Method and system for monitoring using performance of moving coil of high-thrust vibrating table

Abstract

The invention discloses a high-thrust vibrating table moving coil use performance monitoring method and system, and the method comprises the steps: arranging strain gauges and temperature sensors at different positions of a vibrating table moving coil at the same time, on one hand, carrying out the fitting of real-time data measured by the strain gauges, and obtaining a stress distribution function of a moving coil reinforced armor plate in the axial height direction; a debonding evaluation function is formed through derivation of the stress distribution function and subtraction of a standard pasting coefficient obtained by a standard strain gauge, and then a debonding area between the armor plate and the moving coil is determined by means of the debonding evaluation function; on the other hand, real-time data measured by the temperature sensor are used for fitting to obtain a whole moving coil temperature distribution function, and the temperature change condition in the moving coil operation process is evaluated through the temperature distribution function. According to the invention, the operating temperature, connection reliability and other operating performance of the moving coil of the vibrating table can be monitored in real time at the same time, the operating reliability of the high-thrust vibrating table can be effectively improved, and the system has the advantages of simple system, low cost, good using effect and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of vibration tables, and in particular to a method and system for monitoring the performance of a dynamic coil of a large-thrust vibration table. Background Art

[0002] A vibration table is a test equipment used to simulate vibration environment, and is widely used in electronics, automobiles, aerospace and other fields. The dynamic coil is one of the key components of the electric vibration table. It is mainly used to drive the vibration table to drive the table surface to move and generate vibration. The performance of the dynamic coil determines the performance of the vibration table. The dynamic coil assembly of the vibration table is usually composed of a dynamic coil, a reinforced carbon fiber armor plate, a skeleton, lead wires, etc., among which the dynamic coil is the core part of the dynamic coil assembly of the vibration table. The dynamic coil is generally bonded to the skeleton and armor plate with epoxy resin glue.

[0003] During use, the dynamic coil is powered by high-frequency AC to generate Lorentz force. As the vibration table moves towards high thrust, the driving current increases sharply, even reaching thousands of amperes. Under such working conditions, a large amount of heat will inevitably be generated, causing the dynamic coil temperature to rise sharply, resulting in the performance of the vibration table to decline and fail to achieve the required excitation performance parameters. At the same time, due to the strong impact vibration of the high-thrust vibration table during continuous excitation, coupled with the influence of the aging of epoxy resin glue after long-term use, debonding often occurs between the dynamic coil and the reinforced carbon fiber armor plate. The debonding phenomenon will cause the mechanical properties of the vibration table to be damaged, affecting the accuracy of the test results under the high-thrust vibration test and the safety of the vibration table equipment itself. Therefore, during the use of the high-thrust vibration table, it is urgent to monitor the real-time temperature of the dynamic coil and the reliability of the connection between it and the reinforced carbon fiber armor plate. However, at present, the vibration table can only monitor the temperature of a specific local position of the dynamic coil through contact or non-contact temperature measurement methods during use. This monitoring method cannot reflect the overall temperature of the dynamic coil. At the same time, there is a lack of monitoring means and methods for the debonding phenomenon between the dynamic coil and the reinforced carbon fiber armor plate during use, which to a certain extent affects the reliability of the dynamic coil of the high-thrust vibration table. Summary of the invention

[0004] In view of the above problems, the present invention provides a method for monitoring the performance of a large-thrust vibration table dynamic coil, wherein the dynamic coil adopts a cooling structure with water inlet at both ends and water outlet in the middle, comprising the following steps:

[0005] S1, let the axial height of the dynamic coil of the vibration table be l, divide the dynamic coil into n equal parts along the axial direction, and Starting from the position, the interval n strain gauges are arranged on the same side of the armor plate along the axial direction at a height of , respectively denoted as strain gauge i, where: i = 1, 2, L, n; below the strain gauge 1 on the armor plate and at a height of l from the bottom of the moving coil0 The standard strain gauge is arranged at, which is recorded as strain gauge 0;

