CN107741209A - Correction Method of Temperature Effect of Vibrating Wire Displacement Sensor - Google Patents
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- 238000006073 displacement reaction Methods 0.000 title claims abstract description 54
- 238000000034 method Methods 0.000 title claims abstract description 21
- 238000012937 correction Methods 0.000 title claims abstract description 17
- 230000002277 temperature effect Effects 0.000 title description 3
- 238000012360 testing method Methods 0.000 claims abstract description 85
- 230000006698 induction Effects 0.000 claims abstract description 6
- 229910000831 Steel Inorganic materials 0.000 claims description 23
- 239000010959 steel Substances 0.000 claims description 23
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 abstract description 10
- 238000004364 calculation method Methods 0.000 abstract description 6
- 229910052742 iron Inorganic materials 0.000 abstract description 5
- 230000001681 protective effect Effects 0.000 abstract description 2
- 238000010998 test method Methods 0.000 abstract 1
- 238000005259 measurement Methods 0.000 description 7
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- 238000009795 derivation Methods 0.000 description 1
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Abstract
本发明公开了一种振弦式位移传感器的温度影响修正方法，该法考虑不同温度情况下，通过试验及相关计算，得出了试样不同的位移改变量。据此，发明人还设计制作了相应的测试装置以及推算出相应的计算公式。该装置主要包括测试振弦、软铁块、磁铁、感应膜片、线圈、保护套筒、紧固件组成。使用该测试方法和测试装置，能够充分考虑到温度改变量对实测位移改变量的影响。该修正方法可以测量出在对振弦类位移传感器进行位移测试的过程中由于温度的改变引起的位移改变量，大大的提高了测量位移改变量的准确度，可广泛适用于桥梁荷载试验、健康监控等技术领域。
The invention discloses a temperature influence correction method of a vibrating wire displacement sensor. The method considers different temperature conditions, and obtains different displacement changes of samples through tests and related calculations. Accordingly, the inventor also designed and produced a corresponding test device and calculated a corresponding calculation formula. The device mainly consists of a test vibrating wire, a soft iron block, a magnet, an induction diaphragm, a coil, a protective sleeve, and a fastener. Using the test method and test device, the influence of the temperature change on the measured displacement change can be fully considered. This correction method can measure the displacement change caused by the temperature change during the displacement test of the vibrating wire displacement sensor, which greatly improves the accuracy of measuring the displacement change, and can be widely used in bridge load tests, health Surveillance and other technical fields.
Description
技术领域technical field
本发明属于振弦类位移测试技术领域，尤其涉及一种振弦式位移传感器的温度影响修正方法。The invention belongs to the technical field of vibrating wire displacement testing, and in particular relates to a temperature influence correction method of a vibrating wire displacement sensor.
背景技术Background technique
在岩土工程和其它工程的观测和长期检测中，离不开位移传感器。振弦式位移传感器是位移传感器的一种，其工作原理是通过被测试位移改变测试振弦的工作长度，测试振弦的工作长度不同导致测试振弦的振动频率不同，通过测量振弦的频率来测量被测试位移的大小。In the observation and long-term detection of geotechnical engineering and other engineering, displacement sensors are inseparable. The vibrating wire displacement sensor is a kind of displacement sensor. Its working principle is to change the working length of the testing vibrating wire through the tested displacement. Different working lengths of the testing vibrating wire lead to different vibration frequencies of the testing vibrating wire. By measuring the frequency of the vibrating wire To measure the size of the tested displacement.
在对振弦类传感器进行位移测试的过程中，测试前后温度的改变会对测试结果带来较大的误差，因此需要测量出测试振弦由于温度改变引起的位移改变量以减小测试结果的误差。During the displacement test of the vibrating wire sensor, the temperature change before and after the test will bring a large error to the test result. Therefore, it is necessary to measure the displacement change of the test vibrating wire due to the temperature change to reduce the error of the test result. error.
发明内容Contents of the invention
本发明的发明目的是，针对上述问题，提供一种振弦式位移传感器的温度影响修正方法，该修正方法可以测量出在对振弦类位移传感器进行位移测试的过程中由于温度的改变引起的位移改变量。The object of the present invention is to address the above problems and provide a method for correcting the temperature effect of a vibrating wire displacement sensor. The amount of displacement change.
