CN205662571U - Online quantification evaluation system of vibration prescription effect - Google Patents

Abstract

On-line quantitative evaluation system of vibration aging effect, including upper computer system, signal generator, driver, vibrator, acceleration sensor, charge amplifier, oscilloscope, support device; the workpiece is fixedly connected to the vibrator, and adopts elastic support The device supports the workpiece; the upper computer system controls the signal generator to output a sinusoidal excitation signal whose amplitude and frequency are independent and continuously adjustable; the upper computer system includes an excitation frequency acquisition module, an excitation time acquisition module, and a voltage waveform acquisition module , the voltage extraction module, the vibration level conversion module, the excitation amplitude conversion module, the dimensionless processing module, and the relationship setting module between the vibration aging effect and the dimensionless excitation frequency, dimensionless excitation amplitude, and dimensionless excitation time . The utility model has the advantage of being able to realize on-line quantitative evaluation of the vibration aging effect.

Description

An Online Quantitative Evaluation System of Vibration Aging Effect

technical field

The utility model relates to the technical field of vibration aging, in particular to an online quantitative evaluation system and method for vibration aging effects.

Background technique

The evaluation of vibration aging effect is one of the key issues in the field of vibration aging technology research. The so-called vibration aging effect refers to the effect of vibration aging to eliminate residual stress. At present, the evaluation methods of vibration aging effect mainly include: parameter curve method, residual stress measurement method and precision stability detection method.

(1) Parameter curve method: The parameter curve method is summarized according to the regular changes in parameters during the vibration aging process, and can conduct online qualitative evaluation of the effect of vibration aging technology. The evaluation criteria used mainly include: After vibration aging treatment The resonance peak of frequency sweep curve is higher than that before vibration aging treatment; the resonance frequency of frequency sweep curve after vibration aging treatment is lower than that before vibration aging treatment; the bandwidth of frequency sweep curve after vibration aging treatment is narrower than that before vibration aging treatment. Although the parameter curve method is an online, intuitive, fast and convenient method, this method can only describe the effect of vibration aging qualitatively, but cannot give quantitative evaluation results. (2) Residual stress measurement method: In order to accurately evaluate the effect of vibration aging technology to eliminate residual stress, it is necessary to accurately evaluate the residual stress of components before and after vibration aging. However, the distribution of residual stress inside components, especially some complex components. It is difficult to analyze and solve the stress distribution state by theoretical calculation method, so it has very important practical significance to use the method of experimental measurement to evaluate the residual stress inside the component. At present, the experimental measurement methods of residual stress mainly include non-destructive physical measurement method and destructive mechanical measurement method, which can evaluate the residual stress of components before and after vibration aging treatment off-line. The residual stress measurement method is an off-line evaluation method, which can only evaluate the vibration aging effect after the vibration aging process is over. (3) Accuracy stability detection method: The accuracy stability detection method is to evaluate the effect of vibration aging technology by detecting the accuracy of components after vibration aging treatment, and can conduct offline qualitative evaluation of the effect of vibration aging technology, mainly including long-term placement accuracy method, precision method after adding dynamic load, etc. The long-term placement accuracy method is to place the components after vibration aging treatment for a long time and regularly test the dimensional stability of the components. The specific operation process is to test for the first time when it is placed for 15 days, and to test every 30 days thereafter. The total placement time should be More than half a year; the accuracy method after adding dynamic load is to detect the change in dimensional accuracy of components after vibration aging treatment after dynamic load. The accuracy and stability detection method is also an off-line, qualitative evaluation method, and this method requires a long evaluation period. To sum up, it is not difficult to find that although these methods can evaluate the effect of vibration aging qualitatively or quantitatively, they cannot conduct online quantitative evaluation of the effect of vibration aging.

Utility model content

In order to overcome the deficiency that the existing evaluation method of vibration aging effect cannot realize the online quantitative evaluation of vibration aging effect, the utility model proposes an online quantitative evaluation system and method of vibration aging effect.

