23 results about "Strain gradient" patented technology

The invention relates to an intelligent soft rock tunnel surrounding rock deformation automatic monitoring and early warning system, and belongs to the field of tunnel construction safety monitoring. According to the system, multi-source data of surrounding rocks are synchronously acquired through a micron-sized laser displacement sensor, a fiber grating strain sensor, a pore water pressure sensor and a three-dimensional micro-seismic sensor array which are distributed; the edge calculation node fuses the data in real time and calculates the displacement rate, the strain gradient and the osmotic pressure coupling coefficient, and local early warning is triggered in combination with a dynamic threshold value; the cloud early warning platform predicts a deformation trend based on an LSTM-Transform fusion model, generates a multi-stage early warning signal through a risk grading engine, and is linked with the supporting equipment to regulate and control pressure; and meanwhile, a self-calibration device, an explosion-proof shell and a piezoelectric-thermal energy self-powered system are integrated. According to the method, closed-loop control from millimeter-level deformation sensing to active supporting can be achieved, and tunnel construction safety is remarkably improved.

The invention provides a blasting vibration waveform feature extraction and damage range intelligent calibration system. The method comprises the following steps: calculating a waveform irregularity sequence based on original vibration waveform data; then, a fiber grating sensor network is used for collecting strain vibration waves on the surface of the structure, and spatial distribution information of the strain change rate of the structure is mapped into a feature enhancement channel; learning a feature distribution mode based on the waveform data processed by the feature enhancement channel by using a coding and decoding structure, and performing reconstruction operation on the current blasting vibration waveform according to the feature distribution mode; identifying and amplifying abnormal feature differences by comparing an actual waveform irregularity sequence with a reconstruction sequence, and generating reconstruction error peak distribution; and finally, when the strain gradient abrupt change point position detected by the optical fiber sensor network is overlapped with the reconstruction error peak point space, generating a blasting damage area thermodynamic diagram based on the overlapped point space density. The precision and reliability of blasting damage range calibration are improved.

The invention provides an underwater vehicle measuring point layout optimization method and system, and belongs to the technical field of experimental measuring point layout optimization. Comprising the following steps: obtaining simulation data of an underwater vehicle structure through finite element simulation, and extracting strain data of a unit capable of arranging a strain gauge area according to actual engineering constraints; centroid coordinates of the units, sensitivity values of strain response values relative to working conditions and strain gradients are calculated by taking centroids of the units in the areas where the strain gauges can be arranged as nodes; mapping the strain response values of all the nodes to a unified interval to obtain a normalized strain response value; obtaining sensitivity coverage and strain gradient coverage, and calculating space coverage of all nodes; integrating the normalized strain response value, sensitivity coverage, strain gradient coverage and space coverage as optimization indexes, and performing optimization by adopting an improved discrete artificial bee colony algorithm; and a final layout scheme is decided by outputting the relationship between the number of the measuring points and the information amount.

The application belongs to the technical field of load identification of structural health monitoring, and provides a concentrated load positioning method based on principal stress constraint and strain gradient trajectory identification, which comprises the following steps: arranging strain sensors in a monitoring area of a planar structure plate and collecting strain data of measuring points, constructing a strain field inversion function based on a radial basis function and establishing an error optimization function containing a fitting error term and a smooth constraint, introducing a principal stress direction constraint and a gradient projection smooth constraint to form a comprehensive error function and solving to obtain an optimal strain field distribution, then calculating strain gradient vectors of each grid node and tracking a gradient trajectory through a gradient descent method, and finally performing an iterative clustering analysis based on distance statistics on a trajectory end point to output a cluster center as a concentrated load application position identification result. The application can improve the concentrated load positioning accuracy, enhance the anti-noise capability, and realize fast, stable and large-sample-free load position identification.

The invention relates to a surrounding rock loose area monitoring method and system based on optical fiber anchor rod strain, and the method comprises the steps: carrying out the temperature compensation of strain distribution information according to the temperature distribution information, and obtaining the real anchor rod strain distribution data; analyzing axial force distribution and shearing force distribution of the anchor rod according to the strain distribution data of the anchor rod, and constructing a section shearing stress distribution model; according to the shear stress distribution model of the anchor rod, analyzing the strain gradient distribution along the axial direction of the anchor rod; according to the axial force distribution and the strain gradient distribution, a loose area boundary identification model is constructed, the strain abrupt change point position of the anchor rod is determined, and the interface of the surrounding rock loose area and the elastic area is represented through the strain abrupt change point; and connecting the strain mutation points of the anchor rods to form a boundary contour line of the surrounding rock loosening area, and measuring the range of the surrounding rock loosening area. According to the scheme provided by the invention, high-precision positioning and dynamic tracking of the surrounding rock loose area boundary and dynamic optimization of tunnel supporting structure design can be realized.

