A vibration response analysis method and system for a lifting and rotating process of an SFD rotor system

Abstract

This invention provides a method and system for analyzing the vibration response of an SFD rotor system during acceleration and deceleration. The method includes constructing an SFD rotor system; the SFD rotor system includes an SFD dynamic model, in which stiffness varies with rotational speed; calculating the vibration response of the SFD rotor system sequentially according to the rotational speed changes during acceleration and deceleration; and calculating the vibration response in a nonlinear manner during nonlinear changes. The nonlinear vibration response calculation includes: determining an initial displacement response value; wherein the initial displacement response value is determined based on the displacement responses corresponding to preset rotational speeds before the current speed; obtaining the stiffness and damping values ​​at the current rotational speed based on the SFD dynamic model and the initial displacement response value; and calculating the displacement response value based on the stiffness and damping values ​​at the current rotational speed, thereby obtaining the vibration response analysis results under nonlinear conditions.

Description

Technical Field

[0001] This invention relates to the field of aero-engine analysis technology, and more specifically, to a vibration response analysis method and system for the rising and falling rotation process of an SFD rotor system. Background Technology

[0002] Squeeze film dampers (SFDs) possess excellent damping performance, and are incorporated into current aircraft engine rotor systems. Under small eccentricities, actual SFD rotor systems can be considered linear systems, and linear dynamic analysis can effectively perform critical speed analysis and rotor imbalance response analysis, meeting engineering requirements. However, in reality, under large eccentricities, SFD rotor systems exhibit significant nonlinearity, necessitating nonlinear analysis to gain a complete and comprehensive understanding of the rotor system's dynamic behavior.

[0003] Currently, in the vibration response analysis of SFD rotor systems, the SFD rotor system is subjected to large unbalance in the nonlinear region. For the nonlinear response of SFD rotor systems, existing commercial finite element analysis software generally does not have the function of nonlinear unbalance response analysis. SFD rotor systems may operate in the linear region or in the nonlinear region, requiring both linear and nonlinear analysis. However, current engineering designs lack the ability to determine whether the rotor system response has entered the nonlinear region, and also lack the analysis steps after entering the nonlinear region. Summary of the Invention

[0004] The following provides a brief overview of one or more aspects to offer a basic understanding of them. This overview is not an exhaustive summary of all conceived aspects, nor is it intended to identify key or decisive elements of all aspects, nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form to prepare for the more detailed descriptions that follow.

[0005] The purpose of this invention is to provide a vibration response analysis method for the rising and falling rotation process of an SFD rotor system, which can perform nonlinear analysis and calculation of the vibration response of the SFD rotor system during the rising and falling rotation process.

[0006] The present invention also aims to provide a vibration response analysis system for the rising and falling rotation process of an SFD rotor system, which can perform nonlinear analysis and calculation of the vibration response of the SFD rotor system during the rising and falling rotation process.

[0007] Embodiments of the present invention can be implemented in the following ways:

[0008] A vibration response analysis method for the rising and falling rotation process of an SFD rotor system, the method comprising:

[0009] Construct an SFD rotor system; wherein the SFD rotor system includes an SFD dynamic model, and in the SFD dynamic model, the stiffness varies with the rotational speed;

[0010] The vibration response of the SFD rotor system is calculated sequentially according to the speed change during acceleration and deceleration. During the nonlinear change of the vibration response, a nonlinear vibration response calculation is performed, which includes: determining the initial displacement response value; wherein the initial displacement response value is determined based on the displacement response corresponding to a preset number of speeds prior to the current speed; obtaining the stiffness and damping values ​​at the current speed based on the SFD dynamic model and the initial displacement response value; and calculating the displacement response value based on the stiffness and damping values ​​at the current speed.

[0011] Optionally, the vibration response analysis method for the SFD rotor system during the lifting and lowering process further includes:

[0012] The variation law of stiffness and vibration displacement is obtained according to the SFD dynamic model; wherein, the variation law includes the critical vibration displacement value; wherein, the critical vibration displacement value is the vibration displacement value at the boundary between linear and nonlinear changes in stiffness;

[0013] In the process of calculating the vibration response of the SFD rotor system according to the speed change during acceleration and deceleration, the vibration response analysis method of the SFD rotor system during acceleration and deceleration also includes determining whether the vibration response calculation is in a nonlinear change process according to the nonlinearity judgment criterion.

