38 results about "Thermo elastic" patented technology

A non-contact thermo-elastic property measurement and imaging system and method thereof are described. Acoustic energy is incident on a first surface of a specimen under test. The acoustic energy is converted partially into heat by the specimen, causing a slight increase in the temperature in a region of interaction. The temperature increase is imaged using a high sensitivity infrared camera. Presence of defects (surface and subsurface) in the material modifies the distribution of temperature. An image of temperature distribution can be used for nondestructive testing and evaluation of materials. The temperature change in the specimen caused by acoustic excitation is related to thermal and elastic properties of the material. A measurement of the change in the temperature as a function of the amplitude of incident excitation can be used for direct measurement of thermo-elastic property of the specimen.

It is an object of the present invention to accomplish both improvement of a calculation precision and reduction of a calculation time in prediction of a welding distortion of a large welded structure. A method of modeling a welded structure subjected to analysis by generating a mesh and performing thermo-elastic-plastic analysis thereon constructs a global model of the welded structure, and extracts a local model including a welded part from the global model. Next, the method constrains a boundary part of the extracted local model with the remaining portion of the global model, performs thermo-elastic-plastic analysis, and pastes the local model including the analysis result of the thermo-elastic-plastic analysis on the remaining portion of the global model, thereby reconstructing the global model. Thereafter, the method releases the constraint on the boundary part, and performs elastic analysis on the global model, thereby calculating a distortion of the welded structure.

Accurately quantifying optical absorption coefficient using acoustic spectra of photoacoustic signals. Optical absorption is closely associated with many physiological parameters, such as the concentration and oxygen saturation of hemoglobin, and it can be used to quantify the concentrations of non-fluorescent molecules. A sample is illuminated by, for example, a pulsed laser and following the absorption of optical energy, a photoacoustic pressure is generated via thermo-elastic expansion. The acoustic waves then propagate and are detected by a transducer. The optical absorption coefficient of the sample is quantified from spectra of the measured photoacoustic signals. Factors, such as system bandwidth and acoustic attenuation, may affect the quantification but are canceled by dividing the acoustic spectra measured at multiple optical wavelengths.

A balance spring for a balance with a blank containing: niobium: the remainder to 100 wt %, titanium: between 40 and 60 wt %, traces of elements selected from the group formed of O, H, C, Fe, Ta, N, Ni, Si, Cu, Al, between 0 and 1600 ppm by weight individually, and less than 0.3 wt % combined, a step of β-quenching the blank with a given diameter, such that the titanium of the alloy is essentially in solid solution form with β-phase niobium, the α-phase titanium content being less than or equal to 5% by volume, at least one deformation step of the alloy alternated with at least one heat treatment step such that the niobium and titanium alloy obtained has an elastic limit higher than or equal to 600 MPa and a modulus of elasticity lower than or equal to 100 GPa, a winding step to form the balance spring being performed prior to the final heat treatment step, prior to the deformation step, a step of depositing, on the alloy blank, a surface layer of a ductile material such as copper, the surface layer of ductile material being retained on the balance spring, the thermoelastic coefficient of the niobium and titanium alloy being adapted accordingly.

The invention discloses a finite element solution optimization method for structural thermal response caused by re-entry aerodynamic environment, which includes: discretizing the coupled control equation based on heat conduction and material thermoelastic dynamics through the finite element method and providing a corresponding algorithm flow; wherein, In the algorithm process, for time-dependent partial differential equations, the finite element method discretizes the spatial region first, and obtains the grid division of the solution region, and then differentially discretizes the time item. According to the iterative coupling relaxation calculation principle, step by step Advance to capture the vibration of structural materials in space and the nonlinear behavior of thermal response deformation of large spacecraft after de-orbiting and re-entry into a strong aerodynamic thermal environment. The present invention provides an optimization method based on the finite element method for solving thermal-mechanical coupling response, which is beneficial for analyzing and researching the thermal-mechanical coupling response of material structures under strong aerodynamic / thermal environments, and is conducive to carrying out the performance prediction of aircraft and spacecraft structures with simulation.

The invention provides a nested annular MEMS oscillation gyro with period distribution type concentrated mass blocks. The gyro comprises a nested annular harmonic oscillator with the period distribution type concentrated mass blocks, and an electrode which is arranged inside / outside the nested annular harmonic oscillator; the nested annular harmonic oscillator comprises a nested annular flexible frame, the mass blocks arranged on the nested annular flexible frame, and anchors for fixing the oscillator; the whole harmonic oscillator is fixedly anchored with a base by the anchor on the center of the harmonic oscillator; the nested annular flexible frame comprises nested rings and spoke-shaped supporting beams; the mass blocks can be additionally arranged on the nested annular flexible frame in a plurality of kinds of manners; and the electrode can be arranged inside / outside the harmonic oscillator, or the electrodes are arranged inside and outside the harmonic oscillator. The gyro has the relatively high thermo-elastic property Q value, relatively large resonance oscillation mass, and relatively large driving amplitude; and as the design of the internal electrode is adopted or the design of the internal and external electrodes is adopted, the gyro also has the advantages that the capacitance detection area is large, the number of detection and control electrodes is large and the like.

The invention provides a laser thermoforming deformation prediction method and system for a hull outer plate, including: step 1: establishing a process window about heat source parameters and plate parameters; step 2: performing multiple sets of thermal elastic-plastic finite element based on the process window Simulate and extract the equivalent inherent strain results; Step 3: Establish a predictive neural network model based on the equivalent inherent strain results, and generalize the equivalent inherent strain results under other process parameters in the process window; Step 4: Combine the equivalent inherent strain results It is given to the model in the form of anisotropic thermal expansion coefficient as the initial property of the model; Step 5: By applying a unit temperature load to the model, ensure that the size and direction of the thermal strain distribution obtained by calculation are the same as the equivalent inherent strain distribution; Step 6: The thermoelastic finite element simulation is performed to obtain the deformation displacement of the material. The invention can quickly solve the deformation results of large-sized plate parts and complex paths, and realizes the automatic laser heating forming processing of the hull outer plate.