190 results about "Surface strain" patented technology

The invention relates to a lateral deviation full-bridge double-interdigital metal strain gauge capable of measuring surface strain lateral partial derivatives, which comprises a base and four sensitive grids, and is characterized in that both ends of each sensitive grid are respectively connected to an outgoing line, each sensitive grid comprises a sensitive section and a transition section, and axes of the sensitive sections are straight lines and parallelly arranged in the same plane; in the plane determined by the axes of the sensitive sections, the axis direction of the sensitive sections is an axial direction, and the direction perpendicular to the axial direction is a lateral direction; the four sensitive grids are consistent in resistance, the resistance variation amount is consistent under the same strain, the four sensitive grids are called as an upper-upper sensitive grid, an upper-lower sensitive grid, a lower-upper sensitive grid and a lower-lower sensitive grid from top to bottom along the lateral direction, the upper-upper sensitive grid and the upper-lower sensitive grid are arranged in an interdigital mode, and the lower-upper sensitive grid and the lower-lower sensitive grid are also arranged in the interdigital mode; and centers of the four sensitive grids have no deviation in the axial direction and have deviation in the lateral direction. The lateral deviation full-bridge double-interdigital metal strain gauge not only can measure the strain, but also can effectively detect a lateral first-order derivative and a lateral second-order derivative of the surface strain.

The invention discloses an axial deviation double-sensitive grid interdigital metal strain plate capable of measuring axial deviation of surface strain. The metal strain plate comprises a substrate and two sensitive grids, wherein two ends of each sensitive grid are respectively connected with a leading-out line, the two sensitive grids are fixed on the substrate, each sensitive grid comprises a sensitive section and a transition section, and the axes of all the sensitive sections are linear, parallel and within the same plane; the direction perpendicular to the axial direction which is the direction of the axes of the sensitive sections in the plane determined by the axes of the sensitive sections is a transverse direction; the two sensitive grids are consistent in resistance variation under the same strain, and are respectively a left sensitive grid and a right sensitive grid in the axial direction from left to right; and on the plane determined by the axes of the sensitive sections, the left sensitive grid and the right sensitive grid are arranged in an interdigital mode. The metal strain plate can be used for measuring strain and effectively detecting axial first-order deviation of the surface strain.

The invention provides an axial deviation full-bridge full-interdigital metal strain sheet capable of measuring a surface strain axial partial derivative. The axial deviation full-bridge full-interdigital metal strain sheet comprises a substrate and four sensitive gates. The two ends of each sensitive gate are respectively connected with a lead-out line. Each sensitive gate comprises a sensitive segment and a transition segment. The axes of all the sensitive segments are straight lines which are arranged in the same plane in parallel. Direction along the axes of the sensitive segments is an axial direction, and direction perpendicular to the axial direction is a transverse direction. The four sensitive gates are consistent in resistance and consistent in resistance variation under the same strain. The centers of the four sensitive gates are arranged in the same straight line which is parallel to the axis of any sensitive segment of the four sensitive gates. The four sensitive gates are respectively called a left sensitive gate, an intermediate left sensitive gate, an intermediate right sensitive gate and a right sensitive gate from left to right along the direction of the straight line. The centers of the four sensitive gates have deviation in the axial direction and have no deviation in the transverse direction. Any two sensitive gates are arranged in an interdigital mode. Strain can be measured and the surface strain axial first-order and second-order partial derivatives can be effectively detected further.

Methods and assemblies for the construction of liquid-phase alloy nanoparticles are presented. Particle formation is directed by molecular self-assembly and assisted by sonication. In some embodiments, eutectic gallium-indium (EGaIn) nanoparticles are formed. In these embodiments, the bulk liquid alloy is ultrasonically dispersed, fast thiolate self-assembly at the EGaIn interface protects the material against oxidation. The assembly shell has been designed to include intermolecular hydrogen bonds, which induce surface strain, assisting in cleavage of the alloy particles to the nanoscale. X-ray diffraction and TEM analyses reveal that the nanoscale particles are in an amorphous or liquid phase, with no observed faceting.

The invention is an improved process for using surface strain data to obtain real-time, operational loads data for complex structures that significantly reduces the time and cost versus current methods.