[0014] The nonlinear judgment criterion includes: the displacement response value is greater than the critical vibration displacement value.

[0015] Optionally, the nonlinear judgment criterion further includes: the current rotational speed is less than the critical rotational speed corresponding to the current rotational speed;

[0016] The critical speed corresponding to the current speed is the critical speed calculated based on the previous speed of the current speed.

[0017] Optionally, during the process of stiffness changing with rotational speed, the nonlinear vibration response is calculated according to the following formula:

[0018]

[0019] Where M is the mass of the SFD rotor system; D(ω,x′) is the damping of the SFD rotor system; K(ω,x′) is the stiffness of the SFD rotor system; mr is the unbalance of the SFD rotor system; ω is the current rotational speed of the rotor; and x is the displacement response value at the current rotational speed. The first derivative of x; is the second derivative of x; x′ is the initial displacement response value; D, K, ω, x, and x′ are all functions of time.

[0020] Optionally, the step of calculating the vibration response of the SFD rotor system according to the speed change during acceleration and deceleration includes:

[0021] Linear analysis calculations were performed on the SFD rotor system to obtain the linear response results;

[0022] The response in the linear response result is judged according to the speed change sequence of the rising and falling rotation. If the stiffness changes with the speed, the result of the vibration response calculation in the nonlinear method is used to replace the corresponding data in the linear response result to form the vibration response result.

[0023] Optionally, the step of calculating the vibration response of the SFD rotor system according to the speed change during acceleration and deceleration further includes:

[0024] The vibration response results are organized and the organized results are used as the final analysis results;

[0025] The vibration response results are processed using envelope calculation.

[0026] Optionally, the steps of constructing the SFD rotor system include: constructing the SFD dynamic model;

[0027] The steps for constructing the SFD dynamics model include:

[0028] Construct a structural model; wherein the structural model includes an installation edge, an inner oil film ring, and an outer oil film ring, the inner oil film ring and the outer oil film ring are both connected to the installation edge, and an extruded oil film is formed between the inner oil film ring and the outer oil film ring;

[0029] Dynamic modeling is performed to form the dynamic model of the SFD; wherein, dynamic modeling includes constructing the stiffness of the mounting edge, the stiffness of the oil film, the stiffness of the inner ring of the oil film, the stiffness of the outer ring of the oil film, and the oil film damping. The stiffness of the oil film and the stiffness of the outer ring of the oil film are connected in series and then connected in parallel with the stiffness of the inner ring of the oil film to form the stiffness of the SFD.

[0030] Optionally, the step of constructing the SFD rotor system further includes: constructing the SFD rotor system using an SFD dynamics model; wherein the SFD rotor system includes a rotor model and a rotor pivot model, the rotor pivot model supports the rotor model, and the rotor pivot model includes the SFD dynamics model.

[0031] Optionally, the step of determining the initial displacement response value based on the displacement response corresponding to a preset number of rotational speeds before the current rotational speed includes:

[0032] The initial displacement response value is obtained by calculating a simple average or weighted average value based on the displacement response corresponding to a preset number of rotational speeds before the current rotational speed.

[0033] A vibration response analysis system for the rising and falling rotation process of an SFD rotor system, the vibration response analysis system for the rising and falling rotation process of the SFD rotor system comprising:

[0034] A construction module is provided for constructing an SFD rotor system; wherein the SFD rotor system includes an SFD dynamic model, and in the SFD dynamic model, the stiffness varies with the rotational speed;

[0035] The calculation module is used to perform vibration response calculations on the SFD rotor system sequentially according to the speed change during acceleration and deceleration. When the vibration response is in a nonlinear change process, a nonlinear vibration response calculation is used, which includes: determining an initial displacement response value; wherein the initial displacement response value is determined based on the displacement response corresponding to a preset number of speeds before the current speed; and the calculation module is also used to obtain the stiffness and damping values ​​at the current speed based on the SFD dynamic model and the initial displacement response value, and to calculate the displacement response value based on the stiffness and damping values ​​at the current speed.

