阅读说明：本技术 一种热态条件下拉杆轴力测量系统和测量方法 (System and method for measuring axial force of pull rod under thermal state condition ) 是由 杨庆旭 江泉 夏俊元 王驰 万瑜 刘叙笔 金传领 王舒涛 于 2019-09-12 设计创作，主要内容包括：本发明公开了一种热态条件下拉杆轴力的测量系统和测量方法,属于工程现场安全监测技术领域,该系统包括振动传感器、传感器适配器、动态数据采集单元、数据分析模块、数据存储输出设备和振动发生装置。振动发生装置用于引起拉杆振动产生横向自由衰减的振动信号,振动传感器采集所述振动信号,并通过传感器适配器传送至设于所述传感器适配器内的动态数据采集单元。动态数据采集单元基于所述振动信号形成振动时程曲线,并将所述振动时程曲线传送至所述数据存储输出设备,由设于所述数据存储输出设备内的数据分析模块进行处理。本发明提供的系统和方法在热态环境下,可对发电机组的拉杆轴力进行测量,且测量精度高,抗干扰能力强。(The invention discloses a system and a method for measuring the tension rod axial force under a thermal state condition, belonging to the technical field of engineering site safety monitoring. The vibration generating device is used for causing the pull rod to vibrate to generate a vibration signal which is transversely and freely attenuated, the vibration sensor collects the vibration signal and transmits the vibration signal to the dynamic data acquisition unit arranged in the sensor adapter through the sensor adapter. The dynamic data acquisition unit forms a vibration time course curve based on the vibration signal, transmits the vibration time course curve to the data storage and output equipment, and is processed by a data analysis module arranged in the data storage and output equipment. The system and the method provided by the invention can measure the pull rod axial force of the generator set in a thermal state environment, and have high measurement precision and strong anti-interference capability.)

1. A system for measuring the force of a pull rod under a thermal condition is characterized in that: the system comprises a vibration sensor, a sensor adapter, a dynamic data acquisition unit, a data analysis module, data storage and output equipment and a vibration generation device;

the vibration generating device is used for causing the pull rod to vibrate to generate vibration signals which are transversely and freely attenuated, the vibration sensor collects the vibration signals and transmits the vibration signals to the dynamic data collecting unit arranged in the sensor adapter through the sensor adapter, the dynamic data collecting unit forms a vibration time course curve based on the vibration signals and transmits the vibration time course curve to the data storage and output device, and the vibration time course curve is processed by the data analysis module arranged in the data storage and output device.

2. The system of claim 1, wherein: the vibration generating device is a knocking hammer.

3. The system of claim 1, wherein: the data analysis module is used for collecting data, analyzing time domain and analyzing frequency domain.

4. The system of claim 1, wherein: the sensor adapter is in communication connection with the data storage output device through a digital signal transmission unit, and the digital signal transmission unit is a wireless digital signal transmission unit.

5. The system of claim 1, wherein: the vibration sensor is a piezoelectric acceleration sensor, and the data storage and output equipment is a handheld tablet computer.

6. A method for measuring a pull rod shaft force under a thermal condition, which is implemented by using the system for measuring the pull rod shaft force under the thermal condition of any one of claims 1 to 5, and comprises the following steps:

a vibration generating device is adopted to excite a vibration signal of the pull rod which is transversely and freely attenuated;

acquiring the transversely freely attenuated vibration signal by using a vibration sensor, and transmitting the transversely freely attenuated vibration signal to a dynamic data acquisition unit arranged in the sensor adapter through the sensor adapter;

the dynamic data acquisition unit forms a vibration time-course curve based on the vibration signal;

transmitting the vibration time-course curve to data storage output equipment and storing the vibration time-course curve;

performing time-frequency domain analysis on the vibration time-course curve by using a data analysis module in the data storage and output equipment to obtain the transverse vibration frequency f of the pull rod_nAnd based on said transverse vibration frequency f_nAnd calculating to obtain the pull rod axial force N.

7. The method of thermal condition pulldown rod force measurement according to claim 6, further comprising: and mounting the vibration sensor on the pull rod to acquire a transverse free attenuation vibration signal of the pull rod.

8. The method of thermal condition pulldown rod force measurement according to claim 7, wherein: the vibration sensor is arranged in the middle of the pull rod.

9. The method of thermal condition pulldown rod force measurement according to claim 6, wherein: mica sheets are arranged between the vibration sensor and the pull rod in a cushioning mode, and the thickness range of the mica sheets is 0-0.1 mm.

10. The method of thermal condition pulldown rod force measurement according to claim 6, wherein: the pull rod axial force N is calculated by the formula (1):

in the formula, N is axial force,mass per unit length of the tie rod, l is the length of the tie rod, EI is the bending stiffness, f_nIs the nth order vibration frequencyAnd n is the order of the vibration frequency.

Technical Field

The invention belongs to the technical field of engineering site safety monitoring, and particularly relates to a system and a method for measuring the pull rod shaft force under a thermal state condition.

