9 results about "Thermal mechanical coupling" patented technology

The invention belongs to the field of steam turbine safety assessment, and discloses a steam turbine blade safety margin dynamic assessment method, which can obtain the unsteady aerodynamic load distribution of the blade surface under the real geometric and dynamic load conditions by establishing a parameterized three-dimensional finite element model and carrying out transient CFD simulation, and has the advantages that compared with the traditional static working condition hypothesis, the dynamic assessment method has the advantages that the efficiency is high; the influence of dynamic load changes such as power grid AGC adjustment, deep peak regulation and quick start and stop on blade stress and temperature fields can be accurately reflected, so that the authenticity and timeliness of load input are improved. After the aerodynamic load is mapped to a structural mechanical model, the distribution rule of the multi-axis complex stress state of the blade can be obtained by combining centrifugal stress and thermal mechanical coupling stress calculation, and an accurate basis is provided for subsequent safety margin calculation.

The invention belongs to the technical field of power module design, discloses a power module reliability optimization design method, system and equipment based on the thickness of a solder layer and a medium, and aims to solve the problem that the optimal thickness of the solder layer cannot be accurately determined in the prior art. The method comprises the steps that a thermal-mechanical coupling simulation model is constructed, and thermal stress distribution data are obtained through simulation with the thickness of a solder layer as a variable; selecting a theoretical optimal thickness and a rapid change area representative thickness based on a simulation result to prepare a sample, and determining the thickness with a slow aging speed as a first optimal thickness through a power cycle experiment; scanning the aged sample to calculate the porosity, and determining the thickness with smaller porosity as a second optimal thickness; and carrying out collaborative analysis on the three, directly determining if the three are consistent, otherwise, taking the first optimal thickness as the criterion. According to the method, simulation-experiment-observation integrated optimization is realized, and the scientificity and the accuracy of the thickness design of the solder layer are remarkably improved.

The present application belongs to the technical field of generator, and provides a generator winding insulation failure prevention method based on coating electrostatic spraying, which can accurately simulate the accelerated aging and failure of the generator stator winding under the condition of thermal-mechanical coupling load. And according to the experimental device, an improved coating electrostatic spraying process is proposed to effectively improve the insulation damage of the stator winding. Finally, through the analysis of the insulation performance of the stator winding, the effectiveness of the improved process is proved. It is conducive to studying the influence of mechanical load, thermal load and coupling load on the insulation response and the stator insulation aging condition and performance change trend through experimental simulation, and provides a solid foundation for effectively preventing the shutdown failure of the generator winding insulation due to wear.

The invention belongs to the technical field of new energy wind power generation, and discloses an IGBT module failure prediction method and system, and the method comprises the steps: obtaining electric stress data, thermal stress data and mechanical stress data of a to-be-detected IGBT module, carrying out the time-space alignment processing, and obtaining a multi-dimensional feature vector of the to-be-detected IGBT module; performing multi-physical field coupling effect quantitative modeling based on the multi-dimensional feature vector to obtain a coupling feature matrix; the coupling characteristic matrix comprises a corrected electrical-thermal coupling coefficient, a thermal-mechanical coupling coefficient, a normalized electrical-mechanical coupling coefficient, a maximum temperature gradient and strain dominated by mechanical stress; inputting the coupling characteristic matrix into a pre-constructed coupling sensitive failure prediction model, and outputting to obtain a predicted failure cycle index of the to-be-tested IGBT module; according to the method, the accuracy, comprehensiveness and timeliness of IGBT module failure prediction are effectively improved, and a scientific basis is provided for IGBT model selection, life prediction and inverter system optimization.

