21 results about "Thermal strain" patented technology

The present application belongs to the technical field of thermal load deformation and force load deformation measurement, and relates to a thermal and force deformation field decoupling method and system based on two-dimensional visual measurement. According to the temperature field at discrete temperatures, the thermal deformation field at discrete temperatures and the corresponding temperature, and by using a binary function model, the influence coefficient of fitting temperature on thermal strain is obtained, the jumps between discrete data are eliminated, and the continuity and prediction ability of thermal strain are improved. According to the influence coefficient of fitting temperature on thermal strain and the binary function model, a fitted binary function model is obtained, which is more in line with the actual material properties. According to the temperature field under the thermal and force coupling condition, the deformation field under the thermal and force coupling condition and the fitted binary function model, an equivalent thermal deformation field is obtained, the thermal and force coupling deformation is decoupled, the dynamic correlation of thermal strain and deformation field is realized, and the decoupling precision is improved.

This invention discloses a method for controlling welding hot cracks with bilateral symmetrical thermal strain assistance. The method includes preparation before welding and welding. In the welding step, the temperature generated by the two induction coils is stabilized at 302±5℃ before welding begins. During welding, the welding heat source and the two induction coils move synchronously and uniformly from back to front, so that the thermal strain generated by the two induction coils continuously heats the workpieces to be welded on both sides of the weld within the brittle temperature range behind the molten pool until welding is completed. In this way, the thermal strain generated by the two induction coils continuously heats the corresponding workpieces to be welded on both sides of the weld within the brittle temperature range behind the molten pool. The thermal expansion of the workpieces generates a transverse compressive strain pointing towards the weld center in the weld metal within the brittle temperature range (BTR zone) behind the molten pool, thus counteracting the crack-inducing tensile strain generated in the brittle temperature range during welding, thereby effectively controlling the generation of hot cracks.

This technology suppresses the generation of thermal strain during crystal growth, enabling the realization of high-quality SiC single crystals with a low crystal defect density. [Solution] A SiC single crystal substrate is used, comprising a first main surface and a second main surface located opposite the first main surface, wherein the first main surface is a surface inclined with an off-angle of 0° to 8° with respect to the {0001} plane. Here, incident light having two mutually orthogonal polarization components and a wavelength of 520 nm is incident on the first main surface, and the phase difference between the first emitted light and the second emitted light emitted from the second main surface is measured. In the distribution of phase differences obtained, the average value of the phase difference is 10 nm or less, and the maximum value of the phase difference is 70 nm or less.

The application relates to a method for preparing a beryllium-aluminum composite material by adopting electric arc additive manufacturing, and relates to a method for preparing a beryllium-aluminum composite material. In order to solve the problem that solidification cracks are caused by the difference between the thermal physical properties of two phases in the electric arc additive manufacturing process of the beryllium-aluminum composite material. In the process of preparing the beryllium-aluminum composite material by layer-by-layer deposition of the electric arc additive manufacturing, the environmental temperature of the beryllium-aluminum composite material is controlled, and the beryllium-aluminum composite material is controlled to be cooled between adjacent layer deposition, the thermal gradient and the cooling rate in the solidification and cooling process are reduced, the instantaneous stress peak value caused by the rapid shrinkage and the uneven thermal strain is reduced, the crack driving force is reduced, and the problem that the thermal physical properties of the beryllium and aluminum two phases are greatly different is overcome. The preparation period of the method is short, the forming efficiency is high, the cost is low, and the method can meet the manufacturing of large metal components. The near-net forming of the beryllium-aluminum composite material component can also be realized, and the material utilization rate is greatly improved.

This utility model provides a drive gear with an internal self-lubricating oil channel. It relates to the field of gear technology and includes a gear disc. One end of the gear disc has an inner groove, in which a drive shaft is fixedly connected. A tube is formed through the end of the gear disc opposite to the drive shaft, and a bearing rod is inserted into the tube. An oil pipe is inserted into the bearing rod. An expansion plate, made of a thermal strain material, is filled inside the bearing rod. The beneficial effects of this utility model are: a thermal strain expansion oil supply structure is provided inside the gear disc between the drive shaft and the opposite bearing rod. Combined with the internal oil channel distribution within the gear and the centrifugal force during gear rotation, the internal oil fills the inner end of the gear disc's tooth groove and lubricates the contact end with the driven gear when in contact, achieving self-lubrication of the drive gear, reducing maintenance costs, and ensuring the stability of the drive gear during long-term operation.

