Propulsion shafting abnormal torsional vibration suppression method, device and equipment and storage medium

Abstract

The invention discloses a method, device and equipment for inhibiting abnormal torsional vibration of a propulsion shafting and a storage medium, and relates to the technical field of ship propulsion systems.The method comprises the steps that the torsional vibration inherent frequency and the torsional vibration modal shape corresponding to the abnormal torsional vibration frequency of the propulsion shafting are matched; calculating the modal mass and the modal damping ratio of the abnormal torsional vibration of the matching order, and calculating the bearing reaction at the rear stern bearing and the front stern bearing; fitting friction coefficients among the rear stern bearing, the front stern bearing and the propulsion shafting; according to the reaction force, the friction coefficient and the matched torsional vibration modal shape, calculating a friction excitation torque under the torsional vibration modal shape of the corresponding order and a Taylor expansion coefficient corresponding to the friction excitation torque; and according to the matched inherent frequency of the torsional vibration, the modal mass, the modal damping ratio and the Taylor expansion coefficient, a suppression device used for generating electrical damping is arranged on the propulsion shafting so as to suppress the abnormal torsional vibration. According to the application, the abnormal torsional vibration can be accurately suppressed by accurately designing the structural parameters of the suppression device.

Description

Technical Field

[0001] The present application relates to the technical field of ship propulsion systems, and particularly relates to a method, device, equipment and storage medium for suppressing abnormal torsional vibration of a propulsion shafting system. Background Art

[0002] The propulsion shafting system of a ship is a mechanical transmission system that connects the ship's power plant and the propeller. Its main function is to transmit the power and torque generated by the engine to the propeller, thereby pushing the ship forward.

[0003] During the operation of the propulsion shafting system, the frictional excitation generated by the water lubricated bearing may induce abnormal torsional vibration, and further cause vibration noise, which has an adverse effect on the smooth operation of the propulsion shafting system.

[0004] However, in the prior art, there is no effective measure to suppress the abnormal torsional vibration induced by frictional excitation in the propulsion shafting system. The reason is that the generation mechanism is not well understood, the specific conditions and boundary ranges of its occurrence are not clearly recognized, and the current methods require frequent on-site collection of vibration data, which is relatively cumbersome to operate. Summary of the Invention

[0005] The present application provides a method, device, equipment and storage medium for suppressing abnormal torsional vibration of a propulsion shafting system, which can accurately suppress abnormal torsional vibration by precisely designing the structural parameters of the suppression device.

[0006] In a first aspect, an embodiment of the present application provides a method for suppressing abnormal torsional vibration of a propulsion shafting system, the method for suppressing abnormal torsional vibration of the propulsion shafting system comprising:

[0007] Matching the torsional vibration natural frequency and torsional vibration mode shape corresponding to the abnormal torsional vibration frequency of the propulsion shafting system;

[0008] Calculating the modal mass and modal damping ratio of the abnormal torsional vibration of the matching order, and calculating the reaction forces at the aft bearing and the forward aft bearing;

[0009] Fitting the friction coefficients between the aft bearing, the forward aft bearing and the propulsion shafting system;

[0010] Calculating the frictional excitation torque under the torsional vibration mode shape of the corresponding order and the Taylor expansion coefficients corresponding to the frictional excitation torque according to the reaction forces, the friction coefficients and the matched torsional vibration mode shape;

[0011] Setting a suppression device for generating electrical damping on the propulsion shafting system according to the matched torsional vibration natural frequency, modal mass, modal damping ratio and Taylor expansion coefficients to suppress abnormal torsional vibration.

[0012] In combination with the first aspect, in one embodiment, the suppression device includes a sleeve for sleeving on the propulsion shafting. A plurality of piezoelectric ceramic sheets are electrically connected to the sleeve, and a load resistor is further connected to one piezoelectric ceramic sheet.

[0013] In combination with the first aspect, in one embodiment, the suppression device for generating electrical damping is provided on the propulsion shafting according to the matched torsional vibration natural frequency, modal mass, modal damping ratio, and Taylor expansion coefficient, and includes:

[0014] Set the structural parameters of the suppression device to satisfy:

[0015]

[0016] In the formula, ξ j is the matched modal damping ratio, γ 1,j is the Taylor expansion coefficient, M j is the matched modal mass, ω j is the matched torsional vibration natural frequency, κ is the first electromechanical coupling coefficient, and Γ is the second electromechanical coupling coefficient;

[0017] Among them, κ and Γ satisfy:

[0018] κ = C p ω j R L ,

[0019] In the formula, R L is the load resistor, C p is the total capacitance after all piezoelectric ceramic sheets are connected in parallel, and υ is the third electromechanical coupling coefficient;

[0020] Among them, υ and C p satisfy:

[0021]

[0022] In the formula, d 15 is the piezoelectric coefficient of the piezoelectric ceramic material, G p is the shear modulus of the piezoelectric ceramic, n p is the number of piezoelectric ceramic sheets, R p is the radius of the piezoelectric ceramic sheet pasting position, h p is the thickness of the piezoelectric ceramic sheet, L p1 and L p2 are the distances from the head and end of the suppression device to the center of the propeller, is the dielectric constant of the piezoelectric ceramic sheet, and a is the central angle corresponding to the width of each piezoelectric ceramic sheet.

[0023] In combination with the first aspect, in one embodiment, the friction coefficients between the fitted stern bearing, the forward stern bearing and the propulsion shafting include:

[0024] According to the formula: The friction coefficient between the fitted stern bearing and the propulsion shafting;

[0025] In the formula, μ b is the friction coefficient between the rear stern bearing bush and the propulsion shafting, μ b,1 is the dynamic friction coefficient between the rear stern bearing and the propulsion shafting, μ b,0 is the static friction coefficient between the rear stern bearing and the propulsion shafting, a b is a constant, R b is the outer radius of the shafting at the rear stern bearing, ω is the relative angular velocity between the bearing bush and the shafting surface, and sign() is the sign function;

[0026] According to the formula: The friction coefficient between the forward stern bearing and the propulsion shafting;

[0027] In the formula, μ f is the friction coefficient between the forward stern bearing bush and the propulsion shafting, μ f,1 is the dynamic friction coefficient between the forward stern bearing and the propulsion shafting, μ f,0 is the static friction coefficient between the forward stern bearing and the propulsion shafting, a f is a constant, R f is the outer radius of the shafting at the forward stern bearing bush, ω is the relative angular velocity between the bearing bush and the shafting surface, and sign() is the sign function.