The application provides a blasting vibration waveform feature extraction and damage range intelligent calibration system. In the application, a waveform irregularity sequence is calculated based on original vibration waveform data; then, a structure surface strain vibration wave is collected by a fiber grating sensor network, and the spatial distribution information of the strain change rate is mapped to a feature enhancement channel; then, a coding and decoding structure is used to learn a feature distribution pattern based on the processed waveform data of the feature enhancement channel, and a reconstruction operation is performed on the current blasting vibration waveform accordingly; by comparing the actual waveform irregularity sequence with the reconstructed sequence, an amplified abnormal feature difference is identified, and a reconstructed error peak value distribution is generated; finally, when the strain gradient mutation point position detected by the fiber sensor network and the reconstructed error peak point space coincide, a blasting damage area heat map is generated based on the coincidence point space density. The application improves the accuracy and reliability of blasting damage range calibration.

This utility model discloses a mechanical strengthening device for the inner wall surface of a pipe, including a strengthening tool assembly and a machine tool body. The strengthening tool assembly includes a cutting head capable of penetrating deep into the pipe; the cutting head is configured to fit against the inner wall of the pipe, thereby generating a strain gradient on the inner wall surface. The machine tool body includes a feed assembly and a rotating assembly for mounting the pipe and driving the pipe to rotate around its axis. The feed assembly drives the strengthening tool assembly to feed along the axial direction of the pipe. In the mechanical strengthening device for the inner wall surface of the pipe provided in this application, the rotating assembly drives the pipe to rotate, and when the strengthening tool assembly feeds into the inner wall of the pipe, the cutting head acts on the inner wall of the pipe, causing a strain gradient to be generated on the inner wall surface. Therefore, the mechanical strengthening device for the inner wall surface of the pipe provided in this application achieves the strengthening of the inner wall of the pipe.

The invention belongs to the technical field of load identification for structural health monitoring, and provides a concentrated load positioning method based on principal stress constraint and strain gradient trajectory identification, which comprises the following steps: arranging a strain sensor in a plane structure plate monitoring area and collecting strain data of a measuring point; and constructing a strain field inversion function based on a radial basis function, establishing an error optimization function containing a fitting error term and a smooth constraint, introducing a principal stress direction constraint and a gradient projection smooth constraint to form a comprehensive error function, and solving to obtain optimal strain field distribution. And further calculating a strain gradient vector of each grid node, tracking a gradient trajectory through a gradient descent method, finally carrying out iterative clustering analysis based on distance statistics on a trajectory end point, and outputting a cluster center as a concentrated load application position identification result. According to the method, the concentrated load positioning precision can be improved, the anti-noise capability is enhanced, and rapid and stable load position identification without a large number of training samples is realized.

The invention provides a bearing capacity assessment method for a safety handrail manufacturing process based on an industrial internet of things, and the method comprises the steps: reading a groove spacing between adjacent knurling grooves according to a texture depth value, dividing the groove spacing by the texture depth value to obtain a groove spacing depth ratio, and recognizing a knurling section with the groove spacing depth ratio lower than a safety threshold value as a stress superposition risk section; extracting an energy peak value of an acoustic emission signal in the stress superposition risk section and a maximum strain gradient in the pipe wall strain distribution data, and performing weighted fusion to obtain groove root stress superposition strength; extracting position coordinates of each measuring point entering yield for the first time from the strain distribution data, and identifying a transformation degree of a yield initial position from random distribution to linear arrangement along the knurling groove bottom by adopting a support vector machine classification algorithm to obtain a yield position concentration ratio; and according to the yield position concentration ratio and the groove root stress superposition strength, dividing a damage grade corresponding to the texture depth value, and marking the knurled section with the damage grade exceeding a preset warning grade as the initial position of the weak section.