The invention provides a monitoring method for a surrounding rock and full face tunnel boring machine shield interaction process. The method comprises the steps of: A, welding and installing pressure boxes to the outer surface of a shield for testing the extrusion force applied to the shield by surrounding rocks directly, placing cables of the pressure boxes in flexible cable-protecting casing pipes, and leading the cables into the shield and connecting the cables to a reading device; B, installing a surface strain sensor in each of the annular direction and the longitudinal direction of each monitoring point on the inner surface of the shield, and inversely calculating the extrusion force applied to the shield by the surrounding rocks according to the principle of elastic mechanics based on the tested annular and longitudinal strains of the inner surface of the shield; C, according to the acquired distribution rules of the extrusion force applied to the shield by the surrounding rocks, calculating the friction force borne by the shield on the premise of linear distribution of the extrusion force between two adjacent measuring points; D, according to the jamming state judging criteria and jamming risk coefficient calculation method, calculating whether the shield is jammed and giving early warning of a jamming risk level. The method solves the problem in monitoring of surrounding rock and shield interaction in a shield type TMB tunneling process, provides basis for the predictive analysis of jamming accidents and is of great importance for the safety of TBM tunneling.

The invention discloses a triaxial test three-dimensional deformation reconstruction and measurement method and belongs to the technical field of geotechnical experiment testing. The method is characterized in that a transparent square pressure chamber is adopted, a specially-produced rubber membrane whose label can be tracked is marked, two digital cameras at the front and at the back and a corresponding image acquisition control and processing system are employed, through tracking the position change of the angle points of the rubber membrane on an image, a certain hypothesis is adopted to obtain the space coordinate of the characteristic points of the rubber membrane on the surface of a sample, and the images acquired by the two cameras at the front and at the back are spliced so that the measurement of the three-dimensional deformation of the sample during a triaxial test process is realized. Through combination with ANSYS finite element software, a three-dimensional deformation grid and a three-dimensional whole surface strain field of the sample are obtained. The method provided by the invention has the following advantages: the comprehensive deformation characteristics of the sample in the triaxial test process can be obtained from a front direction and a back direction, and the space positions of surface characteristic points in a triaxial test can be obtained for realizing reconstruction of three-dimensional deformation of the sample, and the distribution of the three-dimensional surface strain field of the sample can be obtained.

A portable optical sensor for measuring surface strain in an object, such as pre-stressed concrete articles, is provided. The sensor is a modular device comprising at least first and second modules, each of which includes a laser and image sensor. When placed adjacent to the object, the laser of each module illuminates respective, spaced-apart areas of the object's surface and each module's image sensor captures at least a portion of the light reflected from the illuminated area and generates a speckle image of the area. Speckle images of the areas taken at various times and / or under various object stress conditions are compared to arrive at a surface strain measurement for the object.

The device enables strains of at least one surface (1) of a sample (2) to be measured versus temperature. Strains in a direction perpendicular to a predetermined plane, for example the plane of the surface (1), are measured by composite images. Strains in said plane are measured by image correlation. The measurements by image correlation and by composite images use a common visible light detection camera (3). The sample (2) is arranged in an enclosure (6) transparent at least locally to visible light (L). At least one infrared emitter (9) enables an infrared light to be created in a spectral band for a large part not detected by the camera (3).

The current invention relates to optical gages designed to measure strain on the surface of a test specimen. The gages of this invention is designed to be installed and used in a manner similar to conventional electronic foil strain gages, but to have the advantages of an all-optical gage. The gage of this invention is constructed to allow surface strain on the test specimen to be transferred to a length of optical fiber containing a fiber Bragg grating (FBG). As strain is applied to the fiber, the optical spectrum center wavelength reflected by the Bragg grating shifts in wavelength. This shift in wavelength can be converted directly to units of strain. The current invention provides a gage carrier design for use with fiber optic strain sensors comprising one or more FBGs which provide the benefits of a carrier for ease of handling and mounting without degrading gage performance. The gage carrier provides features that allow the FBG to be precisely positioned and securely bonded to the test specimen in a controlled manner. The carrier additionally provides fiber protection to the installed FBG.

The invention relates to a method for determining a coefficient of thermal expansion. The method comprises the steps of determining a spectral peak movement amount of a to-be-detected sample caused by the variation of unit temperature to be recorded as ChiF; mixing the detected sample and polymer to obtain a mixture, and ultrasonically dispersing the mixture to obtain a composite material; determining a second spectral value of the composite material under a surface strain value by utilizing a strain determining device and a spectral system, linearly fitting the surface strain value and the second spectral value, determining the spectral peak movement quantity of the detected sample, which is caused by the unit strain and is parallel to the strain direction to be recorded as SO; determining the spectral peak movement amount of the detected sample in the composite material caused by the unit temperature variation by utilizing the spectral system to be recorded as ChiC; calculating the coefficient of the thermal expansion of the detected sample according to the following formula if the coefficient alpha E of the polymer is known: alpha F=alpha E-(ChiC-ChiF) / SO. The method is simple, convenient in determination and capable of rapidly and accurately determining the coefficient of the thermal expansion of the detected sample.

