12 results about "Corrosion fatigue" patented technology

The application discloses a steel-concrete composite beam bridge negative bending moment area rigidity degradation analysis method and system. The method first establishes a bridge deck deterioration numerical simulation model, fits the quantitative relationship between the deterioration parameters and the rigidity, and forms a bridge deck deterioration rigidity evaluation model; then, taking the steel-concrete relative slip as an index and the concrete rust expansion cracking as a boundary, the welding bolt reduction coefficient is determined through simulation and test in stages, and the steel-concrete collaborative degradation rigidity evaluation model is formed in combination with the interface slip reduction; then, a corrosion-fatigue coupling test is carried out on a scaled beam test piece, a multi-component deterioration rigidity degradation model is proposed by combining the two types of models, and a reliable calculation model is formed after numerical verification; finally, a deterioration parameter time-varying evolution model is established, the rigidity at different service times is calculated, a full-time domain calculation framework is constructed, and the precise analysis and full-time domain evaluation of the steel-concrete composite beam bridge negative bending moment area rigidity degradation are realized.

The application discloses a granite corrosion fatigue life prediction method based on approximate conformal dimension evolution, relates to the technical field of material damage mechanics, and comprises the following steps: collecting crack images under different cycle numbers of granite subjected to the action of corrosion medium and cyclic load, and constructing a crack set; calculating the approximate conformal dimension of each observation point after pretreatment and obtaining an evolution sequence by monotonicization; driving to establish a discrete damage evolution relationship by using a dimension increment, and calibrating parameters by using early data; and extrapolating damage accumulation of an unobserved interval, and determining the prediction life when a threshold is reached. The application integrates corrosion parameters into edge weights, realizes joint measurement of environment and crack geometry, selects the minimum box dimension by traversing parameters, overcomes single measurement limitations, depicts a corrosion fatigue accumulation process by using an increment-driven recursive model, realizes effective prediction under partial life data by using two-stage calibration and early data extrapolation, and improves engineering practicability and early warning capability.

A stress fatigue corrosion test method for sealed steel wire ropes used in bridge suspension cables includes the following steps: sample preparation, corrosion solution preparation, corrosion test implementation, and corrosion analysis. This invention provides a standardized method for stress corrosion fatigue testing of sealed steel wire ropes in a simulated atmospheric environment containing SO₂ and Cl⁻. Through a design of "closed-loop control - multi-source monitoring - data fusion," it achieves accurate reproduction and full-cycle monitoring of the simulated atmospheric environment containing SO₂ and Cl⁻, significantly improving the authenticity and reliability of the test results.

This invention discloses a method and system for calculating the time-varying reliability of cable corrosion fatigue in cable-stayed bridges. The method includes establishing and validating a finite element model of the cable-stayed bridge; simulating the time history of fluctuating wind speeds in the main girder and main tower using the harmonic synthesis method; obtaining the cable stress time history through buffeting analysis; establishing a probability model of equivalent stress amplitude and cycle number using the rainflow counting method and Miner's theory; constructing a probability model of the depth of dangerous pits and corrosion depth of steel wires under different corrosion degrees based on measured data; establishing a multi-stage series formula coupling pit evolution, pit-crack transformation, and crack propagation; constructing a limit state equation with a 2% wire breakage rate as a threshold; calculating the time-varying reliability of the cable under different wind speeds and corrosion degrees using random sampling; and statistically analyzing the mean and standard deviation of corrosion fatigue life. This invention accurately reflects the wind-corrosion coupling and multi-stage failure mechanism, is computationally reliable, and has strong versatility, making it suitable for safety assessment and life prediction of cables in various types of cable-stayed bridges.

The application provides a 2Cr13 forging method for improving corrosion fatigue resistance of a last-stage blade of a steam turbine, which can realize grain refinement, carbide distribution optimization, surface integrity improvement and favorable residual compressive stress introduction by optimizing temperature gradient between forging heats and inserting surface treatment and heat treatment procedures in the whole forging process, so as to systematically improve service performance of the blade under corrosion-fatigue coupling conditions. The 2Cr13 forging method for improving corrosion fatigue resistance of a last-stage blade of a steam turbine comprises the following steps: top forging, first heat forging of a blank; the temperature of the first heat forging is 1135-1145 DEG C; pre-forging, second heat forging of the first intermediate blank after the top forging, the temperature of the second heat forging is 1125-1135 DEG C, and the second heat temperature is less than the first heat temperature and forms a gradient temperature difference of 5-20 DEG C; finish forging, third heat forging of the second intermediate blank after the pre-forging, the temperature of the third heat forging is 1030-1040 DEG C, and a blade forging piece is obtained.

This invention relates to the field of corrosion fatigue testing technology and discloses a tension-bending stress-corrosion fatigue coupling test device and method, including a base plate, a left anchor frame, a right anchor frame, high-strength steel wire, and a portal frame; the right anchor frame is detachably connected to the top right side of the base plate, and the left anchor frame is connected to the base plate through a tension application mechanism. Compared with traditional steel wire corrosion fatigue tests, which usually only consider the coupling effect of axial tensile stress and corrosive medium, for short bridge cables in working condition, the main beam will experience longitudinal vibration, and the resulting cable bending stress is one of the main reasons for accelerating its fatigue failure. The bending stress, axial tensile stress, and corrosive medium work together to cause cable failure. Previous devices could not realize the coupling effect of the three, and were usually corrosion fatigue coupling tests that only considered axial stress, or fatigue tests with initial corrosion damage.