为达到上述目的，本发明所采用的技术方案是：一种振弦式位移传感器的温度影响修正方法，包括以下步骤：1)测量出测试振弦的原始长度l和截面面积s；2)将所述测试振弦拉紧并将其两端固定在振弦式位移传感器上；3)通过频率测量装置测量所述测试振弦的第一振动频率为f0；4)对所述测试振弦施加测试外力使所述测试振弦产生位移改变量Δl′从而改变所述测试振弦的工作长度，通过温度测量装置测量所述测试振弦的温度改变量为t，通过频率测量装置测量出所述测试振弦的第二振动频率为f″；In order to achieve the above object, the technical solution adopted in the present invention is: a temperature influence correction method of a vibrating wire displacement sensor, comprising the following steps: 1) measuring the original length l and the cross-sectional area s of the vibrating wire; The test vibrating wire is tightened and its two ends are fixed on the vibrating wire displacement sensor; 3) the first vibration frequency of the test vibrating wire is measured by a frequency measuring device as f 0 ; 4) the test vibrating wire Applying a test external force causes the test vibrating wire to produce a displacement change Δl' so as to change the working length of the test vibrating wire. The temperature change of the test vibrating wire is measured by the temperature measuring device as t, and the frequency measuring device measures the value The second vibration frequency of the test vibrating wire is f ";
按公式by formula
计算移改变量Δl′，式中，e为测试振弦的弹性模量，m为测试振弦的质量，α为测试振弦的膨胀系数。Calculate the displacement Δl′, where e is the elastic modulus of the test vibrating wire, m is the mass of the test vibrating wire, and α is the expansion coefficient of the test vibrating wire.
作为一种改进的方式，所述测试振弦为测试钢弦。As an improved manner, the test vibrating wire is a test steel string.
作为一种改进的方式，所述步骤2)中的温度改变量t为所述测试振弦相对外界测试环境的温度改变量。As an improved manner, the temperature change t in the step 2) is the temperature change of the test vibrating wire relative to the external test environment.
作为一种改进的方式，所述步骤2)中的温度改变量t为所述测试振弦相对于所述位移传感器的温度改变量。As an improved manner, the temperature change t in the step 2) is the temperature change of the test vibrating wire relative to the displacement sensor.
作为一种改进的方式，所述位移传感器包括测试振弦、感应膜片以及底座，所述感应膜片固定安装于所述底座上，所述测试振弦的一端与所述底座固定连接，所述测试振弦的另一端连接所述感应膜片，所述测试振弦、所述感应膜片以及所述底座上分别设置有温度传感器。As an improved way, the displacement sensor includes a test vibrating wire, a sensing diaphragm and a base, the sensing diaphragm is fixedly mounted on the base, one end of the testing vibrating wire is fixedly connected to the base, the The other end of the test vibrating wire is connected to the sensing diaphragm, and temperature sensors are respectively arranged on the testing vibrating wire, the sensing diaphragm and the base.
作为一种改进的方式，所述测试振弦与所述底座通过螺纹紧固件固定连接，所述测试振弦与所述感应膜片通过螺纹紧固件固定连接。As an improved manner, the test vibrating wire is fixedly connected to the base by a threaded fastener, and the test vibrating wire is fixedly connected to the induction diaphragm by a threaded fastener.
由于采用上述技术方案，本发明具有以下有益效果：Owing to adopting above-mentioned technical scheme, the present invention has following beneficial effect:
该修正方法的操作步骤简单，在使用振弦式位移传感器测量位移值的过程中，温度的变化会对振弦式位移传感器测量的测量结果造成一定的影响，使用该方法可以对振弦式位移传感器测量的测量结果进行修正，提高振弦式位移传感器的测量结构的准确性，使最终测得的位移值精确。The operation steps of this correction method are simple. In the process of using the vibrating wire displacement sensor to measure the displacement value, the change of temperature will have a certain impact on the measurement results measured by the vibrating wire displacement sensor. This method can be used for vibrating wire displacement. The measurement results measured by the sensor are corrected to improve the accuracy of the measurement structure of the vibrating wire displacement sensor, so that the final measured displacement value is accurate.
由于所述步骤4)中的温度改变量t为所述测试振弦相对外界测试环境的温度改变量，测试振弦相对外界测试环境的温度改变量对振弦式位移传感器的测量结果造成一定的影响，该修正方法可以对测量结果进行修正。Because the temperature change t in the step 4) is the temperature change of the test vibrating wire relative to the external test environment, the temperature change of the test vibrating wire relative to the external test environment has a certain effect on the measurement results of the vibrating wire displacement sensor. Influence, this correction method can correct the measurement results.
