TWI649543B - Method for detecting deterioration of strcutural part - Google Patents

Abstract

A method for detecting degradation of a structural member includes detecting a time domain vibration waveform of the structural member by a sensor disposed on the structural member. Then, the processor of the electrical connection sensor performs time-frequency domain conversion on the time domain vibration waveform to obtain the actual modal parameters of the plurality of modes of the frequency domain vibration waveform of the structural member. Then, the actual modal parameters of the modalities are compared with the modal parameter data in the database to determine whether the structural component has degradation defects. When there is a deterioration defect in the structural member, the degree and position of the deterioration defect are more judged. The modal parameter data includes a plurality of sets of modal parameters having different degrees of degradation defects at a plurality of locations.

Description

Structural member degradation detection method

The present invention relates to a method for detecting degradation of a structural member, and more particularly to a method for detecting degradation of a structural member using natural frequency and amplitude analysis thereof.

In recent years, domestic industrial pipeline-related accidents have been frequently transmitted. When industrial pipelines leak due to abnormalities, they often cause major disasters such as casualties and property losses. The most common cause of industrial pipelines is human factors, followed by material degradation of pipelines/equipment. In order to avoid such disasters, full-time monitoring of industrial pipelines is a top priority. Although manufacturers have developed a monitoring system for this purpose, the concept is based on monitoring process parameters, analyzing operating conditions and performance, and still lacks degradation detection. In other words, this type of monitoring system can only be detected when the pipeline is damaged and leaks, and it cannot meet the needs of the factory for safe operation and risk reduction.

The main technical shortcomings of industrial pipeline safety monitoring are summarized as follows: First, the environmental or process parameter sensors built on the site are used for process monitoring to regulate the production process, and the safety diagnostic module lacks proper logic judgment analysis. . Second, there is a lack of monitoring technology for remote sensing degradation. The commonly used non-destructive detection technology is only applicable to the local pipeline location where the sensor is located, and the detection technology of this type can only be sensed when the pipeline rupture fluid escapes. It is not possible to issue an early warning signal when deterioration occurs. Third, the operating environment of the industrial plant varies with the system, structure and components. The sensor must have the durability requirement to overcome the high temperature/high humidity environment and long-term monitoring. In other words, due to limitations of existing pipeline inspection methods and techniques, damage or degradation of the pipeline is difficult to detect immediately, thus losing a good opportunity for immediate maintenance and strain. Therefore, in the field of industrial safety, it is necessary to develop diagnostic monitoring related technologies to establish a complete pipeline safety monitoring system.

The invention aims to provide a method for detecting deterioration of a structural member, which utilizes analysis of time domain and frequency domain signals, and compares with a pre-built database to detect the position and degree of deterioration defects of the structural member, so as to achieve The purpose of real-time monitoring and alarming.

A method for detecting degradation of a structural member according to the present invention includes the steps of: detecting a time domain vibration waveform of the structural member by a sensor disposed on the structural member; and electrically connecting the processor to the time domain of the sensor The vibration waveform performs time-frequency domain conversion to obtain the actual modal parameters of the plurality of modes of the frequency domain vibration waveform of the structural member; respectively comparing the actual modal parameters of the modalities with the modal parameter data in the database To determine whether the structural member has a deterioration defect; when there is a deterioration defect in the structural member, the degree and position of the deteriorated defect are further judged; wherein the modal parameter data includes a plurality of sets of comparisons in which the structural member has different degrees of deterioration defects at a plurality of positions respectively. Modal parameters.

In summary, the method for detecting degradation of a structural member proposed by the present invention mainly uses a sensor to obtain time domain data of a structural member, and then uses a processor to analyze time domain/frequency domain data, and The related degradation information of the structural components in the database is compared to obtain the position and extent of the structural component degradation defects. Thereby, the relevant personnel can monitor the state of the structural member, and when the structural member is deteriorated, the deterioration warning can be known in advance, and the necessary maintenance measures can be performed in time, thereby reducing the accident of the construction caused by the deterioration of the structural member. chance.

The above description of the disclosure and the following description of the embodiments of the present invention are intended to illustrate and explain the spirit and principles of the invention, and to provide further explanation of the scope of the invention.

