Damping loss factor detection method for conveying pipeline

Abstract

The invention provides a damping loss factor detection method for a conveying pipeline, and relates to the technical field of material mechanics, and the method comprises the steps: obtaining the measured motion response amount and strain response amount of a target cylindrical shell based on preset vibration excitation and load applied to the target cylindrical shell; calculating target kinetic energy of the target cylindrical shell based on the motion response quantity, and calculating target strain energy of the target cylindrical shell based on the strain response quantity; according to the target kinetic energy and the target strain energy, the Lagrange quantity is calculated; according to the target kinetic energy and the specific damping capacity of the target cylindrical shell, the total energy consumption dissipated by the target cylindrical shell through the form is calculated; according to the Lagrange quantity, the total energy consumption and the target strain energy, damping loss factors of the target cylindrical shell in all directions are calculated; and according to a modal strain energy method, based on the damping loss factors in all directions, calculating to obtain a structural damping loss factor of the target cylindrical shell. The calculation accuracy of the damping loss factor of the cylindrical shell material can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of material mechanics, and in particular to a method for detecting a damping loss factor of a transmission pipeline. Background Art

[0002] The damping loss factor is an important parameter to measure the energy dissipation capacity of a material or structure during vibration. During vibration or fluctuation, part of the mechanical energy will be converted into heat energy due to internal friction, air resistance, internal friction within the material, etc., thereby gradually attenuating the vibration amplitude. The damping loss factor is used to quantify this energy dissipation. The damping loss factor can be understood as the ability of a system to "slow down" vibration. The larger the value of this factor, the faster the system vibration decays and the more energy is lost; the smaller the value, the longer the vibration will last and the less energy will be lost.

[0003] In engineering applications, the damping loss factor is an important parameter for the design and analysis of vibration control and noise control. By adjusting the damping characteristics of the structure, unnecessary vibration and noise can be effectively reduced, thereby improving the performance and life of the structure. Traditional structural damping analysis methods usually perform analysis based on the assumption that the material is isotropic, assuming that the damping characteristics of the material are the same in all directions. This method may be applicable to some simple structures or homogeneous materials, but for complex structures, especially multi-layer composite materials or orthotropic materials, this assumption will lead to inaccurate analysis results. Therefore, a method is needed to improve the accuracy of the calculation of the damping loss factor of cylindrical shell materials. Summary of the invention

[0004] The present application provides a method for detecting the damping loss factor of a transmission pipeline, which can improve the accuracy of calculating the damping loss factor of a cylindrical shell material.

[0005] In a first aspect of the present application, a method for detecting a damping loss factor of a transmission pipeline is provided, the method comprising:

[0006] Based on a preset vibration excitation applied to a target cylindrical shell, a measured motion response of the target cylindrical shell is obtained, and based on a load applied to the target cylindrical shell, a measured strain response of the target cylindrical shell is obtained;

[0007] Calculating a target kinetic energy of the target cylindrical shell based on the motion response amount, and calculating a target strain energy of the target cylindrical shell based on the strain response amount;

[0008] Calculating a Lagrangian according to the target kinetic energy and the target strain energy;

[0009] According to the target kinetic energy and the specific damping capacity of the target cylindrical shell, calculating the total energy dissipated by the target cylindrical shell in the form of a kinetic energy;

[0010] Calculating the damping loss factor of the target cylindrical shell in each direction according to the Lagrangian, the total energy consumption and the target strain energy;

[0011] According to the modal strain energy method, based on the damping loss factors in various directions, the structural damping loss factor of the target cylindrical shell is calculated.

[0012] Optionally, the damping loss factor of the target cylindrical shell in each direction is calculated according to the Lagrangian, the total energy consumption and the target strain energy, and is calculated by the following formula:

[0013]

[0014] Among them, η 11 , η 12 , η 22 are the damping loss factors of the target cylindrical shell in each direction, ΔU is the total energy consumption, U max is the target strain energy.

[0015] Optionally, after calculating the damping loss factor of the target cylindrical shell in each direction according to the Lagrangian, the total energy consumption and the target strain energy, the method further includes:

[0016] According to the motion response, the stress component of the target cylindrical shell is analyzed, and then the stress vector of the target cylindrical shell is calculated, which is specifically calculated by the following formula:

[0017] {σ} T ={σ x , σ θ , σ xθ}

[0018] Among them, {σ} T is the stress matrix, σ x is the normal stress in the x direction, σ θ is the normal stress in the θ direction, σ xθ for x-θ Shear stress on a plane;

[0019] According to the strain response, the strain vector of the target cylindrical shell is analyzed and specifically calculated by the following formula:

[0020] {e} T ={e x , e θ , e xθ}

[0021] Among them, {e} T is the strain matrix, ex is the normal strain in the x direction, e θ is the normal strain in the θ direction, e xθ for x-θ Shear strain on a plane;

[0022] The relationship between the stress vector and the strain vector is as follows:

[0023] {σ}=[Q] T {e}

[0024] Where, {σ} is the stress vector, {e} is the strain vector, [Q] T is the transformed reduced stiffness matrix;

[0025] The reduced stiffness matrix after the conversion is expressed as follows:

[0026]

[0027] Among them, [Q] T is the reduced stiffness matrix after transformation, Q ij is the reduced stiffness, i, j∈(1,2,6).

[0028] Optionally, calculating the damping loss factor of the target cylindrical shell in each direction according to the Lagrangian, the total energy consumption and the target strain energy specifically includes:

[0029] The total energy consumption is calculated according to the stress vector and the strain vector, specifically by the following formula:

[0030]

[0031] Wherein, ΔU is the total energy consumption, L is the Lagrangian, h is the length of the target cylindrical shell, {e} T is the strain matrix, {σ} T is the stress matrix, η 11 , η 12 , η 22 are the damping loss factors of the target cylindrical shell in each direction respectively.

[0032] Optionally, the calculating of the structural damping loss factor of the target cylindrical shell based on the damping loss factor in each direction according to the modal strain energy method specifically includes:

[0033] The structural damping loss factor is calculated based on the following formula:

[0034]

[0035] Wherein, η is the structural damping loss factor, ΔU is the total energy consumption, and U max is the target strain energy.