The application provides a bridge parallel steel wire pull cable corrosion fatigue residual life prediction method, and relates to the technical field of bridge safety evaluation, comprising: obtaining first information and second information; establishing a random traffic flow model based on the first information; performing cable force time history analysis considering vehicle-bridge dynamic response based on the second information and preset bridge road roughness, and obtaining the response time history of the bridge system; processing the response time history based on the rain flow counting method to obtain all stress amplitudes of the bridge and corresponding cycle times; based on all the stress amplitudes and corresponding cycle times, the time increment method is used to calculate the corrosion fatigue duration of the bridge parallel steel wire pull cable, and the fatigue life of the bridge parallel steel wire pull cable is output. The application is used for evaluating the residual life of the pull cable changing with the external environment during the service period, the evaluation model can be dynamically updated combined with the actual inspection results, and the effective combination of the theoretical model and the measured data is realized.

The application discloses high-speed train axle steel with high corrosion fatigue resistance and a stable residual stress layer, which is prepared by adopting a high-silicon-medium-chromium-rare earth composite alloying design and combining an innovative heat treatment process of incomplete quenching and two-stage tempering, so that the prepared axle steel has excellent conventional mechanical properties, Rm is greater than or equal to 750 MPa, Rp0.2 is greater than or equal to 600 MPa, and -40 DEG C KV2 is greater than or equal to 60 J, has super-high corrosion fatigue resistance, and has a beneficial surface residual compressive stress, and thus can meet the use requirements in a corrosive environment such as a coastal area and a high-humidity environment.

The present application relates to the field of crack propagation test of stress corrosion, corrosion fatigue and fracture toughness, and particularly relates to a system for in-situ monitoring of crack length of compact tension specimen in harsh corrosion environment and a use method thereof. Two short sides of a T-shaped connecting assembly are fixed at both sides of a center crack opening of a CT specimen, a long side head of the T-shaped connecting assembly is inserted into a through hole on one side of a turning block, a displacement transmission rod is clamped by a separated ohmic clamp on the other side of the turning block, an inductive core on the upper end of the displacement transmission rod is threadedly connected to a LVDT inserted into a high-temperature and high-pressure kettle cover, a spacer is threadedly and tightly sealed on the high-temperature and high-pressure kettle cover, a water cooling jacket is arranged outside the spacer, the LVDT is connected to the upper end of the spacer through a thread and a sealing washer, and the LVDT is connected to a data collector. The present application uses the flexibility method to obtain a relationship expression between the opening displacement of the crack opening of the CT specimen and the crack length, so that the crack length of the CT specimen in the harsh corrosion environment can be monitored in-situ.

This invention provides a neural network-based method for predicting the corrosion fatigue life of steel structures and their welds, belonging to the technical field of corrosion fatigue life prediction for steel structures and their welds. To overcome the shortcomings of existing steel structure corrosion fatigue prediction schemes in terms of generalization ability and prediction accuracy, the method preprocesses the collected multi-source corrosion fatigue data; constructs a main fatigue life prediction network; constructs a corrosion-induced stress amplification coefficient subnetwork ℓ₁; and constructs data loss functions respectively. L data Monotonic physical constraint loss function L MR Continuous damage mechanical loss function L CDM The model is trained; the life prediction of steel structures and their welded structures is performed based on transfer learning; the present invention is applied to the prediction of corrosion fatigue life of steel structures and their welds.

The application provides a gradient recycled concrete multi-objective optimization design method and system, and belongs to the technical field of material composition design of gradient structure recycled concrete. The method comprises the following steps: constructing an initial data set, and outputting a label as a coupling damage factor; screening out decision variables which have a significant influence on the coupling damage factor; constructing a proxy model based on Stacking integrated learning; taking the proxy model as a fitness function, taking minimization of the coupling damage factor as an objective, coupling with a non-dominated sorting genetic algorithm to establish a multi-objective optimization framework and solving, and obtaining a Pareto optimal solution set; selecting a solution from the solution set for test verification, supplementing new data to the initial data set, and iteratively optimizing. The gradient recycled concrete multi-objective optimization design method and system are adopted, the collaborative optimization of the gradient recycled concrete multi-layer structure is realized, and the technical problems of difficult quantitative characterization of corrosion-fatigue coupling damage and low efficiency of experience trial and error are solved.

This invention relates to the field of offshore wind power structure health monitoring and life assessment technology, and particularly to a system for assessing the corrosion fatigue life reliability of offshore wind power structures. The invention collects multi-source parameters of the offshore wind power structure using a sensor array, and preprocesses these parameters at the edge and cloud levels to determine high-dimensional feature vectors. Then, a life prediction unit uses an improved multilayer perceptron neural network to predict the remaining corrosion fatigue life of the offshore wind power structure. An assessment unit establishes a dynamic coupling model between corrosion fatigue damage and reliability to determine the probability of corrosion fatigue failure, and the offshore wind power structure is corrected based on the comparison between the corrosion fatigue failure probability and a preset failure probability. Finally, the corrosion fatigue assessment status is determined by the corrosion fatigue assessment characterization value calculated by the analysis unit, and relevant parameters are adjusted based on the corrosion fatigue assessment status. This invention improves the efficiency of assessing the corrosion fatigue life reliability of offshore wind power structures.