Novel bolt pin connection structure and load state detection method thereof

Abstract

The invention relates to the technical field of bolt pin stress detection, in particular to a novel bolt pin connection structure and a load state detection method thereof. Comprising a cap opening, an expansion pin and a threaded locking pin rod, the expansion pin is an axial hollow cylinder, the front end of the expansion pin is axially divided into eight elastic locking plates which are uniformly distributed in the circumferential direction, radial telescopic grooves are formed in the roots of four of the locking plates so that the locking plates can be elastically opened in the radial direction, and the front end of a rod body of the threaded locking pin rod is a conical propelling end head. The threaded clamping lock pin rod is coaxially inserted into an inner cavity of the expansion pin, the conical pushing end of the threaded clamping lock pin rod extrudes the inner wall of the lock piece through rotation, the lock piece is forced to be opened in the radial direction, a conical locking face is arranged on the inner wall of the cap opening, and after the expansion pin is inserted into the cap opening, the opened outer surface of the lock piece is tightly connected with the conical condensation face of the cap opening in a pressed mode. A resistance strain gauge is arranged in the axial center area of the inner cavity of the expansion pin. According to the invention, the strain change of the bolt can be monitored in real time, so that whether the bolt is loosened or not can be accurately judged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pin stress detection, and in particular to a novel pin connection structure and a load state detection method thereof. BACKGROUND

[0002] Traditional pins, as basic connectors in the industrial field, have a technical background and development history spanning from ancient civilizations to modern industries. In application fields, traditional pins are widely used in construction, machinery, automobiles, aviation, and railways due to their simplicity, reliability, and cost-effectiveness. The mechanical principle of pin connection is based on friction and mechanical locking to ensure the stability and reliability of the connection. To maintain the performance of pin connections, regular maintenance inspections, tightening, and replacement are required to prevent loosening and corrosion. Non-destructive testing techniques such as ultrasonic, magnetic particle, and penetration testing are used to detect internal defects in pins to ensure the safety of the connection.

[0003] However, the limitations of traditional pins lie in the inability to achieve real-time monitoring of their preload and state, which restricts their performance and safety in critical applications. First, traditional pins cannot achieve real-time monitoring of their preload and state. Once the pins loosen or have defects, it is difficult to discover in time, which may lead to serious safety hazards. This is because the design and function of traditional pins are mainly based on mechanical locking and friction, lacking built-in sensors or monitoring mechanisms. Their state detection relies on regular manual inspection or non-destructive testing techniques such as ultrasonic, magnetic particle, and penetration testing, which can detect internal defects in pins but cannot provide real-time feedback on the dynamic changes of the pins. Second, the maintenance cost of pins is high and inefficient. The maintenance of pins requires regular inspection, tightening, and replacement, especially in harsh environments, where pins are prone to failure due to corrosion, fatigue, and other factors, increasing maintenance costs and workload. Although the materials and design of traditional pins consider strength and toughness to some extent, stress concentration phenomena still occur under complex stress environments. Local stress concentration can lead to fatigue failure, affecting the reliability of the connection. At the same time, the manufacturing process of traditional pins (such as forging, machining) may cause surface defects or residual stress, further reducing their fatigue life. Therefore, there is room for improvement. SUMMARY

[0004] To achieve real-time monitoring of the strain changes of the bolt and accurately determine whether the bolt is loose, and automatically trigger an alarm when the bolt is loose or the warning force is abnormal, the present application provides a novel pin connection structure and a load state detection method thereof.