On-line quantitative evaluation system of vibration aging effect, including upper computer system, signal generator, driver, vibrator, acceleration sensor, charge amplifier, oscilloscope, support device; the workpiece is fixedly connected to the vibrator, and adopts elastic support The device supports the workpiece; the upper computer system controls the signal generator to output a sinusoidal excitation signal with independent and continuously adjustable amplitude and frequency; the sinusoidal excitation signal output by the signal generator is input into the exciter through the driver to drive the excitation The device generates vibration; the acceleration sensor is installed on the workpiece, the output of the acceleration sensor is connected to the input channel of the charge amplifier, the output channel of the charge amplifier is connected to the oscilloscope, and the oscilloscope is connected to the host computer system.

The upper computer system includes an excitation frequency f acquisition module for obtaining the excitation frequency f (kHz) of the vibration aging, an excitation time t acquisition module for obtaining the excitation time t (min) of the vibration aging, and obtaining the voltage of the voltage waveform displayed by the oscilloscope The waveform acquisition module is a voltage extraction module that obtains the voltage peak value U (V) from the voltage waveform, and converts the voltage peak value into an output acceleration vibration level a (ms ^-2 ) vibration level a conversion module that converts the output acceleration vibration level a The excitation amplitude A conversion module converted into the excitation amplitude A (μm) of vibration aging, the dimensionless processing module for dimensionless processing of the excitation frequency f, excitation amplitude A, and excitation time t, and the vibration aging effect F and dimensionless excitation frequency dimensionless excitation amplitude Dimensionless excitation time Interrelationships between modules are set.

The vibration level conversion module presets the sensitivity value s (pC/ms ^-2 ) of the acceleration sensor, the sensitivity coefficient S (pC/Unit) of the input channel of the charge amplifier, and the amplification factor K (Unit/V); the output acceleration vibration level The conversion relationship between and the peak voltage is: The conversion relationship between the output acceleration vibration level and the excitation amplitude is: The dimensionless processing module presets the excitation frequency f and the dimensionless excitation frequency conversion relationship between Excitation Amplitude A and Dimensionless Excitation Amplitude conversion relationship between And the excitation time t and the dimensionless excitation time conversion relationship between Among them, f ₀ is 1 kHz, A ₀ is 1 μm, and t ₀ is 1 min.

Further, the acceleration sensor is a piezoelectric acceleration sensor.

Further, the supporting device is an elastic element.

The technical concept of the utility model is: an online quantitative evaluation system for the vibration aging effect is composed of a host computer system, a signal generator, a driver, a vibration exciter, an acceleration sensor, a charge amplifier and an oscilloscope; the workpiece is fixedly connected to the vibration exciter; The workpiece is supported by a supporting device so that the exciter can excite the workpiece; the upper computer system obtains the dimensionless excitation frequency in real time dimensionless excitation amplitude and the dimensionless excitation time And according to the vibration aging effect F and the dimensionless excitation frequency dimensionless excitation amplitude Dimensionless excitation time On-line quantitative evaluation of the vibration aging effect.

The beneficial effects of the utility model are:

1. It can convert the charge signal output by the acceleration sensor into the acceleration vibration level, and then convert the acceleration vibration level into the excitation amplitude value, and obtain the excitation amplitude value acting on the workpiece in real time and accurately.

2. Able to establish vibration aging effect F and dimensionless excitation frequency dimensionless excitation amplitude and the dimensionless excitation time The quantitative functional relationship between them can realize the online quantitative evaluation of the vibration aging effect.

3. The upper computer system can automatically obtain the dimensionless excitation frequency dimensionless excitation amplitude and the dimensionless excitation time On-line quantitative evaluation of vibration aging effects is realized without manual operation, which reduces workload and improves work efficiency.