[0006] Starting from the water inlet of the moving coil, k temperature sensors are arranged in sequence along the winding direction of the moving coil and numbered in sequence, respectively denoted as temperature sensor j, where: j = 1, 2, L, k; temperature sensor 1 is located at the water inlet of the moving coil, temperature sensor k is located at the water outlet of the moving coil, and the angle coordinate of temperature sensor j along the winding direction of the coil with the position of temperature sensor 1 as the origin is β j ;

[0007] S2, real-time monitoring of the measured values ​​of all strain gauges and temperature sensors, the measured strain of strain gauge i is recorded as ε i , the measured strain of the standard strain gauge is recorded as ε 0 , the measured temperature value of temperature sensor j is recorded as T j ;

[0008] S3, define the axial height of the armor plate where the strain gauge is attached from the bottom of the moving coil as x, and use the ε obtained by real-time measurement 1 ,ε 2 ,L,ε n And the axial height value of the corresponding strain gauge L,l, the stress distribution function ε(x) on the armor plate along the axial height direction is fitted, and the stress distribution function derivative ε′(x) is further solved;

[0009] S4. Define the standard adhesion coefficient α and calculate the standard adhesion coefficient Calculate the debonding evaluation function Δf(x)=α-ε′(x);

[0010] S5. Define the upper limit of the debonding threshold λ max , calculate all debonding evaluation function values ​​Δf(x) when x changes from 0 to l x＝0～l , and the absolute value of the debonding evaluation function value exceeds the upper limit of the debonding threshold λ max The value range of indicates that the dynamic coil and the armor plate are debonded at the position of the armor plate within the axial height range corresponding to the value range from the bottom of the dynamic coil.

[0011] S6. Define the angle coordinate of the moving coil with the position of temperature sensor 1 as the origin and the angle coordinate of the rotation along the winding direction of the coil as β, and use the measured values ​​T of temperature sensor 1 to temperature sensor k 1 ,T 2 ,L,T k and its corresponding angular coordinate value β 1 ,β 2 ,L,β k , the temperature distribution function T(β) from the dynamic coil water inlet to the dynamic coil water outlet is fitted.

[0012] Preferably, in step S3, the stress distribution function ε(x) is obtained by fitting using an n-1 degree polynomial.

[0013] Preferably, in step S6, the temperature distribution function T(β) is obtained by fitting using a k-1 degree polynomial.

[0014] Preferably, the number n of equal parts of the moving coil along the axial direction ranges from 5 to 8.

[0015] Preferably, the height of the strain gauge 0 from the bottom of the moving coil is l 0 The value range is 0.04l~0.05l.

[0016] Preferably, the temperature sensor is a thermocouple temperature sensor.

[0017] Preferably, the strain gauge is a metal foil strain gauge.

[0018] Preferably, the upper limit of the debonding threshold λ max The value range is 0.9α~1.0α.

[0019] The present invention further discloses a system for monitoring the performance of a dynamic coil of a large-thrust vibration platform, comprising a dynamic coil, a reinforced armor plate, a strain gauge, a temperature sensor, and an external processing module. The inner and outer sides of the dynamic coil are fixedly connected to the reinforced armor plate by epoxy resin, the strain gauge and the temperature sensor are bonded and cured on the reinforced armor plate by epoxy resin glue, the strain gauge and the temperature sensor are electrically connected to the external processing module by data lines, and the external processing module adopts the method for monitoring the performance of a dynamic coil of a large-thrust vibration platform.

[0020] Furthermore, the moving coil is wound by a single-layer or double-layer coil.