The detailed features and advantages of the present invention are set forth in the Detailed Description of the Detailed Description of the <RTIgt; </ RTI> <RTIgt; </ RTI> </ RTI> </ RTI> <RTIgt; The objects and advantages associated with the present invention can be readily understood by those skilled in the art. The following examples are intended to describe the present invention in further detail, but are not intended to limit the scope of the invention.

Referring to FIG. 1 and FIG. 2 together, FIG. 1 is a structural and structural degradation detecting system according to an embodiment of the present invention, and FIG. 2 is a schematic diagram of an embodiment of the present invention. Method for detecting degradation of structural members. As shown, the degradation detection system 1 includes a sensor 12, a processor 14, and a database 16. In the degradation detection system and method of the structural member of the present invention, first, the sensor 12 is disposed on the structural member 10 to be detected, and the sensor 12 is electrically connected to the processor 14, and the processor 14 is connected in advance. The database 16 is built to complete the construction of the degradation detection system 1. Then, the vibration of the structural member 10 is generated, so that the sensor 12 disposed on the structural member 10 detects the time domain vibration waveform of the structural member 10, as shown in step S201. The structural member 10 of the present invention is exemplified by a pipeline. However, the structural member 10 may be a device commonly used in other industries such as a tank, and the present invention is not limited to the pipeline. In practice, before the step of detecting the time domain vibration waveform of the structural member 10 by the sensor 12 disposed on the structural member 10, the degradation detecting method of the structural member 10 further includes exciting the source or flowing through the structural member 10 The fluid causes the structural member 10 to produce the time domain vibration waveform. In other words, in actual operation, the signal can be transmitted to the structural member 10 through the excitation source to cause vibration, and the fluid can be generated by the structural member 10 to cause vibration.

Please refer to FIG. 3 and FIG. 4 . FIG. 3 is a schematic diagram of a time domain vibration waveform of a structural component detected by a sensor according to an embodiment of the present invention, and FIG. 4 is implemented according to one embodiment of the present invention. The schematic diagram of the frequency domain vibration waveform of the structural member detected by the sensor shown in the example. As shown in FIG. 3, when the structural member 10 generates vibration, the sensor 12 detects the time domain vibration waveform of the structural member 10, as shown in FIG. The sensor 12 will further transmit the time domain vibration waveform to the processor 14. Next, in step S203, the processor 14 performs time-frequency domain conversion on the time domain vibration waveform to obtain actual mode parameters of the plurality of modes of the frequency domain vibration waveform of the structural member 10. As shown in FIG. 4, the frequency domain vibration waveform includes a plurality of modes M1 to M5. In practice, the manner of time-frequency domain conversion performed by the processor 14 may be Fast Fourier Transform (FFT), Hilbert-Huang Transform (HHT), or wavelet analysis (Wavelet). Analysis) and so on.

Next, in step S205, the processor 14 compares the actual modal parameters of the modalities M1 MM5 with the modal parameter data in the database 16 to determine whether the structural member 10 has a degradation defect, such as a degradation defect Def. When the processor 14 determines that the structural member 10 has a deterioration defect, then in step S207, the processor 14 further determines the degree and position of the deterioration defect. In this embodiment, the modal parameter data includes a plurality of sets of contrast modal parameters of the structural member 10 having different degrees of degradation defects at a plurality of locations.

Please refer to FIG. 1, FIG. 4 and FIG. 5 together. FIG. 5 is a waveform diagram of a plurality of sets of modal parameters in a database 16 according to an embodiment of the present invention. In this embodiment, the actual modal parameter of each modality includes an amplitude value of a characteristic frequency (or referred to as a natural frequency), and each set of modal parameters corresponds to a plurality of first degradation curves. As shown in FIG. 4 and FIG. 5, the actual modal parameters of the modal M1~M5 respectively include the characteristic frequencies f1~f5, and the contrast modal parameters MA1~MA5 respectively correspond to different first degradation curves, wherein each The first degradation curves correspond to the proposed degradation defect bits having a degree of deterioration value and located at a position of the structural member 10. The processor 14 in step S207 determines the degree and location of the degradation defect, and includes comparing the amplitude values of the characteristic frequencies with the first degradation curves of each group of the comparison modal parameters, thereby determining the degree of degradation defects. With location. Specifically, when the processor 14 obtains the actual modal parameter of a modality of the structural member 10, it can know the amplitude value of a characteristic frequency included in the actual modal parameter, such as the actual mode of the modal M1 of FIG. The state parameter includes the amplitude value V1 of the characteristic frequency f1, and the actual modal parameter of the mode M2 includes the amplitude value V2 of the characteristic frequency f2 and the like. In this embodiment, the reference modal parameters MA1~MA5 are individually corresponding to the modalities M1~M5 of the structural member 10.