[0036] The beneficial effects of the vibration response analysis method and system for the rising and falling process of the SFD rotor system provided in the embodiments of the present invention include:

[0037] This invention provides a vibration response analysis method for an SFD rotor system during acceleration and deceleration. The method includes constructing an SFD rotor system, wherein the SFD rotor system includes an SFD dynamic model, and in the SFD dynamic model, the stiffness varies with the rotational speed. Vibration response calculations are performed on the SFD rotor system sequentially according to the rotational speed changes during acceleration and deceleration. During nonlinear changes in the vibration response, a nonlinear vibration response calculation is employed, which includes: determining an initial displacement response value; wherein the initial displacement response value is determined based on the displacement responses corresponding to a preset number of rotational speeds prior to the current rotational speed; obtaining the stiffness and damping values ​​at the current rotational speed based on the SFD dynamic model and the initial displacement response value; and calculating the displacement response value based on the stiffness and damping values ​​at the current rotational speed. By obtaining the initial displacement response value in advance and using it to obtain the stiffness and damping values ​​at the current rotational speed, the vibration displacement response value under nonlinear conditions can be calculated, thereby obtaining the vibration response analysis results under nonlinear conditions.

[0038] Embodiments of the present invention also provide a vibration response analysis system for the rising and falling rotation process of an SFD rotor system. By obtaining an initial displacement response value in advance and using the initial displacement response value to obtain the stiffness value and damping value at the current rotational speed, the system can calculate the vibration displacement response value under nonlinear conditions, thereby obtaining the vibration response analysis results under nonlinear conditions. Attached Figure Description

[0039] The above-described features and advantages of the present invention will be better understood after reading the following detailed description of embodiments of the present disclosure in conjunction with the accompanying drawings. In the drawings, components are not necessarily drawn to scale, and components having similar related characteristics or features may have the same or similar reference numerals.

[0040] Figure 1 A step diagram illustrating the vibration response analysis method for the rising and falling rotation process of an SFD rotor system according to one aspect of the present invention is shown.

[0041] Figure 2 A schematic diagram of a structural model provided according to one aspect of the present invention is shown;

[0042] Figure 3 A schematic diagram of the structure for SFD dynamics modeling provided according to one aspect of the present invention is shown;

[0043] Figure 4 A schematic diagram of the oil film radius gap in an SFD model under static conditions provided according to one aspect of the present invention is shown;

[0044] Figure 5 A schematic diagram of the eccentricity in an SFD model during rotor operation is shown according to one aspect of the present invention;

[0045] Figure 6 The figure shows the variation curves of stiffness and eccentricity in the SFD dynamic model provided according to one aspect of the present invention;

[0046] Figure 7 A diagram showing the damping characteristic relationship in an SFD dynamic model provided according to one aspect of the present invention is shown;

[0047] Figure 8 A dynamic model of an SFD rotor system according to one aspect of the present invention is shown;

[0048] Figure 9 A flowchart of the execution step S02 provided according to one aspect of the present invention is shown;

[0049] Figure 10 A graph showing multiple calculation results obtained in execution step S02 according to one aspect of the present invention is shown.

[0050] Figure 11 A comparison diagram of vibration response during lifting and lowering rotation according to one aspect of the present invention is shown;

[0051] Figure 12 A comparative diagram of several results provided according to one aspect of the present invention is shown.

[0052] Figure label:

[0053] 100 - SFD rotor system; 111 - Rotor model; 112 - Rotor pivot model; 120 - Structural model; 121 - Mounting edge; 122 - Inner oil film ring; 123 - Outer oil film ring; 124 - Extruded oil film; 125 - SFD dynamic model; 131 - First curve; 132 - Second curve. Detailed Implementation

[0054] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should be noted that the aspects described below with reference to the accompanying drawings and specific embodiments are merely exemplary and should not be construed as limiting the scope of protection of the present invention in any way.

[0055] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," "outer," or "vertical" appear, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed when in use, and does not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0056] At the same time, it should be noted that the terms "first" and "second" are used only for distinguishing descriptions and should not be interpreted as indicating or implying relative importance.

