Method and equipment for determining transverse vibration enveloping property of test stand on test piece, medium and product

Abstract

The invention discloses a method, equipment, medium and product for determining the transverse vibration envelope of a test bed to a test piece, and relates to the field of rotor dynamics analysis and test.The method comprises the steps that a transverse vibration dynamics model of a test bed rotor system is established, and an interface between the test bed rotor system and a test piece rotor system is determined; excitation of a first preset unit unbalance amount is applied to the interface, steady-state response analysis is carried out on a transverse vibration dynamic model of the test bed rotor system, and a frequency response characteristic curve of vibration displacement peak-to-peak values on all bearing journals of the test bed rotor is obtained; based on the frequency response characteristic curve and the amplification coefficient of the vibration displacement peak-to-peak value on the bearing journal, determining the transverse vibration critical rotation speed enveloping property of the test bench to the test piece; and determining the transverse vibration amplitude enveloping property of the test bench to the test piece based on the frequency response characteristic curve and the sensitivity coefficient on the examination bearing changing along with the impedance of the interface and the rotating speed of the test bench. According to the invention, the analysis efficiency and accuracy of the test bench on the transverse vibration envelope of the test piece are improved.

Description

Technical Field

[0001] The present application relates to the field of rotor dynamics analysis and testing, and in particular to a method, equipment, medium and product for determining the transverse vibration envelope of a test piece using a test bench. Background Art

[0002] A large rotor test bench is a complex system for testing the performance of rotor test pieces. Its dynamic performance is directly related to whether the test bench can operate safely and reliably. For the large rotor test bench that has been built, it is necessary to be able to meet the experimental requirements of different test piece rotors. Therefore, when designing the test piece, it is necessary to consider the impact of the test piece on the dynamic performance of the test bench rotor. In other words, when the newly designed test piece rotor is connected to the test bench, the lateral vibration of the test bench rotor cannot exceed the standard. Therefore, the issue of the lateral vibration envelope of the test piece by the test bench is raised. The lateral vibration envelope refers to the range of dynamic parameters of the test piece rotor that ensures that the lateral vibration index of the test bench rotor does not exceed the limit.

[0003] The conventional method for evaluating the dynamic envelope of the test bench rotor to the lateral vibration of the test piece rotor is to directly combine the test piece with the test bench rotor to obtain the dynamic performance indicators of the overall shaft system, and then evaluate whether the test piece can meet the dynamic requirements of the overall shaft system. If it cannot meet the requirements, the test piece needs to be redesigned for combined calculation. However, this method of dynamic design of the test piece rotor is very cumbersome and has low accuracy. Summary of the invention

[0004] The purpose of this application is to provide a method, device, medium and product for determining the lateral vibration envelope of a test piece by a test bench, so as to improve the efficiency and accuracy of determining the lateral vibration envelope of a rotor test bench for a test piece.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] In a first aspect, the present application provides a method for determining the lateral vibration envelope of a test piece by a test bench, comprising:

[0007] Establish the transverse vibration dynamics model of the test bench rotor system and determine the interface between the test bench rotor system and the test piece rotor system;

[0008] Applying an excitation of a first preset unit unbalance amount on the interface, performing a steady-state response analysis on the transverse vibration dynamics model of the test bench rotor system, and obtaining a frequency response characteristic curve of the peak-to-peak value of the vibration displacement on all bearing journals of the test bench rotor;

[0009] Based on the frequency response characteristic curve, the transverse vibration envelope of the test bench to the test piece is determined; the transverse vibration envelope includes the transverse vibration critical speed envelope and the transverse vibration amplitude envelope; wherein:

[0010] Based on the frequency response characteristic curve and the amplification factor of the peak-to-peak value of the vibration displacement on the bearing journal, the envelope of the critical speed of transverse vibration of the test bench for the test piece is determined; the amplification factor is the ratio of the speed difference between the critical speed and the half-power point; the critical speed is the speed corresponding to the maximum peak-to-peak value of the vibration displacement on the frequency response characteristic curve;

[0011] Based on the frequency response characteristic curve and the sensitivity coefficient, the envelope of the lateral vibration amplitude of the test piece by the test bench is determined; the sensitivity coefficient is the sensitivity coefficient on the test bearing that changes with the impedance of the interface and the rotational speed of the test bench; the sensitivity coefficient is the ratio of the amplitude at the journal of the test bearing to the amplitude of the interface; the test bearing is the bearing with the largest critical speed peak-to-peak value in the X direction and the largest critical speed peak-to-peak value in the Y direction among all the bearings of the test bench rotor.