The invention discloses a selective laser melting forming method and application for reducing the porosity of nickel-based superalloy.The method comprises the steps that a nickel-based alloy workpiece is prepared through selective laser melting, then the nickel-based alloy workpiece is subjected to subzero treatment in liquid nitrogen at the temperature of-196 DEG C for 10-60 min, then the nickel-based alloy workpiece is placed at the high temperature of 650 DEG C for heat preservation for 10-60 min, and through multiple cooling-heating cycles, the porosity of the nickel-based superalloy is reduced; the thermal mechanical coupling effect and microstructure regulation and control are combined, the density and comprehensive performance of the selective laser melting formed nickel-based alloy are remarkably improved, the porosity of the nickel-based high-temperature alloy can be reduced to 0.1% or below, and efficient pore closing is achieved. And meanwhile, dynamic release and redistribution of thermal strain in the circulation process are achieved, local stress concentration is effectively reduced, microcrack initiation is inhibited, the fatigue life of a component is prolonged, and the problems that in the prior art, nickel-based high-temperature alloy is treated at high temperature and high pressure, so that the yield strength is reduced, and the high-temperature durability is degraded are solved.

The application is suitable for the technical field of computer-aided fuel nozzle design, and particularly relates to a coupling design method and equipment for a fuel nozzle needle valve cone angle and a seat surface stress, comprising: obtaining a design variable vector and a target performance vector; generating a geometric model based on the design variable vector; performing thermal analysis and thermal-mechanical coupling analysis on the geometric model to obtain an analysis result; calculating a performance index of the geometric model based on the analysis result; judging whether a convergence condition is met according to the performance index and the target performance vector, and if the convergence condition is met, determining the geometric model as a final design model; if the convergence condition is not met, updating the design variable vector based on the performance index and the target performance vector; and iterating the above process until the convergence condition is met. The method can improve the sealing performance of the fuel nozzle and the engineering applicability of the design result.

The invention discloses an anti-scald curling iron with a thermal trigger self-locking structure, and belongs to the technical field of personal care electric appliances. The curling iron comprises a handle unit, a heating cylinder unit, a protective cover unit and a sliding rotary lock catch unit. The sliding rotary lock catch unit comprises a sliding track mechanism, a rotary trigger mechanism and a thermal trigger lock catch mechanism; the sliding rail mechanism achieves stable switching of the protective cover between the using position and the protective position. The rotary triggering mechanism guides the protective cover to rotate when the protective cover reaches the protective position; the thermal triggering lock catch mechanism automatically drives a spring bolt to complete locking at high temperature through a bimetal temperature-sensitive element; intelligent safety protection is achieved through thermal mechanical coupling, and the problem that a traditional protective cover is manually forgotten to be locked and the locking state is disjointed with the thermal risk of equipment, so that the scalding hidden danger is caused is solved.

The invention is suitable for the technical field of computer-aided oil nozzle design, and particularly relates to an oil nozzle needle valve cone angle and seat surface stress coupling design method and device. Generating a geometric model based on the design variable vector; performing thermal analysis and thermal-mechanical coupling analysis on the geometric model to obtain an analysis result; calculating a performance index of the geometric model based on the analysis result; according to the performance index and the target performance vector, whether a convergence condition is met or not is judged, and if the convergence condition is met, the geometric model is determined as a final design model; if the convergence condition is not met, updating the design variable vector based on the performance index and the target performance vector; and iterating the process until the convergence condition is met. According to the method, the sealing performance of the oil nozzle and the engineering applicability of a design result can be improved.

This disclosure provides a method for controlling the interfacial microstructure and properties of TiAl / Ti2AlNb alloy diffusion-bonded joints, comprising: subjecting the TiAl / Ti2AlNb alloy diffusion-bonded joints to electro-pulse treatment and thermomechanical treatment respectively; wherein the electro-pulse parameters are: pulse voltage of 30~50V, pulse frequency of 120~180Hz, and pulse time of 10~30s; the thermomechanical treatment parameters are: deformation temperature of 1050℃~1150℃, holding time of 20~40min, and deformation controlled below 15%, wherein the deformation direction during the thermomechanical treatment is parallel to the alloy diffusion-bonded interface. This invention employs an integrated technology of post-weld electro-pulse and thermomechanical coupling treatment, which can eliminate the defect of equal brittleness at the interface of the TiAl / Ti2AlNb alloy joint, while simultaneously allowing for more complete microstructure evolution, a more uniform and finer diffusion layer microstructure, and ultimately resulting in better strength and toughness at the TiAl / Ti2AlNb alloy joint, yielding a bi-alloy material with excellent comprehensive mechanical properties.