30 results about "Length scale" patented technology

The invention discloses a flow-induced vibration velocity effect similarity method based on an equivalent mode, and belongs to the field of aircraft structure dynamic strength optimization. According to the method, the scaling model is established, the flow velocity difference caused by different sound velocities of the scaling model and the full-size model is considered at the same time, a new thickness scaling factor is established in combination with the velocity ratio on the basis of a length scaling factor, and the structural vibration parameters of the full-size model are predicted through the scaling model. The influence caused by flow velocity difference can be made up, the characteristic frequency and the structural response of the full-size model can be accurately predicted through the scaling model, and the flow-induced vibration velocity effect similarity prediction precision based on the equivalent mode is improved. According to the method, a complex structure characteristic frequency is changed into a similar form only containing the combination of a thickness scaling factor and a length scaling factor through an equivalent modal method, and a curved plate flow-induced vibration structure response similar expression is deduced, so that the defects of a current flow-induced vibration similarity theory are overcome; and the prediction reliability of the aircraft structure dynamic response similarity method is improved.

To provide a bevel dimension gauge capable of measuring bevel dimensions of a plurality of types at a time.SOLUTION: A bevel dimension gauge comprises: a tabular first piece including a first regulation end abutting on a workpiece surface on which a bevel is formed; a tabular second piece including a second regulation end abutting on the workpiece surface and a third regulation end orthogonal to the second regulation end so as to abut on a root surface of the workpiece; and a third piece supported rotatably around a predetermined reference axis to the first piece. The first piece includes an angle scale indicating an angle around the reference axis to the first regulation end, the second piece includes a length scale along the third regulation end, and the third piece includes a fourth regulation end abutting on a bevel surface of the workpiece on the first end side in a longitudinal direction from the reference axis, and an angle indication part for indicating, on the angle scale, an angle of the fourth regulation end to the first regulation end on the second end side in the longitudinal direction from the reference axis.SELECTED DRAWING: Figure 1

Systems and methods include a computer-implemented method for determining and storing a length scale dimension in spatial coordinate systems. A mapping of three-dimensional (3D) grid locations (x,y,z) relative to a continuous surface of the Earth is determined. The 3D grid locations have a grid point spacing in an (x,y) space defining map view coordinates of the continuous surface independent of an elevation z. A length scale (l) is determined for each 3D location. The length scale defines a 3D distance between 3D grid locations, and also defines a structural or geometrical length scale at the 3D location relevant to a given task. Then, (x,y,z,l) information is stored for each 3D grid location. The (x,y,z,l) information defines, for each (x,y) coordinate, a z-coordinate defining an elevation of the continuous surface at the (x,y) coordinate and the local length scale at the (x,y,z) coordinate.

The utility model discloses a combined type gap measuring scale which comprises a first plate body and a second plate body which are respectively formed by three edges connected end to end, any acute angle edge of the first plate body is provided with scale marks, the scale marks are composed of a plurality of length scale lines, and the length scale lines are arranged on the first plate body. The numerical value represented by each length scale line is the distance from the point of the length scale line on the acute angle side to the other acute angle side, the second plate body is a right triangle, and at least one edge of the second plate body is provided with an indexing mark. According to the utility model, the first plate body and the second plate body are matched for use, so that other obstacles around cannot interfere with the caliper during measurement; the right angle can be used to determine whether to be perpendicular to the measured object. According to the utility model, the integrated characteristic of a vernier caliper is abandoned, mechanical structures such as a combined bayonet are not provided, the overall structure is simple, the manufacturing cost is low, and the measurement precision is improved.

The invention discloses a strong shear turbulence grid adaptive simulation method coupled with a k-omega series model. The method mainly comprises the following steps of: 1, judging whether a shielding function is applied or not; step 2, identifying a self-adaptive length scale of a shear layer; 3, constructing a scale-related adjustment function based on the turbulence energy spectrum integral; 4, reconstructing the turbulence viscosity of the k-omega series model by using an adjustment function; and 5, performing turbulence simulation by using the reconstructed turbulence viscosity. According to the method, the self-adaptive sub-grid length scale of the shear layer is constructed and introduced into the initial region of the quasi-two-dimensional free shear layer, so that the sub-grid length scale of the initial region of the free shear layer is effectively reduced, and the problem that an existing RANS-LES hybrid model is highly dependent on grids is solved. The calculation accuracy is improved, meanwhile, the calculation consumption is greatly reduced, the turbulence simulation process is remarkably accelerated, and an effective numerical simulation method is provided for solving low-consumption and high-precision simulation of strong shear flow in the complex engineering flow problem.