The application relates to the technical field of image processing, and discloses a kind of tubular element pressure edge abnormality identification method, the application gradient pressure load is applied to tubular element and surface image sequence and distributed strain signal are acquired synchronously;With distributed strain signal as boundary constraint correction original displacement field, the displacement solving precision of annular edge curved surface position is optimized;Synchronous extraction strain gradient and profile curvature variation, realize the collaborative analysis of mechanical deformation characteristics and geometric feature, identify the mechanical anomaly induced by stress concentration, and capture the profile distortion caused by slight deformation;Construct space-time characteristics and execute three-dimensional Gaussian filtering processing, improve the identifiable degree of weak edge abnormality and early implicit anomaly;Through response change rate and area comprehensive determination, improve the objectivity, stability and anti-interference ability of edge abnormality determination, reduce the misjudgment and missed judgment probability in industrial detection process.

The invention discloses a sound box part quality detection method and system, and relates to the technical field of automatic detection. The method is used for solving the problem that defects such as potential fatigue risk and voice coil offset of a loudspeaker box structural member are difficult to identify and regulate early. The method comprises the following steps: firstly, synchronously acquiring multi-source signals through a vibration sensor, a laser vibration meter and a microphone, and constructing a coupling matrix containing vibration energy, strain gradient and harmonic characteristics; then, based on an S-N curve and thermal-mechanical coupling simulation, calculating a fatigue damage index of temperature compensation, and outputting a material fatigue risk label; multi-scale deformation and transient impact characteristics are extracted in combination with a graph attention and self-attention mechanism, and a voice coil offset direction and an amplitude interval are predicted in combination with sound pressure harmonics and thermal compensation information. Finally, the composite defect grade is judged through a dynamic threshold value strategy and fed back to a process control module, a limiting and current adjusting strategy is executed, a quality detection and parameter optimization closed-loop system is constructed, and the detection precision and the structural reliability are improved.

The application discloses a gradient structure Ag / FeMnCrNi layered composite material and a preparation method, and belongs to the field of metal surface modification. The layered composite material comprises Ag layers and FeMnCrNi layers arranged alternately, the thickness of the Ag layers and the FeMnCrNi layers in one modulation period is the same, and the thickness of the Ag layers and the FeMnCrNi layers in each modulation period is gradiently increased. The Ag layers and the FeMnCrNi layers are alternately deposited by direct current magnetron sputtering using an Ag target and a FeMnCrNi target to obtain the gradient structure Ag / FeMnCrNi composite material. The method utilizes the design idea of the multi-scale gradient non-uniform structure, combines the multi-principal element effect of the HEA with the constraint effect of the gradient layer interfacial heterogeneity, constructs a soft and hard heterostructure gradient, and in the plastic deformation process, the strain gradient is generated due to the different deformations of the soft and hard components, new dislocation structures are activated, the mechanical behavior of the whole metal layered composite material is affected, and finally the breakthrough of the mechanical properties is realized.

The invention relates to the field of metal plastic processing, and discloses a high-toughness aluminum alloy foil embossing treatment process which comprises the following steps: pretreating the surface of an aluminum alloy foil to obtain a clean surface; and a gradient insulating layer with the thickness in macroscopic continuous gradient change is formed on the clean surface, wherein the thickness gradient direction of the insulating layer is matched with the expected strain gradient direction on the foil during embossing forming. According to the invention, through the cooperation of the gradient insulating layer and the programmed pulse current, selective electroplastic treatment is carried out on a high-strain area in the embossing process. Through the treatment, the material is locally subjected to dynamic recovery, the plastic deformation capacity is improved, and therefore the area which deforms most severely and is prone to cracking is directly strengthened. As a result, on the premise that the overall strength of the material does not need to be excessively sacrificed, generation of microcracks is effectively restrained, and the limit depth-to-width ratio of aluminum alloy foil embossing and the forming success rate of complex patterns are increased.

The present invention detects the presence or absence of an internal rear surface structure which cannot be visually observed from the front surface of an object to be measured, and estimates the size of the internal rear surface structure.　This detection device detects an internal rear surface structure including at least one among a hollow portion that can exist inside an object to be measured and a notch portion that can exist in the rear surface of the object to be measured. The detection device comprises: an image acquisition unit that acquires images obtained by imaging the object to be measured before and after deformation; a strain distribution calculation unit that calculates a strain distribution on the front surface of the object to be measured by comparing and analyzing the images obtained by imaging the object to be measured before and after deformation; a strain gradient distribution calculation unit that calculates a strain gradient distribution by differentiating the calculated strain distribution in a distance direction; and an internal rear surface structure detection unit that estimates the size of the internal rear surface structure by analyzing the calculated strain gradient distribution.