[0012] Optionally, it is characterized in that establishing a transverse vibration dynamics model of the test bench rotor system specifically includes:

[0013] According to the shape and size of the shaft system, a transverse vibration dynamic model of the test bench rotor system is established by using the Riccati transfer matrix method; the shaft system consists of the test bench rotor system and the test piece rotor system.

[0014] Optionally, it is characterized in that, based on the frequency response characteristic curve and the amplification factor of the peak-to-peak value of the vibration displacement on the bearing journal, determining the transverse vibration critical speed envelope of the test bench for the test piece specifically includes:

[0015] Based on the frequency response characteristic curve, determining the amplification factor of the peak-to-peak value of the vibration displacement on the bearing journal;

[0016] Determine whether all the magnification factors are less than the set multiple;

[0017] If so, the test bench rotor has an envelope property over all the test piece rotors;

[0018] If not, determine the lateral vibration critical speed envelope of the test bench for the test piece based on the operating speed range.

[0019] Optionally, it is characterized in that determining the lateral vibration critical speed envelope of the test bench for the test piece according to the working speed range specifically includes:

[0020] Applying different transverse impedances on the interface, the effective critical speed of the test bearing is obtained; the finite critical speed is the critical speed with an amplification factor greater than a set multiple;

[0021] According to the effective critical speed and in combination with the critical speed setting range, the envelope of the initial lateral vibration critical speed of the test piece by the test bench is determined;

[0022] The envelope of the critical speed of lateral vibration of the test bench for the test piece is determined according to the envelope of the initial critical speed of lateral vibration of the test bench for the test piece and the operating speed range.

[0023] Optionally, it is characterized in that the critical speed setting range is 0.83nt-1.27nt; nt is the critical speed.

[0024] Optionally, based on the frequency response characteristic curve and the sensitivity coefficient, determining the transverse vibration amplitude envelope of the test piece by the test bench specifically includes:

[0025] Determining the test bearing according to the frequency response characteristic curve;

[0026] Excitation of a second preset unit unbalance amount at the interface time, and calculation of the sensitivity coefficient;

[0027] The transverse vibration amplitude envelope of the test bench for the test piece is determined based on the sensitivity coefficient and the maximum amplitude at the journal of the test bearing.

[0028] In a second aspect, the present application provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement any of the above-mentioned methods for determining the lateral vibration envelope of a test piece by a test bench.

[0029] In a third aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any of the above-mentioned methods for determining the lateral vibration envelope of a test piece by a test bench.

[0030] In a fourth aspect, the present application provides a computer program product, including a computer program, which, when executed by a processor, implements any of the above-mentioned methods for determining the lateral vibration envelope of a test piece by a test bench.

[0031] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0032] The present application provides a method, device, medium and product for determining the transverse vibration envelope of a test piece by a test bench, by establishing a transverse vibration dynamics model of the test bench rotor system, and determining the interface between the test bench rotor system and the test piece rotor system; applying an excitation of a first preset unit unbalance amount on the interface, performing a steady-state response analysis on the transverse vibration dynamics model of the test bench rotor system, and obtaining a frequency response characteristic curve of the peak-to-peak value of the vibration displacement on all bearing journals of the test bench rotor; based on the frequency response characteristic curve and the amplification factor of the peak-to-peak value of the vibration displacement on the bearing journal, determining the transverse vibration critical speed envelope of the test piece by the test bench; based on the frequency response characteristic curve and the sensitivity coefficient on the assessment bearing that changes with the impedance of the interface and the speed of the test bench, determining the transverse vibration amplitude envelope of the test piece by the test bench. The present application improves the efficiency and accuracy of the test bench in analyzing the transverse vibration envelope of the test piece. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 A schematic diagram of a flow chart of a method for determining the transverse vibration envelope of a test piece by a test bench provided in one embodiment of the present application;

[0035] Figure 2 This is a schematic diagram of the turbine test bench rotor system;

[0036] Figure 3 is the equivalent node graph;

[0037] Figure 4 It is a schematic diagram of the discretization model of a simple rotor system;

[0038] Figure 5 It is a schematic diagram of the state variables on the cross section at the left end of the disk;

[0039] Figure 6 The schematic diagram of the modeling boundary for the transverse vibration envelope analysis of the turbine test bench shaft system;

[0040] Figure 7 The steady-state response Bode diagram of the journal center at bearing C and bearing D;

[0041] Figure 8 It is a schematic diagram of the definition of the rotor response Bode diagram and the amplification factor AF;