The utility model relates to the related technical field of engines, and discloses a depth measuring device which is used for detecting the distance from a workpiece mounting surface to a reference surface, the depth measuring device comprises a positioning piece and a measuring piece, the positioning piece is used for being inserted in a workpiece and used for abutting against the reference surface, the positioning piece is provided with length scale marks, and the measuring piece is used for measuring the length scale marks. The measuring piece is used for being inserted into the workpiece and used for abutting against the mounting face, and the measuring piece is connected with the positioning piece in a nested mode and can move in the length direction of the positioning piece. According to the utility model, the positioning piece and the measuring piece are arranged, the positioning piece and the measuring piece are mutually nested and connected and are inserted into the workpiece, and the positioning piece is provided with the length scale marks, so that during measurement, the positioning piece and the measuring piece are respectively abutted against and fixed with the reference surface and the mounting surface, and the length scale marks are measured according to the relative position of the other end of the measuring piece and the length scale marks; the device can measure the distance from an installation surface to a reference surface, is convenient to use, is high in measurement efficiency, is low in requirements for operation conditions, and is suitable for on-site use.

The invention discloses a ruler for measuring the length and the width of a corn, the ruler structurally comprises a measuring ruler, width scale marks, length scale marks and a bottom plate mechanism, the width scale marks are arranged on the front end face of the measuring ruler, the length scale marks are arranged on the front end face of the measuring ruler, and a width marking block moves leftwards on the front end face of a ruler plate; a magnetic plate can carry out positioning magnetic attraction on a transverse sliding rod, an LED lamp can carry out identification prompting on measured scales during measurement, the watching effect of the measured scales is improved, then width scale lines are measured through a measuring head on a movable block, the length and width of a corn can be measured by one person, and the measurement efficiency is improved. The four elastic bands independently carry out the firmness of automatic elastic clamping on the fingers of a measuring person, it is ensured that the fingers of the measuring person can be clamped between the plate body and the adjusting plate, and the measuring ruler is prevented from falling off or shifting from the hands of the measuring person when the corn is measured. And the effect of quickly and accurately measuring the length and width of the corn is improved.

The utility model discloses a drawing measuring scale for engineering cost. The drawing measuring scale comprises a length scale. According to the drawing measuring ruler for the construction cost, through the arrangement of the length ruler, the width ruler and the limiting mechanism, during measurement, equipment is placed at one corner of a drawing, so that the length ruler is aligned with the long edge of the drawing, the width ruler in the inner cavity of the length ruler is rotated, and an included angle of 90 degrees is formed between the width ruler and the bottom length ruler; at the moment, a limiting iron rod on a supporting plate on one side of the width ruler is loosened, the limiting iron rod returns to the initial position under the reverse acting force provided by a buffer spring on the surface, then the limiting iron rod is inserted into a limiting groove formed in the surface of the length ruler and is in magnetic connection with a magnetic block in the limiting groove, and limiting of the width ruler can be completed; the limiting iron rod is pulled outwards to be separated from the limiting groove, then the width ruler is rotated into the cavity to be stored, the length and the width of the drawing can be measured at the same time, and the measuring efficiency is improved.