[0028] In combination with the first aspect, in one embodiment, calculating the friction excitation torque corresponding to the torsional vibration mode shape of the corresponding order and the Taylor expansion coefficient corresponding to the friction excitation torque according to the support reaction force, the friction coefficient and the matched torsional vibration mode shape includes:

[0029] According to the formula:

[0030]

[0031] Calculate the friction excitation torque corresponding to the torsional vibration mode shape of the corresponding order;

[0032] In the formula, F j is the friction excitation torque corresponding to the torsional vibration mode shape of the corresponding order, and are the mode shape values at the rear stern bearing and the forward stern bearing respectively under the torsional vibration mode shape of the corresponding order, N b and N f are the support reaction forces at the rear stern bearing and the forward stern bearing respectively, R b and R fare the outer radii at the aft shaft bearing and the forward shaft bearing of the shafting respectively, Ω is the rotational speed of the shafting, and q j (t) is the torsional vibration displacement in the torsional vibration mode coordinate system of the corresponding order;

[0033] According to the formula: perform Taylor expansion on the friction excitation torque;

[0034] In the formula, γ 0,j 、γ 1,j 、γ 2,j 、γ 3,j are the coefficients of the Taylor expansion;

[0035] Among them, γ 1,j is expressed as:

[0036]

[0037] Combined with the first aspect, in one implementation manner, the torsional vibration natural frequency and modal vibration mode corresponding to the abnormal torsional vibration frequency of the matching propulsion shafting include:

[0038] Determine the abnormal torsional vibration frequency of the propulsion shafting;

[0039] Establish a torsional vibration analysis model of the propulsion shafting, and obtain the torsional vibration natural frequencies at multiple orders of the torsional vibration analysis model;

[0040] Determine the torsional vibration natural frequency of the order closest to the abnormal torsional vibration frequency, and determine the torsional vibration modal vibration mode of the corresponding order.

[0041] Combined with the first aspect, in one implementation manner, it further includes:

[0042] Normalize the torsional vibration modal vibration mode of the abnormal torsional vibration according to the maximum absolute value.

[0043] In the second aspect, an embodiment of the present application provides a device for suppressing abnormal torsional vibration of a propulsion shafting, and the device for suppressing abnormal torsional vibration of the propulsion shafting includes:

[0044] A calculation module, which is used for:

[0045] Match the torsional vibration natural frequency and torsional vibration modal vibration mode corresponding to the abnormal torsional vibration frequency of the propulsion shafting;

[0046] Calculate the modal mass and modal damping ratio of the abnormal torsional vibration of the matching order, and calculate the reaction forces at the aft shaft bearing and the forward shaft bearing;

[0047] Fit the friction coefficients between the aft shaft bearing, the forward shaft bearing and the propulsion shafting;

[0048] Calculate the frictional excitation torque corresponding to the torsional vibration mode shape of the corresponding order and the Taylor expansion coefficients corresponding to the frictional excitation torque according to the reaction force, the friction coefficient, and the matching torsional vibration mode shape.

[0049] A setting module is configured to set a suppression device for generating electrical damping on the propulsion shafting according to the matching torsional natural frequency, modal mass, modal damping ratio, and Taylor expansion coefficients to suppress abnormal torsional vibration.

[0050] In a third aspect, an embodiment of the present application provides a device for suppressing abnormal torsional vibration of a propulsion shafting. The device for suppressing abnormal torsional vibration of the propulsion shafting includes a processor, a memory, and a program for suppressing abnormal torsional vibration of the propulsion shafting stored on the memory and executable by the processor. When the program for suppressing abnormal torsional vibration of the propulsion shafting is executed by the processor, the steps of the above-mentioned method for suppressing abnormal torsional vibration of the propulsion shafting are implemented.

[0051] In a fourth aspect, a computer-readable storage medium stores a program for suppressing abnormal torsional vibration of a propulsion shafting. When the program for suppressing abnormal torsional vibration of the propulsion shafting is executed by a processor, the steps of the above-mentioned method for suppressing abnormal torsional vibration of the propulsion shafting are implemented.

[0052] The beneficial effects brought by the technical solution provided by the embodiment of the present application at least include:

[0053] In the method for suppressing abnormal torsional vibration of the propulsion shafting in the present application, the torsional natural frequency and torsional vibration mode shape corresponding to the abnormal torsional vibration frequency of the propulsion shafting are matched; the modal mass and modal damping ratio of the abnormal torsional vibration of the corresponding order are calculated, and the reaction forces at the rear stern bearing and the front stern bearing are calculated; the friction coefficients between the rear stern bearing, the front stern bearing and the propulsion shafting are fitted; the frictional excitation torque corresponding to the torsional vibration mode shape of the corresponding order and the Taylor expansion coefficients corresponding to the frictional excitation torque are calculated according to the reaction force, the friction coefficient, and the matching torsional vibration mode shape; a suppression device for generating electrical damping is set on the propulsion shafting according to the matching torsional natural frequency, modal mass, modal damping ratio, and Taylor expansion coefficients to suppress abnormal torsional vibration.

[0054] Therefore, through detailed dynamic theory derivation, the present application obtains a critical discrimination formula for eliminating abnormal torsional vibration. By accurately designing the structural parameters of the suppression device to meet the requirements of the critical discrimination formula, abnormal torsional vibration can be accurately suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a schematic flowchart of an embodiment of the method for suppressing abnormal torsional vibration of the propulsion shafting in the present application;

[0056] Figure 2 It is a schematic installation diagram of the suppression device in the present application;

[0057] Figure 3 Schematic diagram of the structural composition of the suppression device of the present application;

[0058] Figure 4 Schematic diagram of the structural dimensions of the suppression device of the present application;

[0059] Figure 5 Simplified diagram of the propulsion shafting of the present application;

[0060] Figure 6 Time-domain and frequency-domain diagrams of abnormal torsional vibration of the propulsion shafting in Embodiment 1 of the present application, Figure 6 (a) is the time-domain curve diagram, Figure 6 (b) is the frequency-domain curve diagram;

[0061] Figure 7 Effect diagram of suppression after installing the suppression device in Embodiment 1 of the present application, Figure 7 (a) is the time-domain curve diagram, Figure 7 (b) is the frequency-domain curve diagram;

[0062] Figure 8 Time-domain and frequency-domain diagrams of abnormal torsional vibration of the propulsion shafting in Embodiment 2 of the present application, Figure 8 (a) is the time-domain curve diagram, Figure 8 (b) is the frequency-domain curve diagram;

[0063] Figure 9 Effect diagram of suppression after installing the suppression device in Embodiment 2 of the present application, Figure 9 (a) is the time-domain curve diagram, Figure 9 (b) is the frequency-domain curve diagram;

[0064] Figure 10 Structural block diagram of an embodiment of the abnormal torsional vibration suppression device for the propulsion shafting of the present application;

[0065] Figure 11 Schematic diagram of the hardware structure of the abnormal torsional vibration suppression equipment for the propulsion shafting involved in the embodiment solution of the present application. Detailed implementation manners

[0066] In order to enable those skilled in the art to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present application.

