62 results about "Crack size" patented technology

The invention relates to the technical field of crack monitoring, in particular to a concrete structure crack full-life-cycle monitoring method and system, and the method comprises the following steps: arranging sound wave points to obtain a stress change to generate an initial signal, extracting an image feature recognition extension path, analyzing a size acceleration to generate an extension identifier, and screening an active cycle at intersection time to generate an evolution fragment. And classifying crack behaviors according to displacement and width trends to generate an annotation set. According to the method, stress evolution is reflected based on interval transit time, a crack expansion trend is extracted in combination with an image feature point track, an active state is identified by superimposing crack size speed increase synchronism, a high-frequency change fragment is positioned through multi-index time intersection, and crack behavior types are divided according to a displacement direction and a width increase trend. Continuous tracking and classified marking of the whole process from crack starting to evolution are achieved, the response capacity to abnormal crack behaviors is enhanced, and the precision and timeliness of structural safety state recognition are improved.

The invention relates to an aero-engine stator part crack critical dimension comprehensive determination method and system, and belongs to the technical field of aviation, the method comprises the following steps: obtaining an aero-engine typical hot end stator part geometric model and material parameters, and carrying out static strength analysis according to fluid-thermal-solid coupling load characteristics in actual working conditions; inserting an initial crack into a first principal stress plane of a dangerous part of the real component, carrying out crack propagation simulation to determine a crack propagation path, and calculating a critical crack size of a dangerous point; analyzing critical crack sizes under different failure modes, such as cooling failure and buckling failure; and integrating analysis results under the multi-failure mode, and determining a comprehensive critical dimension as a final judgment standard. According to the method, through combination of fracture failure and function failure analysis, accurate judgment of the critical dimension of the crack is realized, limitation of a traditional single fracture criterion is broken through, comprehensive function failure analysis is realized, the accuracy of a maintenance decision is remarkably improved, and a scientific basis is provided for condition-based maintenance decision.

The invention relates to the technical field of material mechanical property testing, and discloses a material indentation and scratch testing device and method under a composite energy field, and the device comprises a supporting experiment table, a vertical micro-motion platform, a horizontal micro-motion platform, a high-definition optical microscope, a force sensor, a displacement sensor and an additional energy field generation system. According to the method, a controllable additional energy field is synchronously applied while a mechanical indentation or scratch load is applied to a hard and brittle material sample, and load displacement data is collected in real time. In the data processing stage, the real hardness is calculated by adopting a corrected proportion sample resistance model, the elastic modulus is calculated based on the Oliver-Pharr theory, and the fracture toughness of the material is analyzed and calculated according to the size of the indentation tip crack. The problem that in-situ mechanical property characterization cannot be carried out in a composite energy field in a traditional test is solved, the hardness calculation precision is improved, the fracture toughness measurement function is expanded, and the experimental device and method are provided for research of a hard and brittle material composite machining mechanism.

The invention relates to the technical field of mechanical structure strength evaluation and structural design, and provides a safety evaluation and design method for a ship longitudinal welding structure, which comprises the following steps: determining a damaged key part; detecting the size of the minimum detectable crack in the ship longitudinal welding structure by adopting a nondestructive detection method; carrying out regularization and normalization processing on the crack obtained by detection; calculating a stress intensity factor amplitude corresponding to the current crack; judging whether the crack is expanded or not by combining a fatigue crack expansion threshold value predicted by a Zhu-Xuan model; based on a nondestructive testing result and a three-dimensional crack propagation analysis model, establishing a crack propagation digital twinborn body; and according to crack propagation prediction results and residual life evaluation results of the crack propagation digital twin under different structure schemes, safety and reliability of different welding structure forms, size parameters and process schemes are compared, and optimal design of the ship longitudinal welding structure is achieved.

The application discloses a micro-nano circular plate fracture analysis method considering coupling of surface effect and plastic zone, and firstly establishes a three-dimensional curved surface coordinate system suitable for a surface layer, and then further corrects a Dugdale cohesion force model according to a superposition principle after considering surface correlation of the plate, and then simplifies the Dugdale cohesion force model into a hyper-singular integral equation by using Hankel transformation, and finally obtains influences of the surface effect on the plastic zone size and crack surface displacement by numerically solving the hyper-singular integral differential equation.The method can accurately capture the nonlinear coupling relationship between the crack size, the surface shear modulus, the torsional displacement and the stress intensity factor under the micro-nano scale, effectively corrects calculation deviation generated by traditional classical theory when the surface effect is ignored, ensures the accuracy of the fracture analysis under different scales, and realizes more accurate and more comprehensive theoretical description of the elastic-plastic fracture behavior of the micro-scale material.