The invention discloses a strong shear turbulence grid adaptive simulation method coupled with a k-epsilon series model. The method mainly comprises the following steps of: 1, judging whether a shielding function is applied or not; step 2, identifying a self-adaptive length scale of a shear layer; 3, constructing a scale-related adjustment function based on the turbulence energy spectrum integral; 4, reconstructing the turbulence viscosity of the k-epsilon series model by using an adjustment function; and 5, performing turbulence simulation by using the reconstructed turbulence viscosity. According to the method, the self-adaptive sub-grid length scale of the shear layer is constructed and introduced into the initial region of the quasi-two-dimensional free shear layer, so that the sub-grid length scale of the initial region of the free shear layer is effectively reduced, and the problem that an existing RANS-LES hybrid model is highly dependent on grids is solved. The calculation accuracy is improved, meanwhile, the calculation consumption is greatly reduced, the turbulence simulation process is remarkably accelerated, and an effective numerical simulation method is provided for solving low-consumption and high-precision simulation of strong shear flow in the complex engineering flow problem.

The invention discloses a strong shear turbulence grid adaptive simulation method coupled with an SA series model. The method mainly comprises the following steps of: 1, judging whether a shielding function is applied or not; step 2, identifying a self-adaptive length scale of a shear layer; 3, constructing a scale-related adjustment function based on the turbulence energy spectrum integral; 4, reconstructing the turbulence viscosity of the SA series model by using an adjustment function; and 5, performing turbulence simulation by using the reconstructed turbulence viscosity. According to the method, the self-adaptive sub-grid length scale of the shear layer is constructed and introduced into the initial region of the quasi-two-dimensional free shear layer, so that the sub-grid length scale of the initial region of the free shear layer is effectively reduced, and the problem that an existing RANS-LES hybrid model is highly dependent on grids is solved. The calculation accuracy is improved, meanwhile, the calculation consumption is greatly reduced, the turbulence simulation process is remarkably accelerated, and an effective numerical simulation method is provided for solving low-consumption and high-precision simulation of strong shear flow in the complex engineering flow problem.

This application relates to the field of data processing technology and discloses a method for processing heterogeneous multi-scale data in Gaussian process regression. The method first acquires the raw data and performs feature transformation, standardization, and dimensionality reduction preprocessing to construct a multi-level validation dataset. Second, it reconstructs the Gaussian process regression kernel function, introducing a learnable Minkowski distance parameter to replace the traditional fixed Euclidean distance metric. Next, it uses a tree-structured Parzen estimator strategy to perform global iterative optimization on the validation set with the goal of minimizing prediction error, determining the optimal Minkowski distance parameter. Subsequently, it trains the model based on the optimal parameter and an automatic correlation determination mechanism, jointly optimizing hyperparameters such as signal variance and length scale through maximum likelihood estimation. Finally, it performs prediction and outputs the mean and variance. This invention, through adaptive parameterization of the kernel function metric, effectively overcomes the shortcomings of traditional models in adapting to non-spherical distributions and multi-dimensional heterogeneous features, significantly improving prediction accuracy and generalization performance.

The invention provides a multi-scale micro-fissure zone method for predicting damage and fracture of a quasi-brittle material. Comprising the following steps: proposing a microfissure zone hypothesis with distribution characteristics according to a fracture process zone concept, reconstructing an energy-minimization variational equation by adopting microfissure distribution equivalent transformation, and deducing a stress balance equation and a microfissure density parameter evolution rule under a thermodynamic framework. And associating macroscopic elastic rigidity and microfracture density parameters based on a homogenization method, forming a material softening relationship by an equivalent constitutive function, processing irreversible damage and asymmetric tension-compression stress response, and calculating and verifying representative example numerical values. According to the method, the phase field model and the micro-mechanical damage model are combined, the value contradiction that the length scale parameter approaches 0 can be overcome, the energy degradation process is effectively calibrated, the real damage distribution characteristic and the energy degradation behavior in the crack propagation process are reflected, and the accuracy of the crack propagation is improved. The method has important significance and remarkable progress in predicting the damage and cracking phenomena of the engineering structure.