Taking the modality M1 as an example, when the processor 14 obtains the amplitude value V1 of the characteristic frequency f1 of the modal M1, the amplitude value V1 and the position of the sensor 12 on the structural member 10 can be determined according to the figure. A plurality of first degradation curves included in the comparison modal parameter MA1 of the plurality of sets of modal parameters in the database 16 are found to be corresponding to the first degradation curve, and the first degradation curve corresponds to The degree of deterioration and the position at which the deterioration defect level is determined and located at a position of the structural member is the deterioration defect of the structural member 10. Since the position of the sensor 12 on the structural member 10 may just make the processor 14 unable to clearly compare the first degradation curve corresponding to the amplitude value, and the degree and position of the deterioration defect cannot be found, the practice is For the operation, the more the modalities of the structural members 10 are searched in FIG. 5, the above problems can be avoided and the degree and position of the deterioration defects of the structural members 10 can be more accurately compared.

Since the deterioration detecting system 1 detects the degree and position of the deterioration defect of the structural member 10 through the amplitude value at the same characteristic frequency as shown in FIG. 5 above, it may be limited by the setting of the sensor 12 on the structural member 10. The positional factor cannot be used to compare the first degradation curve of the structural member 10 with the amplitude value, so that the degree and position of the deterioration defect of the structural member 10 cannot be judged. For example, as shown in FIG. 5, when the sensor 12 is disposed in the node interference zone DA, the sensor 12 may fall on the same node of the plurality of first degradation curves of a comparison modal parameter due to the amplitude value. . At this time, the sensor 12 cannot judge which degree of the deterioration defect of the structural member 10 and the position corresponds to which of the plurality of first degradation curves. In view of this, in an embodiment, before detecting the time domain vibration waveform of the structural member 10 by the sensor 12 disposed on the structural member 10, the characteristic frequency corresponding to each group of modal parameters according to the database 16 is included. The size is determined to determine the position of the sensor 12 disposed on the structural member 10. In the embodiment of FIG. 1 and FIG. 5, the processor 14 estimates the preferred sensor 12 setting position based on the characteristic frequency of the modal parameter of the pre-configured database 16. In a preferred embodiment, the sensor 12 is disposed at a distance from one end of the structural member that is less than or equal to 1/2 of the wavelength of the characteristic frequency having the largest value. Therefore, in the embodiment of FIG. 5, among the characteristic frequencies of the plurality of reference modal parameters MA1 to MA5, the characteristic frequency of the reference modal parameter MA5 is the maximum value. At this time, the processor 14 determines that the ideal set position of the sensor 12 is the measurement area TA according to the length of the wavelength corresponding to the characteristic frequency of the maximum value of the modal parameter MA5. In other words, the relevant engineering personnel can set the sensor 12 at a position 1/2 of the wavelength from the both ends of the structural member 10 to be tested according to the judgment result of the processor 14. In this way, it is possible to prevent the position of the sensor 12 from falling on the node interference area DA of the structural member 10, and the processor 14 cannot obtain the degree and position of the deterioration defect of the structural member 10.

The foregoing embodiment of FIG. 5 mainly applies the amplitude values at the same characteristic frequency to compare the extent and position of the deterioration defects of the structural member 10. In yet another embodiment, a change in the characteristic frequency can be applied to compare the extent and location of the degradation defect of the structural member 10. Please refer to FIG. 1 , FIG. 4 and FIG. 6 together. FIG. 6 is a waveform diagram of a plurality of sets of modal parameters in a database 16 according to another embodiment of the present invention. In this embodiment, the actual modal parameters of each modality of the structural member 10 include a characteristic frequency, such as frequencies f1 and f2, and each set of modal parameters MF1 and MF2 includes a plurality of second degradation curves, such as The two degradation curves P1 to P16 and Q1 to Q16 are as shown in FIG. 6. Please refer to FIG. 7. FIG. 7 is a flowchart of a method for detecting a degradation of a structural member according to another embodiment of the present invention. 7 is substantially the same as FIG. 2 except that the difference between the processor determining the degree and position of the deterioration defect described in step S207 of FIG. 7 includes steps S2071 and S2072. In step S2071, the processor 14 obtains at least two sets of degradation estimation parameters according to the characteristic frequencies of the modalities and the second degradation curves included in the set of modal parameters. Next, in step S2072, the processor 14 determines the degree and location of the degradation defect according to the at least two sets of degradation estimation parameters.