[0057] In the description of this invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an integral connection, or a detachable connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or a connection within two components, etc. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0058] Figure 1 This diagram illustrates the steps of the vibration response analysis method for the SFD rotor system during the rising and falling rotation process provided in this embodiment. Please refer to the attached diagram. Figure 1 This embodiment provides a vibration response analysis method for the rising and falling rotation process of an SFD rotor system.

[0059] Specifically, the vibration response analysis method for the SFD rotor system during the lifting and lowering process includes the following steps:

[0060] S01: Construct the SFD rotor system 100.

[0061] Since vibration response analysis of the SFD rotor system 100 is required under nonlinear conditions, the constructed dynamic model of the SFD rotor system 100 must possess nonlinear capabilities. Specifically, the steps for constructing the SFD rotor system include:

[0062] S11: Construct the SFD dynamic model 125.

[0063] Figure 2 A schematic diagram of the structural model 120 provided in this embodiment is shown. Figure 3 This diagram illustrates the structure of the SFD dynamics modeling provided in this embodiment. Please refer to the reference diagram. Figure 2 and Figure 3 In this embodiment, the step of constructing the SFD dynamic model 125 includes: constructing a structural model 120. The structural model 120 includes a mounting edge 121, an inner oil film ring 122, and an outer oil film ring 123. Both the inner and outer oil film rings 122 and 123 are connected to the mounting edge 121, and a compression oil film 124 is formed between the inner and outer oil film rings 122 and 123. Specifically, the inner oil film ring 122 is a squirrel cage spring support, and the outer oil film ring 123 is a limiter.

[0064] The steps in constructing the SFD dynamic model 125 also include: dynamic modeling. For example... Figure 3As shown, the dynamic modeling includes constructing the stiffness k1 of the mounting edge 121, the oil film stiffness k2, the stiffness k3 of the inner oil film ring 122, the stiffness k4 of the outer oil film ring 123, and the oil film damping D2. The oil film stiffness k2 and the stiffness k4 of the outer oil film ring 123 are connected in series, and then connected in parallel with the stiffness k3 of the inner oil film ring 122 to form the stiffness K of the SFD. SFD The stiffness K of SFD SFD It is connected in series with the stiffness k1 of the mounting edge 121 to form the fulcrum stiffness K.

[0065] Figure 4 This embodiment shows a schematic diagram of the oil film radius gap in the SFD model under static conditions. Figure 5 This embodiment shows a schematic diagram of the eccentricity in the SFD model during rotor operation. Figure 5 The lower boundary of the eccentricity shown is the lower boundary position of the extruded oil film 124 in the SFD model under static conditions. Please refer to the reference. Figures 2-5 In this embodiment, the oil film radius gap under static conditions is Cr, and during rotor operation, the eccentricity of the inner ring 122 of the oil film is e, and the eccentricity ε is ε=e / Cr.

[0066] The stiffness and damping characteristics of an SFD are related to the eccentricity ε and the rotor speed ω, meaning they are functions of ε and ω. Therefore, dynamic modeling of an SFD requires defining its stiffness K. SFD The functional relationship between k2 and (ε, ω). k2 = f(ε, ω) is a function related to the rotational speed ω, therefore, during the rising and falling rotation process, K... SFD It will change with the rotation speed.

[0067] Figure 6 The graph showing the variation curves of stiffness and eccentricity in the SFD dynamic model 125 provided in this embodiment is shown. Figure 6 As shown, the horizontal axis represents eccentricity, and the vertical axis represents stiffness. When the eccentricity is less than 0.4, k2 = 0, therefore K SFD =k3, at this time K SFD This is a constant value. When the eccentricity is greater than 0.4 and less than 1, k2 exhibits a curvilinear change. Therefore, correspondingly, the stiffness k24 obtained by connecting the oil film stiffness k2 and the stiffness k4 of the outer ring 123 of the oil film in series also exhibits a curvilinear change, thus yielding K. SFD It also exhibits a curved change. When the eccentricity is greater than or equal to 1, it indicates that the eccentricity e is equal to the oil film radius clearance Cr under static conditions. At this point, the oil film clearance does not exist, and the stiffness K of the SFD... SFD This is equivalent to the inner ring 122 stiffness k3 and the outer ring 123 stiffness k4 of the oil film being connected in parallel, at which point K SFD = k3 + k4. Therefore, K SFD The change curve is as follows Figure 6The first curve 131 in the figure is shown.