[0005] In a first aspect, the present application provides a novel pin connection structure, which adopts the following technical solutions:

[0006] The new pin connection structure comprises a cap, an expansion pin and a threaded locking pin rod, the expansion pin is an axial hollow cylinder, the front end of the expansion pin is divided into eight elastic locking pieces with a 45-degree circumferential distribution, the roots of four locking pieces are provided with radial expansion grooves, the threaded locking pin rod comprises a rod body and an external thread segment, the front end of the rod body is a conical pushing end, the threaded locking pin rod is coaxially inserted into the inner cavity of the expansion pin, the conical pushing end is extruded against the inner wall of the locking piece by rotating, and the locking piece is forced to expand radially, the cap is an annular sleeve, the inner wall of the cap is provided with a conical locking surface, after the expansion pin is inserted into the cap, the outer surface of the expanded locking piece is tightly pressed against the conical locking surface of the cap, and the axial center region of the inner cavity of the expansion pin is provided with a resistance strain gauge, and the lead wire of the resistance strain gauge is led out through a sealing hole in the tail of the expansion pin.

[0007] By adopting the above technical scheme, the eight elastic locking pieces with a 45-degree circumferential distribution at the front end of the expansion pin (the roots of four locking pieces are provided with radial expansion grooves) are combined with the conical pushing end of the threaded locking pin rod, the pushing end is extruded against the inner wall of the locking piece by rotating, the locking piece is forced to expand radially, the uniform and tight pressing of the locking piece against the conical locking surface of the inner wall of the cap is ensured, the stress is effectively dispersed, the local stress concentration is reduced, the mechanical stability and the anti-loosening ability of the connection are significantly improved, and the loosening failure of the traditional bolt caused by uneven stress is avoided; secondly, the design of the resistance strain gauge integrated in the axial center region of the inner cavity of the expansion pin enables the lead wire to be led out through the sealing hole in the tail, and the strain change of the bolt can be monitored in real time with high precision, the data are analyzed by combining with an intelligent detection system, the loosening or overload state can be timely warned, the problems of low efficiency and large error of manual detection are solved; in addition, the elastic deformation mechanism of the locking piece expansion groove and the sealing measures (such as silicone rubber filling) enhance the anti-rust and corrosion resistance, and prolong the service life; overall, the innovation is applicable to key infrastructures such as bridges, railways and tunnels, reduces the maintenance cost and accident risk, and improves the safety and reliability.

[0008] Optionally, an annular groove is arranged at the joint interface between the expansion pin and the cap, the groove is filled with a silicone rubber sealing layer, the silicone rubber forms an elastic sealing body after curing, and external water vapor and corrosive media are isolated.

[0009] By adopting the technical scheme, the elastic sealing body formed by curing the silicone rubber in the annular groove constructs a high-elasticity physical barrier at the mechanical connection interface between the expansion pin and the cap mouth. The barrier uses the compression resilience of the silicone rubber to tightly fill the micro gaps caused by the expansion of the locking sheet, completely isolates the penetration of external water vapor, salt mist and acid and alkali corrosion medium, effectively solves the corrosion failure problem of the traditional metal connecting piece caused by the invasion of corrosion medium, and at the same time, the excellent weather resistance and aging resistance of the silicone rubber can resist ultraviolet rays, temperature difference deformation and cold and hot cycle impact for a long time, avoid the hardening and cracking of the sealing layer, significantly prolong the service life of the connecting structure in high-humidity and strong-corrosion environments such as bridges and tunnels, and in addition, the low-molecular-volatility characteristics and the buffering and vibration-absorbing effect of the silicone rubber reduce the fretting wear risk of the connection interface caused by vibration, further guarantee the long-term stability of the bolt pretightening force, and thus the structural safety and maintenance economy of the key infrastructure are improved as a whole.

[0010] Optionally, the contact surface of the locking sheet is an inclined surface with an inclination angle of 30°-60°. When the threaded locking pin rod is screwed in, the inclined surface decomposes the axial thrust into a radial expansion component and a circumferential constraint component, reducing the eccentric load of the threaded locking pin rod.

[0011] By adopting the technical scheme, when the threaded locking pin rod is screwed in, the inclined contact surface of the locking sheet decomposes the axial thrust into a radial expansion component and a circumferential constraint component, significantly reducing the eccentric stress borne by the threaded locking pin rod, and the circumferential constraint component forms a self-centering effect, forcing the locking sheet to uniformly slide along the conical locking surface of the cap mouth, eliminating unilateral stress concentration.