The invention relates to a nuclear power plant main pipeline damage tolerance establishment method. The method comprises the following steps: S1, determining the critical crack size of the main pipeline of the nuclear power plant at the end of the life; and S2, performing finite element calculation based on the established finite element model of the crack-free structure of the main pipeline so as to obtain stress distribution of the crack-free structure under each load working condition. S3, according to the initial crack size and the finite element calculation result, stress intensity factor calculation, transient pairing, elastic-plastic correction and fatigue crack propagation calculation are conducted in sequence, and the life end crack size of the main pipeline is obtained. And S4, when it is judged that the life end crack size of the main pipeline is smaller than the critical crack size, the step S3 is executed again to conduct iterative calculation on the initial crack size. And when the final crack size of the service life of the main pipeline is judged to be greater than the critical crack size, taking the initial crack size updated by the last iteration as the structural damage tolerance. The nuclear power pipeline defect evaluation period can be shortened, and the evaluation efficiency is improved.

The invention discloses a crack tolerance analysis method for a saddle-shaped welding seam of an integral reinforcing connecting pipe of nuclear pressure-bearing equipment, and belongs to the technical field of reliability. The method comprises the following steps: firstly, establishing a three-dimensional model containing a crack structure and defining crack parameters; carrying out finite element analysis after applying a load; and the critical crack size is determined by iteratively adjusting the crack depth in the failure evaluation diagram. Carrying out sampling analysis by taking the load and the material parameters as random variables to obtain a critical crack size set; and finally, the failure probability reaches a target allowable value by adjusting a crack detection threshold value of nondestructive testing. According to the method, finite element simulation is carried out, the critical crack size of the saddle-shaped welding seam of the integral reinforcing connecting pipe of the pressure-bearing equipment under the complex load is checked based on a failure evaluation icon, the relation between the critical crack size and the allowable crack size is established by assuming that the crack size detected by nondestructive testing obeys normal distribution, and the test efficiency is improved while the number of experiments is reduced. And the reliability of a calculation result is ensured.

The invention belongs to the field of wheel-rail tribology, and particularly discloses a wheel-rail fatigue crack intelligent quantitative characterization method based on microscopic analysis images, which comprises the following steps: carrying out image enhancement and noise reduction preprocessing on scanning electron microscope and optical microscope images of wheel-rail rolling contact fatigue cracks; inputting the image into a YOLOv8-CSSTAM model for target detection, and outputting an image crack prediction frame and a proportional scale prediction frame; on the basis of an automatic calibration algorithm of an image scale, calculating the widest connected region of the image in the scale prediction frame, and performing OCR character recognition to obtain the image scale; performing median filtering, threshold segmentation, edge smoothing and small area filling processing on the crack image in the crack prediction frame; carrying out Harris corner detection on the processed image to obtain candidate corners; and screening the angular points to obtain crack feature angular points, and then calculating crack size features. The method can quickly and accurately obtain crack information in the wheeltrack rolling contact fatigue crack image, wherein the crack information comprises the crack depth, the crack width and the crack propagation angle.

The utility model relates to the technical field of slitting machines, in particular to a slitting machine with an edge wire breakage alarm function, which comprises a slitting machine body, a mounting support is arranged on the side portion of the slitting machine body, and an annular proximity switch high-speed sensor is arranged at the top end of the mounting support. A protective sleeve is arranged on the inner ring of the annular proximity switch high-speed sensor, a bag body to be cut penetrates through the protective sleeve, a control box is further arranged on the slitting machine body, a control processor is arranged in the control box, an alarm is further arranged on the slitting machine body, and the annular proximity switch high-speed sensor and the alarm are connected with the control processor. According to the utility model, the thin strip edge wire penetrates through the annular proximity switch high-speed sensor, the inductor gives an alarm when the edge wire is broken, and a quality inspector can stop a unit to confirm and judge the size of a crack for repair treatment, so that the product quality is ensured, and customer complaints caused by the crack problem are prevented.