[0036] Optionally, the Lagrangian is calculated according to the target kinetic energy and the target strain energy, specifically by the following formula:

[0037] L=T max -U max

[0038] Wherein, L is the Lagrangian, T max is the target kinetic energy, U max is the target strain energy;

[0039] Obtaining the length and density of the target cylindrical shell;

[0040] The strain energy of the target cylindrical shell is calculated based on the length of the target cylindrical shell, specifically by the following formula:

[0041]

[0042] Where U is the strain energy, h is the length of the target cylindrical shell, {e} T is the strain matrix, {σ} T is the stress matrix;

[0043] Based on the length and density of the target cylindrical shell, the kinetic energy of the target cylindrical shell is calculated, specifically by the following formula:

[0044]

[0045] Wherein, T is the kinetic energy, h is the length of the target cylindrical shell, ρ is the density of the target cylindrical shell, and u0, v0, and w0 are the displacement components of a point on the midplane (ie, z=0) along the (x, θ, z) coordinate direction, respectively.

[0046] Optionally, the calculating the target kinetic energy of the target cylindrical shell based on the motion response amount, and the calculating the target strain energy of the target cylindrical shell based on the strain response amount, specifically includes:

[0047] At both ends of the target cylindrical shell (x=0, h), the assumed displacement field expression is as follows:

[0048]

[0049] Where u0, v0, w0 are the displacement components of a point on the midplane (i.e. z = 0) along the (x, θ, z) coordinate direction, A, B and C are the magnitudes of the displacement amplitudes, m is the axial wave number, n is the circumferential wave number, and ω is the vibration angular frequency;

[0050] Based on the principle of minimum potential energy, the Lagrangian equation for the energy function is constructed as follows:

[0051]

[0052] Among them, A, B and C are the magnitudes of displacement amplitude, T max is the target kinetic energy, U max is the target strain energy;

[0053] Based on the Lagrange equation, the control characteristic equation is obtained as follows:

[0054]

[0055] Among them, C ij are the coefficients in the equation, A, B and C are the magnitudes of the displacement amplitudes;

[0056] Solving for the roots by imposing the condition of a non-trivial solution on the governing characteristic equation yields the following determinant:

[0057] α0ω 6 +α1ω 4 +α2ω 2 +α3=0

[0058] Among them, α i (i=0, 1, 2, 3) is a constant, ω is the vibration angular frequency;

[0059] Solving the vibration angular frequency according to the determinant;

[0060] The vibration angular frequency is substituted into the displacement field expression to calculate the target strain energy and the target kinetic energy.

[0061] In a second aspect of the present application, a damping loss factor detection device for a transmission pipeline is provided, the device comprising an acquisition module and a processing module, wherein:

[0062] The acquisition module is used to acquire the measured motion response of the target cylindrical shell based on the preset vibration excitation applied to the target cylindrical shell, and to acquire the measured strain response of the target cylindrical shell based on the load applied to the target cylindrical shell;

[0063] The processing module is used to calculate the target kinetic energy of the target cylindrical shell based on the motion response amount, and calculate the target strain energy of the target cylindrical shell based on the strain response amount;

[0064] The processing module is used to calculate the Lagrangian according to the target kinetic energy and the target strain energy;

[0065] The processing module is used to calculate the total energy dissipated by the target cylindrical shell in the form of a kinetic energy according to the target kinetic energy and the specific damping capacity of the target cylindrical shell;

[0066] The processing module is used to calculate the damping loss factor of the target cylindrical shell in each direction according to the Lagrangian, the total energy consumption and the target strain energy;

[0067] The processing module is used to calculate the structural damping loss factor of the target cylindrical shell based on the damping loss factors in various directions according to the modal strain energy method.

[0068] In the third aspect of the present application, an electronic device is provided, including a processor, a memory, a user interface and a network interface, the memory is used to store instructions, the user interface and the network interface are both used to communicate with other devices, and the processor is used to execute the instructions stored in the memory so that the electronic device executes any one of the methods described above.

[0069] In a fourth aspect of the present application, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores instructions, and when the instructions are executed, any of the methods described above is executed.

[0070] In summary, one or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0071] This application can improve the accuracy of the calculation of the damping loss factor of cylindrical shell materials by combining measured data with an accurate energy calculation method. The principle is to obtain the motion and strain response of the cylindrical shell based on the preset vibration excitation, thereby calculating the target kinetic energy and target strain energy respectively, and then using the Lagrangian to calculate the total energy consumption of the system. In addition, combined with the specific damping capacity, the energy dissipation is converted into the damping loss factor in each direction, thereby avoiding the error of the isotropic assumption in traditional analysis. This process more accurately reflects the true damping characteristics of the material in different directions through the modal strain energy method, thereby greatly improving the accuracy of the damping loss factor calculation.

[0072] By introducing the anisotropic properties of materials and combining them with accurate energy analysis methods, a detailed calculation of the damping loss factor in all directions of the cylindrical shell is achieved. The effects of stress and strain in different directions are taken into account, avoiding the errors caused by the traditional method of ignoring the anisotropic properties of materials. By calculating the structural damping loss factor based on the modal strain energy method, the actual damping behavior of the target cylindrical shell can be described more accurately, thereby improving the accuracy and reliability of the damping calculation, which is conducive to more accurate structural design and performance prediction.

[0073] By accurately constructing the control equation based on the Lagrangian and combining the vibration characteristics of the cylindrical shell with the stress-strain relationship, the kinetic energy and strain energy of the target cylindrical shell are accurately calculated. By solving the control characteristic equation, the vibration angular frequency is obtained, and the kinetic energy and strain energy of the structure are further calculated. This process utilizes the principle of minimum potential energy and effectively considers the influence of the energy distribution of the structure during vibration, thereby improving the accuracy of the calculation results. This method can more accurately predict the dynamic performance of the structure, help optimize the design, and improve the structural stability and seismic performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Figure 1 It is a flow chart of a method for detecting damping loss factor of a transmission pipeline disclosed in an embodiment of the present application;

[0075] Figure 2 is a schematic structural diagram of a target cylindrical shell disclosed in an embodiment of the present application;

[0076] Figure 3 It is a schematic diagram of an angle difference disclosed in an embodiment of the present application;

[0077] Figure 4 It is a module schematic diagram of a damping loss factor detection device for a transmission pipeline disclosed in an embodiment of the present application;

[0078] Figure 5 It is a structural schematic diagram of an electronic device disclosed in an embodiment of the present application.