[0012] Optionally, the resistance strain gauge is packaged on a detachable ceramic substrate, and the substrate is fixed in the positioning groove in the inner wall of the expansion pin through spring buckles on both sides, forming a modular quick-release structure.

[0013] By adopting the technical scheme, the cooperation of the spring buckles and the positioning groove allows quick disassembly and replacement of the strain gauge module, avoiding the cumbersome process of disassembling the entire bolt for the traditional welded sensor, reducing maintenance time, especially suitable for high-altitude or closed environments such as bridges and tunnels, reducing the risk of manual work and downtime losses, and at the same time, the ceramic substrate provides excellent insulation and thermal stability, effectively isolating electromagnetic interference and high-temperature deformation, ensuring low measurement accuracy error of the strain gauge, and the modular structure enhances durability. The corrosion resistance of the ceramic substrate combined with the elastic buffer of the spring buckles prevents micro displacement or poor contact caused by vibration, prolonging the service life of the sensor.

[0014] In a second aspect, the application provides a load state detection method applied to the novel pin bolt connecting structure, adopting the following technical scheme:

[0015] A novel pin bolt connecting structure load state detection method, the novel pin bolt connecting structure load state detection method comprising the following steps:

[0016] an initial strain value of the resistance strain gauge when the locking piece of the thread locking pin rod is fully opened;

[0017] Based on the wireless sensor, strain data and temperature data in the inner cavity of the expansion pin are collected in real time to generate a real-time strain sequence.

[0018] According to the initial strain value and the real-time strain sequence, a strain deviation value is calculated, and the material thermal expansion effect is compensated in combination with the temperature data.

[0019] Based on the strain deviation value, a strain timing change rate is obtained, and when the strain deviation value is greater than a preset loosening threshold or the strain timing change rate is greater than a preset overload rate threshold, a hierarchical alarm signal is triggered.

[0020] By using the above technical scheme, the initial strain value (when the locking piece is fully opened) and the real-time strain sequence of the resistance strain gauge are collected synchronously, and the material thermal expansion effect is dynamically compensated in combination with the temperature sensor data, which significantly eliminates the measurement error caused by environmental temperature change, improves the accuracy of the strain deviation value, solves the misjudgment problem of the traditional resistance strain gauge caused by temperature drift, and based on the double-threshold triggering mechanism of the strain deviation value and the timing change rate, the pre-tightening force decay and the overload risk state can be distinguished, the failure mode can be accurately located through the hierarchical alarm signal, the false negative rate of single threshold alarm is reduced, the safety of key infrastructures such as bridges and railways is greatly improved, relying on the real-time transmission of data by the wireless sensor, remote monitoring and automatic work order generation are realized, the bolt state can be obtained without climbing or disassembling the structure by the operation and maintenance personnel, the detection efficiency in high-risk environment is improved and the maintenance cost is reduced, the strain change of the bolt is monitored in real time, so that whether the bolt is loose or not can be accurately judged, and the alarm is automatically triggered when the bolt is loose or the pre-warning force is abnormal.

[0021] In a preferred example, the application can be further configured as follows: the wireless sensor is used to collect strain data and temperature data in the inner cavity of the expansion pin in real time to generate a real-time strain sequence, specifically including:

[0022] According to a preset sampling frequency, the pin strain data is collected in the axial central region of the expansion pin, the temperature sensor data is synchronously obtained, and a strain-temperature correlation matrix is established.

[0023] The original pin strain data is subjected to wavelet denoising processing to eliminate vibration interference noise, the denoised pin strain data is fused with the strain-temperature correlation matrix, and a real-time strain sequence is output.

[0024] By adopting the technical scheme, high-precision strain data and temperature data are synchronously collected in the axial central region of the expansion pin by a preset sampling frequency, a strain-temperature correlation matrix is constructed, the material thermal expansion effect is dynamically compensated, the measurement error caused by temperature drift is eliminated, the strain data precision is improved, the original strain data is processed by combining a wavelet denoising algorithm, vibration interference noise is effectively filtered out, the real load signal is retained, and the reliability of the real-time strain sequence is ensured.

