CN-121808203-B - GIS flange bolt tightening quality judging method based on torque corner curve analysis

CN121808203BCN 121808203 BCN121808203 BCN 121808203BCN-121808203-B

Abstract

The invention belongs to the technical field of data processing, and particularly relates to a GIS flange bolt tightening quality judging method based on torque and rotation angle curve analysis, which comprises the steps of resampling torque and rotation angle data based on preset angle step length, and calculating instantaneous tangential stiffness by adopting a Gaussian kernel weighted difference operator so as to smoothly inhibit high-frequency friction noise in the aluminum alloy tightening process; and calculating an accumulated damage value based on the deviation of the instantaneous rigidity and the reference value, and judging that micro yield occurs and stopping when the accumulated damage value exceeds a threshold value. According to the invention, transient viscous sliding interference and actual plastic deformation are effectively distinguished through an energy integration thought, the problem of misjudgment caused by no obvious yield point and individual difference of cast aluminum alloy is solved, and high-precision nondestructive judgment of bolt tightening quality is realized.

Inventors

LIU BINGLIN
ZHANG YING
ZOU XUEBIN
ZHU YINUO
DENG XUECHAO

Assignees

中科力祥科技股份有限公司

Dates

Publication Date: 20260508
Application Date: 20260309

Claims (7)

1. The GIS flange bolt tightening quality judging method based on torque corner curve analysis is characterized by comprising the following steps of: resampling the corner data based on a preset angle step length to obtain an angle domain sequence, and obtaining torque values corresponding to sampling points in the angle domain sequence; calculating an angle domain sequence and a corresponding torque value in a sliding window containing a plurality of sampling points by adopting a Gaussian kernel weighted difference operator so as to determine the instantaneous tangential stiffness at each sampling point; based on arithmetic average value of all instantaneous tangent stiffness in the linear elastic zone and change rate of instantaneous tangent stiffness, constructing dynamic elastic reference value of sampling point after exceeding the linear elastic zone; calculating a damage accumulated value based on the instantaneous tangential stiffness and the dynamic elastic reference value, wherein the increment of the damage accumulated value is positively correlated with the torque value and the attenuation degree of the instantaneous tangential stiffness; the increment of the damage accumulated value is equal to the product of an activating factor at the sampling point, a torque value and a radian value after the conversion of a preset standard angle step, and the value range of the standard angle step is 0.1-1.0 degree; The method for acquiring the activating factors at the sampling points comprises the steps of calculating the relative attenuation rate of the rigidity at each sampling point according to a dynamic elastic reference value and the instantaneous tangential rigidity, comparing the relative attenuation rate of the rigidity with a preset noise threshold, and setting the activating factors to zero when the relative attenuation rate of the rigidity is smaller than the noise threshold, otherwise, making the activating factors and the relative attenuation rate of the rigidity be in exponential positive correlation, wherein the value range of the noise threshold is 0.02-0.05; Calculating the difference value of the dynamic elastic reference value and the instantaneous tangent stiffness at the sampling point, wherein the dynamic elastic reference value is related to the arithmetic average value of the instantaneous tangent stiffness, and the relative stiffness attenuation rate at the sampling point is equal to the ratio of the difference value to the dynamic elastic reference value at the sampling point; And in response to the damage accumulation value exceeding a preset damage accumulation threshold, determining that micro-yielding occurs and triggering shutdown.
2. The method for judging tightening quality of a GIS flange bolt based on torque rotation angle curve analysis according to claim 1, wherein the calculation formula of the instantaneous tangential stiffness at the sampling point is: ; in the formula, Is the first Instantaneous tangential stiffness at the individual sampling points; is the radius of the sliding window, and ; For data points within the sliding window relative to the first Index offsets for the sample points; Is the first Torque values for the sampling points; Is the first An arithmetic average value of torque values of all sampling points in the sliding window corresponding to the sampling points; Is the first Corner values of the sampling points; Is the first An arithmetic average value of the rotation angle values of all sampling points in the sliding window corresponding to the sampling points; Is the first Gaussian weight coefficients for each sample point.
3. The method for judging tightening quality of a GIS flange bolt based on torque rotation angle curve analysis according to claim 2, wherein the Gaussian weight coefficient of the sampling point is obtained by taking the index offset of each data point in the sliding window relative to a central point as an independent variable.
4. The GIS flange bolt tightening quality judging method based on torque corner curve analysis according to claim 1 is characterized in that the determining the linear elastic region according to the torque value comprises scanning an angle domain sequence, and intercepting the section of the torque value between 30% and 60% of a target value as the linear elastic region.
5. The method for judging tightening quality of the flange bolts of the GIS based on torque corner curve analysis according to claim 4, wherein the calculation formula of the dynamic elastic reference value of the sampling point is as follows: ; in the formula, Is the first A dynamic elastic reference value at each sampling point, , A sequence number of the last sampling point of the linear elastic region; Is the arithmetic average value of the instantaneous tangent stiffness at all sampling points in the linear elastic region; Is the first Instantaneous tangential stiffness at the individual sampling points; Is the first Corner values of the sampling points; An ending rotation angle value of the linear elastic region; is the hardening coefficient.
6. The method for judging the tightening quality of the GIS flange bolts based on torque rotation angle curve analysis according to claim 5, wherein the target value and the hardening coefficient of the torque are obtained by tightening test of samples in the same batch, and the specific method comprises the following steps: Calculating the average value of all sample yield limit torques, setting a target value of the torque as a certain proportion of the average yield limit torque, and taking the proportion as 60-75%; And determining the ratio of the slope of the trend line to the average instantaneous tangential stiffness of the sample as the hardening coefficient.
7. The method for judging tightening quality of the GIS flange bolts based on torque rotation angle curve analysis according to claim 1, wherein the method for determining the damage accumulation threshold value is as follows: The method comprises the steps of carrying out tightening test on samples in the same batch until yielding occurs, calculating damage accumulation values of each sample at the yield point, selecting the minimum value in the critical damage accumulation values of all samples, and setting the damage accumulation threshold value to be a certain proportion of the minimum value, wherein the proportion is 70-85%.