[0067] To make the purpose, technical solutions and advantages of the present application clearer, the embodiments of the present application will be further described in detail below in conjunction with the accompanying drawings.

[0068] In a first aspect, an embodiment of the present application provides a method for suppressing abnormal torsional vibration of a propulsion shafting system.

[0069] In one embodiment, with reference to Figure 1 , Figure 1 is a schematic flowchart of an embodiment of the method for suppressing abnormal torsional vibration of the propulsion shafting system of the present application. As Figure 1 shown, the method for suppressing abnormal torsional vibration of the propulsion shafting system includes:

[0070] S1. Match the torsional vibration natural frequency and the torsional vibration mode shape corresponding to the abnormal torsional vibration frequency of the propulsion shafting system;

[0071] Specifically, step S1 includes:

[0072] S11. Determine the abnormal torsional vibration frequency of the propulsion shafting system;

[0073] S12. Establish a torsional vibration analysis model of the propulsion shafting system, and obtain the torsional vibration natural frequencies at multiple orders of the torsional vibration analysis model;

[0074] S13. Determine the torsional vibration natural frequency of the order closest to the abnormal torsional vibration frequency, and determine the torsional vibration mode shape of the corresponding order.

[0075] In this embodiment, a torsional vibration analysis model of the propulsion shafting system can be established using finite element software, the torsional vibration natural frequencies and their mode shapes of the propulsion shafting system can be calculated based on the finite element model, and then it can be analyzed which order of torsional vibration natural frequency the abnormal torsional vibration belongs to. Preferably, the torsional vibration mode shape with abnormal vibration can also be normalized according to the maximum absolute value at the same time.

[0076] S2. Calculate the modal mass and modal damping ratio of the abnormal torsional vibration of the matching order, and calculate the reaction forces at the aft bearing and the forward aft bearing;

[0077] First, obtain the torsional vibration modal mass with abnormal vibration. Suppose the abnormal vibration occurs in the j-th order torsional vibration mode. Its modal mass can be directly obtained in finite element software such as ANSYS, or can be obtained by exporting the mass matrix M and the modal shape of the abnormal vibration and then calculating through the following formula:

[0078]

[0079] In the formula, is the normalized j-th order torsional vibration mode shape, is transpose matrix of, M j is the modal mass of the j-th order torsional vibration.

[0080] Then, obtain the modal damping ratio of the j-th torsional vibration mode of the propulsion shafting. The modal damping ratio can be obtained through modal experiments. If it is difficult to conduct modal tests on-site, an empirical value of 0.01 - 0.1 can be taken.

[0081] Finally, calculate the reaction forces N b and N f at the aft bearing and the forward aft bearing based on the finite element model.

[0082] S3. Fit the friction coefficients between the aft bearing, the forward aft bearing and the propulsion shafting;

[0083] The friction coefficients μ b between the aft shaft bearing and the shafting at different rotational speeds are provided by the manufacturer or measured experimentally. Use the following exponential function to fit the three coefficients of μ b,0 , μ b,1 , and a b :

[0084]

[0085] In the formula, μ b is the friction coefficient between the aft shaft bearing and the propulsion shafting, μ b,1 is the dynamic friction coefficient between the aft bearing and the propulsion shafting, μ b,0 is the static friction coefficient between the aft bearing and the propulsion shafting, a b is a constant, R b is the outer radius of the shafting at the aft bearing, ω is the relative angular velocity between the bearing bush and the surface of the propulsion shafting, and sign() is the sign function.

[0086] Similarly, the friction coefficients μ f between the forward aft shaft bearing and the shafting at different rotational speeds are provided by the manufacturer or measured experimentally. Use the following exponential function to fit the three coefficients of μ f,0 , μ f,1 , and a f :

[0087]

[0088] In the formula, μ f is the friction coefficient between the forward aft shaft bearing and the propulsion shafting, μ f,1 is the dynamic friction coefficient between the forward aft bearing and the propulsion shafting, μ f,0 is the static friction coefficient between the forward aft bearing and the propulsion shafting, a f is a constant, R f is the outer radius of the shafting at the forward aft bearing, ω is the relative angular velocity between the bearing bush and the surface of the propulsion shafting, and sign() is the sign function.

[0089] It should be noted that in this embodiment, only two water-lubricated bearings are considered. For a propulsion shafting system with three or more water-lubricated bearings, it can be extended to multiple bearings according to step S3.

[0090] S4. Calculate the friction excitation torque corresponding to the torsional vibration mode shape of the corresponding order and the Taylor expansion coefficients corresponding to the friction excitation torque according to the reaction force, friction coefficient, and the matched torsional vibration mode shape.

[0091] Specifically, using the reaction force and friction coefficient obtained above, combined with the obtained normalized j-th order mode shape, calculate the friction excitation torque F of the stern bearing and the propulsion shafting system in the j-th order mode shape. j :

[0092]

[0093] In the formula, F j is the friction excitation torque in the j-th mode, and are the mode shape values of the j-th torsional vibration mode at the aft stern bearing and the forward stern bearing respectively, N b and N f are the support reaction forces at the aft stern bearing and the forward stern bearing respectively, R b and R f are the outer radii of the propulsion shafting system at the aft stern bearing and the forward stern bearing respectively, Ω is the rotational speed of the propulsion shafting system, q j (t) is the torsional vibration displacement in the coordinate system of the j-th torsional vibration mode.

[0094] Then, expand F j in Taylor series:

[0095]

[0096] In the formula, γ 0,j , γ 1,j , γ 2,j , γ 3,j are the coefficients of the Taylor expansion, where γ 1,j can be expressed as:

[0097]

[0098] It should be noted that considering the occupied weight and the reason related to the parameters involved in the friction excitation torque, the Taylor expansion coefficients mainly consider γ 1,j ; since the torsional amplitude value of the propulsion shafting system is very small, most cases in engineering can be attributed to the first formula of Equation (6).

[0099] S5. According to the matched torsional natural frequency, modal mass, modal damping ratio, and Taylor expansion coefficients, a suppression device for generating electrical damping is set on the propulsion shafting to suppress abnormal torsional vibration.