[0025] In a preferred example, the application can be further configured to: based on the initial strain value and the real-time strain sequence, calculating a strain deviation value, and combining temperature data to compensate for the material thermal expansion effect, specifically including:

[0026] Based on the real-time strain sequence and the initial strain value, a strain drift caused by thermal expansion is corrected according to a temperature compensation coefficient, and a strain deviation value is output:

[0027] ΔE = | (ΔS t - α · ΔT) - S p |, wherein ΔS t is the real-time strain sequence, S p is the initial strain value, and α is the temperature compensation coefficient.

[0028] According to the strain deviation value, the strain time sequence change rate is analyzed, and the pin bolt load state is determined according to the strain time sequence change rate.

[0029] By adopting the technical scheme, the thermal expansion drift in the real-time strain sequence is dynamically corrected by introducing the temperature compensation coefficient, the measurement error caused by environmental temperature change is reduced, the misjudgment problem caused by the temperature drift of the traditional strain gauge is solved, the strain-temperature correlation matrix is used to calibrate the data in real time, the strain deviation value is ensured to truly reflect the pin bolt caused by the mechanical load effect rather than the thermal effect interference, and the physical meaning clear input data is provided for the loosening or overload judgment. Based on the strain deviation value, the strain time sequence change rate analysis captures the strain gradient change caused by the micro displacement, and the pre-tightening force attenuation and overload risk state can be distinguished by combining the double-threshold triggering mechanism.

[0030] In a preferred example, the application can be further configured to: based on the strain deviation value, a strain change rate is obtained, when the strain deviation value is greater than a preset loosening threshold or the strain change rate is greater than a preset overload rate threshold, a hierarchical alarm signal is triggered, and specifically including:

[0031] When the strain deviation value is greater than the preset loosening threshold, a first-level early warning is triggered, and a loosening risk report is generated;

[0032] When the strain time sequence change rate is greater than the preset overload rate threshold, a second-level early warning is triggered, and an audible and visual warning is started;

[0033] Train a preset pin failure prediction model based on the strain deviation value, and output a future failure probability of the pin.

[0034] By adopting the technical scheme, risk grading management is realized through the double-threshold triggering mechanism, the first-level early warning is directed to the pre-tightening force attenuation problem (such as strain accumulation caused by bolt loosening), a structured report (containing positioning information and risk level) is generated through wireless transmission to guide maintenance personnel to accurately investigate, the second-level early warning is directed to the instantaneous overload risk (such as strain mutation rate exceeding limit caused by impact load), a site warning is started through millisecond-level response to force the equipment to be unloaded or shut down, and malignant accidents such as structure fracture are avoided, the real-time strain deviation value is input into the pin failure prediction model, the model is trained based on the strain deviation value sequence and historical failure spectral characteristics to identify the loosening probability and fracture risk coefficient, and a future failure probability of the pin is output.

[0035] In summary, the present application has at least one of the following beneficial technical effects:

[0036] 1. The 8 circumferentially distributed 45° elastic locking pieces at the front end of the expansion pin (4 of which are provided with radial expansion grooves) in combination with the conical pushing end head of the threaded locking pin shaft are designed to be rotated to make the pushing end head extrude the inner wall of the locking piece, force the locking piece to be radially elastically expanded, ensure the uniform and close compression of the locking piece and the conical locking surface of the cap opening, effectively disperse stress and reduce local stress concentration, significantly improve the mechanical stability and anti-loosening ability of the connection, and avoid the loosening failure of traditional bolts caused by uneven stress; secondly, the design of integrating the resistance strain gauge in the axial central region of the expansion pin cavity makes the lead wire drawn out through the tail sealing hole, and the strain change of the bolt can be monitored in real time with high precision, the data are analyzed by the intelligent detection system, the loosening or overload state can be timely warned, and the problems of low efficiency and large error of manual detection are solved; in addition, the structure enhances the anti-rust and corrosion resistance through the elastic deformation mechanism and sealing measures (such as silicone rubber filling) of the locking piece expansion groove, prolongs the service life; overall, the innovation is applicable to key infrastructures such as bridges, railways and tunnels, reduces the maintenance cost and accident risk, and improves the safety and reliability;