Description

GIS flange bolt tightening quality judging method based on torque corner curve analysis Technical Field The invention relates to the technical field of data processing. More specifically, the invention relates to a GIS flange bolt tightening quality judging method based on torque corner curve analysis. Background Gas insulated metal-enclosed switchgear (GIS) is a critical transmission and control device in electrical power systems, the housing of which is usually made of cast aluminum alloy, and is internally filled with high-pressure insulating gas, so that the tightening quality of the flange bolts directly determines the sealing performance and operation safety of the device. Because the cast aluminum alloy material lacks an obvious yield point, and because of the existence of micro cutting fluid or metal scraps in the assembly process, high-frequency viscous sliding friction is very easy to generate between threads, and the technical challenge is brought to the accurate judgment of the tightening quality. The existing tightening quality judging technology generally adopts a torque corner method, and the main means is to calculate the instantaneous slope, namely the rigidity, of a torque-corner curve based on the data of adjacent sampling points and compare the instantaneous slope, namely the rigidity, with a preset fixed threshold value to judge whether the tightening quality judging technology is qualified or not. However, the method for calculating the rigidity based on the two-point difference and relying on the fixed threshold has the obvious defects that on one hand, the two-point difference algorithm is extremely sensitive to noise, instant friction jump caused by viscous sliding is amplified through differential operation to form a severe saw-tooth waveform, so that the algorithm is difficult to distinguish whether friction interference or real rigidity is reduced, and false alarm is caused, on the other hand, slope attenuation is extremely weak and is often covered by natural hardening trend of materials when aluminum alloy is subjected to microscopic yield, the fixed parameter standard cannot identify the early plastic deformation, individual fluctuation caused by difference of shell material hardness and processing texture is difficult to adapt, and the sliding screw bolt is easily misjudged as qualified. Disclosure of Invention The invention provides a GIS flange bolt tightening quality judging method based on torque corner curve analysis, which comprises the steps of obtaining torque data and corner data in the bolt tightening process; the method comprises the steps of carrying out resampling on corner data based on a preset angle step length to obtain an angle domain sequence, obtaining torque values corresponding to sampling points in the angle domain sequence, calculating the angle domain sequence and the corresponding torque values in a sliding window comprising a plurality of sampling points by adopting a Gaussian kernel weighted difference operator to determine instantaneous tangent stiffness at each sampling point, determining a linear elastic region according to the torque values, constructing a dynamic elastic reference value of the sampling points beyond the linear elastic region based on an arithmetic average value of all instantaneous tangent stiffness and a change rate of the instantaneous tangent stiffness in the linear elastic region, calculating a damage accumulation value based on the instantaneous tangent stiffness and the dynamic elastic reference value, wherein the increment of the damage accumulation value is positively correlated with the attenuation degree of the torque values and the instantaneous tangent stiffness, and judging that micro-yielding occurs and triggering shutdown is triggered in response to the damage accumulation value exceeding a preset damage accumulation threshold. The method has the advantages that the data dimension is unified through angle domain resampling, non-physical noise caused by motor rotation speed fluctuation is eliminated, the Gaussian kernel weighted difference operator is adopted to calculate rigidity, compared with a traditional difference method, viscous sliding friction noise in the aluminum alloy screwing process can be effectively restrained, signal saw-tooth is avoided, a dynamic elastic reference value is constructed, the method can adapt to natural hardening trend in the flange face flattening process, misjudgment caused by nonlinear increase of rigidity is avoided, the transient friction interference and continuous microscopic yield are distinguished by utilizing integral effect based on a distinguishing mechanism of a damage accumulated value, the detection difficulty caused by lack of obvious yield point and easiness in friction interference of a cast aluminum alloy material is solved, and the misinformation rate is greatly reduced while high sensitivity is ensured. Preferably, the calculation formula of the instantaneous