The present application relates to the technical field of computer vision and road engineering, and particularly relates to a pavement crack lightweight segmentation and quantification method based on enhanced feature fusion. The method comprises the following steps: decoding and reading pavement images and performing verification, then performing grid division and cutting, and performing pixel normalization processing on the effective sub-images after cutting; a lightweight crack segmentation network is constructed; the preprocessed standard images are input into the lightweight crack segmentation network, and feature extraction, feature fusion, target detection and pixel segmentation are sequentially completed, and a crack detection frame and a binary segmentation mask are output; the lightweight crack segmentation network is trained, the optimal model is saved according to the iteration optimization of the verification set index; the segmentation mask output by the model is denoised, the crack geometric size is calculated, and the final detection quantification result is output. The method has the advantages that the small-scale crack recognition capability is improved, the crack length and width can be automatically and accurately measured, the crack size measurement error is small, and the method is suitable for large-scale pavement inspection operation.

The utility model relates to a hydraulic ring geological crack measuring device, which belongs to the technical field of crack measurement and comprises two supporting columns, lifting frames are arranged on the sides, close to each other, of the two supporting columns, sliding plates are slidably mounted on the outer sides of the lifting frames, and measuring rods are fixedly connected to the bottom ends of the sliding plates. Servo motors are fixedly mounted at the bottom ends of the inner walls of the sliding plates, and gears are fixedly connected to output shafts of the servo motors. The beneficial effects of the utility model lie in that the rotation of the output shaft of the servo motor can drive the gear to rotate, so that the gear can roll on the rack, the sliding plate can be driven to move, the position of the measuring rod can be moved to the geological fracture measuring position, and the measuring rod can be moved to the geological fracture measuring position in the measuring process. A worker can measure the size of the crack without approaching the edge of the crack, so that the use safety of the device can be improved, and the life safety of the worker is ensured.

The invention discloses an unmanned aerial vehicle for high-altitude crack measurement and a measurement method thereof. The unmanned aerial vehicle for high-altitude crack measurement comprises an unmanned aerial vehicle body, a laser range finder, a camera module and an upper computer, the laser range finder comprises an emitter and is used for measuring the distance between the laser range finder and a detected wall surface and forming a light spot on the detected wall surface; the shooting direction of the camera module is consistent with the light emitting direction of the emitter, and the camera module is used for shooting the light spot and the detected crack to the same picture; the upper computer is used for judging whether the light emitting direction is perpendicular to the detected wall surface or not according to the shot picture and calculating the size of the crack; the laser range finder and the camera module are arranged on the unmanned aerial vehicle body. The method has the advantages that the perpendicularity with the wall where the crack is located during shooting is detected, and the accuracy of crack size calculation is improved.

The present application relates to the technical field of sealing material testing, and specifically discloses a system and method for testing the air tightness and deformation performance of sealing materials under crack lapping, which comprises a gas pressure adjusting module, a sealing box module, a temperature environment control cabin and a monitoring module. The monitoring module is used to collect data such as the temperature, pressure, volume and deformation of the sample of each component. The collected data can be used to calculate the intrinsic permeability coefficient of the sealing material sample, the displacement deformation when the crack is lapped, the puncture failure pressure and the permeability coefficient when the crack is lapped. The sample pad component in the system is an important part of the sealing box module. It can simulate the size and shape of the crack lapped with the sealing material according to the need. In combination with the gas pressure adjusting module and the monitoring module, the system can realize the testing of the permeability, deformation and puncture failure resistance performance of the sealing material under various working conditions.

The invention discloses a high-speed railway RCF crack size characterization method based on an ACFM technology By signal. The method comprises the steps that a finite element model of a high-speed railway steel rail is established; adopting a control variable method, taking one of the crack length, the crack pocket depth and the crack inclination angle as a variable and taking the other two of the crack length, the crack pocket depth and the crack inclination angle as a fixed quantity, carrying out ACFM detection simulation, detecting the crack to obtain a By signal, and extracting characteristic parameters of the By signal; obtaining a quantitative relationship between the By signal characteristic parameter and the crack geometric parameter; based on the quantitative relationship, establishing a By signal-crack size mapping model through a polynomial regression algorithm or a support vector regression algorithm; inputting a to-be-measured By signal into the By signal-crack size mapping model, and outputting three quantitative results of the crack length, the crack pocket depth and the crack inclination angle. The method not only provides a theoretical basis for developing a more comprehensive ACFM quantization algorithm, but also lays a technical foundation for online intelligent monitoring and maintenance of the high-speed railway steel rail.