This invention relates to the field of sliding bearing simulation and optimization technology, and more specifically to a high-precision simulation and optimization design method for hydrostatic thrust sliding bearings. It establishes an efficient decoupling model of the fluid-solid-thermal three-physics field of the hydrostatic thrust sliding bearing, decomposing the overall thermodynamic field into two subfields, which are coupled with the fluid force field and the solid force field, respectively. Then, it constructs a gap oil film flow / thermal field model and a friction pair deformation solid / thermal field model, achieving equivalent coupling through data transfer. The oil film control equations are iteratively solved to obtain oil film pressure, temperature, and flow velocity; the friction pair equations, including elastic constitutive and thermal strain equations, are solved to obtain their elastic and thermal deformations, with bidirectional data transfer achieving coupled iteration. Based on the above method, simulations are performed, establishing sub-models of oil film flow and friction pair deformation, using local interpolation and dynamic meshing to process the interface; the oil cavity is optimized based on the simulation results, parametric analysis is used to establish the mapping between structural parameters and lubrication performance, the objective function and constraints are defined, and the optimal oil cavity structure is obtained through algorithms.

This application discloses an ultrasonic thermal strain measurement method and system based on equivalent thermal dose correction, relating to the field of thermotherapy monitoring: acquiring the initial temperature of biological tissue; during the heating process of biological tissue, acquiring ultrasonic echo signal sequences of the target area at preset time intervals; calculating the cumulative thermal strain of the target area at each measurement moment based on the ultrasonic echo signal sequence; coupling and predicting the temperature and equivalent thermal dose at the current moment based on the equivalent thermal dose and temperature at the previous measurement moment, obtaining the predicted values ​​of the temperature and equivalent thermal dose at the current moment; establishing a temperature inversion equation including cumulative thermal strain and equivalent thermal dose, iteratively solving the equation using the predicted value as the initial value, and outputting the corrected temperature value and updated equivalent thermal dose value at the current moment. This application achieves dynamic compensation for the nonlinear changes in acoustic parameters caused by tissue thermal denaturation, thereby improving the temperature measurement accuracy during the ablation stage, expanding the temperature measurement range, and realizing real-time synchronous monitoring of temperature and equivalent thermal dose.

The application discloses a kind of ultra-thin saw blade deformation degree identification method, equipment and medium, belong to precision machining online detection technical field.The application first monitors the temperature difference gradient evolution trend of saw blade edge and center in real time, and executes logic filtering using threshold value based on hardware noise reference automatic determination, to remove the non-thermal displacement interference caused by main shaft mechanical vibration or electromagnetic interference in time domain.On this basis, real-time temperature and axial displacement are synchronously collected, and a geometric constraint correction model containing logarithmic correction term is constructed to calculate real-time deformation coefficient.The logarithmic correction term corrects the physical distortion of the classical unconstrained thermal strain linearization model when dealing with limited disc structure, and successfully realizes the quantitative separation of "harmless thermal displacement" and "abnormal unstable deformation".Finally, the system executes closed-loop judgment according to the deviation degree of real-time deformation coefficient to theoretical thermal response reference, and outputs control signal.The application does not need experimental calibration weight, has very high signal-to-noise ratio and cross-device universality, can sensitively capture saw blade warping precursor, and effectively protects high-value ultra-thin saw blade from plastic damage.

The application discloses a wind power tower door frame welding deformation software prediction optimization method in the field of wind power tower, and comprises the following method steps: a wind power tower model is established in software, a local interception method is used to extract a part containing a door frame and a door frame surrounding reinforcing rib as a simulation analysis area; the base material material model of the wind power tower body and the door frame is set as S355 grade steel; in the software model, the distribution of heat flow density is described by a Gaussian normal distribution function in probability analysis; a sequential coupling analysis method is used to simulate the numerical value of the welding process; a temperature field is used as a load and applied to mechanical analysis to solve a quasi-static equilibrium equation; and the total strain tensor is decomposed into elastic strain, plastic strain and thermal strain. The application constructs an explicit high-precision prediction model among U, I and v and welding deformation, and realizes direct mapping from a multi-dimensional parameter space to a complex deformation response.