[0042] Fig. 9 It is the envelope diagram of the transverse vibration critical speed of the turbine test bench rotor system for the damped test piece;

[0043] Fig.10 It is a schematic diagram of the amplification factor of the intermediate shaft journal amplitude of the turbine test bench rotor system relative to the interface amplitude of the test piece;

[0044] Fig.11 This is a schematic diagram of the maximum limit amplitude of the bearing in the X direction for the turbine test bench rotor system;

[0045] Fig.12 This is a schematic diagram of the maximum limit amplitude of the Y direction of the bearing for the turbine test bench rotor system;

[0046] Fig.13 A schematic diagram of the structure of a computer device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0048] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0049] In an exemplary embodiment, Figure 1 As shown, a method for determining the lateral vibration envelope of a test piece by a test bench is provided, comprising the following steps:

[0050] S1: Establish the transverse vibration dynamic model of the test bench rotor system and determine the interface between the test bench rotor system and the test piece rotor system.

[0051] As an optional implementation method, a transverse vibration dynamics model of the test bench rotor system is established, specifically including:

[0052] According to the shape and size of the shaft system, a transverse vibration dynamic model of the test bench rotor system is established by using the Riccati transfer matrix method; the shaft system consists of the test bench rotor system and the test piece rotor system.

[0053] S2: applying an excitation of a first preset unit unbalance amount on the interface, performing a steady-state response analysis on the transverse vibration dynamics model of the test bench rotor system, and obtaining a frequency response characteristic curve of the peak-to-peak value of the vibration displacement on all bearing journals of the test bench rotor.

[0054] S3: Based on the frequency response characteristic curve, determine the transverse vibration envelope of the test bench to the test piece; the transverse vibration envelope includes the transverse vibration critical speed envelope and the transverse vibration amplitude envelope; wherein:

[0055] S31: Based on the frequency response characteristic curve and the amplification factor of the peak-to-peak value of the vibration displacement on the bearing journal, determine the envelope of the critical speed of lateral vibration of the test bench for the test piece; the amplification factor is the ratio of the speed difference between the critical speed and the half-power point; the critical speed is the speed corresponding to the maximum peak-to-peak value of the vibration displacement on the frequency response characteristic curve.

[0056] As an optional implementation, S31 specifically includes:

[0057] Based on the frequency response characteristic curve, the amplification factor of the peak-to-peak value of the vibration displacement on the bearing journal is determined.

[0058] Determine whether all the magnification factors are less than the set multiple.

[0059] If so, the test bench rotor has an envelope property over all the test piece rotors.

[0060] If not, determine the lateral vibration critical speed envelope of the test bench for the test piece based on the operating speed range, including:

[0061] Different transverse impedances are applied on the interface to obtain the effective critical speed of the test bearing; the finite critical speed is the critical speed with an amplification factor greater than a set multiple.

[0062] According to the effective critical speed and the critical speed setting range, the envelope of the initial lateral vibration critical speed of the test bench for the test piece is determined. The critical speed setting range is 0.83nt-1.27nt; nt is the critical speed.

[0063] The envelope of the critical speed of lateral vibration of the test bench for the test piece is determined according to the envelope of the initial critical speed of lateral vibration of the test bench for the test piece and the operating speed range.

[0064] S32: Based on the frequency response characteristic curve and the sensitivity coefficient, determine the lateral vibration amplitude envelope of the test bench to the test piece; the sensitivity coefficient is the sensitivity coefficient on the test bearing that changes with the impedance of the interface and the rotation speed of the test bench; the sensitivity coefficient is the ratio of the amplitude at the journal of the test bearing to the amplitude of the interface; the test bearing is the bearing with the largest critical speed peak-to-peak value in the X direction and the largest critical speed peak-to-peak value in the Y direction among all the bearings of the test bench rotor.

[0065] As an optional implementation manner, based on the frequency response characteristic curve and the sensitivity coefficient, determining the transverse vibration amplitude envelope of the test piece by the test bench specifically includes:

[0066] The test bearing is determined according to the frequency response characteristic curve.

[0067] The excitation of the second preset unit unbalance amount is performed at the interface time, and the sensitivity coefficient is calculated.

[0068] The transverse vibration amplitude envelope of the test bench for the test piece is determined based on the sensitivity coefficient and the maximum amplitude at the journal of the test bearing.

[0069] This application takes a turbine rotor test bench as an example to analyze the lateral vibration envelope of the test piece by the rotor test bench.