由于所述步骤4)中的温度改变量t为所述测试振弦相对于所述位移传感器其它结构的温度改变量，位移传感器其它结构的温度改变量对振弦式位移传感器的测量结果造成一定的影响，该修正方法可以对测量结果进行修正。Because the temperature change t in the step 4) is the temperature change of the test vibrating wire relative to other structures of the displacement sensor, the temperature change of other structures of the displacement sensor has a certain effect on the measurement results of the vibrating wire type displacement sensor. , the correction method can correct the measurement results.
由于所述测试振弦和所述感应膜片以及所述底座分别设置有温度传感器，通过三个温度传感器求平均值可较为准确的测出温度变化量t。Since the test vibrating wire, the sensing diaphragm and the base are respectively provided with temperature sensors, the temperature change t can be measured more accurately by averaging the three temperature sensors.
附图说明Description of drawings
图1是位移传感器的整体结构示意图；1 is a schematic diagram of the overall structure of the displacement sensor;
图2是位移传感器的内部结构原理图；Figure 2 is a schematic diagram of the internal structure of the displacement sensor;
附图中：1-测试振弦，2-保护套筒，3-软铁块，4-磁铁，5-底座，6-感应膜片，7-线圈，8-螺纹紧固件。In the accompanying drawings: 1-test vibrating wire, 2-protective sleeve, 3-soft iron block, 4-magnet, 5-base, 6-inductive diaphragm, 7-coil, 8-threaded fastener.
具体实施方式detailed description
本发明公开了一种振弦式位移传感器的温度影响修正方法，包括以下步骤：The invention discloses a temperature influence correction method for a vibrating wire displacement sensor, which comprises the following steps:
1)测量出测试振弦1的原始长度l和截面面积s。1) Measure the original length l and cross-sectional area s of the test vibrating wire 1 .
2)将测试振弦1拉紧并将其两端固定在振弦式位移传感器上，位移传感器包括测试振弦1、软铁块3、磁铁4、线圈7。2) Tighten the test vibrating wire 1 and fix its two ends on the vibrating wire displacement sensor. The displacement sensor includes the test vibrating wire 1, the soft iron block 3, the magnet 4, and the coil 7.
3)测试振弦1的一端通过螺纹紧固件8固定连接于底座5，底座5固定于保护套筒2上，测试振弦1的另一端通过螺纹紧固件8与感应膜片6固定连接，在测试振弦1中间安装一个软铁块3，在软铁块3下面放置绑有线圈7的磁铁4，通电之后，线圈7带电激励测试钢弦1振动，通过频率测量装置测量测试振弦1的第一振动频率为f0。3) One end of the test vibrating wire 1 is fixedly connected to the base 5 through the threaded fastener 8, the base 5 is fixed on the protective sleeve 2, and the other end of the test vibrating wire 1 is fixedly connected to the induction diaphragm 6 through the threaded fastener 8 A soft iron block 3 is installed in the middle of the test vibrating string 1, and a magnet 4 bound with a coil 7 is placed under the soft iron block 3. After power is applied, the coil 7 is electrified to stimulate the test steel string 1 to vibrate, and the test vibrating string is measured by a frequency measuring device The first vibration frequency of 1 is f 0 .
4)对振弦式位移传感器施加测试外力，测量测试振弦1的温度改变量为t，温度改变量t可以为测试振弦1相对外界测试环境的温度改变量或着是测试振弦1相对于位移传感器其它结构的温度改变量。4) Apply a test external force to the vibrating wire displacement sensor, measure the temperature change of the test vibrating wire 1 as t, and the temperature change t can be the temperature change of the test vibrating wire 1 relative to the external test environment or the relative temperature of the test vibrating wire 1 Compared with the temperature change of other structures of the displacement sensor.
测量出测试振弦1的第二振动频率为f″；Measure the second vibration frequency of the test vibrating wire 1 as f ";
按公式by formula
计算移改变量Δl′，式中，e为测试振弦1的弹性模量，m为测试振弦1的质量，α为测试振弦1的膨胀系数。Calculate the displacement Δl′, where e is the elastic modulus of the test vibrating wire 1, m is the mass of the test vibrating wire 1, and α is the expansion coefficient of the test vibrating wire 1.