This invention proposes a device for detecting micron-level cracks in in-pile materials under high temperature and high pressure, comprising a sealing head, a gas pipeline, a top cover, an outer sleeve, a double-layer corrugated pipe, a bottom cover, a CT sample block, a pressure sensor placement device, and a force-bearing rod. The double-layer corrugated pipe is connected to the gas pipeline, and a sealing head is installed on the gas pipeline. A top cover is installed between the first corrugated pipe and the gas pipeline. One end of the second corrugated pipe is connected to the force-bearing rod, and a bottom cover is installed between the second corrugated pipe and the force-bearing rod. The force-bearing rod is provided with a detection end fixing hole and a space. The CT sample block is located in the space, and the pressure sensor placement device is installed on the CT sample block. This application can simulate the load under actual application conditions and directly detect the size of the sample crack by reducing the DC potential, with an accuracy of micron-level. All parameter signals are transmitted to the host computer for display via serial communication, and parameters such as crack size changes, device temperature, device pressure, and excitation signal magnitude are monitored in real time.

The invention relates to a device and method for evaluating the crack healing capacity of a memory alloy fiber cement-based material, and belongs to the field of concrete crack healing, the device comprises a partition manufacturing mold and a crack prefabricating device, the partition manufacturing mold is used for manufacturing a low-melting-point alloy partition, and the partition size is consistent with the crack size of the cement-based material; the crack simulator is used for simulating cracks of cement-based materials; the crack prefabricating device comprises a test mold, a steel support and a steel clamp. A plurality of cement-based material pouring areas are arranged on the test mold; the multiple steel clamps are arranged on the steel support, located over the cement-based material pouring area and used for fixing the partition, and a plurality of memory alloy fibers are prefabricated on the partition. The crack healing capability is comprehensively evaluated by taking the crack closing rate as a main part and taking the shrinkage deformation utilization rate as an auxiliary part. According to the method, accurate control over the crack size, the fiber distribution direction at the crack and the length of the fiber unbonded area can be achieved, and reasonable evaluation on the crack healing capacity can be achieved.

The disclosure provides a high-temperature fatigue life prediction method based on EIFS, and relates to the technical field of reliability design. The method comprises the following steps: acquiring first test data of crack propagation test and high-cycle fatigue test on a smooth member, and second test data of test on a notched member; determining equivalent initial defect sizes of the smooth member and the notched member according to the first test data and the second test data; obtaining an equivalent stress intensity factor difference and a fatigue crack propagation rate of the notched member under a high-temperature condition according to the second test data; fitting a function relationship among the fatigue crack propagation rate, the equivalent stress intensity factor difference and a crack size to obtain a crack propagation function; and determining a predicted fatigue life of the notched member under the high-temperature condition based on the crack propagation function, the equivalent initial defect size of the notched member and a limit crack size. The disclosure can realize accurate high-temperature fatigue life prediction.

The invention discloses a pearlitic steel rail and a welding method of a joint thereof, the pearlitic steel rail is added with a specific amount of Ce element, and a specific joint welding method is adopted, so that the rail bottom pushing convex crack size of the obtained steel rail joint is reduced from more than 156 [mu] m to less than 25 [mu] m, and the average size of the pushing convex crack is reduced by more than 80%; the other structure properties of the joint meet TB / T 1632, meanwhile, the properties are remarkably improved, the average impact property is larger than 12.6 J, and the average hardness of the section hardness of the welded joint reaches 94%-98% of the average hardness of base metal.

This application discloses an in-situ non-destructive method for repairing and reinforcing fatigue cracks in steel structures based on laser technology, relating to the field of steel structure building technology. The method includes the following steps: initial flaw detection of the area to be repaired in the steel structure to obtain the crack size of the fatigue crack; cleaning the area to be laser-repaired and reinforced; scanning and repairing along the crack trajectory using laser remelting technology to allow the fatigue crack to heal naturally; secondary flaw detection of the remelted repair area after laser remelting; if the test is qualified, the repair process is completed; if the test is unqualified, the residual crack depth is obtained, and the following steps are continued; reinforcing auxiliary materials are printed on the surface of the steel structure using laser cladding technology to form a cladding layer covering the remelted repair area; a residual compressive stress layer is introduced onto the surface of the cladding layer. This application eliminates the need for beveling and milling of the original steel structure, enabling direct repair of fatigue cracks, and also allows for the addition of external reinforcing auxiliary materials to effectively integrate with the original steel structure to achieve the reinforcement purpose.

The present application relates to a concrete surface crack detection method and system, comprising the following steps: obtaining concrete surface image information, extracting crack feature information based on the obtained hidden layer output; the crack feature information obtained is added to the hidden layer output and channel correlation information, and the output feature is obtained after fusion and random reordering processing; based on the output feature, a prediction box corresponding to the dimension of the crack feature information is obtained, the prediction box matching the crack size is selected and the redundant prediction box is removed, the coordinate information of the prediction box where the crack is located is decoded and output, and the position where the crack is located is obtained.