[0079] Explanation of the reference numerals: 401, acquisition module; 402, processing module; 501, processor; 502, communication bus; 503, user interface; 504, network interface; 505, memory. DETAILED DESCRIPTION

[0080] In order to enable technicians in this field to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments.

[0081] In the description of the embodiments of the present application, words such as "for example" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "for example" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "for example" or "for example" is intended to present related concepts in a specific way.

[0082] In the description of the embodiments of the present application, the meaning of the term "multiple" refers to two or more. For example, multiple systems refer to two or more systems, and multiple screen terminals refer to two or more screen terminals. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. The terms "include", "comprise", "have" and their variations all mean "including but not limited to", unless otherwise specifically emphasized.

[0083] This embodiment discloses a method for detecting the damping loss factor of a transmission pipeline. Figure 1 , including the following steps S110-S150:

[0084] S110, based on a preset vibration excitation applied to the target cylindrical shell, obtaining a measured motion response of the target cylindrical shell, and based on a load applied to the target cylindrical shell, obtaining a measured strain response of the target cylindrical shell.

[0085] The target cylindrical shell in this application is a laminated cylindrical shell, which is a water delivery pipeline for submarines, referring to Figure 2 , is a cylindrical structure composed of multiple laminated composite materials, which is composed of steel, polyurethane and composite materials from the inside to the outside. It is mainly used as a water pipe for submarines. Because this structure has a high strength, stiffness and weight ratio, and its performance can be optimized by rationally designing the material properties of each layer. The laminated cylindrical shell is composed of multiple composite layers, and each layer usually has different fiber directions, thicknesses and material properties. Each layer has different mechanical properties, and the overall structure formed by the stacking of these layers has complex anisotropic mechanical properties.

[0086] Among them, the target kinetic energy is the maximum kinetic energy of the target cylindrical shell. Kinetic energy is the energy of an object due to its motion. For a vibrating system (such as a cylindrical shell), the kinetic energy is related to its vibration speed and mass distribution. The maximum kinetic energy represents the maximum value of the system kinetic energy during the entire vibration process. Usually, this occurs when the structural vibration speed is the maximum, that is, when the vibration displacement reaches zero.

[0087] The target strain energy is the maximum strain energy of the target cylindrical shell. Strain energy is the elastic energy stored in the structure due to deformation. For an elastic body (such as a cylindrical shell), when an external force causes it to deform, stress and strain will be generated inside the material, thereby storing energy. This stored energy is strain energy. The maximum strain energy represents the strain energy when the system is deformed to the maximum during the entire vibration cycle, which usually occurs when the system displacement reaches the maximum and the velocity is zero.

[0088] In order to calculate the target kinetic energy of the target cylindrical shell, it is necessary to apply vibration excitation to the target cylindrical shell and select an appropriate excitation method, such as frequency sweep, impact test or white noise excitation, to stimulate the vibration response of the cylindrical shell. Accelerometers, displacement sensors or strain sensors are installed at different positions of the cylindrical shell to monitor the vibration response in real time. The time domain data under the excitation, such as acceleration or displacement signals, are recorded. These signals reflect the dynamic behavior of the structure at different frequencies. The time domain data is then converted to the frequency domain using the fast Fourier transform (FFT) to identify the main vibration modes and frequencies, extract the displacement and acceleration data corresponding to the main vibration frequencies, and use them to calculate the kinetic energy of the target cylindrical shell.

[0089] In order to calculate the target strain energy of the target cylindrical shell, a mechanical loading device is used to apply a known static or dynamic load (such as concentrated force, distributed force, etc.) to deform the cylindrical shell. During the loading process, strain data is measured using strain gauges or digital image correlation technology (DIC). Strain gauges are installed at key locations on the cylindrical shell to record strain data under different load conditions. Digital image correlation technology calculates strain by taking images before and after deformation. The measured strain data is combined with the geometric characteristics of the cylindrical shell to calculate the strain energy.

[0090] S120, calculating a target kinetic energy of the target cylindrical shell based on the motion response amount, and calculating a target strain energy of the target cylindrical shell based on the strain response amount.

[0091] For the target cylindrical shell, the strain energy expression is as follows:

[0092]

[0093] Where U is the strain energy, h is the length of the target cylindrical shell, {e} T is the strain matrix, {σ} T is the stress matrix. The strain matrix and stress matrix will be explained in the following content.

[0094] The kinetic energy expression of the target cylindrical shell is as follows:

[0095]

[0096] Wherein, T is kinetic energy, h is the length of the target cylindrical shell, ρ is the density of the target cylindrical shell, and u0, v0, and w0 are the displacement components of a point on the midplane (i.e., z=0) along the (x, θ, z) coordinate direction, respectively.

[0097] Classical shell theory is an extension of classical laminate theory. The Kirchhoff hypothesis in classical laminate theory is also applicable to classical shell theory. Assumptions: (1) The straight line perpendicular to the mid-plane before deformation (i.e., the transverse normal) remains a straight line after deformation; (2) The transverse normal does not elongate (i.e., it is inextensible); (3) The transverse normal rotates so that it remains perpendicular to the mid-plane after deformation; (4) The layers are perfectly bonded together and the thickness of each layer is uniform; (5) The transverse shear stress on the top and bottom surfaces of the shell is zero.

[0098] Kirchhoff hypothesis requires that the displacement (u, v, w) satisfies the following conditions:

[0099]

[0100] w(x,θ,z,t)=w0(x,θ,t)

[0101] Where u0, v0, and w0 are the displacement components of a point on the midplane (i.e., z = 0) along the (x, θ, z) coordinate direction. The displacement field means that the straight line perpendicular to the x-θ plane before deformation remains perpendicular to the midplane after deformation. The Kirchhoff hypothesis is equivalent to ignoring the transverse shear and transverse normal effects, that is, the deformation is entirely caused by bending and in-plane stretching.

[0102] Then, at both ends of the target cylindrical shell (x = 0, h), the assumed displacement field expression is as follows:

[0103]

[0104] Among them, u0, v0, w0 are the displacement components of a point on the midplane (i.e. z=0) along the (x, θ, z) coordinate direction, respectively. A, B and C are the magnitudes of the displacement amplitudes. The displacement amplitude determines the intensity or amplitude of the vibration. Different vibration modes may have different displacement amplitudes. m is the axial wave number, which determines the number of vibration modes along the x direction and describes the periodic characteristics of the vibration, that is, how many wave cycles there are in the length direction of the shell. n is the circumferential wave number, which determines the number of vibration modes along the θ direction. Different n values ​​will lead to different vibration modes, such as symmetric modes and antisymmetric modes. ω is the angular frequency of vibration, which describes the frequency characteristics of the cylindrical shell in free vibration. It determines the vibration speed or periodicity of the system and is an important indicator of the natural frequency of the structure.