[0070] The complete shaft system of the turbine test bench consists of a hydraulic dynamometer rotor, an intermediate shaft rotor, a coupling and a test piece rotor, such as Figure 2 As shown. The overall working principle of the turbine test bench is the transmission and absorption of work. After the high-pressure and high-temperature gas generated by the combustion of the fuel is input into the cylinder of the turbine test piece, the turbine test piece rotor is driven to rotate at high speed to generate output work, which is transmitted to the hydraulic dynamometer rotor through the coupling and the intermediate support shaft and absorbed by the hydraulic dynamometer. In the shaft system, the turbine test piece rotor is radially supported by two sets of oil film bearings, the intermediate shaft rotor is also radially supported by two sets of oil film bearings, and the hydraulic dynamometer rotor is supported by two sets of rolling bearings. The output work of the turbine rotor during operation is transmitted to the hydraulic dynamometer rotor through the coupling and the intermediate shaft and absorbed by the dynamometer. The model of the turbine test bench rotor system is shown as follows. Figure 3 As shown, it consists of a hydraulic dynamometer, an intermediate shaft assembly, a coupling and other parts. It is assumed that the stiffness of the support of each bearing in the test bench rotor system is much greater than the bearing stiffness, that is, it is considered that the bearing seat does not participate in the vibration, and each bearing is modeled as an elastic-damping element. The overall shaft system of the turbine test bench is supported by three pairs of bearings. The hydraulic dynamometer rotor uses two angular contact ball bearings of the same model, and the intermediate shaft and the turbine test piece rotor both use two sliding bearings. Figure 2 As shown, the support positions of each bearing are at A, B, C, and D respectively.

[0071] The rated speed of the test piece is 3270rpm (54.5Hz), and long-term tests are carried out in the range of 2943rpm to 4578rpm. When calculating the transverse vibration of the turbine test bench, the calculation boundary is the entire shaft system, that is, extending from the hydraulic dynamometer end to the test piece end.

[0072] Step 1: Establish the transverse vibration dynamics model of the test bench rotor system: including but not limited to the finite element method and the transfer matrix method, to establish the transverse vibration dynamics model of the test bench rotor system.

[0073] The actual rotor is an elastic system with continuous mass distribution and infinite degrees of freedom. This application uses the Riccati transfer matrix method as an example (including but not limited to this method) to discretize a continuous simple rotor system into a mechanical model with limited degrees of freedom. This mechanical model can reflect the dynamic characteristics of the original rotating machinery and is easy to analyze and calculate.

[0074] (1) Set nodes according to the shape and size of the shaft system. The nodes are generally selected at the impeller, coupling, interface mutation of the shaft, support point and end position of the rotor system, so that the shaft section between the nodes is a uniform cross-section shaft. The equivalent nodes are as follows Figure 3 shown.

[0075] (2) The mass and moment of inertia of several subsystems are aggregated to several nodes, and the parameters are aggregated. After the parameters are aggregated, the rotor can be obtained into a disk-shaft dynamic model consisting of N rigid thin disks (nodes) with concentrated mass and moment of inertia, N massless elastic shaft segments, and L elastic damping supports, as shown in Figure 4 As shown. In this embodiment, the total weight of the test bench rotor system is about 1860kg, which is divided into 43 nodes. The hydraulic dynamometer impeller has a mass of 270kg and a diameter moment of inertia of 6.8kg×m 2 , Polar moment of inertia 11kg×m 2 , as a concentrated mass attached to the middle node of the rotor. The two sets of rolling bearings supporting the dynamometer rotor are of the same model, with a span of 1000mm and a radial stiffness of 2.5×10 5 N / mm, the damping of the rolling bearing is very small and can be ignored.

[0076] For the jth section of the rotor, its state vector is recorded as Z j , which is determined by the radial displacement of the cross section X j 、Twist angle A j , bending moment M j and shear force Q j The amplitude composition is expressed as:

[0077]

[0078] Where T is the transpose.

[0079] It is related to the state vector Z of section j+1 j+1 There is a certain relationship between them:

[0080] Z j+1 =T j Z j .

[0081] Among them, T jIt is the transfer matrix between the two sections, and its elements can be obtained by analyzing the forces and deformations on the components.

[0082] The state variables on the left side of the disk are as follows: Figure 5 As shown, the state variables of the left end section of the disk are recorded as two groups, f and e, and are recorded as:

[0083]

[0084] The positive direction of each variable is defined as follows Figure 5 As shown (note that θ y and M x The positive direction of θ is opposite to that in the general Cartesian coordinate system, and the representation of θ and M subscripts is also different from that in the general Cartesian coordinate system. x is the component of the bending moment on the x-axis; M y is the component of the bending moment on the y-axis; Q x is the component of shear force on the x-axis; Q y is the component of shear force on the y-axis; x and y are transverse linear displacements; θ is the cross-sectional angular displacement.