以下给出计算公式的基本推导过程：The basic derivation process of the calculation formula is given as follows:
钢弦的长度、截面面积、弹性模量、质量和膨胀系数分别为l、s、e、m、α。The length, cross-sectional area, elastic modulus, mass and expansion coefficient of the steel string are l, s, e, m, α respectively.
由于待测试样的应变值ε的计算公式为而钢弦的长度l为定值，即应力ε与外力作用钢弦的产生伸长量Δl′成正比例关系，分析应变值ε的误差即为分析外力作用钢弦的产生伸长量Δl′的误差大小。Since the calculation formula of the strain value ε of the sample to be tested is The length l of the steel string is a fixed value, that is, the stress ε is proportional to the elongation Δl′ of the steel string under the external force, and the error of the analysis of the strain value ε is the result of the analysis of the elongation Δl’ of the steel string under the external force The size of the error.
钢弦两端拉紧固定时，其振动频率f0与钢弦拉力T满足关系式1：When both ends of the steel string are tightened, the vibration frequency f 0 and the tension T of the steel string satisfy the relation 1:
此时令4ml2＝k，对应的钢弦应变为式2所示：At this time, 4ml 2 =k, and the corresponding steel string strain is shown in formula 2:
变化温t℃时，钢弦将产生的长度变化量Δl为式3所示：When changing the temperature t°C, the length change Δl of the steel string is shown in Equation 3:
Δl＝ltα (式3)Δl=ltα (Formula 3)
由于钢弦的两端固定，温度变化将导致钢弦内力产生变化，内力变化量ΔT如式4所示：Since the two ends of the steel string are fixed, the temperature change will cause the internal force of the steel string to change, and the internal force change ΔT is shown in Equation 4:
温度变化后钢弦的振动基频为f′，可以采用下式表示：After the temperature changes, the vibration fundamental frequency of the steel string is f', which can be expressed by the following formula:
T-ΔT＝4ml2f′2 T-ΔT=4ml 2 f '2
化简后得到公式4ml2f0 2-setα＝4ml2f′2 After simplification, the formula 4ml 2 f 0 2 -setα＝4ml 2 f ′2 is obtained
即 which is
当同时由于外力作用钢弦的产生伸长量Δl′，钢弦的频率为f″，此时有式6，At the same time, due to the external force, the elongation Δl' of the steel string is produced, and the frequency of the steel string is f", at this time there is formula 6,
式6化简后得式7Equation 6 is simplified to get Equation 7
算例：Examples:
某测试传感器的钢弦长度为0.1m，质量为0.00098646kg，直径为0.4mm，钢弦的弹性模量为200Gpa，膨胀系数为0.00001，钢弦张紧后初始频率为2000Hz，初始温度为20℃，外界温度变化导致钢弦温度改变，同时外力作用传感器发生受力改变，此时钢弦频率为2500Hz，常规做法不考虑温度影响修正，求得钢弦伸长量为0.353mm，而根据式7考虑温度修正后，算得不同温度下钢弦相对伸长量差值较大，当忽略温度影响时该量值会被误认为是传感器受外力作用的真实改变量。实算结果比较见表1。The steel string of a test sensor has a length of 0.1m, a mass of 0.00098646kg, and a diameter of 0.4mm. The elastic modulus of the steel string is 200Gpa, and the expansion coefficient is 0.00001. After the steel string is tensioned, the initial frequency is 2000Hz, and the initial temperature is 20°C. , the external temperature change causes the temperature of the steel string to change, and at the same time, the force of the external force sensor changes. At this time, the frequency of the steel string is 2500Hz. The conventional method does not consider the correction of the temperature effect, and the elongation of the steel string is obtained as 0.353mm. According to formula 7 After considering the temperature correction, the difference in the relative elongation of the steel string at different temperatures is calculated to be large. When the influence of temperature is ignored, this value will be mistaken for the real change of the sensor due to the external force. The actual calculation results are compared in Table 1.
表1常规做法与修正后计算结果Table 1 Conventional practice and revised calculation results
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110608664A (en) * | 2019-09-30 | 2019-12-24 | 中铁第一勘察设计院集团有限公司 | Bridge type vibrating wire strain gauge based on online correction |
| CN112945426A (en) * | 2021-01-29 | 2021-06-11 | 西南石油大学 | Vibrating wire sensor and stress displacement testing method |
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Application publication date: 20180227 |