[0068] Due to the stiffness K of SFD SFD The stiffness K is formed by connecting the stiffness k1 of the mounting edge 121 in series. Therefore, the stiffness K of the SFD is... SFD Once the variation law of the support stiffness K is clarified, the variation law of the support stiffness K is also clarified. The variation curve of the support stiffness K is as follows: Figure 6 The second curve 132 is shown in the figure.

[0069] Figure 7 A schematic diagram of the damping characteristics in the SFD dynamic model 125 is given, illustrating three modes: line segment ABE represents the constant damping mode, line segment ABCD represents the enhanced damping mode, and line segment ANFG represents the weakened damping mode. Selecting a specific variation mode or compiling other damping modes and substituting them into the SFD dynamic model will affect the calculated vibration response of the rotor system.

[0070] S12: The SFD rotor system 100 is constructed using the SFD dynamic model 125.

[0071] Figure 8 A dynamic model of the SFD rotor system 100 provided in this embodiment is shown. For example... Figure 8 As shown, the SFD rotor system 100 includes a rotor model 111 and a rotor pivot model 112. The rotor pivot model 112 supports the rotor model 111, and the rotor pivot model 112 includes an SFD dynamic model 125, meaning the pivot stiffness is the pivot stiffness K formed in the SFD dynamic model 125. In such a case... Figure 8 In the model shown, the rotor model 111 is supported by two rotor support point models 112, which are the first support point and the second support point, respectively. The stiffness of the first support point is K. Z1 The stiffness of the second support point is K. Z2 .at the same time, Figure 8 D Z1 M represents the damping of the rotor system, and M represents the mass of the rotor.

[0072] Generally, the motion laws of a dynamic model can be described by dynamic equations. The dynamic equations are:

[0073]

[0074] Where M is the mass of the SFD rotor system 100; D(ω,x) is the damping of the SFD rotor system 100; K(ω,x) is the stiffness of the SFD rotor system 100; mr is the unbalance of the SFD rotor system 100; ω is the current rotational speed of the rotor; and x is the displacement response value at the current rotational speed. The first derivative of x; Let x be the second derivative of x; t be time. Specifically, the mass, damping, and stiffness of the SFD rotor system 100 are all represented by matrices.

[0075] S02: Perform vibration response calculations on the SFD rotor system 100 according to the speed changes during acceleration and deceleration.

[0076] Specifically, since the rotational speed changes differently during acceleration and deceleration, step S02 requires calculating the vibration response during acceleration by increasing speed and calculating the vibration response during deceleration by decreasing speed. The following explanation uses the vibration response calculation during acceleration as an example to illustrate the specific process of step S02. Figure 9 A flowchart of step S02 in this embodiment is shown. Figure 10 The diagram shows a graph of multiple calculation results obtained in step S02 of this embodiment, and... Figure 10 In the diagram, Z1 represents the vibration response displacement entering the nonlinear phase, and Z2 represents the vibration response displacement reaching the oil film gap Cr. Please refer to [reference needed]. Figure 9 and Figure 10 The process of step S02 includes:

[0077] S21: Perform linear analysis calculations on the SFD rotor system 100 to obtain the linear response results.

[0078] Specifically, when performing linear analysis calculations on the SFD rotor system 100, it is assumed that the stiffness of the SFD rotor system 100 does not change with the rotational speed, and K can be used as an example. SFD Linear analysis was performed on k3 to obtain the linear response result, which is: Figure 10 The curve A1 shown in the figure.

[0079] S22: Judge the response in the linear response result according to the speed change sequence of the acceleration.

[0080] If the stiffness varies with the rotational speed, the result of the nonlinear vibration response calculation is used to replace the corresponding data in the linear response result to form the vibration response result. Specifically, this vibration response result is... Figure 10 The graph shown is line A2.

[0081] It should be noted that the vibration response analysis during acceleration is used as an example for illustration. If the vibration response analysis during deceleration is performed, step S22 is to judge the response in the linear influence result according to the speed change sequence during deceleration.