[0105] S130, calculating the Lagrangian according to the target kinetic energy and the target strain energy.

[0106] In analytical mechanics, the Lagrangian of a dynamic system, also known as the Lagrangian function, or "Lagrangian" for short, is a function that describes the dynamic state of the entire physical system. For general classical physical systems, it is usually defined as kinetic energy minus potential energy. For the target cylindrical shell, the Rayleigh-Ritz method is used to calculate the natural frequency of the cylindrical shell. This is a variational method that derives the system's equations of motion and natural frequencies by constructing the Lagrangian equations and combining them with the principle of minimum potential energy. First, the Rayleigh method constructs an energy functional, the Lagrangian, based on the relationship between the maximum values ​​of kinetic energy T and strain energy U:

[0107] L=T max -U max

[0108] Where L is the Lagrangian, T max is the target kinetic energy, U max is the target strain energy.

[0109] Based on the principle of minimum potential energy, the Lagrangian equation for the energy function is constructed as follows:

[0110]

[0111] Among them, A, B and C are the magnitudes of displacement amplitude, T max is the target kinetic energy, U max is the target strain energy.

[0112] The principle of minimum potential energy is an important principle of the calculus of variations in mechanics. It states that for a static equilibrium system, the total potential energy of the system is at its minimum value in the equilibrium state. This principle is widely used in structural analysis and optimization design, especially in solid mechanics, elasticity mechanics and structural mechanics, to solve problems such as deformation, displacement and stress distribution of structures. In elasticity mechanics, the total potential energy (also called the potential energy functional) usually consists of two parts: strain energy (representing the energy inside the system) and work done by external forces.

[0113] In dynamic problems, the Lagrange equation introduces the difference between kinetic energy T and potential energy U, the so-called Lagrange quantity L, which is expressed as: L = TU. For a vibrating system, using the principle of minimum potential energy, the Lagrange equation can be constructed in the form of:

[0114]

[0115] Here A, B, and C are the displacement amplitudes of the system. By solving these equations, the equilibrium position or vibration mode of the system can be obtained. In this case, the principle of minimum potential energy is actually to find the stable state of the system under given conditions, that is, to find the conditions that make the Lagrangian L reach the stationary value (minimum or maximum).

[0116] According to the Lagrange equation, kinetic energy expression and strain energy expression, the control characteristic equation is as follows:

[0117]

[0118] Among them, C ij are the coefficients in the equation, and A, B, and C are the magnitudes of the displacement amplitudes. The roots are solved by imposing nontrivial solution conditions on the governing characteristic equation, which is the determinant [C ij ] is equal to zero, we can get the following determinant:

[0119] α0ω 6 +α1ω 4 +α2ω 2 +α3=0

[0120] Among them, α i (i=0, 1, 2, 3) is a constant, and ω is the vibration angular frequency. By using the eigenvalue and eigenvector functions of matlab, we can get the above information about ω. 2 The third-order equation has three pairs of different angular frequencies, three positive roots and three negative roots, where the three positive roots represent the three angular frequencies of the cylindrical shell in the axial, circumferential and radial directions. The minimum angular frequency is given priority. By substituting the solved vibration angular frequency ω into the displacement field expression, the corresponding target strain energy U can be calculated. max and target kinetic energy T max , the calculation of these two energies is based on the previous integral expressions.

[0121] S140, calculating the total energy dissipated by the target cylindrical shell in the form of a damping device according to the target kinetic energy and the specific damping capacity of the target cylindrical shell.

[0122] In a free vibration system, there is an energy exchange between kinetic energy and strain energy. When the system vibrates within a vibration cycle, kinetic energy and strain energy are periodically converted to each other. In the ideal case without damping, this conversion is complete and there is no energy loss. However, in a real system with damping, a part of the energy is dissipated due to the damping effect in each vibration cycle. The specific damping capacity (SDC) of the structure can be defined as the ratio of the total energy dissipated by the system in each stress cycle (i.e., dissipated energy) to the maximum strain energy of the system, and then the following formula can be obtained:

[0123]

[0124] Among them, ψ is the specific damping capacity, η is the structural damping loss factor, ΔU is the total energy consumption, U max is the target strain energy.

[0125] According to the influence of the damping loss factor in different directions on energy dissipation, the dissipated energy in each direction can be expressed as:

[0126] ΔU x =2πη 11 U max

[0127] ΔU y =2πη 22 U max

[0128] ΔU xy =2πη 12 U max

[0129] The total energy dissipation ΔU is the sum of the dissipated energy in all directions, which represents the energy dissipated by the system due to internal damping during the entire cycle. The expression formula for the total energy dissipation is as follows:

[0130]

[0131] Among them, η 11 , η 12 , η 22 are the damping loss factors of the target cylindrical shell in each direction, ΔU is the total energy dissipation, U max is the target strain energy.

[0132] In one possible implementation, for general orthotropic layers, the constitutive relation of the laminated cylindrical shell under plane stress conditions is as follows:

[0133] {σ}=[Q] T {e}

[0134] Where {σ} is the stress vector, {e} is the strain vector, [Q] T is the reduced stiffness matrix after transformation.

[0135] Specifically, Love shell theory is one of the classical elastic shell theories, which is suitable for describing the deformation behavior of thin shell structures under external forces. The shell is a special structural form, one of whose dimensions (thickness) is much smaller than the other two dimensions (length and width). The shell can withstand complex load conditions, including bending, torsion, tension and compression. An important feature of thin shell structures is that their deformation mainly depends on geometric nonlinear effects. Using Love shell theory, the strain components of the target cylindrical shell are defined as follows:

[0136] e x =e1+zk1

[0137] e θ =e2+zk2

[0138] e xθ =γ+2zτ

[0139] Where e1, e2 and γ are surface strains, and k1, k2 and τ are surface curvatures. Surface strain and surface curvature are defined as follows:

[0140]

[0141] Among them, u0, v0, w0 are the displacement components of a point on the mid-plane (i.e., z = 0) along the (x, θ, z) coordinate direction, R is the radius of the target cylindrical shell, e1, e2 and γ are the surface strains, and k1, k2 and τ are the surface curvatures.