This invention relates to the field of metallurgical lifting equipment testing technology, specifically a method for predicting the fatigue crack propagation life of metal structures in metallurgical cranes. The method includes: collecting structural stress spectrum, strain monitoring time-series data of stress concentration areas, lifting operation spectrum, and temperature and humidity data under service conditions; constructing an initial crack parameter model; calculating the stress intensity factor variation spectrum, including the amplitude of the stress intensity factor at the crack tip corresponding to each load cycle; calculating the crack propagation increment per cycle and accumulating the crack size evolution data; setting a critical crack propagation size threshold based on structural integrity assessment criteria; and predicting the fatigue crack propagation life by comparing the evolution data with the threshold. This method refines the calculation dimensions of the stress intensity factor, restores the dynamic evolution process of crack size, closely matches the actual service load characteristics of metallurgical cranes, and optimizes the accuracy of crack propagation life prediction.

The invention discloses a design method of a turbine disc characteristic simulation piece with bolt hole induced end tooth crack propagation, and belongs to the technical field of aero-engine fatigue fracture tests. The method comprises the following steps: designing an initial shape of a simulation piece dominated by arc end teeth; through double-stage static strength analysis, the characteristic sizes of bolt holes and the like are preferentially and alternately adjusted so as to be matched with a crack-free stress field of a real turbine disc; introducing a surface crack at a dangerous point, and optimizing the crack size by taking J integral of a crack tip and a correction stress gradient from a bolt hole to the crack tip as double standards; an initial defect with the controllable size is machined through the electric spark technology; and finally, on the basis of direct-current potential drop technology monitoring, the crack is prefabricated to the target size from the defect through the fatigue load. According to the invention, high-fidelity simulation of the crack propagation behavior under the structure coupling effect is realized, and a low-cost and high-reliability test means is provided for life prediction and safety evaluation of the turbine disc.

This application discloses a method for repairing concrete foundations of substations, including the following steps: drilling, pile placement, pouring, protection, and curing. The drilling step involves creating a repair hole at the crack in the concrete foundation of the substation, with the hole size larger than the crack size. The pile placement step involves cleaning the inside and surrounding area of ​​the repair hole, inserting a pile into the hole, and positioning the pile to create gaps between the pile and the inner wall of the hole. The pouring step involves injecting filling grout into the repair hole to fully fill the gaps. The protection step involves laying a protective cloth over the repair hole, filling the gaps between the cloth and the concrete foundation, as well as between the cloth and the pile, with filling grout. The curing step involves curing the repaired area. This method for repairing concrete foundations of substations offers fast repair speed, high repair strength, and good corrosion resistance.

The invention discloses a fractured reservoir multi-parameter inversion method based on an improved grey wolf optimization algorithm, and relates to the technical field of seismic exploration, and the method comprises the steps: firstly constructing a multi-scale-multi-direction-multi-phase fluid plaque saturated coupling fracture rock physical model based on a Chapman multi-scale fracture theory; secondly, based on an anisotropic reflectivity theory, establishing a frequency and azimuth angle dependent PP wave seismic forward modeling method; and finally, providing an improved grey wolf optimization algorithm (GWO-G) based on a Gaussian threshold search strategy aiming at the nonlinearity and multi-extremum characteristics of an inversion problem, and verifying through three-parameter and six-parameter inversion experiments of a single-interface model under the conditions of no noise and containing 10% Gaussian noise. The method has the beneficial effects that key parameters such as the fracture density, the fracture scale, the porosity and the fluid saturation can be stably, accurately and synchronously inverted, and a powerful technical means is provided for fine description and efficient development of unconventional oil and gas reservoirs.

The present disclosure relates to an aero-engine stator crack critical size comprehensive judgment method and system, belonging to the field of aviation technology, the method comprising: obtaining the typical hot end stator component geometric model of the aero-engine, material parameters, and carrying out static strength analysis for the flow-thermal-solid coupling load characteristics in the actual working condition; inserting an initial crack in the first principal stress plane of the real component dangerous position and carrying out crack propagation simulation to determine the crack propagation path and calculate the critical crack size of the dangerous point; analyzing the critical crack size under different failure modes such as cooling failure and buckling failure; integrating the analysis results under multiple failure modes to determine the comprehensive critical size as the final judgment standard. The present disclosure realizes accurate judgment of crack critical size by combining fracture failure and functional failure analysis, breaks through the limitations of traditional single fracture criterion, comprehensively analyzes functional failure, significantly improves the accuracy of maintenance decision, and provides a scientific basis for condition-based maintenance decision.