[0082] Furthermore, when performing step 22, a nonlinear judgment criterion can be formulated to determine whether the vibration response is in a nonlinear change process.

[0083] In this embodiment, the nonlinearity criterion includes: the displacement response value is greater than the critical vibration displacement value. The critical vibration displacement value is obtained from the variation law of high stiffness and vibration displacement based on the SFD dynamic model 125. Specifically, the critical vibration displacement value is the vibration displacement value at the boundary between linear and nonlinear changes in stiffness. Optionally, in this embodiment, as... Figure 6 As shown, the critical vibration displacement value is the eccentricity e when the eccentricity ε is 0.4.

[0084] Furthermore, the nonlinear judgment criterion also includes: the current rotational speed is less than the critical rotational speed corresponding to the current rotational speed. This critical rotational speed is calculated based on the previous rotational speed. Specifically, since this embodiment performs vibration response analysis during acceleration, the previous rotational speed is a speed less than the previous calculation point of the current rotational speed. It is understandable that in other embodiments, when performing vibration response analysis during deceleration, the previous rotational speed is a speed greater than the previous calculation point of the current rotational speed.

[0085] When the vibration response is determined to be in a nonlinear change process according to the nonlinearity criterion, a nonlinear method is used to calculate the vibration response. Since the stiffness and damping values ​​of the SFD rotor system 100 change with the rotational speed during the nonlinear change process, and this change is related to the displacement response value x at the current rotational speed, it is difficult to directly calculate the displacement response value x using formula 1. To calculate the displacement response value x, it can be achieved using the following formula:

[0086]

[0087] Where M is the mass of the SFD rotor system 100; D(ω,x′) is the damping of the SFD rotor system 100; K(ω,x′) is the stiffness of the SFD rotor system 100; mr is the unbalance of the SFD rotor system 100; ω is the current rotational speed of the rotor; and x is the displacement response value at the current rotational speed. The first derivative of x; ω is the second derivative of x; x′ is the initial displacement response value; D, K, ω, x, and x′ are all functions of time.

[0088] In Equation 2, the damping and stiffness of the SFD rotor system 100 are determined by the initial displacement response value. Therefore, the calculation of this nonlinear vibration response includes the following steps:

[0089] S221: Determine the initial displacement response value.

[0090] The initial displacement response is determined based on the displacement response values ​​corresponding to a preset number of speeds prior to the current speed. Specifically, the number of preset speeds can be set according to requirements, for example, it can be determined based on the displacement responses corresponding to the six speeds prior to the current speed.

[0091] Optionally, the initial displacement response value can be calculated using a simple average or a weighted average of the displacement response values ​​corresponding to a preset number of rotational speeds before the current rotational speed. Specifically, the simple average is the average of the sum of multiple displacement response values ​​divided by the number of values, while the weighted average is the average obtained by assigning different weights to different displacement response values. For example, a larger weight can be assigned to displacement response values ​​closer to the current rotational speed, and a smaller weight can be assigned to displacement response values ​​farther from the current rotational speed. It is understood that in some other embodiments, other methods can also be used to determine the initial displacement response value.

[0092] S222: Obtain the stiffness and damping values ​​at the current rotational speed based on the SFD dynamic model 125 and the initial displacement response values.

[0093] Given the SFD dynamic model 125 and the initial displacement response value, according to Figure 6 and Figure 7 The variation diagram shown can be used to obtain the stiffness and damping values ​​under the initial displacement response value.

[0094] S223: Calculate the displacement response value based on the stiffness and damping values ​​at the current rotational speed.

[0095] Substituting the stiffness and damping values ​​obtained in step S222 into Formula 2, the displacement response value can be calculated. The calculated displacement response value is then used to replace the corresponding data in the linear response structure to form the vibration response result.

[0096] Correspondingly, the critical speed value at the current speed can also be calculated. After the relevant calculations for the current speed are completed, if the current speed is the last speed, it means that the vibration response calculation is over. If the current speed is not the last speed, a nonlinear determination is made for the next speed. That is, if the eccentricity of the next speed is greater than 0.4 and less than the critical speed value, it is considered to be in a nonlinear state, and the process of steps S221 to S223 needs to be repeated until the last speed is calculated.