[0142] Once the displacement (u0, v0, w0) of the mid-surface is determined, the strain at any point in the target cylindrical shell can be calculated using the above equations. From the definition of the strain components of the target cylindrical shell, it can be seen that all strain components vary linearly in thickness and are independent of the material change in the shell thickness. For a fixed z value, the strain is usually a nonlinear function of x and θ, and depends on time for dynamic problems.

[0143] For general orthotropic layers, the constitutive relation of laminated cylindrical shells under plane stress conditions is as follows:

[0144] {σ}=[Q] T {e}

[0145] Where {σ} is the stress vector, {e} is the strain vector, [Q] T is the reduced stiffness matrix after transformation.

[0146] Orthotropic materials are a class of materials that have different mechanical properties in different directions. Such materials are usually composed of fibers or laminated structures with different physical properties in multiple directions. Especially in the analysis of composite materials, orthotropic layers are common models. In an orthotropic layer, the material has different elastic modulus, shear modulus and Poisson's ratio along three mutually perpendicular principal directions (usually called 1, 2 and 3 directions).

[0147] The stress vector is a vector that contains the internal stress components of a structure or material. Under plane stress conditions, the stress matrix of the stress vector of an orthotropic material is usually expressed as:

[0148] {σ} T ={σ x , σ θ , σ xθ}

[0149] Among them, {σ} T is the stress matrix, σ xis the normal stress in the x direction, σ θ is the normal stress in the θ direction, σ xθ for x-θ Shear stress on a plane. The components of the stress vector represent the magnitude of the tensile, compressive, or shear stresses to which the material is subjected in different directions. Understanding stress distribution is important for analyzing the behavior of a material under external loads.

[0150] The strain vector describes the degree of deformation of the material under stress. For the plane stress state, the strain matrix of the strain vector is usually expressed as:

[0151] {e} T ={e x , e θ , e xθ}

[0152] Among them, {e} T is the strain matrix, e x is the normal strain in the x direction, e θ is the normal strain in the θ direction, e xθ for x-θ Shear strain on a plane. The strain vector reflects the deformation of a material under load and is the key to describing the geometric changes of a material.

[0153] The reduced stiffness matrix is ​​a matrix used to describe the stress-strain relationship of orthotropic materials under plane stress conditions. It is the core part of the material constitutive relationship and characterizes the stiffness of the material in different directions. The reduced stiffness matrix is ​​usually expressed as:

[0154]

[0155] Among them, [Q] T is the reduced stiffness matrix after transformation, Q ij is the reduced stiffness, i,j∈(1,2,6). For orthotropic materials, the stiffness matrix usually needs to undergo coordinate transformation (i.e. conversion) to adapt to the different laying directions of the material layers. The converted reduced stiffness matrix [Q] T Reflects the stiffness characteristics of the material at a specific laying angle.

[0156] Specifically, for orthotropic materials, the reduced stiffness Q ij (i,j=1,2,6) can be expressed as:

[0157]

[0158] Where E 11 and E 22 is Young's modulus, G 12 is the shear modulus; v 12and v 21 is Poisson's ratio; for orthotropic materials, the shell coordinate system is not consistent with the material coordinate system. Figure 3 ,These laminated shells have multiple layers, and the material coordinates of each layer have different orientations relative to the shell coordinates, with an angle difference α, so the reduced stiffness needs to be converted.

[0159] After coordinate transformation, the stress and strain relationship of a single layer of material becomes:

[0160]

[0161] Among them, σ x is the normal stress in the x direction, σ θ is the normal stress in the θ direction, σ xθ for x-θ Shear stress on the plane, e x is the normal strain in the x direction, e θ is the normal strain in the θ direction, e xθ for x-θ Shear strain on a plane, Q ij is the reduced stiffness, i, j∈(1,2,6).

[0162] S150, calculating the damping loss factor of the target cylindrical shell in each direction according to the Lagrangian, the total energy dissipation and the target strain energy.

[0163] According to the expression formula of total energy consumption, stress matrix and strain matrix, the calculation formula of total energy consumption is obtained:

[0164]

[0165] Where ΔU is the total energy consumption, L is the Lagrangian, h is the length of the target cylindrical shell, {e} T is the strain matrix, {σ} T is the stress matrix, η 11 , η 12 , η 22 are the damping loss factors of the target cylindrical shell in each direction.

[0166] Damping loss factor η ij Describes the energy dissipation characteristics of the material in all directions. In the structural analysis of cylindrical shells, the damping loss factor usually affects the total energy dissipation of the system. The damping loss factor is expressed in matrix form:

[0167]

[0168] Among them, η 11 represents the damping loss factor of the target cylindrical shell in the x direction, η 22represents the damping loss factor of the target cylindrical shell in the θ direction, η 12 represents the shear damping loss factor of the target cylindrical shell in the x-θ plane.

[0169] The total energy dissipation formula represents the energy dissipated by the system through the damping effect during a stress cycle. The role of integration is to calculate the total energy loss of the entire cylindrical shell structure. The damping loss factor matrix [η] converts strain energy into dissipated energy, and finally obtains the total energy dissipation ΔU. This calculation method is suitable for complex structural analysis, especially in structures such as multi-layer composite materials and laminated cylindrical shells. Through the combination of stress, strain and damping factors, the energy loss behavior of the structure can be accurately described.

[0170] S160, according to the modal strain energy method, based on the damping loss factors in various directions, the structural damping loss factor of the target cylindrical shell is calculated.

[0171] The modal strain energy method is a common method for estimating the damping loss factor of a structure, and is widely used in complex structures such as composite structures and laminate shells. This method is based on modal analysis and uses modal strain energy to calculate the energy distribution and dissipated energy of the structure during vibration, thereby obtaining the damping characteristics of the system. Modal analysis is a basic method for solving structural vibration characteristics. Through modal analysis, the natural frequency and modal shape of the structure (i.e., the vibration mode corresponding to each natural frequency) can be determined. For each mode (vibration mode), the total strain energy and kinetic energy of the system in this mode can be solved separately. The damping loss factor indicates the proportion of the energy lost by the system to the total energy of the system in each vibration cycle. The modal strain energy method estimates the damping loss factor of the entire system by calculating the modal strain energy and corresponding loss factors of different parts.