Illustrated with the embodiment of FIG. 6, FIG. 6 shows two different sets of contrast modal parameters MF1 and MF2, wherein the control modal parameter MF1 includes a plurality of second degradation curves P1 P P16, and the control modal parameter MF2 contains more Second degradation curves Q1~Q16. Each second degradation curve represents the degree of degradation of different defect lengths and locations at different frequencies. For example, the second degradation curve Q1 may represent the degree of degradation that the structural member 10 has at different frequencies when the defect length of the structural member is 50 mm and is at a 1/8 tube length position. As another example, the second degradation curve Q7 may represent the degree of degradation that the structural member 10 has at different frequencies when the defect length of the structural member is 150 mm and is located at a 2/8 tube length position.

In this embodiment, it is assumed that the modalities M1 and M2 of the structural member 10 obtained by the processor 14 respectively correspond to the modal parameters MF1 and MF2 in the database 16, and the actual modal parameters of the modalities M1 and M2 are respectively Contains characteristic frequencies f1 and f2. The processor 14 first compares the plurality of second degradation curves P1 P P16 included in the reference modal parameter MF1 in the database 16 shown in FIG. 6 according to the characteristic frequency f1 to find possible degradation defects of the structural member 10. The location and extent. As shown in FIG. 6, the processor 14 obtains a set of degradation estimation parameters in the comparison modal parameter MF1 including degradation prediction parameters DP1~DP8. Similarly, the processor 14 obtains a set of degradation prediction parameters in the comparison modal parameter MF2 including the degradation estimation parameters DQ1 D DQ3. The processor 14 can determine the position and extent of possible degradation defects of the structural member 10 according to the degradation estimation parameters DP1 DPDP8 and the degradation estimation parameters DQ1 D DQ3.

More specifically, in an embodiment, the processor 14 determines, according to the two sets of degradation prediction parameters, the degree and location of the degradation defect, and includes comparing the at least two sets of degradation estimation parameters to filter out at least one repetition. The degradation prediction parameter, the at least one repeated degradation prediction parameter is associated with the degree and location of the degradation defect. In this embodiment, the processor 14 compares the degradation estimation parameters DP1 to DP8 and the degradation estimation parameters DQ1 to DQ3, thereby filtering out the repeated deterioration estimation parameters, that is, the degradation estimation parameters DQ1 to DQ3. At this time, the processor 14 can know the degree and position of the deterioration defect of the structural member 10 as the degree and position of the deterioration defect corresponding to one of the deterioration estimation parameters DQ1 to DQ3.

In practice, if the degree and location of the degradation defect of the structural member 10 are to be more accurately confirmed, the processor 14 may further compare the characteristic frequency included in the actual modal parameter of the other modality with another set of comparison modes. A plurality of second degradation curves included in the state parameters to obtain another set of degradation estimation parameters. Then, the processor 14 compares the other set of degradation prediction parameters with the two sets of degradation estimation parameters, and extracts the repeated portions of the three sets of degradation estimation parameters, and then the structural component 10 is known. More precise degree and location of degraded defects. In other words, the processor 14 can more accurately determine the degree and position of the degradation defect of the structural member 10 by detecting the more characteristic frequency of the modality, and the contrast modal parameters MF1 and MF2 can be tied to Obtained at different time points, for example, the control modal parameter MF1 is obtained at one time point and the control modal parameter MF2 is obtained at another time point. The embodiment of Figs. 5 and 6 of the present invention is mainly a technique for instantly determining the degree of thinning and positioning of the structural member 10 by the amount of change in frequency (or its amplitude). In other words, the spirit of the present invention is to utilize the physical characteristics of the natural frequency of the structural member. When the structural member is thinned, the local rigidity and quality of the structural member change to cause a change in the natural frequency of the entire structural member itself, thereby judging deterioration. The extent and location of the defect. In this way, a set of deterioration monitoring technology for structural parts can be developed without damaging the structural parts, so as to ensure the safety of the structural parts used in the industry, such as important pipelines or tanks, and can be avoided. People are exposed to high-risk work environments.