The invention relates to the technical field of hole site measuring tool equipment, and discloses a measuring device for a U-shaped shell. The measuring device comprises a plurality of groups of measuring units and a center distance measuring assembly. The measuring unit comprises a fixing assembly and a measuring assembly, wherein the fixing assembly comprises a claw which extends into and is fixed in a U shell punched hole; the knob assembly is in transmission connection with the claw to drive the claw to open and close; the shell assembly is provided with a sliding groove. The side surface measuring assembly comprises a distance measuring sensor and a blocking needle installed in the sliding groove. The distance measuring sensor is used for detecting the displacement amount of the blocking needle. The display device is used for displaying the displacement amount of the blocking needle. The center distance measuring assembly comprises a scale plate which is rotatably connected to a group of measuring units; the scale plate is rotationally connected to the other group of measuring units, the scale plate is in sliding connection with the scale plate, and the scale plate and the scale plate are correspondingly provided with length scales. By means of the arrangement, synchronous, rapid and direct measurement of the edge distance, the center distance and the included angle of the hole site is achieved, and the multi-dimensional size of the punching position is accurately obtained at the same time.

The invention discloses a strong shear turbulence dynamic grid adaptive simulation method coupled with a k-epsilon series model. The method mainly comprises the following steps of: 1, judging whether a shielding function is applied or not; step 2, calculating a Vman dynamic coefficient; step 3, identifying the self-adaptive length scale of the shear layer; step 4, constructing a scale-related adjustment function based on the turbulence energy spectrum integral; 5, reconstructing the turbulence viscosity of the k-epsilon series model by using an adjustment function; and 6, performing turbulence simulation by using the reconstructed turbulence viscosity. According to the method, the size of a local grid is identified by constructing a Vman dynamic coefficient, the length scale of the local grid is jointly determined in combination with the length scale of the shear layer adaptive sub-grid, and then the scale correlation function is constructed through the turbulence energy spectrum integral to reconstruct the turbulence viscosity, so that grid adaptive simulation is realized; an effective numerical simulation method is provided for solving low-consumption and high-precision simulation of strong shear turbulence in a complex engineering flow problem.

The invention relates to the technical field of length scale measurement in the modern equipment manufacturing industry, and discloses a method for measuring the radius of a plastic zone in the nano-indentation process of a strength asymmetric material, which comprises the following steps: acquiring stress-strain data of the material to obtain an initial yield function and a hardening function; compiling a user material subprogram according to the initial yield function and the hardening function of the material; performing a nanoindentation experiment on the sample to obtain an experiment load displacement curve of the sample; accessing the user material subprogram into finite element software, and constructing a finite element model to perform analog simulation of a nanoindentation experiment to obtain a simulated load displacement curve of the indenter; comparing the displacement load curve with the experimental load displacement curve; and determining the distance between the initial equivalent yield stress position and the tip of the indenter in the x and y directions through an analog simulation result, and calculating the radius of the plastic zone under different indentation depths. The method can achieve the measurement of the radius of the plastic zone at any indentation depth, and is high in measurement result accuracy.

The invention discloses a field portable accumulated snow parameter testing device and a testing method thereof, belongs to the technical field of accumulated snow parameter monitoring, and solves the problem that an existing accumulated snow parameter testing device is inconvenient to sample. The snow taking device comprises a snow taking pipe and an electronic scale. The snow taking pipe is of a transparent cylindrical structure with the hollow interior and two open ends, and length scales used for measuring the thickness of a snow sample and the equivalent depth of snow water and volume scales used for measuring the volume of the snow sample are arranged on the wall face of the snow taking pipe. An electric heating groove used for melting a snow sample in the snow taking pipe is formed in a shell of the electronic scale. Compared with a rain gauge with a snow melting function and an accumulated snow radar, the rain gauge has the advantages of being compact in structure and high in portability, and field flexible point selection sampling is supported. The snow taking pipe is combined with the electronic scale to weigh in real time and quickly calculate the density, and traditional snow sample transfer errors are eliminated; the electronic scale is integrated with the electric heating groove to achieve integration of snow melting and snow water equivalent measurement, switching of multiple devices is avoided, and the device is particularly suitable for rapid operation in complex terrains.