[0021] Beneficial effects:

[0022] 1. The present invention proposes a method for simultaneously monitoring the temperature condition of the dynamic coil of a large-thrust vibration table and the debonding condition between the dynamic coil and the reinforced carbon fiber armor plate, which not only makes up for the lack of monitoring the debonding condition between the dynamic coil and the reinforced carbon fiber armor plate, but also monitors the temperature of the dynamic coil while monitoring the debonding condition, thereby greatly improving the reliability of the dynamic coil of the large-thrust vibration table;

[0023] 2. The present invention ingeniously uses the derivative of the stress distribution function obtained by fitting to evaluate the adhesion condition, avoiding the tedious and complex calculation of the theoretical stress conditions at each position point, and can accurately determine the specific debonding area between the dynamic coil and the reinforced carbon fiber armor plate, thereby reducing the instability of the mechanical properties of the vibration table caused by the debonding of the dynamic coil and ensuring the safety of the key components of the vibration table;

[0024] 3. The present invention can obtain the overall temperature distribution of the dynamic coil of the large-thrust vibration table by arranging a limited number of temperature sensors. Compared with the traditional local temperature monitoring of the dynamic coil, this method can know the temperature conditions at all positions of the dynamic coil, thereby having a better evaluation effect on the operating temperature conditions of the dynamic coil;

[0025] 4. The system of the present invention is simple, low-cost, has good use effect, and has wide practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a diagram showing the overall idea of ​​the invented method for monitoring the performance of the dynamic coil of a large-thrust vibration table.

[0027] Figure 2 The present invention is a flow chart of the performance monitoring method for the dynamic coil of a large-thrust vibration table.

[0028] Figure 3 This is the theoretical stress distribution function curve in the presence of local debonding.

[0029] Specific implementation steps:

[0030] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments and the accompanying drawings so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0031] The present invention provides a method for monitoring the performance of a dynamic coil of a large-thrust vibration table, wherein the dynamic coil adopts a cooling structure with water inlet at both ends and water outlet in the middle, comprising the following steps:

[0032] S1. Let the axial height of the dynamic coil of the vibration table be l, and divide the dynamic coil into n equal parts along the axial direction. In order to make the measured stress basically reflect the actual stress size of all positions of the dynamic coil, the strain gauge is placed evenly. The strain gauge used is a metal foil strain gauge. The specific arrangement method is from the height of the bottom of the dynamic coil to the height of the dynamic coil. Starting from the position, the interval At a height of , n metal foil strain gauges are arranged on the same side armor plate along the axial direction, denoted as strain gauge i, where: i = 1, 2, L, n; considering the monitoring effectiveness and layout complexity, the number n of equal parts of the moving coil along the axial direction ranges from 5 to 8.

[0033] At the same time, it needs to be below the strain gauge 1 on the armor plate and at a height of l from the bottom of the moving coil 0A standard strain gauge is arranged at , denoted as strain gauge 0, and the standard strain gauge also adopts a metal foil strain gauge. Since the stress at the bottom of the moving coil is very small, there is basically no debonding between the moving coil and the armor plate. Therefore, it can be considered that the position of the standard strain gauge is in the normal bonding area between the moving coil and the armor plate. In addition, according to the force analysis, it can be known that the stress between the moving coil and the armor plate can be considered to increase linearly with the height from the bottom of the moving coil. Therefore, the standard strain gauge can provide a standard reference value for whether debonding occurs at a certain position later. In actual use, the height of strain gauge 0 from the bottom of the moving coil is l 0 The value range is 0.04l~0.05l.

[0034] Starting from the water inlet of the moving coil, k temperature sensors are arranged in sequence along the winding direction of the moving coil and numbered in sequence, respectively denoted as temperature sensor j, where: j = 1, 2, L, k. The temperature sensors are all thermocouple temperature sensors. Temperature sensor 1 is located at the water inlet of the moving coil, and temperature sensor k is located at the water outlet of the moving coil. The angle coordinate of temperature sensor j is β, with the position of temperature sensor 1 as the origin and the angle coordinate of temperature sensor j along the winding direction of the coil being β. j ;

[0035] S2, real-time monitoring of the measured values ​​of all strain gauges and temperature sensors, the measured strain of strain gauge i is recorded as ε i , the measured strain of the standard strain gauge is recorded as ε 0 , the measured temperature value of temperature sensor j is recorded as T j ;