[0100] Design a suppression device on the shaft as Figure 2 shown. There is no mandatory requirement for the installation position. However, if it is installed at a location where the vibration mode changes drastically, it will be easier to suppress the abnormal torsional vibration of this order. If there are abnormal vibrations in multiple torsional vibration modes, a suppression device can be installed at each location where the vibration mode of each abnormal torsional vibration mode changes drastically.

[0101] The detailed structure of the suppression device is as Figure 3 shown, and it consists of two half sleeves, n p piezoelectric ceramic sheets, a load resistor R L , and multiple bolts and nuts. The two half sleeves are clamped on the shaft by multiple (such as 6) bolts and nuts, so as to generate the same torsional vibration as the shafting. The piezoelectric ceramic sheets are bonded to the sleeves and are connected in parallel with each other, and work in the d 15 mode.

[0102] The working principle of this device is as follows: When the sleeve follows the torsional vibration of the rotating shaft, it drives the piezoelectric ceramic sheets to generate electricity and produces an electrical damping effect. By designing the load resistor R L , an electrical damping that can make the abnormal torsional vibration disappear can be generated.

[0103] The structural parameters to be designed for the suppression device are: length L p2 -L p1 , arrangement position [L p1 L p2 , the number of piezoelectric ceramic sheets n p , the thickness h p of the piezoelectric ceramic sheets, the central angle α corresponding to the piezoelectric ceramic, the outer radius R p of the sleeve, the load resistor R L , and the selection of the piezoelectric ceramic material.

[0104] By reasonably designing the structural parameters of the suppression device to make the critical discrimination formula (7) hold, the abnormal vibration of this order of torsional mode can be eliminated.

[0105]

[0106] In the formula, ξ j is the modal damping ratio of the j-th order abnormal torsional vibration, γ 1,j is the Taylor expansion coefficient, M j is the modal mass of the j-th order abnormal torsional vibration, ω jis the natural frequency of the j-th order abnormal torsional vibration. κ and Γ are the first and second electromechanical coupling coefficients respectively, and their values are related to the structural design parameters of the suppression device, and can be specifically expressed as:

[0107]

[0108] In the formula, R L is the load resistance, C p is the total capacitance after all piezoelectric ceramic sheets are connected in parallel, and υ is the third electromechanical coupling coefficient; among them, υ and C p The expressions are as follows:

[0109]

[0110] In the formula, d 15 is the piezoelectric coefficient of the piezoelectric ceramic material, G p is the shear modulus of the piezoelectric ceramic, n p is the number of piezoelectric ceramic sheets, R p is the radius of the position where the piezoelectric ceramic sheet is pasted, h p is the thickness of the piezoelectric ceramic sheet, L p1 and L p2 are the distances from the head and end of the suppression device to the center of the propeller, is the dielectric constant of the piezoelectric ceramic sheet, and a is the central angle corresponding to the width of each piezoelectric ceramic sheet (as Figure 4 shown).

[0111] It should be noted that in the suppression device, the piezoelectric ceramic sheets can be connected in series, in parallel, or in a series-parallel combination form, and only the total capacitance C p needs to be modified accordingly.

[0112] The critical discrimination formula (7) is obtained through rigorous derivation of the dynamic model, so the control accuracy is very high. When actually used, in order to make the suppression effect better, a safety factor of 1.2 can be taken, so formula (7) can be changed to:

[0113]

[0114] Among them, the derivation process of the critical discrimination formula (7) is as follows:

[0115] As Figure 2 shown, the distances from the head and end of the suppression device to the center of the propeller are respectively denoted as L p1 and L p2 , so the length of each group of piezoelectric ceramic sheets is L p2 -L p1 . As Figure 4 shown, the thickness of the piezoelectric sheet is h p , the central angle corresponding to its width is α, and the radius of the sleeve where the piezoelectric sheet is located is R p, so the width of each group of piezoelectric wafers is R p α, and the number of piezoelectric wafers is n p .

[0116] Compared with the entire propulsion shafting, the suppression device is very light, so it has little influence on the natural frequency and vibration mode of the shafting torsional vibration. After considering this suppression device, assuming that abnormal vibration occurs in the j-th torsional mode, the vibration differential equation in this mode is established as follows:

[0117]

[0118] In the formula, M j is the modal mass of the j-th torsional vibration, q j (t) is the torsional vibration displacement in the coordinate system of the j-th torsional vibration mode, ξ j is the modal damping of the j-th torsional vibration, ω j is the natural frequency of the j-th torsional vibration, γ 0,j , γ 1,j , γ 2,j , γ 3,j are the Taylor expansion coefficients of the modal excitation torque, V is the output voltage of the piezoelectric ceramic wafer, υ is the third electromechanical coupling coefficient, C p is the total capacitance of the piezoelectric ceramic wafers after parallel connection, R L is the load resistance.

[0119] Nondimensionalize Equation (11), and introduce the following variables:

[0120]

[0121] In the formula, q0 is a constant.

[0122] Substitute Equation (12) into Equation (11) to obtain:

[0123]

[0124] In the formula, and are the nondimensionalized torsional vibration displacement and output voltage respectively, β 0,j , β 1,j , β 2,j , β 3,j , κ, Γ are the nondimensionalized coefficients, which can be expressed as:

[0125]

[0126] Use the perturbation method to solve Equation (13), and the critical discrimination formula (7) for the system to have abnormal vibration can be obtained.

[0127] The following combines two specific examples to further illustrate the above steps:

[0128] Example 1:

[0129] Suppose a ship propulsion shafting system can be simplified to Figure 5 the shaft segment model shown in. The detailed geometric dimensions of each shaft segment are shown in Table 1. In this table, L represents the length of the shaft segment, Ro represents the outer radius of the shaft segment, and Ri represents its inner radius. The polar moment of inertia of the propeller is 10,000 Kg·m 2 , and the polar moment of inertia of the driving end of the high-elastic clutch is 8,000 Kg·m 2 , and the operating speed is 30 rpm.

[0130] Table 1 Dimensions of each section of the shafting system (m)

[0131]

[0132] This propulsion shafting system has generated abnormal torsional vibration, and the time-domain and frequency-domain results of the torsional vibration are as Figure 6 shown. It can be seen from this that the fundamental frequency and its harmonics characterized as 71.6 Hz in the vibration spectrum. Therefore, it can be confirmed that the abnormal torsional vibration frequency generated by this propulsion shafting system is 71.6 Hz. Next, suppress this abnormal vibration according to the method and process proposed in this application.