The invention discloses a flow-induced vibration speed effect frequency-band-division equivalent method, and belongs to the field of aircraft structure dynamic strength optimization. On the basis of the length scaling factor, the thickness scaling factor is introduced, and the problem that the aerodynamic load frequency and the structure frequency are inconsistent due to the speed difference is compensated through the thickness factor; on the basis, the flow-induced vibration similarity law considering the flow velocity effect is deduced, prediction can be carried out in combination with actual working conditions, similarity theory prediction errors caused by velocity differences are further reduced, and the reliability of the flow-induced vibration equivalent method based on the scaling model is improved. According to the method, a curved plate structure flow-induced vibration similarity criterion expression is established in a frequency division mode by adopting a frequency division band method according to different structural mode types. Complex aircraft structure response prediction is simplified, the defects of the current flow-induced vibration similarity theory are overcome, the prediction reliability of the aircraft structure dynamic response similarity method can be improved, and improvement of the precision and efficiency of high-speed aircraft structure dynamic response assessment is facilitated.

The invention relates to the technical field of grain shape measurement, in particular to a wheat grain shape measurer which comprises a bottom plate, a plurality of placement grooves are distributed in the bottom plate, length scale marks and width scale marks are arranged on the bottom plate close to the placement grooves, longitudinal limiting assemblies and transverse limiting assemblies are arranged in the placement grooves, and a plurality of transparent pressing plates are arranged on the bottom plate. The transparent pressing plates are in one-to-one correspondence with the placing grooves and are arranged above the placing grooves; according to the invention, the plurality of placing grooves are transversely distributed on the bottom plate in an array manner, so that a plurality of wheat grains can be measured at the same time, and the measurement efficiency is improved; the length scale marks and the width scale marks are arranged, so that the length and the width of the wheat can be conveniently and intuitively read; a longitudinal limiting assembly and a transverse limiting assembly are arranged in the placement groove, so that the wheat can be accurately positioned, the wheat is prevented from moving in the measurement process, and the accuracy of a measurement result is ensured; the arrangement of the transparent pressing plate can fix the wheat during measurement, prevents the wheat from jumping or shifting, and does not affect the observation of the grain shape of the wheat at the same time.

The invention discloses a strong shear turbulence dynamic grid adaptive simulation method coupled with an RSM series model. The method mainly comprises the following steps: step 1, judging whether a shielding function is applied or not; step 2, calculating a Vman dynamic coefficient; step 3, identifying the self-adaptive length scale of the shear layer; 4, constructing a scale-related adjustment function based on the turbulence energy spectrum integral coupling RSM series model; 5, reconstructing a Reynolds stress tensor and turbulence viscosity by using an adjustment function; and 6, performing turbulence simulation by using the reconstructed Reynolds stress tensor and turbulence viscosity. According to the method, the size of a local grid is identified by constructing a Vman dynamic coefficient, the length scale of the local grid is jointly determined in combination with the length scale of the shear layer adaptive sub-grid, and then the scale correlation function is constructed through the turbulence energy spectrum integral to reconstruct the turbulence viscosity, so that grid adaptive simulation is realized; an effective numerical simulation method is provided for solving low-consumption and high-precision simulation of strong shear turbulence in a complex engineering flow problem.

The utility model discloses a size measuring device for furniture production, which comprises a horizontal ruler and a right-angle ruler arranged at the left end of the horizontal ruler, the right-angle ruler and the horizontal ruler are arranged at a right angle, a length scale line A is arranged at the left end of the right-angle ruler and located on the outer wall of the front end, and a length scale line B is arranged on the outer wall of the front end of the horizontal ruler. The novel auxiliary thickness measuring device is additionally arranged at the right end of the right-angle ruler of the size measuring device for furniture production, the outer wall of a wood board to be measured is accurately clamped through the fixed stop block and the movable stop block, the thickness of the wood board can be accurately measured, and compared with scale line measurement by only using the right-angle ruler or a horizontal ruler, measurement is more accurate. According to the auxiliary device, errors caused by non-professional measurement can be effectively reduced, the measurement precision is greatly improved, meanwhile, when the auxiliary device is used, tools do not need to be frequently replaced, the trouble of tool switching is avoided, the measurement efficiency is greatly improved, the measurement time is saved, furniture production size measurement is more convenient and efficient, and the production process is powerfully supported.