[0036] S3. Define the axial height of the armor plate to which the strain gauge is attached from the bottom of the moving coil as x, and assume that the stress distribution function ε(x) = Ax (n-1) +Bx (n-2) +L+Cx+D, where A, B, CLR and D are all coefficients. 1 ,ε 2 ,L,ε n And the axial height value of the corresponding strain gauge L and l are all substituted into the fitting to get all the coefficients, and then the stress distribution function ε(x) on the armor plate along the axial height direction is obtained. ε(x) can reflect the stress magnitude at any height from the bottom of the dynamic coil. The derivative of the stress distribution function ε′(x) is further solved to get the rate of change of stress in height.

[0037] S4. Define the standard adhesion coefficient α. Since the location of the standard strain gauge in step S1 is the normal adhesion area, and considering that the stress between the moving coil and the armor plate should be positively correlated with the height to the bottom of the moving coil, the standard adhesion coefficient can be calculated. This coefficient is the value of the ε′(x) function corresponding to the case where no debonding occurs, so the debonding evaluation function Δf(x)=α-ε′(x) is defined and calculated;

[0038] S5. Define the upper limit of the debonding threshold λ max ,λ max The value range of is 0.9α~1.0α, and all debonding evaluation function values ​​Δf(x) are calculated when x changes from 0 to l. x＝0～l , and the absolute value of the debonding evaluation function value exceeds the upper limit of the debonding threshold λ max The value range of indicates that the dynamic coil and the armor plate are debonded at the position of the armor plate within the axial height range corresponding to the value range from the bottom of the dynamic coil.

[0039] S6. Define the angle coordinate of the moving coil rotating along the winding direction with the position of temperature sensor 1 as the origin as β, and set the temperature distribution function T(β) = aβ (k-1) +bβ (k-2) +L+cβ+d, where a, b, cL d are coefficients, and the measured values ​​T of temperature sensor 1 to temperature sensor k are 1 ,T 2 ,L,T k and its corresponding angular coordinate value β 1 ,β 2 ,L,β k Substitute it in and fit all the coefficients to obtain the temperature distribution function T(β) from the dynamic coil water inlet to the dynamic coil water outlet. T(β) can reflect the temperature condition of the entire dynamic coil.

[0040] The present invention further discloses a system for monitoring the performance of a dynamic coil of a large-thrust vibration platform, comprising a dynamic coil, a reinforced armor plate, a strain gauge, a temperature sensor, and an external processing module. The inner and outer sides of the dynamic coil are fixedly connected to the reinforced armor plate by epoxy resin, the strain gauge and the temperature sensor are bonded and cured on the reinforced armor plate by epoxy resin glue, the strain gauge and the temperature sensor are electrically connected to the external processing module by data lines, and the external processing module adopts the method for monitoring the performance of a dynamic coil of a large-thrust vibration platform.

[0041] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited thereto. Various changes that can be made within the knowledge scope of technicians in the relevant technical field without departing from the spirit of the present invention are all within the protection scope of the claims of the present invention.