[0037] 2. When the threaded locking pin shaft is screwed in, the inclined contact surface of the locking piece decomposes the axial thrust into a radial expansion component and a circumferential constraint component, significantly reduces the eccentric load stress borne by the threaded locking pin shaft, and the circumferential constraint component forms a self-centering effect to force the locking piece to uniformly slide along the conical locking surface of the cap opening, eliminating unilateral stress concentration.

[0038] 3. When the threaded locking pin shaft is screwed in, the inclined contact surface of the locking piece decomposes the axial thrust into a radial expansion component and a circumferential constraint component, significantly reduces the eccentric load stress borne by the threaded locking pin shaft, and the circumferential constraint component forms a self-centering effect to force the locking piece to uniformly slide along the conical locking surface of the cap opening, eliminating unilateral stress concentration.

[0039] 4. By synchronously collecting the initial strain value of the resistance strain gauge (when the locking piece is fully opened) and the real-time strain sequence, and combining with the temperature sensor data to dynamically compensate for the thermal expansion effect of the material, the measurement error caused by environmental temperature change is significantly eliminated, the accuracy of the strain deviation value is improved, the misjudgment problem caused by temperature drift of the traditional resistance strain gauge is solved, the double-threshold trigger mechanism based on the strain deviation value and the time sequence change rate can distinguish between pre-tightening force attenuation and overload risk state, and through the hierarchical alarm signal, the failure mode can be accurately located, the false alarm rate of single threshold alarm is reduced, the safety of key infrastructure such as bridges and railways is greatly improved, relying on wireless sensor real-time data transmission, remote monitoring and automatic work order generation are realized, and the bolt state can be obtained without climbing or disassembling the structure by the operation and maintenance personnel, the detection efficiency in high-risk environment is improved and the maintenance cost is reduced, the strain change of the bolt is realized in real time, so that whether the bolt is loose or not is accurately judged, and the alarm is automatically triggered when the bolt is loose or the pre-warning force is abnormal. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 is a structural diagram of a new pin bolt connection structure in an embodiment of the present application;

[0041] Figure 2 is a sectional view of a new pin bolt connection structure in an embodiment of the present application;

[0042] Figure 3 is a detailed structural diagram of a new pin bolt connection structure in an embodiment of the present application;

[0043] Figure 4 is a locking piece structure diagram of a new pin bolt connection structure in an embodiment of the present application;

[0044] Figure 5 is an implementation flowchart of a load state detection method of a new pin bolt connection structure in an embodiment of the present application;

[0045] Figure 6 is an implementation flowchart of step S20 in a load state detection method of a new pin bolt connection structure in an embodiment of the present application;

[0046] Figure 7 is an implementation flowchart of step S30 in a load state detection method of a new pin bolt connection structure in an embodiment of the present application;

[0047] Figure 8 is an implementation flowchart of step S40 in a load state detection method of a new pin bolt connection structure in an embodiment of the present application.

[0048] Reference signs: 1, expansion pin; 2, threaded locking pin rod; 3, cap opening; 4, locking piece. DETAILED DESCRIPTION

[0049] To make the purpose, technical solution, and advantages of this application clearer, the following description is provided in conjunction with the appendix. Figures 1-8 This application will be described in further detail.