[0085] When the rotor system has no external excitation, the transfer relationship of the state variables of the left end sections of two adjacent disk-shaft components can be expressed as:

[0086]

[0087] Among them, u, R, and W are block matrices split for convenient calculation; T 11 、T 12 、T 21 、T 22 For the convenience of calculation, the block matrices are split into: Among them, the matrices u, R and W of the j-th disk-axis component are as follows:

[0088]

[0089] In the above formulas, M and Q represent the bending moment and shear force on the section respectively; EI is the bending stiffness of the shaft section; L is the length of the shaft section; K and C are the stiffness and damping coefficient of the support respectively; m d ,J d ,J p are the lumped mass, lumped diameter moment of inertia and lumped polar moment of inertia on the disk respectively; s = λ + iω is the complex frequency of vibration; Ω is the angular velocity of the rotor, and ν is the shear deformation coefficient of the shaft segment. The superscripts L and R represent the left and right end sections respectively.

[0090] Step 2: Define the interface: Determine the interface between the test bench rotor system and the test piece rotor system.

[0091] In practical applications, since the structure and parameters of the test piece rotor system are unknown before the design is completed, the dynamic influence of the test piece rotor on the test bench rotor is realized through the mechanical impedance (dynamic stiffness) on the interface. Therefore, when analyzing the dynamic characteristics of the test bench rotor system, the influence of the test piece rotor system can be characterized by adding the mechanical impedance of the test piece rotor system on the interface. Figure 6 The figure shows the connection between the turbine test bench and the test piece.

[0092] Step 3: Analyze the frequency response characteristics of the test bench rotor: Apply unit unbalance excitation to the interface node, and obtain the frequency response characteristic curve of the vibration peak-to-peak value on all bearing shaft diameters of the test bench rotor through steady-state response analysis.

[0093] Apply unit unbalance to the system interface node, and perform steady-state response analysis of the system based on the dynamic model established in step 1. The frequency response characteristic curve of the peak-to-peak value of vibration on all bearing shaft diameters of the test bench rotor is obtained through steady-state response analysis. Assume that the generalized force array of external simple harmonic excitation on disk j is F dj Then the transfer relationship of the state variables between two adjacent disk-shaft components can be expressed as:

[0094]

[0095] in,

[0096] Introducing the Riccati transformation f j =S j e j +P j , then the recursive formulas of matrix S and vectors P and e can be derived as follows:

[0097]

[0098] F f Decomposed into block matrices for easy calculation; F e To facilitate calculation, it is decomposed into block matrices.

[0099] According to the right boundary condition f N+1 =0, we get: Where N is the number of nodes. Using the third formula in the recursive formula, the state variables of each disk can be obtained. According to the initial conditions of the disk system S1 = 0 and P1 = 0, the recursive formula of the Riccati transfer matrix method can be written as:

[0100]

[0101] According to the third formula of the recursive formula:

[0102]

[0103] The state variable e of each disk can be obtained N ,e N-1 ...e2,e1 are the responses at each node.

[0104] According to the steady-state analysis model formula, i.e., the rotor motion equation, a unit unbalance is applied to the interface node to obtain the frequency response characteristic diagram of the peak-to-peak value of the vibration on the rotor bearing journal of the test bench.

[0105] In this embodiment, according to the interface node determined in step 2, a 1×10 4 The unit unbalance is N / mm. By analyzing the structure of the test bench rotor system, within the operating speed range, the excitation on the interface cannot excite obvious vibration of bearing A and bearing B. Therefore, only bearing C and bearing D need to be analyzed and the steady-state response Bode diagram is drawn. Figure 7 Bode diagram of the steady-state response at bearings C and D. In the legend, x and y represent the peak-to-peak values ​​of the vibration displacement of the journal along the x and y directions of the coordinate axis, respectively.

[0106] Step 4: Evaluate the effectiveness of the critical speed of the test bench rotor: If the peak-to-peak amplitude magnification factor on at least one bearing journal is greater than 2.5 times, it is necessary to analyze the critical speed envelope range of the test bench rotor to the test piece rotor; if the peak-to-peak vibration magnification factor on all bearing journals is less than 2.5 times, the test bench rotor has an envelope for all test piece rotors. According to the API684-2019 standard, the magnification factor is defined as: the ratio of a critical speed value in the Bode diagram to its bandwidth (speed difference between half-power points), which is 2.5.