The principles used in the degradation detection system and method of the structural member proposed by the present invention can be applied to structural members of various shapes. For example, please refer to FIG. 8 to FIG. 11 together, which respectively show perspective views of structural members of different shapes. As shown in Figures 8-11, the shapes of the structural members that can be applied are solid cylindrical state, curved pipe shape, square tube shape and I-shaped cross-sectional shape. In the solid cylindrical state of Fig. 8, assuming that the length of the structural member is L, the degree of defect (% tube thickness) and characteristic frequency at different modes M1 to M5 of 1/4 L and 1/2 L of the structural member ( The changes in Hz) are shown in Tables 1 and 2 below. Table I  <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> 1/4L </td><td> M1 </td><td> M2 </ Td><td> M3 </td><td> M4 </td><td> M5 </td></tr><tr><td> 0% </td><td> 22.05239 </td> <td> 60.7595 </td><td> 119.0305 </td><td> 196.5821 </td><td> 293.3228 </td></tr><tr><td> 25% </td><td > 21.67752 </td><td> 58.70199 </td><td> 116.0998 </td><td> 195.5517 </td><td> 292.006 </td></tr><tr><td> 50% </td><td> 20.77782 </td><td> 54.38835 </td><td> 111.2858 </td><td> 193.6701 </td><td> 289.0152 </td></tr><tr ><td> 75% </td><td> 18.47006 </td><td> 47.43438 </td><td> 105.8418 </td><td> 190.2872 </td><td> 282.3232 </td> </tr></TBODY></TABLE> Table 2  <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> 1/2L </td><td> M1 </td><td> M2 </ Td><td> M3 </td><td> M4 </td><td> M5 </td></tr><tr><td> 0% </td><td> 22.05239 </td> <td> 60.7595 </td><td> 119.0305 </td><td> 196.5821 </td><td> 293.3228 </td></tr><tr><td> 25% </td><td > 21.08352 </td><td> 60.7286 </td><td> 116.2668 </td><td> 196.3019 </td><td> 287.4922 </td></tr><tr><td> 50% </td><td> 18.96757 </td><td> 60.63222 </td><td> 111.1252 </td><td> 195.4105 </td><td> 279.0904 </td></tr><tr ><td> 75% </td><td> 15.04959 </td><td> 60.32965 </td><td> 104.5329 </td><td> 192.6023 </td><td> 271.1687 </td> </tr></TBODY></TABLE>

In the shape of the elbow of Fig. 9, if the length of the structural member is L, the degree of defect and the characteristic frequency in different modes of 1/4L and 1/2L of the structural member are as shown in Tables 3 and 4 below. Show. Table 3  <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> 1/4L </td><td> M1 </td><td> M2 </ Td><td> M3 </td><td> M4 </td><td> M5 </td></tr><tr><td> 0% </td><td> 107.6097 </td> <td> 299.3441 </td><td> 576.457 </td><td> 912.6012 </td><td> 1229.042 </td></tr><tr><td> 25% </td><td > 107.0839 </td><td> 296.2418 </td><td> 571.8002 </td><td> 908.6208 </td><td> 1227.168 </td></tr><tr><td> 50% </td><td> 105.9831 </td><td> 289.5574 </td><td> 561.6209 </td><td> 900.6288 </td><td> 1222.553 </td></tr><tr ><td> 75% </td><td> 102.8482 </td><td> 272.4134 </td><td> 538.6506 </td><td> 881.1895 </td><td> 1208.208 </td> </tr></TBODY></TABLE> Table 4  <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> 1/2L </td><td> M1 </td><td> M2 </ Td><td> M3 </td><td> M4 </td><td> M5 </td></tr><tr><td> 0% </td><td> 107.6097 </td> <td> 299.3441 </td><td> 576.457 </td><td> 912.6012 </td><td> 1229.042 </td></tr><tr><td> 25% </td><td > 105.8333 </td><td> 295.0557 </td><td> 574.2221 </td><td> 910.5367 </td><td> 1222.309 </td></tr><tr><td> 50% </td><td> 102.1406 </td><td> 283.489 </td><td> 567.4657 </td><td> 905.5377 </td><td> 1212.337 </td></tr><tr ><td> 75% </td><td> 92.93562 </td><td> 264.4272 </td><td> 549.8736 </td><td> 889.8458 </td><td> 1207.469 </td> </tr></TBODY></TABLE>