[0133] (1) Establish a finite element model of the torsional vibration of the propulsion shafting system, and obtain the first few torsional vibration natural frequencies. The numerical values are shown in Table 2. It can be seen from this table that the second-order torsional vibration natural frequency is very close to the abnormal vibration frequency. Therefore, it can be judged that the propulsion shafting system has abnormal vibration in the second-order torsional vibration mode. Normalize the second-order mode shape.

[0134] Table 2 Torsional vibration natural frequencies (ω unit: rad / s)

[0135] Variable <![CDATA[ω1]]> <![CDATA[ω2]]> <![CDATA[ω3]]> <![CDATA[ω4]]> <![CDATA[ω5]]> Value 63.3 Hz 71.7 Hz 191.1 Hz 205.5 Hz 284.7 Hz

[0136] (2) Solve the modal mass, the second-order modal damping ratio, and the front and rear stern bearing reaction forces of the second-order torsional vibration respectively. The calculation results are shown in Table 3.

[0137] Table 3 Modal mass, modal damping, and front and rear stern bearing reaction forces

[0138] Variable <![CDATA[M2]]> <![CDATA[ξ2]]> <![CDATA[N b > <![CDATA[N f > Value 69.8 0.0095 41036N 29858N

[0139] (3) After fitting the friction coefficients provided by the manufacturer, obtain μ b,0 , μ b,1 , a b , μ f,0 , μ f,1 , a f six coefficients, as shown in Table 4.

[0140] Table 4 Fitted friction coefficient values

[0141] Variable <![CDATA[μ b,0 > <![CDATA[μ b,1 > <![CDATA[a b > <![CDATA[μ f,0 > <![CDATA[μ f,1 > <![CDATA[a f > Fitted Value 0.9 0.1 2 0.9 0.1 2

[0142] (4) By using the steps described above, the coefficient γ can be obtained. 1,2 and As shown in Table 5.

[0143] Table 5 Coefficient γ 1,2 and values

[0144]

[0145] (5) Design a suppression device. The designed structural parameters are shown in Table 6. Among them, the piezoelectric sheets are arranged between the thrust bearing and the high elasticity (the 5th shaft section).

[0146] Table 6 Designed structural parameters

[0147]

[0148] According to the design parameters in Table 6, it can be calculated and after being superimposed with ξ2 as shown in the critical discrimination formula (7), and then compared with The comparison result is shown in Table 7. It can be seen that the design result satisfies the critical discrimination formula (7), and the design result can effectively suppress the abnormal torsional vibration.

[0149] Table 7 Check values

[0150]

[0151] To verify the correctness of the method proposed in this application, a nonlinear dynamics modeling and simulation of the propulsion shafting after installing the suppression device is carried out to study its nonlinear response under friction excitation. The calculation results are as Figure 7 shown. It can be seen that the time-domain curve finally decays to zero, and it can also be seen from the spectrum that there is no abnormal vibration frequency in the response. Therefore, the simulation results prove the effectiveness of the method proposed in this application.

[0152] Example 2:

[0153] Still taking the Figure 5 shown propulsion shafting as an example, assuming its operating speed is 20 rpm. Since the torsional vibration modal damping of each order of this shafting has changed, the torsional vibration mode that generates abnormal vibration has also changed.

[0154] Carry out a simulation analysis on the propulsion shafting. The torsional vibration time-domain and frequency-domain results are as Figure 8 shown. It can be seen that the fundamental frequency and its multiples characterized by 205.6 Hz in the vibration spectrum. Therefore, it can be confirmed that the frequency of the abnormal torsional vibration is 205.6 Hz. Next, suppress this abnormal vibration according to the method and process proposed in this application.

[0155] (1) Establish a finite element model of the propulsion shafting torsional vibration, and obtain its first few torsional vibration natural frequencies. The numerical values are shown in Table 8. It can be seen from this table that the fourth torsional vibration natural frequency is very close to the abnormal vibration frequency. Therefore, it can be judged that the propulsion shafting has an abnormal vibration in the fourth torsional vibration mode. Normalize the fourth mode vibration shape.

[0156] Table 8 Torsional Vibration Natural Frequencies (ω in rad / s)

[0157] Variable <![CDATA[ω1]]> <![CDATA[ω2]]> <![CDATA[ω3]]> <![CDATA[ω4]]> <![CDATA[ω5]]> Value 63.3 Hz 71.7 Hz 191.1 Hz 205.5 Hz 284.7 Hz

[0158] (2) Solve the modal mass, the fourth modal damping ratio, and the front and rear stern bearing reaction forces of the fourth torsional vibration respectively. The calculation results are shown in Table 9.

[0159] Table 9 Modal Mass, Modal Damping, and Front and Rear Stern Bearing Reaction Forces

[0160] Variable <![CDATA[M4]]> <![CDATA[ξ4]]> <![CDATA[N b > <![CDATA[N f > Value 72.5 0.004 41036N 29858N

[0161] (3) After fitting the friction coefficients provided by the manufacturer, obtain μ b,0 、μ b,1 、a b 、μ f,0 、μ f,1 、a f six coefficients, as shown in Table 10.

[0162] Table 10 Fitted Friction Coefficient Values

[0163] Variable <![CDATA[μ b,0 > <![CDATA[μ b,1 > <![CDATA[a b > <![CDATA[μ f,0 > <![CDATA[μ f,1 > <![CDATA[a f > Fitted Value 0.9 0.1 2 0.9 0.1 2

[0164] (4) Using the steps described above, the coefficients γ 1,4 and can be obtained as shown in Table 11.

[0165] Table 11 Coefficient γ 1,4 and Value

[0166]

[0167] (5) Design a suppression device. The designed structural parameters are shown in Table 12. Among them, the piezoelectric patches are arranged between the thrust bearing and the high elasticity (the 5th shaft section).

[0168] Table 12 Designed Structural Parameters

[0169]

[0170] According to the design parameters in Table 11, it can be calculated and after superimposing with ξ4 according to the critical discrimination formula (7), and then with Compare the magnitudes, and the verification results are shown in Table 13. It can be seen therefrom that the design results satisfy the critical discrimination formula (7), and the design results can effectively suppress abnormal torsional vibration.

[0171] Table 13 Verification values

[0172]

[0173] In order to verify the correctness of the method proposed in this application, a non-linear dynamics modeling and simulation of the propulsion shafting after installing the suppression device is carried out to study its non-linear response under friction excitation. The calculation results are as Figure 9 shown. It can be seen therefrom that the time-domain curve finally decays to zero, and it can also be seen from the spectrum that there is no abnormal vibration frequency in the response. Therefore, the simulation results prove the effectiveness of the method proposed in this application.

