8 results about "Intensity factor" patented technology

The present application belongs to the technical field of wind power generation, and specifically relates to a wind power tower material crack propagation prediction method and system, which is suitable for fatigue life evaluation of large supporting structures in the wind energy industry. The method comprises: deploying a multi-source heterogeneous sensor network to collect strain, acoustic emission and environmental load data; constructing a digital twin high-fidelity finite element submodel to obtain a dynamic stress intensity factor; constructing a deep neural network, embedding the Paris law of fracture mechanics in the form of residual into the loss function to form a physical information neural network, and realizing crack propagation rate prediction; using the extended finite element method combined with the level set function and the maximum circumferential stress criterion to dynamically track the three-dimensional space expansion path of the crack; combining Monte Carlo simulation and recursive Bayesian update to evaluate the remaining life and trigger graded early warning. The present application solves the problems of insufficient fusion of physical mechanisms and data-driven in the prior art, low prediction accuracy under small samples, and lack of crack space path tracking.

This invention discloses a method for predicting crack propagation path and remaining life of a notched component with irregular cracks, comprising: designing a notched feature specimen of the notched component with irregular cracks based on the principle of local stress field consistency; establishing a three-dimensional model of the notched feature specimen in ABAQUS and establishing an interface connection between ABAQUS and the three-dimensional crack propagation simulation platform Franc3D to perform dynamic simulation of crack propagation and obtain opening, shear, and tearing stress intensity factors; calculating a composite equivalent stress intensity factor as a measure of crack propagation based on the opening, shear, and tearing stress intensity factors obtained from the simulation, and extracting the composite equivalent stress intensity factor at the leading edge point with the largest increment; estimating fatigue crack propagation life based on the composite equivalent stress intensity factor at the leading edge point with the largest increment; and fitting a crack propagation curve based on the stress-life curve and the fatigue crack propagation life expression. This invention effectively improves the prediction accuracy of crack leading edge trajectory and the accuracy of crack propagation life assessment.

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 application discloses a method for improving the fracture plugging effect of drilling fluid by combining a three-pore medium flow model with dislocation fracture mechanics, and comprises the following steps: inputting a parameter set, constructing a three-pore medium flow model, configuring a solving mode, and solving and calculating to obtain the fluid pressure p in the fracture f , distributing simulation results, constructing an equation group by writing program codes, importing p f data, running the program, calculating a dislocation distribution function f(t k ), and further obtaining a fracture width W(t k ), a fracture tip stress intensity factor K I ; the fracture intensity factor K I under different conditions is obtained by modifying parameters, a K I vs. related parameter graph is drawn, a toughness coefficient K IC of a target formation is imported, for example, K IC >= K I , which indicates that the fracture will continue to expand; the fracture width and fracture re-expansion during the drilling process are predicted in real time, the plugging material is reasonably designed, the one-time plugging success rate of the fracture leakage is improved, and the continuous leakage and malignant leakage are avoided.

This application discloses a method, device, storage medium, and program product for safety performance assessment of cracked jacket structures, belonging to the field of offshore wind power structural health monitoring and safety assessment technology. By real-time acquisition of strain field data and environmental loads, and combining this with a digital twin model of the cracked jacket structure, a first real-time stress intensity factor is obtained. By comparing the first real-time stress intensity factor with the current effective stress intensity, the model parameters of the digital twin model of the cracked jacket structure are updated, overcoming the limitation of traditional static models that cannot dynamically reflect crack propagation and structural performance degradation. Therefore, continuous, real-time perception and accurate assessment of the safety status of cracked jacket structures are achieved, providing a basis for timely detection of risks associated with cracked jacket structures.

This invention belongs to the field of reservoir development technology, specifically providing a method for simulating fracture networks in deep coal and rock fracture systems, including the following steps: S1, calculating key rock mechanics parameters and geostress parameters of deep coal and rock based on well logging interpretation data; S2, calculating equivalent rock mechanics parameters and equivalent geostress parameters of deep coal and rock; S3, calculating the equivalent stress intensity factor at the fracture tip and the critical stress for fracture initiation; S4, based on the equivalent stress intensity factor at the fracture tip and the critical stress for fracture initiation, simulating the fracture morphology, length, and branch fracture density using a lightning simulation-based fracture propagation calculation method; this invention solves the problem of low accuracy in existing deep coal and rock hydraulic fracturing fracture propagation methods. The fracture morphology, length, and branch fracture density simulated by this invention are highly consistent with electromagnetic waves and data ranges, laying the foundation for subsequent research on the propagation morphology of hydraulic fractures in coal and rock formations.

The application discloses a rock dynamic fracture I-type stress intensity factor calculation method, system and device, relates to the rock dynamics technical field, and the method comprises the following steps: collecting an image sequence of a granite test piece with a straight cut groove in a Brazilian disc through a dynamic impact test on the granite test piece; performing semantic segmentation on the image by using a Mask2former model, identifying a crack region, and automatically positioning a crack tip position at each moment based on a segmentation result; processing the image sequence based on a DIC method to obtain displacement field data of a test piece surface; determining a displacement field sub-region participating in calculation in a Williams equation based on the crack tip position and the displacement field data; and iteratively solving the I-type dynamic stress intensity factor based on a least square method by adjusting the shape and size of the displacement field sub-region, so that the measurement accuracy and efficiency of the dynamic stress intensity factor are significantly improved.

The invention discloses a method and system for obtaining interface adhesion parameters between an ice layer and an icing substrate, the method comprises the following steps: collecting the apparent adhesion force of the ice layer and the icing substrate interface, establishing an adhesion simulation model between the ice layer and the icing substrate, carrying out statics analysis on the adhesion simulation model, and calculating the interface adhesion parameters through adhesion simulation calculation to obtain the interface adhesion parameters between the ice layer and the icing substrate. Interface stress distribution between the ice layer and the icing substrate is obtained; calculating and obtaining stress intensity factor distribution of each point of the interface according to the relationship between the stress intensity factors and the stress; performing polynomial fitting by using the stress intensity factor of each point of the interface to obtain a current critical stress intensity factor; calculating the interface fracture energy of the ice layer and the icing substrate according to the relationship between the critical stress intensity factor and the fracture energy; the method comprises the following steps: establishing a debonding simulation model between an ice layer and an icing substrate, carrying out simulation calculation of interface debonding by using the debonding simulation model, and carrying out inversion according to interface fracture energy and collected apparent adhesion to obtain interface peak strength.