The present application relates to the field of robot flexible welding, more particularly, the present application relates to a kind of based on visual guidance's grid rod robot flexible welding control method, method includes: using visual sensor and electrical parameter module obtains basic gap width and electrical parameter, in combination with the parameter of previous sampling period, determine the effective heat input index of current sampling period;Based on the fusion of gap deviation ratio and heat overshoot numerical value, calculate the thermal strain trend factor representing deformation trend;Using the factor to scale process reference, obtain wire feeding and amplitude compensation operator;By smoothing processing, generate the target parameter of next sampling period and control actuator.The present application realizes parameter dynamic calibration by distortion prediction, improves weld formation consistency.

The present application relates to the technical field of superconducting cables, and discloses a method and apparatus for calculating the thermal stress and thermal strain of a CORC cable, a computer device, a computer-readable storage medium, and a computer program product. The method comprises: acquiring a cable core inner surface temperature and a cable core outer surface temperature of a CORC cable, and on the basis of the cable core inner surface temperature and the cable core outer surface temperature, using a thermal balance equation of the CORC cable to determine a steady-state radial temperature distribution of a cable core; acquiring a Young's modulus, a Poisson's ratio, and a thermal expansion coefficient of a cable core functional layer, and on the basis of the steady-state radial temperature distribution, the Young's modulus, the Poisson's ratio, and the thermal expansion coefficient, using a stress-strain balance equation of the CORC cable to determine the thermal strain of the CORC cable; and on the basis of the thermal strain of the CORC cable, calculating the thermal stress of the CORC cable using a stress-strain relationship. The present application achieves rational analysis of the thermal stress and thermal strain of a CORC cable, providing a scientific basis and effective means for evaluating low-temperature shrinkage of superconducting cables.

A method for predicting the multiphysics coupling process of natural hydrogen flow, heat transfer, and rock thermal strain within underground pores, belonging to the field of natural hydrogen resource exploration, focuses on establishing a multiphysics coupling model based on phase field variables to describe the flow, heat transfer, and rock thermal strain within formation pores. A porous medium geometric model is established based on the underground pore structure of the rock. This model is then meshed to obtain several grid cells reflecting different spatial distribution locations of natural hydrogen within the underground pore structure. Initial and boundary conditions are set for the porous medium geometric model. Based on the multiphysics coupling model, the spatiotemporal evolution characteristics of hydrogen volume fraction, water volume fraction, fluid temperature, rock matrix temperature, and rock matrix thermal strain values ​​in each grid cell of the porous medium geometric model are solved to obtain their temporal and spatial distribution. This invention achieves a more accurate and systematic assessment of the natural hydrogen accumulation mechanism and its stability.

A method for reducing thermal strain in a reticle includes determining the target operating temperature of the reticle during use, adjusting the thermal expansion (TE) characteristics of the reticle based on the target operating temperature, and irradiating the reticle to perform a manufacturing process.

The present application relates to the technical field of optical fiber sensing health monitoring, in particular to an integrated optical cable health monitoring system based on distributed sensing, comprising: after quality assessment of the collected original optical signal, demodulating vibration, temperature and strain distribution data. By establishing the space-time correlation mapping of vibration spectrum and temperature profile, the position of vibration event and its accompanying temperature change trend are accurately identified by using pattern matching. The system further compensates the dynamic thermal strain of the strain data according to the temperature trend, removes the temperature interference, and extracts the net mechanical strain distribution reflecting the real mechanical load. Comparing and analyzing the net strain with the material fatigue threshold, the abnormal points are located and the health status diagnosis report is generated. Through multi-parameter collaborative analysis and dynamic cross compensation, the accuracy of event identification and the reliability of strain evaluation are effectively improved, so as to realize the precise monitoring and early warning of optical cable structure health.

This invention discloses a method, device, and medium for temperature measurement and cracking risk early warning of large-volume concrete, relating to the field of concrete risk early warning technology. The method includes: determining shrinkage-driven signs using baseline thermal strain sequences and data from a monitoring dataset; calculating risk ratios for areas exhibiting shrinkage-driven signs to form a shrinkage-dominant precursor risk identification result; calculating temperature and humidity disturbance ratios for sampling locations near the cooling zone to form a cooling side effect identification result; and combining the shrinkage-dominant precursor risk identification result with the cooling side effect identification result to perform regional-level and structural-level cracking risk early warning determinations for the concrete structure, storing the results in a monitoring database. This invention, by combining thermal strain differentials with humidity change trends, achieves a quantitative assessment of shrinkage-driven effects and can identify critical conditions for crack initiation in advance.