[0174] In summary, for the method for suppressing abnormal torsional vibration of the propulsion shafting in this application, by matching the torsional natural frequency and torsional mode shape corresponding to the abnormal torsional vibration frequency of the propulsion shafting; calculating the modal mass and modal damping ratio of the abnormal torsional vibration of the matching order, and calculating the reaction forces at the aft bearing and the forward aft bearing; fitting the friction coefficients between the aft bearing, the forward aft bearing and the propulsion shafting; according to the reaction forces, the friction coefficients and the matching torsional mode shape, calculating the friction excitation torque under the corresponding order torsional mode shape, and the Taylor expansion coefficients corresponding to the friction excitation torque; according to the matching torsional natural frequency, modal mass, modal damping ratio and Taylor expansion coefficients, a suppression device for generating electrical damping is arranged on the propulsion shafting to suppress abnormal torsional vibration.

[0175] Thus, through detailed dynamic theory derivation in this application, a critical discrimination formula for eliminating abnormal torsional vibration is obtained. By precisely designing the structural parameters of the suppression device to meet the requirements of the critical discrimination formula, abnormal torsional vibration can be accurately suppressed.

[0176] In a second aspect, an embodiment of this application also provides a device for suppressing abnormal torsional vibration of a propulsion shafting.

[0177] In one embodiment, referring to Figure 10 , Figure 10 is a schematic diagram of the functional modules of an embodiment of the device for suppressing abnormal torsional vibration of the propulsion shafting of this application. As Figure 10 shown, the device for suppressing abnormal torsional vibration of the propulsion shafting includes a calculation module and a setting module.

[0178] Among them, the calculation module is used for:

[0179] Match the torsional natural frequency and torsional mode shape corresponding to the abnormal torsional vibration frequency of the propulsion shafting;

[0180] Calculate the modal mass and modal damping ratio of the abnormal torsional vibration of the matching order, and calculate the reaction forces at the rear stern bearing and the front stern bearing;

[0181] Fit the friction coefficients between the rear stern bearing, the front stern bearing and the propulsion shafting;

[0182] According to the reaction forces, the friction coefficients and the matching torsional vibration mode shapes, calculate the friction excitation torque under the corresponding order torsional vibration mode shape, and the Taylor expansion coefficients corresponding to the friction excitation torque;

[0183] Set a module, which is used to set a suppression device for generating electrical damping on the propulsion shafting according to the matching torsional vibration natural frequency, modal mass, modal damping ratio and Taylor expansion coefficients to suppress the abnormal torsional vibration.

[0184] Further, in one embodiment, the suppression device includes a sleeve for sleeving on the propulsion shafting, and a plurality of piezoelectric ceramic sheets are electrically connected to the sleeve, and a load resistor is also connected to one piezoelectric ceramic sheet.

[0185] Further, in one embodiment, the setting module sets a suppression device for generating electrical damping on the propulsion shafting according to the matching torsional vibration natural frequency, modal mass, modal damping ratio and Taylor expansion coefficients, including:

[0186] Set the structural parameters of the suppression device so that it satisfies:

[0187]

[0188] In the formula, ξ j is the matching modal damping ratio, γ 1,j is the Taylor expansion coefficient, M j is the matching modal mass, ω j is the matching torsional vibration natural frequency, κ is the first electromechanical coupling coefficient, and Γ is the second electromechanical coupling coefficient;

[0189] Among them, κ and Γ satisfy:

[0190] κ = C p ω j R L ,

[0191] In the formula, R L is the load resistor, C p is the total capacitance after all piezoelectric ceramic sheets are connected in parallel, and υ is the third electromechanical coupling coefficient;

[0192] Among them, υ and C p satisfy:

[0193]

[0194] wherein, d 15 is the piezoelectric coefficient of the piezoelectric ceramic material, G p is the shear modulus of the piezoelectric ceramic, n p is the number of piezoelectric ceramic wafers, R p is the radius of the bonding position of the piezoelectric ceramic wafers, h p is the thickness of the piezoelectric ceramic wafers, L p1 and L p2 are the distances from the center of the propeller to the head and the end of the damping device, is the dielectric constant of the piezoelectric ceramic wafers, and a is the central angle corresponding to the width of each piezoelectric ceramic wafer.

[0195] Furthermore, in one embodiment, the calculation module fits the friction coefficients between the aft bearing, the forward aft bearing and the propulsion shafting, including:

[0196] According to the formula: Fit the friction coefficient between the aft bearing and the propulsion shafting;

[0197] wherein, μ b is the friction coefficient between the aft shaft bearing and the propulsion shafting, μ b,1 is the dynamic friction coefficient between the aft bearing and the propulsion shafting, μ b,0 is the static friction coefficient between the aft bearing and the propulsion shafting, a b is a constant, R b is the outer radius of the shafting at the aft bearing, ω is the relative angular velocity between the bearing and the shafting surface, and sign() is the sign function;

[0198] According to the formula: Fit the friction coefficient between the forward aft bearing and the propulsion shafting;

[0199] wherein, μ f is the friction coefficient between the forward aft shaft bearing and the propulsion shafting, μ f,1 is the dynamic friction coefficient between the forward aft bearing and the propulsion shafting, μ f,0 is the static friction coefficient between the forward aft bearing and the propulsion shafting, a f is a constant, R f is the outer radius of the shafting at the forward aft bearing, ω is the relative angular velocity between the bearing and the shafting surface, and sign() is the sign function.

[0200] Furthermore, in one embodiment, the calculation module calculates the friction excitation torque and the Taylor expansion coefficients corresponding to the friction excitation torque under the corresponding order torsional vibration mode according to the support reaction force, the friction coefficient and the matched torsional vibration mode shape, including:

[0201] According to the formula:

[0202]

[0203] Calculate the frictional excitation torque corresponding to the modal vibration mode of the corresponding order;

[0204] In the formula, F j is the frictional excitation torque corresponding to the torsional vibration modal vibration mode of the corresponding order, and are the vibration mode values at the aft stern bearing and the forward stern bearing respectively in the torsional vibration modal vibration mode of the corresponding order, N b and N f are the support reaction forces at the aft stern bearing and the forward stern bearing respectively, R b and R f are the outer radii at the aft stern bearing and the forward stern bearing of the shafting respectively, Ω is the rotational speed of the shafting, q j (t) is the torsional vibration displacement in the coordinate system of the torsional vibration modal of the corresponding order;

[0205] According to the formula: Perform Taylor expansion on the frictional excitation torque;

[0206] In the formula, γ 0,j 、γ 1,j 、γ 2,j 、γ 3,j are the coefficients of the Taylor expansion;

[0207] Among them, γ 1,j is expressed as:

[0208]

[0209] Furthermore, in one embodiment, the calculation module matches the torsional vibration natural frequency and the modal vibration mode corresponding to the abnormal torsional vibration frequency of the propulsion shafting, including:

[0210] Determine the abnormal torsional vibration frequency of the propulsion shafting;

[0211] Establish a torsional vibration analysis model of the propulsion shafting, and obtain the torsional vibration natural frequencies at multiple orders of the torsional vibration analysis model;

[0212] Determine the torsional vibration natural frequency of the order closest to the abnormal torsional vibration frequency, and determine the torsional vibration modal vibration mode of the corresponding order.