[0107] The effective critical speed refers to the speed that can effectively excite the resonance of the rotating shaft. In this application, step 3 is used to calculate the Bode diagram of the steady-state displacement response under interface excitation. The peak speed with a peak-to-peak magnification factor greater than 2.5 in the Bode diagram is the effective damped critical speed (effective critical speed) of the test bench shaft system. When evaluating the effectiveness of the critical speed of the test bench rotor, if the peak-to-peak magnification factor of the vibration on all bearing journals is less than 2.5 times, the test bench rotor has an envelope for all test piece rotors; if the peak-to-peak amplitude magnification factor on at least one bearing journal is greater than 2.5 times, it is necessary to analyze the envelope range of the critical speed of the test bench rotor for the test piece rotor.

[0108] The amplification factor AF is a simplified measure of the amount of damping available at the natural frequency. It is defined as the ratio of a critical speed value in the Bode diagram to its bandwidth (the speed difference between the half-power points), such as Figure 8 The calculation method of the amplification factor AF is shown in the formula:

[0109]

[0110] N c1 is the first critical speed of the rotor, A c1 is the peak-to-peak value of the first critical speed amplitude, 0.707×A c1 The corresponding point is the half-power point, and N1 and N2 are the rotor speeds corresponding to the half-power point.

[0111] The amplification factor is calculated based on the steady-state response Bode diagram of the journal center at bearings C and D calculated in step 3, which shows that the critical speed corresponding to the peak-to-peak value of the vibration displacement has an amplification factor greater than 2.5, which is the effective critical speed.

[0112] Step 5: Determine the envelope of the critical speed of the test bench rotor to the test piece rotor: Apply different transverse impedances on the interface to obtain the critical speeds of each order of the test bench rotor that vary with the impedance. The transverse impedance represents different test piece rotors. Determine the range of the transverse impedance of the interface within the range of 127%-83% of the operating speed. When designing the test piece rotor, the corresponding transverse impedance within this speed range needs to be avoided.

[0113] According to the analysis and calculation in step 4, different transverse impedances are applied to the nodes of the interface to obtain the corresponding effective critical speed on the test bearing D. According to the principle that there is no intersection in the range of 0.83 to 1.27, the envelope of the system for the critical speed nt of the test bench is determined, such as Fig. 9 As shown. The red solid line in the figure shows the critical speed of the test bench rotor system, the pink area is based on the initial lateral vibration critical speed envelope range of 0.83~1.27nt; the pink dotted line is the hypothetical lateral dynamic stiffness characteristics at the interface of the current test piece rotor; the intersection of the dotted line and the solid line is the critical speed of the current test piece rotor system; the blue dotted line Nma is the minimum operating speed, and Nmc is the maximum operating speed. Fig. 9 The envelope range of the test bench rotor system to the test piece rotor system can be obtained, indicating that it has an envelope under this working condition.

[0114] Step 6: Determine the test bench rotor test bearing and its amplitude: Based on the calculation results of step 3, select the bearing with the largest critical speed peak-to-peak value in the X direction and the bearing with the largest critical speed peak-to-peak value in the Y direction from all the bearings of the test bench rotor as the test bearings.

[0115] (1) According to the steady-state response model established in step 3, a unit unbalance excitation is applied to the interface to obtain the steady-state peak-to-peak response of all bearings on the test bench rotor.

[0116] (2) At each speed, the bearing with the largest critical speed peak-to-peak value in the X direction and the bearing with the largest critical speed peak-to-peak value in the Y direction are selected as the test bearings.

[0117] Figure 7 is the steady-state response Bode diagram of the journal center at bearings C and D in this case. Figure 7 It can be seen that the peak-to-peak value of the critical speed of the bearing D journal in the X direction and the Y direction is the largest, so bearing D is selected as the test bearing.

[0118] Step 7: Calculate the relationship between the amplitude at the journal of the tested bearing and the amplitude at the interface: Apply unit unbalance excitation on the interface to obtain the sensitivity coefficient of the tested bearing that changes with the interface impedance and the test bench speed. The sensitivity coefficient is defined as the ratio of the amplitude at the journal of the tested bearing to the amplitude at the interface.