The embodiment of the application provides a constitutive model calibration method of an anisotropic tension-compression asymmetric material, which improves the description ability of complex mechanical behaviors of the anisotropic tension-compression asymmetric material by coupling the constitutive model of anisotropic yield, nonlinear hardening and elastic modulus degradation. A gradient-enhanced physical information neural network is further introduced as a parameter automatic calibration tool, which can simultaneously and accurately identify the anisotropic parameters, nonlinear hardening parameters and modulus degradation parameters in the model which are strongly coupled and difficult to separate by embedding the physical control equation and the stress-strain gradient relationship of the constitutive model as constraints into network training under the condition of only requiring limited experimental data. The method effectively overcomes the inherent defects of the traditional calibration method, such as the serious dependence on a large number of repeated tests and the poor physical consistency in the parameter identification process, and improves the efficiency and reliability of simulation-driven design.

The application relates to a surrounding rock loose zone monitoring method and system based on optical fiber anchor rod strain, which comprises the following steps: temperature compensation is performed on strain distribution information according to temperature distribution information, and real anchor rod strain distribution data are obtained; the axial force distribution and the shear force distribution of the anchor rod are analyzed according to the anchor rod strain distribution data, and a cross-section shear stress distribution model is constructed; the strain gradient distribution along the axial direction of the anchor rod is analyzed according to the anchor rod shear stress distribution model; a loose zone boundary identification model is constructed according to the axial force distribution and the strain gradient distribution, the strain mutation point position of the anchor rod is determined, the surrounding rock loose zone and the elastic zone are characterized by the strain mutation point, the strain mutation points of the anchor rods are connected, the boundary contour line of the surrounding rock loose zone is formed, and the range of the surrounding rock loose zone is determined. The scheme provided by the application can realize high-precision positioning, dynamic tracking of the surrounding rock loose zone boundary and dynamic optimization of a tunnel supporting structure design.

The application discloses a magnetic refrigeration material with a wide working temperature range and a preparation method and application thereof. The magnetic refrigeration material is a wrinkled alloy film with a non-uniform strain gradient. The wrinkled alloy film with the non-uniform strain gradient is obtained by transferring the alloy film. The wrinkled alloy film has an extremely wide working temperature range as the magnetic refrigeration material. The application utilizes the different expansion coefficients and weak van der Waals interaction between the alloy film and a NaCl substrate, so that the film presents a self-supporting wrinkled morphology on the substrate. The film with the wrinkled morphology is simple in preparation process and can be easily separated from the substrate while the wrinkled morphology is reserved to obtain the wrinkled film. After the non-uniform strain gradient is introduced, the saturation magnetization of the wrinkled film under the wide temperature range is significantly improved compared with the bulk alloy and the flat film. Meanwhile, the magnetic entropy change result shows that the wrinkled film as the magnetic refrigeration material has an extremely wide working temperature range, and the magnetic refrigeration capacity of the wrinkled film is much higher than that of the bulk alloy and the flat film.

The invention discloses a heat-conducting interface material based on a flexoelectric effect, a preparation method and an application method, the heat-conducting interface material is a composite film, and is formed by compounding a flexible polymer matrix and particles which are dispersed in the flexible polymer matrix and have obvious flexoelectric response, the heat conduction interface material is configured as follows: when the heat conduction interface material is arranged between a heat source and a cold source with temperature difference, the temperature difference induces local strain gradient to be generated in the heat conduction interface material, the local strain gradient excites the flexoelectric response particles to generate a flexoelectric effect, and a flexoelectric polarization field is generated in the composite film; the flexoelectric polarization field is used for changing the electrostatic potential and force constant distribution at the interface of the heat conduction interface material and the heat source and / or the cold source so as to reconstruct the phonon dispersion relation and improve the phonon mode matching and transmissivity, so that the interface thermal resistance is reduced, and the heat dissipation performance is improved.

The invention relates to a surrounding rock real large deformation reconstruction method based on an optical fiber interface slippage mechanism. The method comprises the following steps: firstly, acquiring an axial strain curve of an optical fiber, performing spatial differential based on the curve, and calculating an interface shear stress borne by a strain gradient field and the optical fiber; then, a plastic slippage area is identified based on the strain gradient field, the interface shear stress, the preset ultimate shear strength and the residual sliding friction stress; then, calculating the slip compensation amount of the plastic slip area based on a friction force mechanical model; and finally, distributing the slip compensation amount to the center of the plastic slip area, and correcting a real surrounding rock strain peak value. According to the method, failure data can be changed into effective data, real deformation information of the rock mass can be mined from the data which seems to be distorted by utilizing the friction mechanical characteristics after sliding, and the effective service life of a monitoring system in the damage stage is greatly prolonged. The interface damage degree is quantified, and a basis is provided for evaluating the anchoring quality of a supporting structure.