[0213] Furthermore, in one embodiment, the calculation module is also used for:

[0214] Normalize the torsional vibration modal vibration mode of the abnormal torsional vibration by the maximum absolute value.

[0215] Among them, the function realization of each module in the above abnormal torsional vibration suppression device of the propulsion shafting corresponds to each step in the above embodiment of the abnormal torsional vibration suppression method of the propulsion shafting, and its function and realization process will not be elaborated here one by one.

[0216] In a third aspect, an embodiment of the present application provides an abnormal torsional vibration suppression device for a propulsion shafting. The abnormal torsional vibration suppression device for a propulsion shafting can be a device with data processing functions such as a personal computer (PC), a laptop computer, a server, etc.

[0217] Referring to Figure 11 , Figure 11 FIG. is a schematic hardware structure diagram of the abnormal torsional vibration suppression device for a propulsion shafting involved in the solution of the embodiment of the present application. In the embodiment of the present application, the abnormal torsional vibration suppression device for a propulsion shafting may include a processor, a memory, a communication interface, and a communication bus.

[0218] Among them, the communication bus can be of any type and is used to interconnect the processor, the memory, and the communication interface.

[0219] The communication interface includes interfaces such as input / output (I / O) interfaces, physical interfaces, and logical interfaces for implementing the interconnection of components inside the abnormal torsional vibration suppression device for a propulsion shafting, as well as interfaces for implementing the interconnection between the abnormal torsional vibration suppression device for a propulsion shafting and other devices (such as other computing devices or user devices). The physical interface can be an Ethernet interface, an optical fiber interface, an ATM interface, etc.; the user device can be a display screen (Display), a keyboard (Keyboard), etc.

[0220] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical memory, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0221] The processor can be a general-purpose processor, and the general-purpose processor can call the abnormal torsional vibration suppression program stored in the memory and execute the abnormal torsional vibration suppression method provided by the embodiment of the present application. For example, the general-purpose processor can be a central processing unit (CPU). Among them, the method executed when the abnormal torsional vibration suppression program is called can refer to the various embodiments of the abnormal torsional vibration suppression method of the present application, which will not be elaborated here.

[0222] Those skilled in the art can understand that Figure 11The hardware structure shown does not constitute a limitation on this application. It may include more or fewer components than those shown, or combine certain components, or have a different component arrangement.

[0223] Fourthly, an embodiment of this application also provides a readable storage medium.

[0224] A propulsion shafting abnormal torsional vibration suppression program is stored on the readable storage medium of this application. When the propulsion shafting abnormal torsional vibration suppression program is executed by a processor, the steps of the propulsion shafting abnormal torsional vibration suppression method as described above are implemented.

[0225] Among them, the method implemented when the propulsion shafting abnormal torsional vibration suppression program is executed can refer to the various embodiments of the propulsion shafting abnormal torsional vibration suppression method of this application, which will not be elaborated here.

[0226] It should be noted that the serial numbers of the above embodiments of this application are only for description and do not represent the superiority or inferiority of the embodiments.

[0227] Through the description of the above embodiments, those skilled in the art can clearly understand that the above embodiment methods can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of this application, in essence, or the part that makes a contribution to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium as described above (such as ROM / RAM, magnetic disk, optical disc), and includes several instructions for causing a terminal device to execute the methods described in the various embodiments of this application.

[0228] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products or devices. The descriptions of terms such as "first", "second", and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit that "first", "second", and "third" are different types.

[0229] In the description of the embodiments of this application, "exemplary", "for example" or "for instance" etc. are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "exemplary", "for example" or "for instance" in the embodiments of this application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Exactly speaking, the use of words such as "exemplary", "for example" or "for instance" is intended to present relevant concepts in a specific manner.

[0230] In the description of the embodiments of the present application, unless otherwise specified, " / " means "or". For example, A / B may mean A or B. The "and / or" in the text is merely an association relationship describing associated objects, indicating that there can be three relationships. For example, A and / or B may mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of the present application, "a plurality of" means two or more than two.

[0231] In some processes described in the embodiments of the present application, there are a plurality of operations or steps that appear in a specific order. However, it should be understood that these operations or steps may not be executed in the order in which they appear in the embodiments of the present application or may be executed in parallel. The serial numbers of the operations are only used to distinguish different operations, and the serial numbers themselves do not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed in sequence or in parallel, and these operations or steps may be combined.

[0232] The above are only the preferred embodiments of the present application, and do not limit the scope of the present application. Any equivalent structural or equivalent process transformation made using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, is similarly included in the scope of protection of the present application.

[0233] The above are only the preferred embodiments of the present application, and do not limit the scope of the present application. Any equivalent structural or equivalent process transformation made using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, is similarly included in the scope of protection of the present application.

Claims

1. A method for suppressing abnormal torsional vibration of a propulsion shaft system, characterized in that: The method for suppressing abnormal torsional vibration of a propulsion shaft system comprises: Match the torsional vibration natural frequency and torsional vibration mode shape corresponding to the abnormal torsional vibration frequency of the propulsion shaft system; Calculate the modal mass and modal damping ratio of the abnormal torsional vibration of the matching order, and calculate the support reaction forces at the rear stern bearing and the front stern bearing; Fit the friction coefficient between the rear stern bearing, front stern bearing and propulsion shafting; According to the support reaction force, friction coefficient and matching torsional vibration mode shape, the friction excitation torque under the corresponding order torsional vibration mode shape and the Taylor expansion coefficient corresponding to the friction excitation torque are calculated; According to the matched torsional vibration natural frequency, modal mass, modal damping ratio and Taylor expansion coefficient, a suppression device for generating electrical damping is arranged on the propulsion shaft system to suppress abnormal torsional vibration.