Background

In the research on the structural safety problem during load operation in the engineering of thermal power generation and the like under the very-temperature environment, in addition to understanding and mastering the mechanical characteristics and the change condition of the material under the non-normal-temperature environment, the research on the strength, the rigidity, the stability and the like of the structure under the comprehensive action of temperature and load is required, and the structural stress-strain test under the very-temperature environment is urgently required. While the test of thermal generator sets and the like under the thermal state working condition often faces the severe test conditions of high temperature, high pressure, electromagnetic field interference and the like at the same time, and the mechanical test instrument and the method under the conventional condition can not completely meet the requirements and can not be directly applied on site.

To know the stress deformation state of the structure under the condition of very high temperature operation, a special stress strain sensor is needed for carrying out the field stress strain test, if a medium-high temperature strain gauge is selected, a special strain gauge mounting method and a measuring lead are adopted, the temperature distribution and the change condition of the temperature distribution need to be measured simultaneously, the method is used for correcting the characteristic parameters of the strain gauge such as the thermal output and the sensitivity coefficient and correcting the experimental test data, the measured real stress strain can be obtained, and the process is more complicated than the test at the normal temperature. Besides, the testing process is influenced by the changes of the field temperature, the humidity and the like, and is also influenced by the severe environment conditions of the field electromagnetic field interference and the like, and the precision and the stability of the testing result can not be ensured.

Disclosure of Invention

In order to solve the problems, the invention provides a pull rod axial force measuring system under a thermal state condition, which can measure the pull rod axial force of a generator set under the thermal state environment, and has high measuring precision and strong anti-interference capability.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows: the system comprises a vibration sensor, a sensor adapter, a dynamic data acquisition unit, a data analysis module, data storage and output equipment and a vibration generation device; the vibration generating device is used for causing the pull rod to vibrate to generate vibration signals which are transversely and freely attenuated, the vibration sensor collects the vibration signals and transmits the vibration signals to the dynamic data collecting unit arranged in the sensor adapter through the sensor adapter, the dynamic data collecting unit forms a vibration time course curve based on the vibration signals and transmits the vibration time course curve to the data storage and output device, and the vibration time course curve is processed by the data analysis module arranged in the data storage and output device.

Preferably, the vibration generating device causing the free damping vibration of the pull rod is a knocking hammer.

Preferably, the data analysis module is used for data acquisition, time domain analysis and frequency domain analysis.

Preferably, the sensor adapter is in communication connection with the data storage output device through a digital signal transmission unit, and the digital signal transmission unit is a wireless digital signal transmission unit.

Preferably, the vibration sensor is a piezoelectric acceleration sensor, and the data storage and output device is a handheld tablet computer.

The test signal of the pull rod axial force measurement system provided by the invention adopts a wireless digital signal transmission technology, the length of an analog signal line is greatly shortened, the quality of the test signal is improved, the measurement precision is high, and the anti-interference capability is good.

The invention also provides a method for measuring the pull rod shaft force under the thermal state condition, which is simple and convenient to operate and can accurately measureAxial force of the power equipment pull rod under the condition of calorimetric state. The method comprises the following steps: a vibration generating device is adopted to excite a vibration signal of the pull rod which is transversely and freely attenuated; acquiring the transversely freely attenuated vibration signal by using a vibration sensor, and transmitting the transversely freely attenuated vibration signal to a dynamic data acquisition unit arranged in the sensor adapter through the sensor adapter; the dynamic data acquisition unit forms a vibration time-course curve based on the vibration signal; transmitting the vibration time-course curve to data storage output equipment and storing the vibration time-course curve; performing time-frequency domain analysis on the vibration time-course curve by using a data analysis module in the data storage and output equipment to obtain the transverse vibration frequency f of the pull rod_nAnd based on said transverse vibration frequency f_nAnd calculating to obtain the pull rod axial force N.

Preferably, the vibration signal of the pull rod is acquired using a vibration sensor mounted on the pull rod.

Preferably, the method further comprises: and mounting the vibration sensor on the pull rod to acquire a transverse free attenuation vibration signal of the pull rod.

Preferably, the vibration sensor is installed at the middle position of the pull rod.

Preferably, a mica sheet is arranged between the vibration sensor and the pull rod in a cushioning mode, and the thickness range of the mica sheet is 0-0.1 mm.

Preferably, the pull rod axial force N is calculated by formula (1):

in the formula, N is axial force,mass per unit length of the tie rod, l is the length of the tie rod, EI is the bending stiffness, f_nIs the nth order vibration frequency, and n is the order of vibration frequency.

According to the method for measuring the pull rod force under the thermal state condition, the transient hammering method is adopted to excite the pull rod to vibrate, the vibration frequency value of the vibration signal is obtained through signal analysis by collecting the vibration signal, the operation is simple and rapid, and the pull rod force measuring method is not easily influenced by the environment.

According to the invention, the mica sheet is arranged between the vibration sensor and the pull rod, so that the heat insulation and insulation effects on the sensor are achieved in the test process, the influence of environmental conditions on the test result is further reduced, and the measurement result is more accurate.