The application discloses a kind of coal seam roof horizontal well directional wear layer fracturing step-by-step scale numerical simulation method, comprising: using finite element simulation software Abaqus to establish single perforation numerical model, perforation area numerical model and whole stratum numerical model;Single perforation numerical model crack result after single perforation simulation end processing is introduced into perforation area numerical model as the initial crack of perforation area simulation calculation;Then the crack result of perforation area numerical model after perforation area simulation end processing is introduced into whole stratum numerical model, as the initial crack of whole stratum simulation calculation, finally obtain wear layer extended crack, indirectly realize the simulation of cross-scale directional wear layer fracturing crack propagation process.The method solves the problem of huge number of grid division and crack propagation simulation across interface caused by the large gap between perforation size and fracturing crack size, and has broad application prospect in the numerical simulation of interface fracturing in broken soft coal seam roof horizontal well.

The present disclosure provides a method for evaluating the original fatigue quality of a notched member, and relates to the technical field of reliability design. The method comprises the following steps: obtaining a long crack propagation threshold value of the notched member, a long crack propagation threshold value, a fatigue limit and an elliptical geometric parameter of a fatigue source area of a smooth member based on test data obtained by conducting crack propagation tests and high-cycle fatigue tests on the notched member and the smooth member; determining an equivalent initial crack size of the smooth member; determining an equivalent circle parameter of the fatigue source area; determining a fatigue notch factor of the notched member according to the equivalent circle parameter of the fatigue source area, the elliptical geometric parameter of the fatigue source area and the equivalent initial crack size of the smooth member; and determining an equivalent initial crack size of the notched member according to the long crack propagation threshold value of the notched member, a geometric shape factor, the fatigue notch factor and the equivalent initial crack size of the smooth member. The present disclosure can accurately evaluate the original fatigue quality of the notched member based on different hole forming processes.

The invention relates to the technical field of gear steel rolling, and particularly discloses a rolling method for accurately controlling a medium-large-specification Mn-Cr series gear steel structure. According to the method, the problems that in the prior art, Mn-Cr series gear steel is prone to element segregation, center shrinkage cavities, cooling cracks, insufficient dimensional precision and the like are solved by optimizing the heating system, improving the rolling technology, precisely controlling cooling after rolling and conducting matched quality detection. The gear steel meeting German DIN and public standards can be stably produced, the low-power center porosity grade of a rolled product is smaller than or equal to 1.0 grade, the decarburization depth is smaller than or equal to 0.2 mm, no center crack exists, the size precision reaches + / -0.1 mm, and stable batch production is achieved.

The present application relates to the technical field of mechanical structure strength evaluation and structure design, and provides a safety evaluation and design method for a ship longitudinal weld structure, comprising determining a damage key position; using a nondestructive testing method to detect the minimum detectable crack size in the ship longitudinal weld structure; performing regularization and normalization processing on the detected crack; calculating the stress intensity factor amplitude corresponding to the current crack; judging whether the crack will expand in combination with the fatigue crack propagation threshold value predicted by the Zhu-Xuan model; based on the nondestructive testing result and the three-dimensional crack propagation analysis model, establishing a crack propagation digital twin; comparing the safety and reliability of different weld structure forms, size parameters and process schemes according to the crack propagation prediction result and the residual life evaluation result of the crack propagation digital twin under different structure schemes, to realize the optimization design of the ship longitudinal weld structure.

The present application belongs to the technical field of service structure safety evaluation, and in particular to a creep life evaluation method for cracks in the heat affected zone of a welded structure, comprising the following steps: step one, determining the material parameters of the welded structure; step two, constructing a finite element model of the heat affected zone of the welded joint containing different lengths of initial cracks; step three, determining the boundary conditions of the welded structure; step four, simulating the creep damage, determining the maximum creep damage position of each crack front and the creep life; and step five, constructing a correlation between crack size and corresponding creep life. The creep life evaluation method for cracks in the heat affected zone of a welded structure simulates the creep damage evolution process of the welded structure under different initial crack lengths, constructs a quantitative functional relationship between crack length and creep life, and uses this relationship to predict the creep life of the welded structure by only obtaining the crack length in the structure, significantly improving the engineering applicability and efficiency of life evaluation.