In the form of the square tube of Fig. 10, if the length of the structural member is L, the degree of defect and the characteristic frequency in different modes of 1/4L and 1/2L of the structural member are as shown in Tables 5 and 6 below. Show. Table 5  <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> 1/4L </td><td> M1 </td><td> M2 </ Td><td> M3 </td><td> M4 </td><td> M5 </td></tr><tr><td> 0% </td><td> 79.61369 </td> <td> 217.4225 </td><td> 420.4544 </td><td> 682.7447 </td><td> 998.1407 </td></tr><tr><td> 25% </td><td > 78.88281 </td><td> 214.2276 </td><td> 416.3346 </td><td> 680.6828 </td><td> 995.8001 </td></tr><tr><td> 50% </td><td> 77.32048 </td><td> 206.8515 </td><td> 407.3621 </td><td> 675.946 </td><td> 989.165 </td></tr><tr ><td> 75% </td><td> 72.86193 </td><td> 189.1832 </td><td> 389.8823 </td><td> 624.6216 </td><td> 968.927 </td> </tr></TBODY></TABLE> Table 6  <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> 1/2L </td><td> M1 </td><td> M2 </ Td><td> M3 </td><td> M4 </td><td> M5 </td></tr><tr><td> 0% </td><td> 79.61369 </td> <td> 217.4225 </td><td> 420.4544 </td><td> 682.7447 </td><td> 998.1407 </td></tr><tr><td> 25% </td><td > 78.00208 </td><td> 217.2905 </td><td> 417.5578 </td><td> 679.9839 </td><td> 993.1377 </td></tr><tr><td> 50% </td><td> 74.25027 </td><td> 216.9309 </td><td> 409.6331 </td><td> 646.52 </td><td> 981.6498 </td></tr><tr ><td> 75% </td><td> 64.82471 </td><td> 215.732 </td><td> 391.9877 </td><td> 565.5287 </td><td> 960.5893 </td> </tr></TBODY></TABLE>

In the shape of the I-shaped cross section of Fig. 11, if the length of the structural member is L, the degree of defect and the characteristic frequency of the different modes of 1/4L and 1/2L of the structural member are as follows: Table 7 and Table 8 Table 7 shown  <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> 1/4L </td><td> M1 </td><td> M2 </ Td><td> M3 </td><td> M4 </td><td> M5 </td></tr><tr><td> 0% </td><td> 219.8807 </td> <td> 561.3934 </td><td> 1001.138 </td><td> 1492.311 </td><td> 2007.315 </td></tr><tr><td> 25% </td><td > 219.0764 </td><td> 557.3356 </td><td> 995.5444 </td><td> 1490.648 </td><td> 2006.844 </td></tr><tr><td> 50% </td><td> 217.4524 </td><td> 549.2907 </td><td> 984.642 </td><td> 1486.917 </td><td> 2003.783 </td></tr><tr ><td> 75% </td><td> 211.2352 </td><td> 536.2614 </td><td> 967.8168 </td><td> 1481.157 </td><td> 1997.218 </td> </tr></TBODY></TABLE>Table eight  <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> 1/2L </td><td> M1 </td><td> M2 </ Td><td> M3 </td><td> M4 </td><td> M5 </td></tr><tr><td> 0% </td><td> 219.8807 </td> <td> 561.3934 </td><td> 1001.138 </td><td> 1492.311 </td><td> 2007.315 </td></tr><tr><td> 25% </td><td > 217.679 </td><td> 561.4051 </td><td> 996.8888 </td><td> 1492.386 </td><td> 2000.988 </td></tr><tr><td> 50% </td><td> 210.4497 </td><td> 561.2004 </td><td> 987.3976 </td><td> 1491.165 </td><td> 1990.76 </td></tr><tr ><td> 75% </td><td> 199.0602 </td><td> 560.656 </td><td> 970.7511 </td><td> 1488.125 </td><td> 1978.935 </td> </tr></TBODY></TABLE>