[0172] First, the natural frequencies and corresponding modal shapes of the structure are solved by finite element analysis or other numerical methods. Each mode represents the vibration mode of the structure at a specific frequency. For each mode, the modal strain energy of different parts of the structure is calculated. For example, if it is a laminate structure, the strain energy of each layer of material needs to be calculated. The modal strain energy U j Through integration, we can get:

[0173]

[0174] Among them, {∈ j} is the strain generated by the modal shape in this part, and [C] is the elastic stiffness matrix of the material. Based on the constitutive damping properties of each part of the material (such as the material loss factor η of each layer), i), calculate the local damping loss factor of the part. Generally speaking, energy dissipation is related to the intrinsic damping performance of the material. According to the modal strain energy and local damping loss factor of each part, the modal damping loss factor of the overall structure η total It can be calculated by weighted average:

[0175]

[0176] Among them, U i is the modal strain energy of the ith part, η i is the material loss factor of this part. In this way, the damping loss factor of the overall structure can be calculated.

[0177] According to the above principle, the structural damping loss factor is calculated based on the following formula:

[0178]

[0179] Among them, η is the structural damping loss factor, ΔU is the total energy consumption, and U max is the target strain energy.

[0180] This application can improve the accuracy of the calculation of the damping loss factor of cylindrical shell materials by combining measured data with an accurate energy calculation method. The principle is to obtain the motion and strain response of the cylindrical shell based on the preset vibration excitation, thereby calculating the target kinetic energy and target strain energy respectively, and then using the Lagrangian to calculate the total energy consumption of the system. In addition, combined with the specific damping capacity, the energy dissipation is converted into the damping loss factor in each direction, thereby avoiding the error of the isotropic assumption in traditional analysis. This process more accurately reflects the true damping characteristics of the material in different directions through the modal strain energy method, thereby greatly improving the accuracy of the damping loss factor calculation.

[0181] This embodiment also discloses a device for detecting the damping loss factor of a transmission pipeline, referring to Figure 4 The device includes an acquisition module 401401 and a processing module 402402, wherein:

[0182] The acquisition module 401 is used to acquire the measured motion response of the target cylindrical shell based on the preset vibration excitation applied to the target cylindrical shell, and to acquire the measured strain response of the target cylindrical shell based on the load applied to the target cylindrical shell.

[0183] The processing module 402 is used to calculate the target kinetic energy of the target cylindrical shell based on the motion response amount, and calculate the target strain energy of the target cylindrical shell based on the strain response amount.

[0184] The processing module 402 is used to calculate the Lagrangian according to the target kinetic energy and the target strain energy.

[0185] The processing module 402 is used to calculate the total energy dissipated by the target cylindrical shell through the form according to the target kinetic energy and the specific damping capacity of the target cylindrical shell.

[0186] The processing module 402 is used to calculate the damping loss factor of the target cylindrical shell in each direction according to the Lagrangian, the total energy consumption and the target strain energy.

[0187] The processing module 402 is used to calculate the structural damping loss factor of the target cylindrical shell based on the damping loss factors in various directions according to the modal strain energy method.

[0188] In a possible implementation, the processing module 402 is used to calculate the damping loss factor of the target cylindrical shell in each direction according to the Lagrangian, the total energy consumption and the target strain energy, and is calculated by the following formula:

[0189]

[0190] Among them, η 11 , η 12 , η 22 are the damping loss factors of the target cylindrical shell in each direction, ΔU is the total energy dissipation, U max is the target strain energy.

[0191] In a possible implementation, the processing module 402 is used to analyze the stress components of the target cylindrical shell according to the motion response amount, and then calculate the stress vector of the target cylindrical shell, which is specifically calculated by the following formula:

[0192] {σ} T ={σ x , σ θ , σ xθ}

[0193] Among them, {σ} T is the stress matrix, σ x is the normal stress in the x direction, σ θ is the normal stress in the θ direction, σ xθ for x-θ Shear stress on a plane.

[0194] The processing module 402 is used to analyze the strain vector of the target cylindrical shell according to the strain response, which is specifically calculated by the following formula:

[0195] {e} T ={e x , e θ , e xθ}

[0196] Among them, {e} T is the strain matrix, ex is the normal strain in the x direction, e θ is the normal strain in the θ direction, e xθ for x-θ Shear strain on a plane.

[0197] The relationship between stress vector and strain vector is as follows:

[0198] {σ}=[Q] T {e}

[0199] Where {σ} is the stress vector, {e} is the strain vector, [Q] T is the reduced stiffness matrix after transformation.

[0200] The converted reduced stiffness matrix is ​​expressed as follows:

[0201]

[0202] Among them, [Q] T is the reduced stiffness matrix after transformation, Q ij is the reduced stiffness, i, j∈(1,2,6).

[0203] In a possible implementation, the processing module 402 is used to calculate the total energy consumption according to the stress vector and the strain vector, specifically by the following formula:

[0204]

[0205] Where ΔU is the total energy consumption, L is the Lagrangian, h is the length of the target cylindrical shell, {e} T is the strain matrix, {σ} T is the stress matrix, η 11 , η 12 , η 22 are the damping loss factors of the target cylindrical shell in each direction.

[0206] In a possible implementation, the processing module 402 is configured to calculate the structural damping loss factor based on the following formula:

[0207]

[0208] Among them, η is the structural damping loss factor, ΔU is the total energy consumption, and U max is the target strain energy.

[0209] In a possible implementation, the processing module 402 is used to calculate the Lagrangian according to the target kinetic energy and the target strain energy, specifically by the following formula:

[0210] L=T max -Umax

[0211] Where L is the Lagrangian, T max is the target kinetic energy, U max is the target strain energy.

[0212] The acquisition module 401 is used to acquire the length and density of the target cylindrical shell.

[0213] The processing module 402 is used to calculate the strain energy of the target cylindrical shell based on the length of the target cylindrical shell, specifically by the following formula:

[0214]

[0215] Where U is the strain energy, h is the length of the target cylindrical shell, {e} T is the strain matrix, {σ} T is the stress matrix.

[0216] The processing module 402 is used to calculate the kinetic energy of the target cylindrical shell based on the length and density of the target cylindrical shell, specifically by the following formula:

[0217]

[0218] Wherein, T is kinetic energy, h is the length of the target cylindrical shell, ρ is the density of the target cylindrical shell, and u0, v0, and w0 are the displacement components of a point on the midplane (i.e., z=0) along the (x, θ, z) coordinate direction, respectively.