The utility model discloses a penis angle and length measuring device, which comprises a connecting part and two measuring rulers, and is characterized in that the measuring rulers are provided with length scales along the length direction and are provided with chutes along the length direction; the connecting part is in sliding connection with the sliding grooves of the two measuring rulers and can move in the length direction of the measuring rulers along the sliding grooves; the working axis of the connecting part is parallel to the depth direction of the sliding grooves, one of the sliding grooves can rotate around the working axis relative to the connecting part, the penis root and the penis head can be aligned through the structure, and measurement is more accurate.

The utility model discloses a distance measuring device, which solves the technical problem of narrow application range of the existing distance measuring device. The distance measuring device comprises a ruler with length scales, the ruler is provided with at least two moving parts capable of axially sliding and circumferentially rotating, positioning parts used for fixing the positions of the moving parts are arranged between the moving parts and the ruler, and the moving parts are connected with grippers used for abutting against measured parts. According to the technical scheme, the moving piece can move in the axial direction of the scale and can also rotate around the scale in the circumferential direction, the vertical distance between the two measured pieces in the same plane can be measured, the vertical distance between the two measured pieces in different planes can also be measured, and the application range is expanded. By adopting the inventive concept and the preferable technical scheme provided by the utility model, the problem that the distance between two shafts, two shaft holes, one shaft and one hole, the distance between the shaft and the plane, the distance between the hole and the plane and the distance between the two planes cannot be accurately measured in the prior art can be solved.

The invention discloses a strong shear turbulence grid adaptive simulation method coupled with an RSM series model. The method mainly comprises the following steps of: 1, judging whether a shielding function is applied or not; step 2, identifying a self-adaptive length scale of a shear layer; 3, constructing a scale-related adjustment function based on the turbulence energy spectrum integral coupling RSM series model; 4, reconstructing a Reynolds stress tensor and turbulence viscosity by using an adjustment function; and 5, performing turbulence simulation by using the reconstructed Reynolds stress tensor and turbulence viscosity. According to the method, the self-adaptive sub-grid length scale of the shear layer is constructed and introduced into the initial region of the quasi-two-dimensional free shear layer, so that the sub-grid length scale of the initial region of the free shear layer is effectively reduced, and the problem that an existing RANS-LES hybrid model is highly dependent on grids is solved. The calculation accuracy is effectively improved, the calculation consumption is reduced, the turbulence simulation process is remarkably accelerated, and an effective numerical simulation method is provided for solving low-consumption and high-precision simulation of strong shear flow in complex engineering flow.

The utility model relates to the related technical field of architectural design, in particular to a special measuring device for architectural design, which comprises a protractor; a rotatable ruler is arranged at the top of the protractor, length scales are engraved on one side of the top of the ruler, a threaded rod is rotationally connected into the ruler, the bottom end of the threaded rod penetrates through the protractor and extends to a hexagonal fixing block, and the fixing block is fixedly connected with the threaded rod. According to the utility model, the ruler, the length scales, the screw rod, the fixed block, the hexagonal groove, the pointer mechanism and the sliding mechanism are matched with one another, so that the measuring tool has the integrated function of measuring the diameter, the length and the angle, and the problem that the measuring mode is different due to the fact that more objects need to be measured in the building design is solved. Therefore, different measuring tools are needed when the angle, the diameter and the length are measured, and inconvenience is caused.

The system and method for calculating the lateral mixing coefficient of pollutants in vegetated ecological rivers, by selecting three different types of vegetation, carried out pollutant concentration tests in flumes with vegetation on beach, and calculated the measured TMC values ​​by linear graphical method. Through dimensional analysis, the parameters affecting TMC were studied, and the characteristics of vegetation were innovatively taken into account, and the adjustment length scale was introduced and dimensionless with the vegetation inundation height, so as to construct a new TMC influencing factor. Based on the flume test results and dimensional analysis, the flume was divided into the slope-main flume area and the slope-beach area in the horizontal direction, and the empirical formula for TMC prediction was constructed for each area. Error analysis shows that the formula can predict TMC well. The system and method for calculating the lateral mixing coefficient of pollutants in vegetated ecological rivers of the present invention are of great significance for evaluating the diffusion of pollutants, predicting the response and stability of ecosystems, and guiding related environmental management and protection work.