The invention relates to the technical field of pile foundation construction, in particular to a pile foundation construction quality monitoring method based on multi-data fusion, which comprises the following steps of: establishing a local coordinate system by taking a pile foundation construction position as an original point, and collecting pile foundation position coordinates of each pile foundation during construction; according to the value conditions of the same pile foundation at multiple time points, construction deviation corresponding to the position coordinates of the pile foundation is calculated, and an abnormal area corresponding to the construction deviation is calculated by taking a construction abnormal point as a checking object; associating the abnormal region of the construction deviation with a strain value, performing spatial integration by using a strain gradient, and configuring a construction feature cluster under spatial evolution; performing multi-level condition judgment on each pile body by utilizing the construction characteristic cluster, and outputting a quality description label corresponding to each pile foundation; and on the basis of the quality description labels of all the pile foundations, the construction positions of the pile foundations are reset, and parameters of next-time construction are adjusted according to the hierarchical conditions related to the quality description labels. Accuracy and efficiency of pile foundation construction monitoring are achieved.

This invention relates to the field of geotechnical engineering, and in particular to a method for controlling cracks in bedrock-constrained concrete based on strain gradient design. Within a range of 0-0.5m from the bedrock surface, each meter... 3 Add 45kg-75kg of rubber aggregate and 5kg of basalt fiber to the concrete, replacing 200kg-400kg of fine aggregate while maintaining the same concrete volume; within a range of 0.5m-1.0m from the bedrock surface, per m 3 Add 15kg-35kg of rubber aggregate and 5kg of basalt fiber to the concrete, replacing 80kg-200kg of fine aggregate; within 1.0m-1.5m of the bedrock surface, per m 3 Add 5kg-10kg of rubber aggregate and 5kg of basalt fiber to the concrete, replacing 40kg-75kg of fine aggregate; from 1.5m away from the bedrock to the top of the concrete, for every 0.5m beyond that, increase the amount of rubber aggregate added to the concrete by 1kg per m³. 3 Add 5 kg of rubber aggregate to the concrete, gradually decreasing it by 30% each time, replacing the weight of sand in the concrete mix proportion, until the top of the concrete contains 0 kg of rubber aggregate.

The invention discloses a polymer composite TIM heterogeneous interface heat conduction multi-scale simulation method based on strain gradient response, which adopts parameter transfer to realize cross-scale calculation, and sequentially comprises the following steps of: (1) calculating phonon properties and electric polarization properties of a polymer composite TIM heterogeneous interface on the basis of a first principle under a micro scale, obtaining a force constant matrix and phonon state density and polarization intensity of materials on two sides of an interface; (2) under a mesoscale, based on a machine learning potential function, performing unbalanced molecular dynamics simulation to obtain thermal conductivity, thermal boundary resistance and phonon work quantity spectral density of the polymer composite TIM heterogeneous surface; and (3) under the macroscale, establishing a finite element analysis model which comprises a heat source, a TIM and a cold source, and performing temperature field and heat flux density calculation on the finite element analysis model. Through a'parameter transfer 'strategy, the spanning from the quantum mechanics scale to the continuous medium scale is realized, the limitation of a single-scale method is overcome, and the calculation precision and the simulation scale are both considered.

The invention relates to the technical field of micro-nano ultrasonic transducers, and discloses a two-dimensional material-based flexoelectric micro-nano ultrasonic transducer structure, which comprises a substrate layer, a lower electrode layer, a flexoelectric layer and an upper electrode layer which are sequentially arranged from bottom to top to form a four-layer stacked framework, the lower electrode layer is made of a two-dimensional material, and the flexoelectric layer is made of a two-dimensional flexoelectric material; the flexoelectric layer is made of two-dimensional flexoelectric materials, the two-dimensional flexoelectric materials can be selected in various types, when the flexoelectric layer is subjected to mechanical vibration to generate a strain gradient, positive and negative charge centers in the layer can deviate to form remarkable electric polarization, the polarization cannot be counteracted due to strain symmetry of a single-layer structure, a bottom lining layer does not need to be added, and the cost is reduced. Therefore, the overall structure is simplified, production process steps are reduced, and the production cost is reduced. The vibration of the nanoscale structure can cause a high strain gradient field, so that strong flexoelectric response and high transduction efficiency are induced, and the high responsivity of the transducer is ensured.