[0219] In a possible implementation, the processing module 402 is used to assume that the displacement field expression at both ends of the target cylindrical shell (x=0, h) is as follows:

[0220]

[0221] Among them, u0, v0, w0 are the displacement components of a point on the midplane (i.e., z=0) along the (x, θ, z) coordinate direction, A, B and C are the magnitudes of the displacement amplitudes, m is the axial wave number, n is the circumferential wave number, and ω is the vibration angular frequency.

[0222] The processing module 402 is used to construct the Lagrangian equation about the energy function based on the minimum potential energy principle. The Lagrangian equation is as follows:

[0223]

[0224] Among them, A, B and C are the magnitudes of displacement amplitude, T max is the target kinetic energy, U max is the target strain energy.

[0225] The processing module 402 is used to obtain the control characteristic equation based on the Lagrange equation as follows:

[0226]

[0227] Among them, C ij are the coefficients in the equation, and A, B and C are the magnitudes of the displacement amplitudes.

[0228] The processing module 402 is used to solve the roots by applying the condition of non-trivial solution to the control characteristic equation, and obtain the following determinant:

[0229] α0ω 6 +α1ω 4 +α2ω 2 +α3=0

[0230] Among them, α i (i=0, 1, 2, 3) is a constant, and ω is the vibration angular frequency.

[0231] The processing module 402 is used to solve the vibration angular frequency according to the determinant.

[0232] The processing module 402 is used to substitute the vibration angular frequency into the displacement field expression to calculate the target strain energy and the target kinetic energy.

[0233] It should be noted that: when the device provided in the above embodiment realizes its function, only the division of the above functional modules is used as an example. In actual application, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, the device and method embodiments provided in the above embodiment belong to the same concept, and the specific implementation process is detailed in the method embodiment, which will not be repeated here.

[0234] This embodiment also discloses an electronic device, referring to Figure 5 The electronic device may include: at least one processor 501 , at least one communication bus 502 , a user interface 503 , a network interface 504 , and at least one memory 505 .

[0235] The communication bus 502 is used to realize the connection and communication between these components.

[0236] The user interface 503 may include a display screen (Display) and a camera (Camera), and the optional user interface 503 may also include a standard wired interface and a wireless interface.

[0237] The network interface 504 may optionally include a standard wired interface or a wireless interface (such as a WI-FI interface).

[0238] Among them, the processor 501 may include one or more processing cores. The processor 501 uses various interfaces and lines to connect various parts in the entire server, and executes various functions of the server and processes data by running or executing instructions, programs, code sets or instruction sets stored in the memory 505, and calling data stored in the memory 505. Optionally, the processor 501 can be implemented in at least one hardware form of digital signal processing (Digital Signal Processing, DSP), field programmable gate array (Field-Programmable Gate Array, FPGA), and programmable logic array (Programmable Logic Array, PLA). The processor 501 can integrate one or a combination of a central processing unit (Central Processing Unit, CPU), a graphics processing unit (Graphics Processing Unit, GPU) and a modem. Among them, the CPU mainly processes the operating system, user interface and application programs; the GPU is responsible for rendering and drawing the content to be displayed on the display screen; the modem is used to process wireless communications. It can be understood that the above-mentioned modem may not be integrated into the processor 501, and it can be implemented separately through a chip.

[0239] The memory 505 may include a random access memory (RAM) or a read-only memory (ROM). Optionally, the memory includes a non-transitory computer-readable storage medium. The memory 505 may be used to store instructions, programs, codes, code sets or instruction sets. The memory 505 may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as a touch function, a sound playback function, an image playback function, etc.), instructions for implementing the above-mentioned various method embodiments, etc.; the data storage area may store data involved in the above-mentioned various method embodiments, etc. The memory 505 may also be at least one storage device located away from the aforementioned processor 501. The memory 505 as a computer storage medium may include an operating system, a network communication module, a user interface 503 module, and an application program for a method for detecting a damping loss factor of a conveying pipeline.

[0240] exist Figure 5In the electronic device shown, the user interface 503 is mainly used to provide an input interface for the user and obtain data input by the user; and the processor 501 can be used to call an application program stored in the memory 505 for a method for detecting a damping loss factor of a transmission pipeline. When executed by one or more processors 501, the electronic device executes one or more methods in the above-mentioned embodiments.

[0241] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the order of the actions described, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required for the present application.

[0242] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0243] In the several embodiments provided in this application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are only schematic, such as the division of units, which is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some service interfaces, and the indirect coupling or communication connection of devices or units can be electrical or other forms.

[0244] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0245] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0246] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a memory 505 and includes several instructions for a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the various embodiments of the present application. The aforementioned memory 505 includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a magnetic disk or an optical disk.

[0247] The present application also discloses a computer-readable storage medium, which stores instructions. When executed by one or more processors 501, the electronic device executes one or more of the methods described in the above embodiments.

[0248] The above is only an exemplary embodiment of the present disclosure, and the scope of the present disclosure cannot be limited thereto. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the disclosure of the specification and the truth of practice, it will be easy for those skilled in the art to think of other embodiments of the present disclosure. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the technical field that are not recorded in the present disclosure. The description and examples are regarded as exemplary only, and the scope and spirit of the present disclosure are defined by the claims.

Claims

1. A method for detecting the damping loss factor of a transmission pipeline, characterized in that: The method comprises: Based on a preset vibration excitation applied to a target cylindrical shell, a measured motion response of the target cylindrical shell is obtained, and based on a load applied to the target cylindrical shell, a measured strain response of the target cylindrical shell is obtained; Calculating a target kinetic energy of the target cylindrical shell based on the motion response amount, and calculating a target strain energy of the target cylindrical shell based on the strain response amount; Calculating a Lagrangian according to the target kinetic energy and the target strain energy; According to the target kinetic energy and the specific damping capacity of the target cylindrical shell, calculating the total energy dissipated by the target cylindrical shell in the form of a kinetic energy; Calculating the damping loss factor of the target cylindrical shell in each direction according to the Lagrangian, the total energy consumption and the target strain energy; According to the modal strain energy method, based on the damping loss factors in various directions, the structural damping loss factor of the target cylindrical shell is calculated.

2. A method for detecting damping loss factor of a transmission pipeline according to claim 1, characterized in that: The damping loss factor of the target cylindrical shell in each direction is calculated according to the Lagrangian, the total energy consumption and the target strain energy, and is calculated by the following formula: Among them, η 11 , η 12 , η 22 are the damping loss factors of the target cylindrical shell in each direction, ΔU is the total energy consumption, U max is the target strain energy.