[0119] The amplitude envelope of the test bench rotor system to the test piece rotor system described in this application is to analyze the sensitivity of the test bench rotor system journal amplitude relative to the interface amplitude at different frequencies (expressed as the amplitude amplification factor). An excitation of unit unbalance is applied to the interface node to obtain the sensitivity coefficient on the tested bearing that changes with the interface impedance and the test bench speed. The sensitivity coefficient is defined as the ratio of the amplitude at the journal of the tested bearing to the amplitude of the interface. In the calculation process, the sensitivity coefficient is the lateral amplitude Ac at the center of the bearing journal and the lateral amplitude Ac' on the interface under different combinations of lateral stiffness and speed, and the ratio of the two in the x and y directions is taken, that is, the amplification coefficient AF' is calculated. x and AF' y , the calculation formula is as follows. Since the transverse amplitude responses of the journals at bearings C and D of the turbine test bench rotor system are different, the one with the larger amplitude at each speed, i.e. the one with higher sensitivity, is taken when calculating the sensitivity.

[0120]

[0121] Fig.10 The sensitivity coefficient AF' of the maximum bearing journal lateral amplitude in the x direction to the lateral amplitude on the interface under different combinations of interface additional lateral impedance and test bench speed is shown. x .like Fig.10 As shown, the larger the sensitivity coefficient is, the more sensitive the test bench journal is to the interface vibration, and the smaller the envelope of the possible amplitude of the test piece at the interface is.

[0122] Step 8: Calculate the maximum peak-to-peak value on the test bench rotor interface: API684-2019 standard stipulates that the peak-to-peak value of the critical speed amplitude at the journal of the tested bearing cannot be greater than 25.4um. Assuming that the maximum peak-to-peak value of the amplitude on the journal of the tested bearing is 25.4um, calculate the maximum peak-to-peak value of the amplitude on the interface based on the sensitivity coefficient obtained in step 7.

[0123] Through Fig.10 After analysis and processing, it is found that within the working speed range, the amplitude of the interface corresponding to the bearing with the largest amplitude at a displacement peak-to-peak value of 25.4um is the maximum peak-to-peak value of the test bench rotor on the interface.

[0124] Step 9: Determine the envelope of the test bench rotor to the transverse vibration amplitude of the test piece rotor: When the amplitude at the bearing journal is at its maximum value, the maximum amplitude range of the transverse vibration at the interface is calculated based on the distribution of the sensitivity coefficient. Design parameters of the test piece rotor that exceed this amplitude range need to be avoided.

[0125] When the amplitude at the bearing journal under test is the maximum value, the maximum amplitude range of the transverse vibration at the interface is calculated based on the distribution of the sensitivity coefficient. The design parameters of the test rotor that exceed this amplitude range need to be avoided. Fig.11 and Fig.12 As shown, when the vibration at the bearing journal where the test bench rotor has the largest amplitude is the maximum value of 25.4um, the maximum amplitude range at the interface is obtained according to the sensitivity coefficient conversion formula obtained in step 8. The lateral vibration amplitude corresponding to this amplitude range is the envelope of the test bench rotor to the test piece rotor.

[0126] Technical innovations of this application:

[0127] This application models the dynamic characteristics of the unknown test piece rotor as the mechanical impedance at the interface between the test bench rotor and the test piece rotor, and uses the impedance matching principle of the mechanical impedance synthesis method at the interface to determine the influence of the test piece rotor on the lateral vibration unbalance response of the test bench rotor, thereby deriving the design limit range of the unknown test piece.

[0128] This application determines the envelope of the test bench rotor's lateral vibration to the test piece rotor. During the design phase of the test piece rotor, the newly designed test piece rotor should avoid this envelope range, so as to avoid the problem of excessive lateral vibration of the test bench after the new test piece is connected to the test bench. This application can avoid the blindness of the test piece rotor design, reduce unnecessary economic losses, improve the efficiency of the design, and has important economic and social benefits.

[0129] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Fig.13As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a method for determining the lateral vibration envelope of a test piece by a test bench is implemented.

[0130] Those skilled in the art will understand that Fig.13 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components. In an exemplary embodiment, a computer device is provided, including a memory and a processor, the memory stores a computer program, and the processor implements the above-mentioned test bench to determine the lateral vibration envelope of the test piece when executing the computer program.

[0131] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, the method for determining the transverse vibration envelope of a test piece by the test bench is implemented.

[0132] In an exemplary embodiment, a computer program product is provided, including a computer program, which, when executed by a processor, implements the above-mentioned method for determining the transverse vibration envelope of a test piece by a test bench.

[0133] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0134] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0135] The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.