[0097] S23: Organize the vibration response results and use the organized results as the final analysis results.

[0098] After obtaining the vibration response results, these results can be processed and used as the final analysis result. This analysis result is as follows: Figure 10Curve A3 in the figure. Optionally, the vibration response results can be processed using envelope calculation, i.e., the maximum value in the vibration response results can be taken.

[0099] at the same time, Figure 11 A comparison graph of vibration response during lifting and rotating is shown. Figure 11 The results shown by the solid line are the vibration response analysis results under the condition of speed increase. Figure 11 The results shown by the dashed line are the vibration response analysis results under reduced rotation conditions. Figure 11 It can be seen that the vibration response results during lifting and rotating are not the same.

[0100] Figure 12 A comparison chart of multiple results is shown. Figure 12 In the diagram, the thin dashed line represents the linear analysis result, the solid line represents the nonlinear analysis structure (i.e., the analysis result obtained in step S23 of this embodiment), and the long dashed line represents the measured data. According to... Figure 12 It can be seen that the analysis results obtained from the embodiments of the present invention are closer to the measured data than the linear analysis results, and the analysis accuracy is higher.

[0101] Embodiments of the present invention also provide a vibration response analysis system for the rising and falling rotation process of an SFD rotor system, which can realize the above-mentioned vibration response analysis method for the rising and falling rotation process of an SFD rotor system. Specifically, the vibration response analysis system for the rising and falling rotation process of an SFD rotor system includes:

[0102] A construction module is provided for constructing an SFD rotor system 100, wherein the SFD rotor system 100 includes an SFD dynamic model 125, and in the SFD dynamic model 125, the stiffness varies with the rotational speed. Specifically, this construction module can be used to perform the above step S01.

[0103] The calculation module is used to perform vibration response calculations on the SFD rotor system 100 sequentially according to the speed changes during acceleration and deceleration. When the vibration response is nonlinearly changing, a nonlinear vibration response calculation is used, which includes: determining the initial displacement response value; wherein the initial displacement response value is determined based on the displacement response corresponding to a preset number of speeds before the current speed; and the calculation module is also used to obtain the stiffness and damping values ​​at the current speed based on the SFD dynamic model 125 and the initial displacement response value, and to calculate the displacement response value based on the stiffness and damping values ​​at the current speed. Specifically, this calculation module can be used to execute the above step S02.

[0104] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A vibration response analysis method for an SFD rotor system during the rising and falling rotation process, characterized in that, The vibration response analysis method for the SFD rotor system during the rising and falling rotation process includes: Construct an SFD rotor system; wherein the SFD rotor system includes an SFD dynamic model, and in the SFD dynamic model, the stiffness varies with the rotational speed; The vibration response of the SFD rotor system is calculated sequentially according to the speed change during acceleration and deceleration. During the nonlinear change of the vibration response, a nonlinear vibration response calculation is performed, which includes: determining the initial displacement response value; wherein the initial displacement response value is determined based on the displacement response corresponding to a preset number of speeds prior to the current speed; obtaining the stiffness and damping values ​​at the current speed based on the SFD dynamic model and the initial displacement response value; and calculating the displacement response value based on the stiffness and damping values ​​at the current speed.

2. The vibration response analysis method for the lifting and lowering process of the SFD rotor system according to claim 1, characterized in that, The vibration response analysis method for the SFD rotor system during the rising and falling rotation process also includes: The variation law of stiffness and vibration displacement is obtained according to the SFD dynamic model; wherein, the variation law includes the critical vibration displacement value; wherein, the critical vibration displacement value is the vibration displacement value at the boundary between linear and nonlinear changes in stiffness; In the process of calculating the vibration response of the SFD rotor system according to the speed change during acceleration and deceleration, the vibration response analysis method of the SFD rotor system during acceleration and deceleration also includes determining whether the vibration response calculation is in a nonlinear change process according to the nonlinearity judgment criterion. The nonlinear judgment criterion includes: the displacement response value is greater than the critical vibration displacement value.