Description of drawings

Figure 1 On-line quantitative evaluation system of vibration aging effect

Fig.2 Schematic diagram of the dimensions of Cr12MoV steel samples

detailed description

With reference to accompanying drawing, further illustrate the utility model:

The on-line quantitative evaluation system of the vibration aging effect includes a host computer system, a signal generator, a driver, an exciter 1, an acceleration sensor 2, a charge amplifier, an oscilloscope, and a support device 4; the workpiece 3 is fixedly connected to the exciter 1, and The workpiece 3 is supported by an elastic supporting device 4; the host computer system controls the signal generator to output a sinusoidal excitation signal with independent amplitude and frequency and continuously adjustable; the sinusoidal excitation signal output by the signal generator is input via the driver vibrator 1, so as to drive the vibrator 1 to generate vibration; the acceleration sensor 2 is installed on the workpiece 3, the output terminal of the acceleration sensor 2 is connected to the input channel of the charge amplifier, the output channel of the charge amplifier is connected to the oscilloscope, and the oscilloscope is connected to the upper computer system connect.

The upper computer system includes an excitation frequency f acquisition module for obtaining the excitation frequency f (kHz) of the vibration aging, an excitation time t acquisition module for obtaining the excitation time t (min) of the vibration aging, and obtaining the voltage of the voltage waveform displayed by the oscilloscope The waveform acquisition module is a voltage extraction module that obtains the voltage peak value U (V) from the voltage waveform, and converts the voltage peak value into an output acceleration vibration level a (ms ^-2 ) vibration level a conversion module that converts the output acceleration vibration level a The excitation amplitude A conversion module converted into the excitation amplitude A (μm) of vibration aging, the dimensionless processing module for dimensionless processing of the excitation frequency f, excitation amplitude A, and excitation time t, and the vibration aging effect F and dimensionless excitation frequency dimensionless excitation amplitude Dimensionless excitation time Interrelationships between modules are set.

The vibration level conversion module is preset with the sensitivity value s (pC/ms ^-2 ) of the acceleration sensor 2, the sensitivity coefficient S (pC/Unit) of the input channel of the charge amplifier, and the amplification factor K (Unit/V); the output acceleration vibration The conversion relationship between the level and the peak voltage is: The conversion relationship between the output acceleration vibration level and the excitation amplitude is: The dimensionless processing module presets the excitation frequency f and the dimensionless excitation frequency conversion relationship between Excitation Amplitude A and Dimensionless Excitation Amplitude conversion relationship between And the excitation time t and the dimensionless excitation time conversion relationship between Among them, f ₀ is 1 kHz, A ₀ is 1 μm, and t ₀ is 1 min.

Further, the acceleration sensor 2 is a piezoelectric acceleration sensor.

Further, the supporting device 4 is an elastic element.

The online quantitative evaluation method of vibration aging effect includes the following steps:

(1) Fix the workpiece 3 to the vibrator 1; use the supporting device 4 to support the workpiece 3 so that the vibrator 1 can excite the workpiece 3; connect the signal between the upper computer system and the signal generator connection; connect the signal connection between the signal generator and the driver; connect the signal connection between the driver and the exciter 1; connect the signal connection between the upper computer system and the oscilloscope; connect the oscilloscope and Connect the signal wires between the charge amplifiers; connect the signal wires between the charge amplifier and the acceleration sensor 2; connect the host computer system, the signal generator, the driver, the exciter 1, the oscilloscope, and the power supply of the charge amplifier.

(2) Set the sensitivity value s (pC/ms ⁻² ) of the acceleration sensor 2 in the vibration level conversion module; the sensitivity coefficient S (pC/Unit) and the amplification factor K (Unit/V) of the charge amplifier input channel.

(3), the excitation frequency acquisition module obtains the excitation frequency f (kHz) of the vibration aging; the excitation time acquisition module obtains the excitation time t (min) of the vibration aging; the voltage waveform acquisition module obtains the voltage waveform displayed by the oscilloscope; The extraction module obtains the voltage peak value U(V) from the voltage waveform; the conversion relationship between the acceleration vibration level output from the vibration level conversion module and the voltage peak value is The conversion relationship between the output excitation amplitude and the acceleration vibration level in the excitation amplitude conversion module is

(4), the dimensionless processing module performs dimensionless processing on the excitation frequency f, the excitation amplitude A and the excitation time t, the specific excitation frequency f and the dimensionless excitation frequency The conversion relationship between Excitation Amplitude A and Dimensionless Excitation Amplitude The conversion relationship between And the excitation time t and the dimensionless excitation time The conversion relationship between Among them, f ₀ is 1 kHz, A ₀ is 1 μm, and t ₀ is 1 min.

