented in the form of a software functional unit and sold or used as a separate product, which can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application, in essence, or the part that contributes to the prior art, or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes a number of instructions for causing a computer device (which can be a personal computer, an electronic device, or a network device, etc.) to execute all or part of the steps of the embodiments of the present application.

[0135] In the description of the specification, the description of the terms "one embodiment / way", "some embodiments / ways", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment / way or example are included in at least one embodiment / way or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment / way or example. Also, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments / ways or examples. In addition, the person skilled in the art can combine and combine the different embodiments / ways or examples described in the specification and the features of the different embodiments / ways or examples, without contradiction.

[0136] In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0137] The person skilled in the art should understand that the above-mentioned embodiments are only for the purpose of clearly illustrating the present disclosure, and are not intended to limit the scope of the present disclosure. Based on the above disclosure, other changes or modifications can also be made by those skilled in the art, and these changes or modifications are still within the scope of the present disclosure.

Claims

1. A method for determining the winding parameters of a pressure vessel, characterized in that, Pressure vessels are constructed by layup and winding of fiber or composite materials, including: Based on the pressure vessel mechanical model and boundary conditions, the stress function, strain function and displacement function of all plies are obtained; The failure factor, radial deformation, and relationship between the number of layers and the fiber angle of each layer are composed of stress function, strain function, and displacement function of the ply, combined with the strength failure criterion of pressure vessels. Based on the relationship between failure factor, radial deformation, number of layers and fiber angle of each layer, the fiber angle of each layer is determined by an optimization algorithm. The determination of the fiber angle of each layer based on the relationship between failure factor, radial deformation, number of layers, and fiber angle of each layer through an optimization algorithm includes: Perform the algorithm steps at a given initial number of layers; Algorithm steps: The angle of each fiber layer is used as a variable. Through optimization algorithm, the angle of each fiber layer is determined with the failure factor and radial deformation as the optimization objectives to be minimized. If the failure factor meets the strength requirements, the angle of each fiber layer is the fiber winding angle of the corresponding layer; If the failure factor does not meet the strength requirements, adjust the number of layers and re-execute the algorithm steps; The initial number of layers is obtained by the following method: the total number of layers is determined based on the structural parameters, load index, and material parameters of the pressure vessel, and the total number of layers is used as the preset number of layers; The step of determining that if the failure factor meets the strength requirement, the angle of each fiber layer is the fiber winding angle of the corresponding layer specifically includes: If the failure factor meets the strength requirement, decrease the current layer number by one and re-execute the algorithm steps; continue until the algorithm factor no longer meets the strength requirement. The current layer number plus one is the number of fiber winding layers in the pressure vessel; The fiber angle of each layer in the algorithm steps corresponding to the number of fiber winding layers in a pressure vessel is the fiber winding angle of the corresponding layer.

2. The method for determining the winding parameters of a pressure vessel as described in claim 1, characterized in that: In the step of adjusting the number of layers and re-executing the algorithm if the failure factor does not meet the strength requirements,... If the failure factor does not meet the strength requirements, the number of layers before adjustment should be less than the number of layers the fiber needs to be wound.

3. The method for determining the winding parameters of a pressure vessel as described in claim 1, characterized in that, In the step of adjusting the number of layers and re-executing the algorithm if the failure factor does not meet the strength requirements,... If the failure factor meets the strength requirements, the number of layers before adjustment should be greater than or equal to the number of layers the fiber needs to be wound.

4. The method for determining the winding parameters of a pressure vessel as described in claim 1, characterized in that: The angle of each fiber layer ranges from -90° to 90°.

5. A readable storage medium, characterized in that, It has executable instructions that, when executed, cause a computer to perform the steps of the method for determining the winding parameters of a pressure vessel as described in any one of claims 1-3.

6. An electronic device, characterized in that, The device includes a processor and a memory, the memory storing computer program instructions suitable for execution by the processor, the computer program instructions being executed by the processor to perform the steps of the method for determining the winding parameters of a pressure vessel as described in any one of claims 1-3.

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