[0050] In one embodiment, such as Figures 1-4 As shown, this application discloses a novel pin connection structure, including an expansion pin 1, a threaded locking pin 2, a cap 3, and locking plates 4. The expansion pin 1 is an axially hollow cylinder, with its front end divided axially into eight circumferentially distributed elastic locking plates 4 at 45° angles. The roots of four locking plates 4 are provided with radial expansion grooves, allowing the locking plates 4 to open radially elastically. The locking plates 4 are locked between the pin and the pin rod, ensuring a stable connection. The threaded locking pin 2 includes a rod body and an external threaded section. The front end of the rod body is a conical push-in end. The threaded locking pin 2 is coaxially inserted into the inner cavity of the expansion pin 1. By rotating, its conical push-in end presses against the inner wall of the locking plates 4, forcing the locking plates 4 to open radially. The cap 3 is fixed to the top of the pin rod. The cap 3 is an annular sleeve with a conical locking surface on its inner wall. After the expansion pin 1 is inserted into the cap 3, the outer surface of the opened locking plates 4 is tightly pressed against the conical contraction surface of the cap 3.

[0051] An annular groove is provided at the joint interface between the expansion pin 1 and the cap 3. The groove is filled with a silicone rubber sealing layer. After the silicone rubber is cured, it forms an elastic seal that isolates external moisture and corrosive media. The contact surface of the locking plate 4 is an inclined surface with an inclination angle of 30°-60°. When the threaded locking pin 2 is screwed in, the inclined surface decomposes the axial thrust into a radial expansion component and a circumferential constraint component, reducing the off-center load of the threaded locking pin 2.

[0052] The resistance strain gauge is encapsulated on a detachable ceramic substrate and fixed inside the expansion pin 1. It is used to monitor the strain changes of the bolt in real time and is replaceable, making it easy to maintain and update. The substrate is fixed in the positioning groove on the inner wall of the expansion pin 1 by spring clips on both sides, forming a modular quick-release structure.

[0053] The implementation principle of a novel pin connection structure in this application is as follows:

[0054] During installation, insert the expansion pin 1 into the part to be connected, install the cap 3, and screw the threaded locking pin 2 in with a flathead screwdriver. As the threaded locking pin 2 rotates, it pushes the locking plate 4 of the expansion pin 1 open, completing the connection. After installation, fill the gap between the expansion pin 1 and the cap 3 with silicone rubber to prevent internal oxidation and rust. After initial installation, record the initial strain. When the strain changes, the system determines whether the bolt is loose or the warning force is abnormal, and triggers an alarm to remind maintenance personnel to handle the situation promptly.

[0055] In one embodiment, such as Figure 5 As shown, this application discloses a novel method for detecting the load state of a pin-connected structure, which specifically includes the following steps:

[0056] S10: Obtain the initial strain value of the resistance strain gauge when the locking piece of the thread locking pin is fully opened.

[0057] Specifically, the expansion pin is inserted into the connection site to be connected, the cap is installed, and a flathead screwdriver is used to rotate the thread locking pin. The thread locking pin pushes the locking piece of the expansion pin to open during rotation, completing the connection. After installation is complete, silicone rubber is used to fill the gap between the expansion pin and the cap to prevent internal oxidation and rust. After initial installation is complete, the initial strain value is recorded.

[0058] S20: Real-time strain data and temperature data of the expansion pin cavity are collected based on the wireless sensor to generate a real-time strain sequence.

[0059] S30: Calculate the strain deviation value based on the initial strain value and the real-time strain sequence, and compensate for the thermal expansion effect of the material in combination with the temperature data.

[0060] Specifically, the thermal expansion effect of the material is dynamically compensated in combination with the temperature sensor data, significantly eliminating measurement errors caused by environmental temperature changes, improving the accuracy of the strain deviation value, solving the misjudgment problem caused by temperature drift of traditional resistance strain gauges, and dynamically compensating the thermal expansion effect of the material in combination with the temperature sensor data, significantly eliminating measurement errors caused by environmental temperature changes, improving the accuracy of the strain deviation value, and solving the misjudgment problem caused by temperature drift of traditional resistance strain gauges.

[0061] S40: Obtain the strain rate of change based on the strain deviation value. When the strain deviation value is greater than the preset loosening threshold or the strain rate of change is greater than the preset overload rate threshold, a hierarchical alarm signal is triggered.