Claims

1. A method for monitoring the performance of a large-thrust vibration table dynamic coil, wherein the dynamic coil adopts a cooling structure with water inlet at both ends and water outlet in the middle, characterized in that: The following steps are involved: S1, let the axial height of the dynamic coil of the vibration table be l, divide the dynamic coil into n equal parts along the axial direction, and Starting from the position, the interval n strain gauges are arranged on the same side armor plate along the axial direction at a height of , which are respectively denoted as strain gauge i, where: i = 1, 2, L, n; a standard strain gauge is arranged below strain gauge 1 on the armor plate and at a height of l0 from the bottom of the moving coil, which is denoted as strain gauge 0; Starting from the water inlet of the moving coil, k temperature sensors are arranged in sequence along the winding direction of the moving coil and numbered in sequence, respectively denoted as temperature sensor j, where: j = 1, 2, L, k; temperature sensor 1 is located at the water inlet of the moving coil, temperature sensor k is located at the water outlet of the moving coil, and the angle coordinate of temperature sensor j along the winding direction of the coil with the position of temperature sensor 1 as the origin is β j ; S2, real-time monitoring of the measured values ​​of all strain gauges and temperature sensors, the measured strain of strain gauge i is recorded as ε i , the measured strain of the standard strain gauge is recorded as ε0, and the measured temperature value of the temperature sensor j is recorded as T j ; S3, define the axial height of the armor plate where the strain gauge is pasted from the bottom of the moving coil as x, and use the ε1,ε2,L,ε n And the axial height value of the corresponding strain gauge L,l, the stress distribution function ε(x) on the armor plate along the axial height direction is fitted, and the stress distribution function derivative ε′(x) is further solved; S4. Define the standard adhesion coefficient α and calculate the standard adhesion coefficient Calculate the debonding evaluation function Δf(x)=α-ε′(x); S5. Define the upper limit of the debonding threshold λ max , calculate all debonding evaluation function values ​​Δf(x) when x changes from 0 to l x＝0～l , and the absolute value of the debonding evaluation function value exceeds the upper limit of the debonding threshold λ max The value range of indicates that the dynamic coil and the armor plate are debonded at the position of the armor plate within the axial height range corresponding to the value range from the bottom of the dynamic coil. S6. Define the angle coordinate of the moving coil with the position of temperature sensor 1 as the origin and the angle coordinate of the rotation along the winding direction of the coil as β. Use the measured values ​​T1, T2, L, T of temperature sensor 1 to temperature sensor k. k and their corresponding angular coordinate values ​​β1, β2, L, β k , the temperature distribution function T(β) from the dynamic coil water inlet to the dynamic coil water outlet is fitted.

2. The method for monitoring the performance of a high-thrust vibration table dynamic coil according to claim 1 is characterized in that: In step S3, the stress distribution function ε(x) is obtained by fitting using an n-1 degree polynomial.

3. The method for monitoring the performance of a large-thrust vibration table dynamic coil according to claim 1 is characterized in that: In step S6, the temperature distribution function T(β) is obtained by fitting using a k-1 degree polynomial.

4. The method for monitoring the performance of a high-thrust vibration table dynamic coil according to claim 1 is characterized in that: The number n of equal parts of the moving coil along the axial direction ranges from 5 to 8.

5. The method for monitoring the performance of a large-thrust vibration table dynamic coil according to claim 1 is characterized in that: The value range of the height l0 of the strain gauge 0 from the bottom of the moving coil is 0.04l~0.05l.

6. The method for monitoring the performance of a high-thrust vibration table dynamic coil according to claim 1 is characterized in that: The temperature sensor is a thermocouple temperature sensor.

7. The method for monitoring the performance of a high-thrust vibration table dynamic coil according to claim 1 is characterized in that: The strain gauge is a metal foil strain gauge.

8. The method for monitoring the performance of a high-thrust vibration table dynamic coil according to claim 1 is characterized in that: The upper limit of the debonding threshold λ max The value range is 0.9α~1.0α.

9. A system for monitoring the performance of a dynamic coil of a large-thrust vibration table, comprising a dynamic coil, a reinforced armor plate, a strain gauge, a temperature sensor, and an external processing module. The inner and outer sides of the dynamic coil are fixed to the reinforced armor plate by epoxy resin, the strain gauge and the temperature sensor are bonded and cured on the reinforced armor plate by epoxy resin glue, and the strain gauge and the temperature sensor are electrically connected to the external processing module by data lines, respectively, characterized in that: The external control module adopts a method for monitoring the performance of a large-thrust vibration table dynamic coil as described in any one of claims 1 to 8.

10. A high-thrust vibration table dynamic coil performance monitoring system according to claim 9, characterized in that: The moving coil is wound by a single-layer or double-layer coil.

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