(5), in the vibration aging effect F and the dimensionless excitation frequency dimensionless excitation amplitude Dimensionless excitation time The relationship between setting F and The relationship between is F(f,A,t), and the dimensionless excitation frequency obtained in real time in step (4) dimensionless excitation amplitude and the dimensionless excitation time By substituting it into F(f,A,t), the on-line quantitative evaluation of the vibration aging effect can be carried out.

In step (5), obtain the vibration aging effect F and the dimensionless excitation frequency dimensionless excitation amplitude Dimensionless excitation time The expression F(f,A,t) of the relationship between includes the following steps:

(5.1), vibration aging effect F and dimensionless excitation frequency dimensionless excitation amplitude Dimensionless excitation time The expression F(f,A,t) of the relationship between them can be approximated by the following polynomial: In the formula: a ₁ , a ₂ , ..., a ₁₁ are real coefficients, and a ₁₁ is a constant term of the equation.

(5.2) When the workpiece 3 has not been subjected to vibration aging treatment, that is, when the values of the three process parameters are all 0, the residual stress relief effect of the workpiece 3 should be 0, so the constant term a ₁₁ =0. Therefore, F(f,A,t) can be further expressed as:

(5.3), substituting 10 different combinations of dimensionless process parameters and their corresponding vibration aging effect F into F(f,A,t) can get the 10-elements of the undetermined coefficients a ₁ , a ₂ ,...,a ₁₀ A system of equations of degree 1, by solving this system of equations, the values of the 10 undetermined coefficients can be obtained. This 10-element 1-degree equation system can be expressed in the form of a matrix as:

It can be further expressed as: Ga=F.

In the formula: It is a dimensionless process parameter combination matrix, and the i-th row in the matrix represents the combination polynomial of the dimensionless process parameters during the ith vibration aging treatment; F=[F _i ] is the effect matrix of vibration aging; a=[a _i ] is the undetermined coefficient matrix.

(5.4), in order to solve 10 undetermined coefficients, at least 10 groups of different experimental data are needed, in order to make the matrix equation in the step (5.3) have a unique solution, then the rank of the dimensionless process parameter combination matrix G should satisfy r( G)=10, that is, the dimensionless process parameter combination matrix should be a full-rank matrix. Therefore, the undetermined coefficients can be obtained by solving the following matrix equation:

Substituting the solved 10 undetermined coefficients into the expression F(f,A,t) in step (5.2), the vibration aging effect F and the dimensionless excitation frequency can be established dimensionless excitation amplitude Dimensionless excitation time The expression F(f,A,t) of the relationship between them.

Obtain vibration aging effect F and dimensionless excitation frequency dimensionless excitation amplitude Dimensionless excitation time The specific implementation details of the expressions of the interrelationships are as follows: Assume that the domain of the function F(f, A, t) is a bounded closed area D, and within this area D is a real-valued continuous function. P ₁ (f, A, t), P ₂ (f, A, t), ..., P _k (f, A, t) are k linearly independent real-valued continuous functions defined on D (usually taken as Multivariate polynomial function), where the linear space P made by the combination of P ₁ (f, A, t), P ₂ (f, A, t), ..., P _k (f, A, t) is called linear interpolation space, then any function in P can be expressed as: P(f,A,t)=α ₁ P ₁ (f,A,t)+α ₂ P ₂ (f,A,t)+…+α _k P _k (f,A,t),

In the formula: α ₁ , α ₂ , ..., α _k are real coefficients. According to the Weierstrass approximation theorem, if the function P(f,A,t) can be used to approximate the function F(f,A,t), then for any given ε, there is |F(f,A,t)-P (f,A,t)|<ε, where f,A,t∈D. Therefore, the utility model aims to pass the dimensionless excitation frequency dimensionless excitation amplitude and dimensionless excitation time The multivariate polynomial function composed of these three process parameters is approximated by the multivariate function approximation theory to establish the vibration aging effect F and the dimensionless excitation frequency dimensionless excitation amplitude Dimensionless excitation time The expression F(f,A,t) of the relationship between them.