[0062] Specifically, the dual-threshold triggering mechanism based on the strain deviation value and the rate of change can distinguish between pre-tightening force decay and overload risk states, and accurately locate the failure mode through a hierarchical alarm signal, reducing the false negative rate of a single threshold alarm, significantly improving the safety of key infrastructure such as bridges and railways, relying on real-time data transmission by wireless sensors to achieve remote monitoring and automatic work order generation, and allowing maintenance personnel to obtain the state of the bolt without climbing or disassembling the structure, improving detection efficiency and reducing maintenance costs in high-risk environments, and realizing real-time monitoring of the strain change of the bolt to accurately determine whether the bolt is loose, and automatically triggering an alarm when it is loose or the pre-warning force is abnormal.

[0063] In this embodiment, by synchronously collecting the initial strain value of the resistance strain gauge (when the gauge is fully opened) and the real-time strain sequence, and combining the temperature sensor data to dynamically compensate the thermal expansion effect of the material, the measurement error caused by environmental temperature change is significantly eliminated, the accuracy of the strain deviation value is improved, the misjudgment problem caused by temperature drift of the traditional resistance strain gauge is solved, the dual-threshold trigger mechanism based on the strain deviation value and the time sequence change rate can distinguish between the pre-tightening force attenuation and the overload risk state, and through the hierarchical alarm signal, the failure mode can be accurately located, the false alarm rate of the single threshold alarm is reduced, the safety of the key infrastructure such as the bridge and the railway is greatly improved, relying on the real-time transmission of the wireless sensor data, remote monitoring and automatic work order generation are realized, the bolt state can be obtained without climbing or disassembling the structure by the operation and maintenance personnel, the detection efficiency in the high-risk environment is improved and the maintenance cost is reduced, the strain change of the bolt is realized in real time, so that whether the bolt is loose or not can be accurately judged, and the alarm can be automatically triggered when the bolt is loose or the pre-warning force is abnormal.

[0064] In an embodiment, as shown in Figure 6 In step S20, the strain data and temperature data in the inner cavity of the expansion pin are collected in real time based on the wireless sensor to generate a real-time strain sequence, specifically including:

[0065] S21: According to the preset sampling frequency, the pin strain data is collected in the axial central region of the expansion pin, the temperature sensor data is synchronously acquired, and a strain-temperature correlation matrix is established.

[0066] Specifically, high-precision strain data and temperature data are synchronously collected in the axial central region of the expansion pin through the preset sampling frequency, and a strain-temperature correlation matrix is constructed, so that the complete mechanical behavior in the stress concentration area of the axial center of the expansion pin is captured, the thermal expansion effect of the material can be dynamically compensated, the measurement error caused by temperature drift can be eliminated, and the accuracy of the strain data can be improved.

[0067] S22: The original pin strain data is processed by wavelet denoising to eliminate vibration interference noise, the denoised pin strain data is fused with the strain-temperature correlation matrix, and a real-time strain sequence is output.

[0068] Specifically, the original strain data is processed by combining the wavelet denoising algorithm, the vibration interference noise is effectively filtered out, the real load signal is retained, the real-time strain sequence is output, and the reliability of the real-time strain sequence is ensured.

[0069] In an embodiment, as shown in Figure 7 In step S30, according to the initial strain value and the real-time strain sequence, the strain deviation value is calculated, and the thermal expansion effect of the material is compensated by combining the temperature data, specifically including:

[0070] S31: Based on the real-time strain sequence and initial strain, and according to the temperature compensation coefficient, corrects the strain drift caused by thermal expansion and outputs the strain deviation value.

[0071] ΔE=|(ΔS t -α·ΔT)-S p |, where ΔS t For real-time strain sequences, S p Let be the initial strain, and α be the temperature compensation coefficient.