The application relates to the technical field of micro-electro-mechanical systems and sensors, and discloses a multi-field coupling dynamic modeling method of a micro-resonant pressure sensor, which comprises the following steps: establishing a balance differential equation and a deformation coordination equation of a resonator, introducing a constitutive equation containing thermal strain, constructing mathematical expressions of a pressure film air damping force, an electrostatic force and a molecular force and merging the mathematical expressions into the balance differential equation to establish a multi-field coupling dynamic partial differential equation set; eliminating a spatial variable by adopting a separation of variables method and an integral formula and converting the spatial variable into a nonlinear ordinary differential control equation; obtaining a nonlinear equivalent natural frequency and a free vibration time domain displacement equation by using a perturbation method; superimposing an alternating voltage signal to derive an amplitude-frequency characteristic curve equation of a main resonance state; and combining an excitation source to obtain a time domain dynamic response equation in a state far away from resonance. The application comprehensively considers multi-physical field stress conditions, improves dynamic modeling accuracy, reduces a solving operation burden and provides a theoretical basis for sensor parameter optimization.

Provided is an oriented electromagnetic steel sheet having both low iron loss and low magnetostriction, which is excellent in transformer characteristics. The oriented electromagnetic steel sheet has a heat-strained region extending linearly in a direction transverse to a rolling direction, and in a strain distribution in the rolling direction of the heat-strained region, the strain at both ends of the heat-strained region is a tensile strain that is greater than the strain at the center of the heat-strained region.

This invention discloses a method for early warning of steel structure deformation under thermo-mechanical coupling, relating to the field of structural health monitoring technology. The method includes: acquiring real-time strain and temperature data of the steel structure monitoring area; identifying a pure thermal loading window based on the strain and temperature data and inverting the equivalent thermal strain coefficient; accumulating and integrating the equivalent thermal strain coefficient with the temperature change rate to obtain the thermal strain, and subtracting the thermal strain from the total strain to obtain the force-induced strain; calculating the force-induced strain accumulation rate, which is equal to the integral of the absolute value of the force-induced strain change rate within a preset integration window divided by the window duration; identifying the microplasticity initiation point based on the changing trend of the force-induced strain accumulation rate, using the force-induced strain accumulation rate corresponding to the microplasticity initiation point as the critical accumulation rate, and using the product of the critical accumulation rate and a preset safety factor as an adaptive early warning threshold; outputting a deformation early warning signal when the force-induced strain accumulation rate reaches the threshold. This invention achieves early warning of the risk of plastic deformation in steel structures.

The application discloses a kind of PFC-based granular model and granite thermal damage prediction method and system, it is related to high-temperature well wall stability analysis technical field, including generating initial disc model with required mineral composition and particle size distribution, according to brazilian split, uniaxial and triaxial compression test results and simulation results comparison, calibrate granite model mesoscopic parameter;Simulate the mechanical test of rock under high temperature condition, get stress-strain curve and microcrack propagation situation;Thermal damage is calculated by the change of elastic modulus, the main factors of different grain size and inhomogeneous granite thermal damage are analyzed and determined, and the functional relationship model between granite thermal damage and volume thermal strain is established.The application is based on PFC discrete element, establishes the granular model of multi-mineral granite, and the model can well simulate the mechanical behavior and microcrack propagation process of rock under thermal force coupling condition.

This invention relates to the field of deformation measurement technology, specifically to a method, device, and system for measuring the deformation of post-cast strips in high-rise buildings. The invention obtains the horizontal expansion and contraction per unit temperature change and the vertical bending per unit temperature change at each moment by analyzing the changing trends of the tilt angles of the left and right slab ends at different times, as well as the concrete surface temperature distribution at different times. Based on the distribution of the horizontal expansion and contraction per unit temperature change at different times, a historical expansion and contraction baseline value is obtained for each moment. Based on the horizontal expansion and contraction per unit temperature change, the vertical bending per unit temperature change, and the historical expansion and contraction baseline value at each moment, the frictional locking state at each moment is obtained. Based on the frictional locking state at different times and the concrete temperature change rate, the cumulative unreleased thermal strain at the latest moment is obtained. This invention improves the accuracy of deformation measurement by accurately acquiring the cumulative unreleased thermal strain for quantitative deformation assessment.