In order to obtain the experimental data required to establish the expression F(f,A,t), the sample shown in Fig. 2 was subjected to vibration aging treatment. In order to be able to solve the 10 undetermined coefficients in the expression F(f,A,t) established in step (5.2), it is necessary to select 10 different sets of experimental data, and the dimensionless process parameter combination matrix must be a full-rank matrix, namely The rank of the dimensionless process parameter combination matrix is 10. Considering that there are certain errors in the experimental data testing process, in order to improve the reliability and universality of the established expression F(f,A,t), 11 sets of experimental data were selected to establish the expression F(f,A,t). A,t), see Table 1. Select 10 groups from the 11 groups of experimental data in order to construct the dimensionless process parameter combination matrix G, and specify that r _j (G) is the dimensionless The rank of the process parameter combination matrix G, j=1-11. Using the rank function in the Matlab software to calculate the rank of the constructed dimensionless process parameter combination matrix G in turn, if the solution result satisfies r ₁ (G)=r ₂ (G)=...=r ₁₁ (G)=10, then It shows that the selected experimental data can be used to solve 11 sets of undetermined coefficients. If the solution result does not meet the condition of r ₁ (G)=r ₂ (G)=...=r ₁₁ (G)=10, you need to re-select the experiment data.

Table 1 Dimensionless process parameters and aging effects used to calculate the undetermined coefficient matrix

In the process of solving the 10 undetermined coefficients, firstly, 10 groups of the 11 groups of experimental data are selected each time to construct the dimensionless process parameter combination matrix G; secondly, the inv function in the Matlab software is used to solve the dimensionless process parameter combination matrix G. Inverse matrix G ^-1 , and multiply matrix G ^-1 and vibration aging effect matrix F in Matlab software to solve the undetermined coefficient matrix, so that 11 groups of different undetermined coefficients can be obtained; then these 11 groups of undetermined coefficients Take their average values as the undetermined coefficients of the expression F(f,A,t); finally, substitute the average values of these undetermined coefficients into the expression F(f,A,t) established in step (5.2) to obtain the vibration aging effect F and dimensionless excitation frequency dimensionless excitation amplitude Dimensionless excitation time The expression F(f,A,t) of the relationship between them.

Table 2 shows the 11 groups of undetermined coefficients obtained from the solution. The last column in Table 2 is the mean value of 11 groups of undetermined coefficients. Substituting the mean value of these undetermined coefficients into the expression F(f,A,t) established in step (5.2), the final vibration aging effect F and dimensionless excitation frequency dimensionless excitation amplitude Dimensionless excitation time The expression F(f,A,t) of the relationship between can be expressed as:

Table 2 The numerical value of each group of undetermined coefficients obtained by solving

The content described in the embodiments of this specification is only an enumeration of the realization forms of the utility model concept, and the protection scope of the utility model should not be regarded as being limited to the specific forms stated in the embodiments, and the protection scope of the utility model also extends to Equivalent technical means that those skilled in the art can think of according to the concept of the utility model.

Claims (3)

1. On-line quantitative evaluation system of vibration aging effect, including upper computer system, signal generator, driver, vibrator, acceleration sensor, charge amplifier, oscilloscope, support device; the workpiece is fixedly connected with the vibrator, and adopts elastic The supporting device supports the workpiece; the upper computer system controls the signal generator to output a sinusoidal excitation signal with independent amplitude and frequency and continuously adjustable; the sinusoidal excitation signal output by the signal generator is input into the exciter through the driver to drive The exciter generates vibration; the acceleration sensor is installed on the workpiece, the output of the acceleration sensor is connected to the input channel of the charge amplifier, the output channel of the charge amplifier is connected to the oscilloscope, and the oscilloscope is connected to the host computer system. 2. The online quantitative evaluation system of vibration aging effect according to claim 1, characterized in that the acceleration sensor is a piezoelectric acceleration sensor. 3. The online quantitative evaluation system of vibration aging effect according to claim 2, characterized in that: the supporting device is an elastic element.