In one embodiment, the modal parameter of each mode includes a characteristic frequency having a frequency in the first direction and a frequency in the second direction. The method for detecting degradation of the structural member of the present invention further includes determining the form of the degradation defect according to the frequency in the first direction and the frequency in the second direction. Specifically, in this embodiment, the sensor 12 of the present invention may be a three-axis accelerometer for detecting frequencies in different directions, such as frequencies in the X-axis direction and frequencies in the Y-axis direction. Next, the processor 14 determines the form of the deterioration defect of the structural member 10 based on the amount of change in the frequency in the X-axis direction and the frequency in the Y-axis direction, which may be, for example, a uniform defect or a partial defect. In more detail, in an embodiment, the step of the processor 14 determining the form of the degradation defect according to the frequency in the first direction and the frequency in the second direction comprises determining the frequency of the first direction and the second direction. Whether the frequency change is consistent. When the frequency of the first direction is consistent with the frequency of the second direction, the processor 14 determines that the form of the degradation defect is a uniform defect. On the other hand, when the frequency of the first direction does not coincide with the frequency of the second direction, the processor 14 determines that the form of the degradation defect is a local defect.

In one embodiment, the database 16 is a partial defect sub-database or a uniform defect sub-database. The method for detecting degradation of the structure further includes the processor 14 determining the database 16 according to the form of the degradation defect. Local defect sub-database or uniform defect sub-database. In more detail, in a practical example, the method for detecting degradation of the structural member of the present invention causes the processor 14 to first determine the degradation defect of the structural member 10 according to the frequency in the first direction and the frequency in the second direction. Form. When it is confirmed that the deterioration defect of the structural member 10 is a local defect, the database 16 is a partial defect sub-database. On the other hand, when it is confirmed that the deterioration defect of the structural member 10 is a uniform defect, the database 16 is a uniform defect sub-database. Then, the processor 14 performs the detection procedure of the degree and location of the degradation defect of FIG. 5 or FIG. 6 according to one of the partial defect sub-database or the uniform defect sub-database. More specifically, the deterioration detecting method of the structural member of the present invention preferentially confirms the form of the deterioration defect, and then confirms the degree and position of the deterioration defect by using the method shown in FIG. 5 and/or FIG. 6 to improve the deterioration defect. The accuracy of the judgment of the degree and position. In practice, the degradation detection system and method provided by the present invention can be combined with other portable devices, such as a tablet computer, a smart phone, a notebook computer, etc., to provide instant monitoring and pre-alarm information.

In summary, the degradation detection system and method provided by the present invention provides sensor measurement information, analyzes signals in time domain and frequency domain, and uses a database associated with deterioration defects of structural components to provide Instant monitoring and pre-alarming information to resolve accidents in structural components such as industrial pipelines/slots. The degradation detection system and method provided by the invention can be combined with the wireless transmission technology of the device to construct an industrial security monitoring platform, and provide a high-performance and secure remote monitoring service.

Although the present invention has been disclosed above in the foregoing embodiments, it is not intended to limit the invention. It is within the scope of the invention to be modified and modified without departing from the spirit and scope of the invention. Please refer to the attached patent application for the scope of protection defined by the present invention.

1‧‧‧Degradation detection system

10‧‧‧Structural parts

12‧‧‧ Sensors

14‧‧‧ Processor

16‧‧‧Database

Def‧‧‧Deterioration defect

M1~M5‧‧‧modal

F1~f5‧‧‧ characteristic frequency

V1~V5‧‧‧ amplitude value

DP1~DP8, DQ1~DQ3‧‧‧ Deterioration estimation parameters

MF1, MF2, MA1~MA5‧‧‧ contrast modal parameters

P1~P16, Q1~Q16‧‧‧Second degradation curve

DA‧‧‧ node interference zone

TA‧‧‧ measurement area

1 is a schematic diagram of a degradation detecting system for a structural member and a structural member according to an embodiment of the invention. 2 is a flow chart of a method for detecting a degradation of a structural member according to an embodiment of the invention. 3 is a schematic diagram of a time domain vibration waveform of a structural member detected by a sensor according to an embodiment of the invention. 4 is a schematic diagram of frequency domain vibration waveforms of a structural member detected by a sensor according to an embodiment of the invention. FIG. 5 is a waveform diagram of a plurality of sets of modal parameters in a database according to an embodiment of the present invention. FIG. 6 is a waveform diagram of a plurality of sets of modal parameters in a database according to another embodiment of the present invention. FIG. 7 is a flow chart of a method for detecting a degradation of a structural member according to another embodiment of the present invention. 8 to 11 are perspective views respectively showing structural members of different shapes.