[0136] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0137] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A method for determining the transverse vibration envelope of a test piece using a test bench. It is characterized in that include: Establish the transverse vibration dynamics model of the test bench rotor system and determine the interface between the test bench rotor system and the test piece rotor system; Applying an excitation of a first preset unit unbalance amount on the interface, performing a steady-state response analysis on the transverse vibration dynamics model of the test bench rotor system, and obtaining a frequency response characteristic curve of the peak-to-peak value of the vibration displacement on all bearing journals of the test bench rotor; Based on the frequency response characteristic curve, the transverse vibration envelope of the test bench to the test piece is determined; the transverse vibration envelope includes the transverse vibration critical speed envelope and the transverse vibration amplitude envelope; wherein: Based on the frequency response characteristic curve and the amplification factor of the peak-to-peak value of the vibration displacement on the bearing journal, the envelope of the critical speed of transverse vibration of the test bench for the test piece is determined; the amplification factor is the ratio of the speed difference between the critical speed and the half-power point; the critical speed is the speed corresponding to the maximum peak-to-peak value of the vibration displacement on the frequency response characteristic curve; Based on the frequency response characteristic curve and the sensitivity coefficient, the envelope of the lateral vibration amplitude of the test piece by the test bench is determined; the sensitivity coefficient is the sensitivity coefficient on the test bearing that changes with the impedance of the interface and the rotational speed of the test bench; the sensitivity coefficient is the ratio of the amplitude at the journal of the test bearing to the amplitude of the interface; the test bearing is the bearing with the largest critical speed peak-to-peak value in the X direction and the largest critical speed peak-to-peak value in the Y direction among all the bearings of the test bench rotor.

2. The method for determining the transverse vibration envelope of a test piece by a test bench according to claim 1, It is characterized in that Establish the transverse vibration dynamics model of the test bench rotor system, including: According to the shape and size of the shaft system, a transverse vibration dynamic model of the test bench rotor system is established by using the Riccati transfer matrix method; the shaft system consists of the test bench rotor system and the test piece rotor system.

3. The method for determining the transverse vibration envelope of a test piece by a test bench according to claim 1, It is characterized in that Based on the frequency response characteristic curve and the amplification factor of the peak-to-peak value of the vibration displacement on the bearing journal, the envelope of the lateral vibration critical speed of the test bench for the test piece is determined, specifically including: Based on the frequency response characteristic curve, determining the amplification factor of the peak-to-peak value of the vibration displacement on the bearing journal; Determine whether all the magnification factors are less than the set multiple; If so, the test bench rotor has an envelope property over all the test piece rotors; If not, determine the lateral vibration critical speed envelope of the test bench for the test piece based on the operating speed range.

4. The method for determining the transverse vibration envelope of a test piece by a test bench according to claim 3, It is characterized in that Determine the envelope of the lateral vibration critical speed of the test bench for the test piece according to the working speed range, including: Applying different transverse impedances on the interface, the effective critical speed of the test bearing is obtained; the finite critical speed is the critical speed with an amplification factor greater than a set multiple; According to the effective critical speed and in combination with the critical speed setting range, the envelope of the initial lateral vibration critical speed of the test piece by the test bench is determined; The envelope of the critical speed of lateral vibration of the test bench for the test piece is determined according to the envelope of the initial critical speed of lateral vibration of the test bench for the test piece and the operating speed range.

5. The method for determining the transverse vibration envelope of a test piece by a test bench according to claim 4, It is characterized in that The critical speed setting range is 0.83nt-1.27nt; nt is the critical speed.

6. The method for determining the transverse vibration envelope of a test piece by a test bench according to claim 1, It is characterized in that Based on the frequency response characteristic curve and the sensitivity coefficient, the transverse vibration amplitude envelope of the test piece by the test bench is determined, specifically including: Determining the test bearing according to the frequency response characteristic curve; Excitation of a second preset unit unbalance amount at the interface time, and calculation of the sensitivity coefficient; The transverse vibration amplitude envelope of the test bench for the test piece is determined based on the sensitivity coefficient and the maximum amplitude at the journal of the test bearing.

7. A computer device, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method for determining the lateral vibration envelope of a test piece by a test bench according to any one of claims 1 to 6.

8. A computer-readable storage medium having a computer program stored thereon, It is characterized in that When the computer program is executed by a processor, the method for determining the transverse vibration envelope of a test piece by a test bench according to any one of claims 1 to 6 is implemented.

9. A computer program product comprising a computer program, It is characterized in that When the computer program is executed by a processor, the method for determining the transverse vibration envelope of a test piece by a test bench according to any one of claims 1 to 6 is implemented.

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