A nondestructive method for detecting damage in parts and / or characterizing effective material properties may include: exposing a material to one or more nondestructive stimuli; measuring a response of the material to the stimuli; selecting at least one of a specific length scale or a specific time scale; and analyzing the measurement of the response with a scale-aware single- or multi-physics model to identify anomalies in the measurements as compared to an expected response of the material to the stimuli, wherein the scale-aware single- or multi-physics model is based on the at least one of the specific length scale or the specific time scale.

The present application relates to the technical field of measurement of the geometric center of continuous casting round billets, and particularly relates to a kind of measurement method and measuring tool of the geometric center of continuous casting round billets, including measuring rope and fixing device, the surface of the measuring rope is provided with length scale, fixing device is used to fix measuring rope and can be adsorbed to the end face of continuous casting round billet, fixing device includes fixing piece, locking bolt and magnetic attraction piece, the inside of fixing piece is provided with cavity, and connection hole is opened on outer wall, locking bolt is fixed to the upper end of fixing piece, the end of measuring rope passes through connection hole, magnetic attraction piece is fixedly arranged in cavity, and the lower end of locking bolt is in abutment with magnetic attraction piece.The present application determines the center by identifying the key feature points of flat area on the contour and using the method of intersection of multiple median lines, effectively averages the error caused by local contour deformation, and the obtained center point can better represent the geometric center of the entire section under the influence of deformation, and the result is stable and accurate.

The present invention relates to the technical field of length scale measurement in the modern equipment manufacturing industry, and discloses a method for measuring the radius of the plastic zone during the nanoindentation of a strength-asymmetric material, including: obtaining the stress-strain data of the material to obtain the initial yield function and hardening function; writing a user material subroutine according to the initial yield function and hardening function of the material; performing a nanoindentation experiment on the specimen to obtain the experimental load-displacement curve of the specimen; connecting the user material subroutine to the finite element software, constructing a finite element model to simulate the nanoindentation experiment, and obtaining the simulated load-displacement curve of the indenter; comparing the displacement-load curve with the experimental load-displacement curve; determining the distances between the positions of the initial equivalent yield stress in the x and y directions and the tip of the indenter through the simulation results, and calculating the radius of the plastic zone at different indentation depths. The present invention can achieve the measurement of the radius of the plastic zone at any indentation depth, and the measurement result has high accuracy.

The invention discloses a strong shear turbulence grid adaptive simulation method coupled with a v2-f series model. The method mainly comprises the following steps of: 1, judging whether a shielding function is applied or not; step 2, identifying a self-adaptive length scale of a shear layer; 3, constructing a scale-related adjustment function based on the turbulence energy spectrum integral; 4, using an adjustment function to reconstruct the turbulence viscosity of the v2-f series model; and 5, performing turbulence simulation by using the reconstructed turbulence viscosity. According to the method, the self-adaptive sub-grid length scale of the shear layer is constructed and introduced into the initial region of the quasi-two-dimensional free shear layer, so that the sub-grid length scale of the initial region of the free shear layer is effectively reduced, and the problem that an existing RANS-LES hybrid model is highly dependent on grids is solved. The calculation accuracy is improved, meanwhile, the calculation consumption is greatly reduced, the turbulence simulation process is remarkably accelerated, and an effective numerical simulation method is provided for solving low-consumption and high-precision simulation of strong shear flow in the complex engineering flow problem.

The invention discloses a gaseous ecological network diffusion coefficient optimization method and system, and relates to the technical field of fluid mechanics, and the method comprises the steps: S1, constructing an early warning model; s2, acquiring data information in real time; s3, the turbulence suppression module performs turbulence suppression processing by using the data information; s4, analyzing the flux, and triggering an alarm according to the flux and the current Reynolds number; s5, optimizing a critical Reynolds number Recritnew and a damping length scale by using a loss function, and updating a diffusion coefficient; s6, the steps S2-S5 are cyclically repeated; a diffusion coefficient is updated through a fluid mechanics regularization theory, a'turbulence suppression-biological damping-network feedback 'ternary coupling mechanism is established, and accurate diffusion simulation and dynamic early warning under a high Reynolds number working condition are realized.