3. The vibration response analysis method for the rising and falling process of the SFD rotor system according to claim 2, characterized in that, The nonlinear judgment criterion further includes: the current rotational speed is less than the critical rotational speed corresponding to the current rotational speed; The critical speed corresponding to the current speed is the critical speed calculated based on the previous speed of the current speed.

4. The vibration response analysis method for the lifting and lowering process of the SFD rotor system according to claim 1, characterized in that, During the process of stiffness changing with rotational speed, the nonlinear vibration response is calculated according to the following formula: Where M is the mass of the SFD rotor system; D(ω,x′) is the damping of the SFD rotor system; K(ω,x′) is the stiffness of the SFD rotor system; mr is the unbalance of the SFD rotor system; ω is the current rotational speed of the rotor; and x is the displacement response value at the current rotational speed. The first derivative of x; is the second derivative of x; x′ is the initial displacement response value; D, K, ω, x, and x′ are all functions of time.

5. The vibration response analysis method for the lifting and lowering process of the SFD rotor system according to claim 1, characterized in that, The steps for calculating the vibration response of the SFD rotor system according to the speed change during acceleration and deceleration include: Linear analysis calculations were performed on the SFD rotor system to obtain the linear response results; The response in the linear response result is judged according to the speed change sequence of the rising and falling rotation. If the stiffness changes with the speed, the result of the vibration response calculation in the nonlinear method is used to replace the corresponding data in the linear response result to form the vibration response result.

6. The vibration response analysis method for the rising and falling process of the SFD rotor system according to claim 5, characterized in that, The step of calculating the vibration response of the SFD rotor system according to the speed change during acceleration and deceleration also includes: The vibration response results are organized and the organized results are used as the final analysis results; The vibration response results are processed using envelope calculation.

7. The vibration response analysis method for the rising and falling rotation process of the SFD rotor system according to claim 1, characterized in that, The steps for constructing an SFD rotor system include: constructing the SFD dynamic model; The steps for constructing the SFD dynamics model include: Construct a structural model; wherein the structural model includes an installation edge, an inner oil film ring, and an outer oil film ring, the inner oil film ring and the outer oil film ring are both connected to the installation edge, and an extruded oil film is formed between the inner oil film ring and the outer oil film ring; Dynamic modeling is performed to form the dynamic model of the SFD; wherein, dynamic modeling includes constructing the stiffness of the mounting edge, the stiffness of the oil film, the stiffness of the inner ring of the oil film, the stiffness of the outer ring of the oil film, and the oil film damping. The stiffness of the oil film and the stiffness of the outer ring of the oil film are connected in series and then connected in parallel with the stiffness of the inner ring of the oil film to form the stiffness of the SFD.

8. The vibration response analysis method for the rising and falling process of the SFD rotor system according to claim 7, characterized in that, The steps for constructing an SFD rotor system further include: constructing an SFD rotor system using an SFD dynamics model; wherein the SFD rotor system includes a rotor model and a rotor pivot model, the rotor pivot model supports the rotor model, and the rotor pivot model includes the SFD dynamics model.

9. The vibration response analysis method for the rising and falling process of the SFD rotor system according to claim 1, characterized in that, The steps for determining the initial displacement response value based on the displacement response corresponding to a preset number of rotational speeds before the current rotational speed include: The initial displacement response value is obtained by calculating a simple average or weighted average value based on the displacement response corresponding to a preset number of rotational speeds before the current rotational speed.

10. A vibration response analysis system for the rising and falling rotation process of an SFD rotor system, characterized in that, The vibration response analysis system for the SFD rotor system during the rising and falling rotation process includes: A construction module is provided for constructing an SFD rotor system; wherein the SFD rotor system includes an SFD dynamic model, and in the SFD dynamic model, the stiffness varies with the rotational speed; The calculation module is used to perform vibration response calculations on the SFD rotor system sequentially according to the speed change during acceleration and deceleration. When the vibration response is in a nonlinear change process, a nonlinear vibration response calculation is used, which includes: determining an initial displacement response value; wherein the initial displacement response value is determined based on the displacement response corresponding to a preset number of speeds before the current speed; and the calculation module is also used to obtain the stiffness and damping values ​​at the current speed based on the SFD dynamic model and the initial displacement response value, and to calculate the displacement response value based on the stiffness and damping values ​​at the current speed.

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