3. A method for detecting damping loss factor of a transmission pipeline according to claim 2, characterized in that: After calculating the damping loss factor of the target cylindrical shell in each direction according to the Lagrangian, the total energy consumption and the target strain energy, the method further includes: According to the motion response, the stress component of the target cylindrical shell is analyzed, and then the stress vector of the target cylindrical shell is calculated, which is specifically calculated by the following formula: {s} T ={σ x ,s θ ,s xθ } Among them, {σ} T is the stress matrix, σ x is the normal stress in the x direction, σ θ is the normal stress in the θ direction, σ xθ for x-θ Shear stress on a plane; According to the strain response, the strain vector of the target cylindrical shell is analyzed and specifically calculated by the following formula: {And} T ={and x ,And θ ,And xθ } Among them, {e} T is the strain matrix, e x is the normal strain in the x direction, e θ is the normal strain in the θ direction, e xθ for x-θ Shear strain on a plane; The relationship between the stress vector and the strain vector is as follows: {σ}=[Q] T {e} Where, {σ} is the stress vector, {e} is the strain vector, [Q] T is the transformed reduced stiffness matrix; The reduced stiffness matrix after the conversion is expressed as follows: Among them, [Q] T is the reduced stiffness matrix after transformation, Q ij is the reduced stiffness, i, j∈(1,2,6).

4. A method for detecting damping loss factor of a transmission pipeline according to claim 3, characterized in that: The calculating the damping loss factor of the target cylindrical shell in each direction according to the Lagrangian, the total energy consumption and the target strain energy specifically includes: The total energy consumption is calculated according to the stress vector and the strain vector, specifically by the following formula: Wherein, ΔU is the total energy consumption, L is the Lagrangian, h is the length of the target cylindrical shell, {e} T is the strain matrix, {σ} T is the stress matrix, η 11 , η 12 , η 22 are the damping loss factors of the target cylindrical shell in each direction respectively.

5. The method for detecting the damping loss factor of a transmission pipeline according to claim 1, characterized in that: The method of calculating the structural damping loss factor of the target cylindrical shell based on the damping loss factor in each direction according to the modal strain energy method specifically includes: The structural damping loss factor is calculated based on the following formula: Wherein, η is the structural damping loss factor, ΔU is the total energy consumption, and U max is the target strain energy.

6. A method for detecting damping loss factor of a transmission pipeline according to claim 1, characterized in that: The Lagrangian is calculated according to the target kinetic energy and the target strain energy, specifically by the following formula: L=T max -U max Wherein, L is the Lagrangian, T max is the target kinetic energy, U max is the target strain energy; Obtaining the length and density of the target cylindrical shell; The strain energy of the target cylindrical shell is calculated based on the length of the target cylindrical shell, specifically by the following formula: Where U is the strain energy, h is the length of the target cylindrical shell, {e} T is the strain matrix, {σ} T is the stress matrix; Based on the length and density of the target cylindrical shell, the kinetic energy of the target cylindrical shell is calculated, specifically by the following formula: Wherein, T is the kinetic energy, h is the length of the target cylindrical shell, ρ is the density of the target cylindrical shell, and u0, v0, and w0 are the displacement components of a point on the midplane (ie, z=0) along the (x, θ, z) coordinate direction, respectively.

7. A method for detecting damping loss factor of a transmission pipeline according to claim 6, characterized in that: The step of calculating the target kinetic energy of the target cylindrical shell based on the motion response amount, and calculating the target strain energy of the target cylindrical shell based on the strain response amount, specifically includes: At both ends of the target cylindrical shell (x=0, h), the assumed displacement field expression is as follows: Where u0, v0, w0 are the displacement components of a point on the midplane (i.e. z = 0) along the (x, θ, z) coordinate direction, A, B and C are the magnitudes of the displacement amplitudes, m is the axial wave number, n is the circumferential wave number, and ω is the vibration angular frequency; Based on the principle of minimum potential energy, the Lagrangian equation for the energy function is constructed as follows: Among them, A, B and C are the magnitudes of displacement amplitude, T max is the target kinetic energy, U max is the target strain energy; Based on the Lagrange equation, the control characteristic equation is obtained as follows: Among them, C ij are the coefficients in the equation, A, B and C are the magnitudes of the displacement amplitudes; Solving for the roots by imposing the condition of non-trivial solutions to the governing characteristic equation yields the following determinant: oh oh 6 +a1w 4 +a2w 2 +α3=0 Among them, α i (i=0, 1, 2, 3) is a constant, ω is the vibration angular frequency; Solving the vibration angular frequency according to the determinant; The vibration angular frequency is substituted into the displacement field expression to calculate the target strain energy and the target kinetic energy.

8. A device for detecting damping loss factor of a transmission pipeline, characterized in that: The device comprises an acquisition module (401) and a processing module (402), wherein: The acquisition module (401) is used to acquire the measured motion response of the target cylindrical shell based on a preset vibration excitation applied to the target cylindrical shell, and to acquire the measured strain response of the target cylindrical shell based on a load applied to the target cylindrical shell; The processing module (402) is used to calculate the target kinetic energy of the target cylindrical shell based on the motion response amount, and calculate the target strain energy of the target cylindrical shell based on the strain response amount; The processing module (402) is used to calculate the Lagrangian according to the target kinetic energy and the target strain energy; The processing module (402) is used to calculate the total energy dissipated by the target cylindrical shell in the form of a damping capacity according to the target kinetic energy and the specific damping capacity of the target cylindrical shell; The processing module (402) is used to calculate the damping loss factor of the target cylindrical shell in each direction according to the Lagrangian, the total energy consumption and the target strain energy; The processing module (402) is used to calculate the structural damping loss factor of the target cylindrical shell based on the damping loss factors in various directions according to the modal strain energy method.

9. An electronic device, characterized in that: The electronic device comprises a processor (501), a communication bus (502), a memory (505), a user interface (503), a network interface (504) and a memory (505), wherein the memory (505) is used to store instructions, the user interface (503) and the network interface (504) are both used to communicate with other devices, and the processor (501) is used to execute the instructions stored in the memory (505) so that the electronic device executes the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores instructions, and when the instructions are executed, the method according to any one of claims 1 to 7 is executed.

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