2. The method for suppressing abnormal torsional vibration of a propulsion shaft system according to claim 1, characterized in that: The suppression device comprises a sleeve for sleeved on the propulsion shaft system, a plurality of piezoelectric ceramic sheets are connected to the circuit on the sleeve, and a load resistor is also connected to one of the piezoelectric ceramic sheets.

3. The method for suppressing abnormal torsional vibration of a propulsion shaft system according to claim 2, characterized in that: The suppression device for generating electrical damping is arranged on the propulsion shaft system according to the matched torsional vibration natural frequency, modal mass, modal damping ratio and Taylor expansion coefficient, comprising: The structural parameters of the suppression device are set to satisfy: In the formula, ξ j is the matching modal damping ratio, γ 1,j is the Taylor expansion coefficient, M j is the matching modal mass, ω j is the matching torsional vibration natural frequency, κ is the electromechanical first coupling coefficient, Γ is the electromechanical second coupling coefficient; Among them, κ and Γ satisfy: In the formula, R L is the load resistance, C p is the total capacitance of all piezoelectric ceramics connected in parallel, υ is the electromechanical third coupling coefficient; Among them, υ and C p satisfy: Where, d 15 is the piezoelectric coefficient of the piezoelectric ceramic material, G p is the shear modulus of the piezoelectric ceramic, n p is the number of piezoelectric ceramic sheets, R p h is the radius of the piezoelectric ceramic sticking position, p is the thickness of the piezoelectric ceramic sheet, L p1 and L p2 The distance between the first and last ends of the restraining device and the center of the propeller. is the dielectric constant of the piezoelectric ceramic piece, and a is the central angle corresponding to the width of each piezoelectric ceramic piece.

4. The method for suppressing abnormal torsional vibration of a propulsion shaft system according to claim 3, characterized in that: The friction coefficient between the fitted rear stern bearing, the front stern bearing and the propulsion shaft system includes: According to the formula: Fit the friction coefficient between the rear stern bearing and the propulsion shafting; In the formula, μ b is the friction coefficient between the rear stern bearing and the propulsion shaft system, μ b,1 is the dynamic friction coefficient between the rear stern bearing and the propulsion shaft system, μ b,0 is the static friction coefficient between the rear stern bearing and the propulsion shaft system, a b is a constant, R b is the outer radius of the shafting at the rear stern bearing, ω is the relative angular velocity between the bearing and the shafting surface, and sign() is the sign function; According to the formula: Fit the friction coefficient between the front stern bearing and the propulsion shafting; In the formula, μ f is the friction coefficient between the front stern bearing and the propulsion shaft system, μ f,1 is the dynamic friction coefficient between the front stern bearing and the propulsion shaft system, μ f,0 is the static friction coefficient between the front stern bearing and the propulsion shaft system, a f is a constant, R f is the outer radius of the shaft at the fore and stern bearing, ω is the relative angular velocity between the bearing and the shaft surface, and sign() is the sign function.

5. The method for suppressing abnormal torsional vibration of a propulsion shaft system according to claim 4, characterized in that: The method of calculating the friction excitation torque under the corresponding order torsional vibration mode shape and the Taylor expansion coefficient corresponding to the friction excitation torque according to the support reaction force, the friction coefficient and the matching torsional vibration mode shape includes: According to the formula: Calculate the friction excitation torque under the corresponding order mode shape; In the formula, F j is the friction excitation torque under the corresponding torsional vibration mode, and are the vibration mode values ​​at the rear stern bearing and the front stern bearing under the corresponding order torsional vibration mode, N b and N f are the support reaction forces at the rear stern bearing and the front stern bearing, R b and R f are the outer radius of the shaft system rear stern bearing and front stern bearing respectively, Ω is the shaft system rotation speed, q j (t) is the torsional vibration displacement in the corresponding order torsional vibration modal coordinate system; According to the formula: Taylor expansion of the friction excitation torque; In the formula, γ 0,j , γ 1,j , γ 2,j , γ 3,j is the coefficient of Taylor expansion; Among them, γ 1,j It is expressed as:

6. The method for suppressing abnormal torsional vibration of a propulsion shaft system according to claim 1, characterized in that: The matching of the torsional vibration natural frequency and the modal vibration shape corresponding to the abnormal torsional vibration frequency of the propulsion shaft system includes: Determine the abnormal torsional vibration frequency of the propulsion shafting; Establish a torsional vibration analysis model for the propulsion shaft system and obtain the torsional vibration natural frequencies of the torsional vibration analysis model at multiple orders; Determine the torsional vibration natural frequency of the order closest to the abnormal torsional vibration frequency, and determine the torsional vibration mode shape of the corresponding order.

7. The method for suppressing abnormal torsional vibration of a propulsion shaft system according to claim 6, characterized in that: Also includes: The torsional vibration mode shape of abnormal torsional vibration is normalized according to the maximum absolute value.

8. A propulsion shaft abnormal torsional vibration suppression device, characterized in that: The abnormal torsional vibration suppression device of the propulsion shaft system comprises: A computing module for: Match the torsional vibration natural frequency and torsional vibration mode shape corresponding to the abnormal torsional vibration frequency of the propulsion shaft system; Calculate the modal mass and modal damping ratio of the abnormal torsional vibration of the matching order, and calculate the support reaction forces at the rear stern bearing and the front stern bearing; Fit the friction coefficient between the rear stern bearing, front stern bearing and propulsion shafting; According to the support reaction force, friction coefficient and matching torsional vibration mode shape, the friction excitation torque under the corresponding order torsional vibration mode shape and the Taylor expansion coefficient corresponding to the friction excitation torque are calculated; A setting module is used to set a suppression device for generating electrical damping on the propulsion shaft system according to the matched torsional vibration natural frequency, modal mass, modal damping ratio and Taylor expansion coefficient to suppress abnormal torsional vibration.

9. A propulsion shaft abnormal torsional vibration suppression device, characterized in that: The propulsion shaft system abnormal torsional vibration suppression device includes a processor, a memory, and a propulsion shaft system abnormal torsional vibration suppression program stored in the memory and executable by the processor, wherein when the propulsion shaft system abnormal torsional vibration suppression program is executed by the processor, the steps of the propulsion shaft system abnormal torsional vibration suppression method as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a propulsion shaft system abnormal torsional vibration suppression program, wherein the propulsion shaft system abnormal torsional vibration suppression program, when executed by a processor, implements the steps of the propulsion shaft system abnormal torsional vibration suppression method as described in any one of claims 1 to 7.

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