[0072] Specifically, a temperature compensation coefficient is introduced to dynamically correct the thermal expansion drift in the real-time strain sequence, reducing measurement errors caused by environmental temperature changes. This solves the problem of misjudgment caused by temperature drift in traditional strain gauges. The strain-temperature correlation matrix is ​​used to calibrate the data in real time, ensuring that the strain deviation value truly reflects the pin's mechanical load rather than thermal interference, providing physically meaningful input data for loosening or overload determination.

[0073] S32: Analyze the strain time change rate based on the strain deviation value, and determine the pin load state based on the strain time change rate.

[0074] Specifically, based on strain time-series change rate analysis of strain deviation values, strain gradient changes caused by micro-displacement can be captured, and combined with a dual-threshold triggering mechanism, preload decay and overload risk states can be distinguished.

[0075] In one embodiment, such as Figure 8 As shown, in step S40, the strain change rate is obtained based on the strain deviation value. When the strain deviation value is greater than a preset loosening threshold or the strain change rate is greater than a preset overload rate threshold, a graded alarm signal is triggered, specifically including:

[0076] S41: When the strain deviation value is greater than the preset loosening threshold, a first-level warning is triggered and a loosening risk report is generated.

[0077] Specifically, a dual-threshold triggering mechanism enables risk classification and control. The first-level warning targets the problem of preload decay (such as strain accumulation caused by loose bolts). A structured report (including location information and risk level) is generated through wireless transmission to guide maintenance personnel in accurate troubleshooting.

[0078] S42: When the strain time change rate is greater than the preset overload rate threshold, a secondary warning is triggered and an audible and visual alarm is activated.

[0079] Specifically, the Level 2 warning targets instantaneous overload risks (such as excessive strain mutation rate caused by impact loads). It initiates on-site warnings through millisecond-level response, forcing equipment to reduce load or shut down, thus avoiding serious accidents such as structural fractures.

[0080] S43: training the preset pin failure prediction model based on the strain deviation value, and outputting a future pin failure probability.

[0081] Specifically, the real-time strain deviation value is input into the pin failure prediction model, and the model is trained based on the strain deviation value sequence and the historical failure spectral characteristics to identify the loosening probability and the fracture risk coefficient, and output the future pin failure probability.

[0082] It should be understood that the size of the serial number of each step in the above embodiments does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0083] The above-described embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A new pin connection structure, characterized by, The application relates to a new type of bolt connection structure and a load state detection method thereof.

2. A novel pin dowel connection structure according to claim 1, characterized in that, The application relates to a new type of bolt connection structure and a load state detection method thereof.

3. A new pin connection structure according to claim 1, characterized in that, The application relates to a new type of bolt connection structure and a load state detection method thereof.

4. A new pin connection structure according to claim 1, characterized in that, The application relates to a new type of bolt connection structure and a load state detection method thereof.

5. A load state detection method based on the new pin connection structure according to any one of claims 1-4, characterized in that, The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof.

6. The load state detection method of the new pin connection structure according to claim 5, characterized in that, The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof.

7. The load state detection method of the new pin connection structure according to claim 1, characterized by, The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. 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The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state detection method thereof. The application relates to a new type of bolt connection structure and a load state ΔE = |(ΔS t - α · ΔT) - S p |, wherein ΔS t is a real-time strain sequence, S p is an initial strain amount, and α is a temperature compensation coefficient; The strain time rate of change is analyzed according to the strain deviation value, and the pin bolt load state is determined according to the strain time rate of change.

8. The load state detection method of the new pin connection structure according to claim 1, characterized by, The strain rate of change is obtained based on the strain deviation value, and when the strain deviation value is greater than a preset loosening threshold or the strain rate of change is greater than a preset overload rate threshold, a hierarchical alarm signal is triggered, specifically including: When the strain deviation value is greater than the preset loosening threshold, a first-level early warning is triggered, and a loosening risk report is generated; When the strain time rate of change is greater than the preset overload rate threshold, a second-level early warning is triggered, and an audible and visual warning is started; The preset pin bolt failure prediction model is trained based on the strain deviation value, and a future failure probability of the pin bolt is output.

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