Drawings

FIG. 1 is a schematic structural diagram of a pull rod force measurement system under thermal conditions according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a pull rod force measurement system in an embodiment of the invention under thermal conditions.

Wherein: the system comprises a vibration sensor 1, a high-temperature measurement and control lead 2, a sensor adapter 3, a digital signal transmission unit 4, a data storage output device 5 and a vibration generating device 6.

Detailed Description

For a better understanding of the nature of the invention, its description is further set forth below in connection with the specific embodiments and the drawings.

The invention provides a system for measuring the shaft force of a tension rod under a thermal state condition, which comprises a vibration sensor 1, a sensor adapter 3, a dynamic data acquisition unit positioned in the sensor adapter 3, a digital signal transmission unit 4, a data storage output device 5, a data analysis module positioned in the data storage output device 5 and a vibration generation device 6, wherein the structure of the specific embodiment is shown in figure 1. The vibration sensor 1 is connected with the sensor adapter 3 through a high-temperature measurement and control lead 2.

The vibration generating device 6 is used for causing the pull rod to vibrate to generate a vibration signal; the vibration sensor 1 is used for acquiring vibration signals generated by the vibration of the pull rod; the sensor adapter 3 is used for receiving vibration signals collected by the vibration sensor 1; the dynamic data acquisition unit in the sensor adapter 3 is used for forming a vibration time-course curve by the vibration signal; the digital signal transmission unit 4 is used for communication connection between the sensor adapter 3 and the data storage output device 5; the data storage and output device 5 is used for storing and outputting the received data or the data processed by the data analysis module; the data analysis module is used for collecting data, analyzing a time domain and analyzing a frequency domain.

The vibration sensor 1 is preferably a piezoelectric acceleration sensor; the vibration generating means 6 is preferably a hammer; the digital signal transmission unit 4 is preferably a wireless digital signal transmission unit, the data storage output device 5 is preferably a handheld tablet computer, and the data analysis module is vibration signal analysis software.

The working principle of the invention is as follows: adopt vibration generating device 6 to strike the pull rod, arouse the pull rod through striking and produce horizontal free damping vibration, the data transmission direction is as shown in fig. 2, and vibration sensor 1 gathers the vibration signal of pull rod, and its vibration signal observes and controls wire 2 transmission to sensor adapter 3 through the high temperature, is handled by the dynamic data acquisition unit in the sensor adapter 3, generates the vibration time course curve to transmit this curve to data storage output device 5 through digital signal transmission unit 4. The data storage output device 5 stores the data and the data is processed by a data analysis module in the data storage output device 5.

The invention also provides a method for measuring the pull rod axial force under the thermal state condition, which adopts the measuring system to measure and realizes the accurate and rapid measurement of the pull rod axial force under the thermal state condition.

The specific test method comprises the following steps:

1. the vibration sensor 1 is arranged in the middle of the support and hanger pull rod, so that the vibration sensor 1 can correctly reflect the transverse vibration characteristic of the pull rod, and the signal quality and the signal to noise ratio are improved. Mica sheets with the thickness less than 0.1 mm are padded between the vibration sensor 1 and the pull rod. The mica sheet plays a role in heat insulation and insulation on the sensor in the test process, and the influence of environmental conditions on the test result is reduced. In order to ensure that the vibration sensor 1 can correctly reflect the transverse vibration characteristic of the pull rod and improve the signal quality and the signal to noise ratio, the mounting position of the sensor is as close to the middle position of the pull rod as possible.

2. The vibration generating device 6 transversely knocks the pull rod, the pull rod is triggered by knocking to generate transverse free damping vibration, a vibration signal of the vibration generating device is measured by the vibration sensor 1, and a dynamic data acquisition unit in the vibration sensor 1 forms a vibration time-course curve with the acquired vibration signal. The vibration time course curve is transmitted to the data storage output device 5 through the digital signal transmission unit 4.

3. The vibration signal analysis software in the data storage and output device 5 carries out time-frequency domain analysis to obtain the transverse vibration frequency f of the pull rod_n。

4. And (4) calculating the axial force N of the pull rod through a formula (1).

In the formula, N is axial force,mass per unit length of the tie rod, l is the length of the tie rod, EI is the bending stiffness, f_nIs the nth order vibration frequency, and n is the order of vibration frequency.

The transient hammering method is adopted to excite the pull rod to vibrate, vibration signals are collected, the vibration frequency value of the pull rod is obtained through signal analysis, data are transmitted wirelessly, and the pull rod vibration control device is simple and rapid to operate and is not easily influenced by the environment. The mica sheet is arranged under the vibration sensor in a cushioning mode, so that heat insulation and insulation effects are achieved on the sensor in the testing process, the influence of environmental conditions on testing results is further reduced, and the measuring results are more accurate.

It should be noted that while the invention has been described in terms of the above-mentioned embodiments, there are many other embodiments of the invention. It will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention, and it is intended that all such changes and modifications be covered by the appended claims and their equivalents.