Claims (10)

A method for detecting degradation of a structural member includes: detecting a time domain vibration waveform of the structural member by a sensor disposed on a structural member; and vibrating the time domain by a processor electrically connected to the sensor The waveform performs time-frequency domain conversion to obtain actual modal parameters of a plurality of modalities of a frequency domain vibration waveform of the structural member, and each of the modal actual modal parameters includes a characteristic frequency; and respectively respectively The characteristic frequencies of the actual modal parameters are compared with a plurality of sets of modal parameters included in a modal parameter data in a database to determine the extent and location of the degraded defects; wherein the modal parameters are compared It is used to indicate that the structural member has different degrees of deterioration defects at a plurality of locations. The method for detecting degradation of a structural member according to claim 1, wherein an actual modal parameter of each modality includes an amplitude value of the characteristic frequency, and each set of modal parameters corresponds to a plurality of first degradation curves, Determining the degree and location of the degradation defect includes comparing the amplitude values of the characteristic frequencies with the first degradation curves of each set of the control modal parameters, thereby determining the degree and location of the degradation defect; Each of the first degradation curves corresponds to a proposed degradation defect bit having a degradation level value and located at a location of the structural member. The method for detecting degradation of a structural member according to claim 1, wherein each group of the control modal parameters includes a plurality of second degradation curves, and determining the degree and location of the degradation defects comprises: according to the modalities The characteristic frequency and the second degradation curves included in the set of modal parameters respectively obtain at least two sets of degradation estimation parameters; Determining the extent and location of the degradation defect based on the at least two sets of degradation estimation parameters. The method for detecting degradation of a structural member according to claim 3, wherein determining the degree of the degradation defect and the position system according to the at least two sets of degradation estimation parameters comprises comparing the at least two sets of degradation estimation parameters to filter At least one repeated degradation prediction parameter is associated, the at least one repeated degradation prediction parameter being associated with the extent and location of the degradation defect. The method for detecting degradation of a structural member according to claim 1, wherein before detecting the time domain vibration waveform of the structural member by the sensor disposed on the structural member, the method includes: comparing each group according to the database The modal parameter corresponds to a characteristic frequency to determine the position of the sensor on the structure. The method for detecting degradation of a structural member according to claim 5, wherein the sensor is disposed at a distance from one end of the structural member, the distance being less than or equal to a wavelength corresponding to a characteristic frequency having a maximum value; /2 length. The method for detecting degradation of a structural member according to claim 1, wherein the characteristic frequency has a frequency in a first direction and a frequency in a second direction, and the method for detecting degradation of the structural member further comprises The frequency in the first direction and the frequency in the second direction to determine the form of the degradation defect. The method for detecting degradation of a structural member according to claim 7, wherein the step of determining the form of the degradation defect according to the frequency in the first direction and the frequency in the second direction comprises: determining the first direction Whether the frequency is consistent with the frequency of the second direction; when the frequency of the first direction is consistent with the frequency of the second direction, determining that the form of the deteriorated defect is a uniform defect; When the frequency of the first direction does not coincide with the frequency of the second direction, it is determined that the form of the degradation defect is a local defect. The method for detecting degradation of a structural member according to claim 7, wherein the database may be a partial defect sub-database or a uniform defect sub-database, and the degradation detection method of the structural component further includes the degradation defect The form is used to determine whether the database is the local defect sub-database or the uniform defect sub-database. The method for detecting degradation of a structural member according to claim 1, wherein the method for detecting degradation of the structural member is performed before the step of detecting a time domain vibration waveform of the structural member by the sensor disposed on the structural member Further comprising a source of excitation or a fluid flowing through the structure causes the structural member to generate the time domain vibration waveform.