The present invention relates to a high-speed dynamic vehicle overload detection method based on bridge strain, belonging to the field of detection technology. Said invention uses strain sensor as field sensing device to measure bridge surface strain due to running vehicle, and utilizes integral operation to eliminate the influence of vehicle vibration on the calculated result so as to further obtain load weight value, then utilizes aid load weight value to compare it with standard load weight value pre-stored in data base so as to judge overload of said vehicle.

The invention discloses a method for calculating a work load based on beam surface strain values measured by optical fiber sensors, and aims to utilizing an optical fiber Bragg grating (FBG) technology to measure the beam surface internal strain values and then obtain real-time planar applied bending or torsion work load data. According to the invention, FBG strain sensors are utilized and are pasted on a beam structure at certain intervals, so that the beam is divided into a plurality of regions. By adopting the method, the torque, the bending moment and the shearing force of the cross section where the optical fiber sensor is arranged are calculated, and then the work load value of the region is calculated by utilizing the shearing forces of two adjacent cross sections. Specific embodiment schemes are provided by invention for verifying the precision of the method. Compared with other methods for measuring the work load of the beam in the prior art, the method provided by the invention is interference resistant, time-saving, cost-saving and high in efficiency.

The invention discloses a method of detecting the asphalt pavement structure damage based on fiber grating sensors. The method comprises the following steps: 1) fixedly installing one or more fiber grating sensors on the surface of a rut sample; 2) setting test parameters for accelerating loading, simulating the formation of a rut trough accelerating loading tests and monitoring the fiber grating sensors in real time; 3) monitor strain values of the fiber grating sensors and making the relation curve graph between the number of load and the surface strain values of the sample; and 4) performing the sample structure damage analysis, that is, analyzing the deformation and damage degree of the sample through the surface strain values. The method for detecting the asphalt pavement structure damage is simple in operation and high in feasibility, and is of great theoretical significance on the design and maintenance of pavement structures. The surface fiber grating strain sensors are adopted to monitor the asphalt pavement strain response. The process is simple, implementation is easy, and recycling is realized.

The invention discloses an artificial culture method of Zn-enriched cordyceps militaris mycelia and a culture medium thereof; according to weight percentage, the formulation components of the culture medium comprise: 1.0 to 3.0 percent of glucose, 0.5 to 1.0 percent of peptone, 0.1 to 1.0 percent of yeast extract, 1.0 to 2.0 percent of agar powder and the rest of water, and the pH value of the culture medium is 5.0 to 7.5. The artificial culture method comprises the steps of test tube slant surface strain culture (activation), test tube liquid strain culture, triangular flask liquid seed culture, seeding tank culture, fermenter culture, plate-frame filtration, crashing, drying in vacuum, crashing and leading the mycelia into powder. The operation is simple, the culture period is short, the yield of mycelia is high, no pollution and waste are produced, and the method has the function of supplementing zinc, thus being capable of carrying out industrial production.

The invention provides a transverse deviation double sensitive gate interdigital metal strain sheet capable of measuring a surface strain transverse partial derivative. The transverse deviation double sensitive gate interdigital metal strain sheet comprises a substrate and two sensitive gates. The two ends of each sensitive gate are respectively connected with a lead-out line. The two sensitive gates are fixed on the substrate. Each sensitive gate comprises a sensitive segment and a transition segment. The axes of all the sensitive segments are straight lines which are arranged in the same plane in parallel. In the plane determined by the axes of the sensitive segments, direction along the axes of the sensitive segments is an axial direction, and direction perpendicular to the axial direction is a transverse direction. The two sensitive gates are consistent in resistance and consistent in resistance variation under the same strain, and the two sensitive gates are respectively called an upper sensitive gate and a lower sensitive gate from the top to the bottom along the transverse direction. In the plane determined by the axes of all the sensitive segments, the upper sensitive gate and the lower sensitive gate are arranged in an interdigital mode. The centers of the two sensitive gates have no deviation in the axial direction and have deviation in the transverse direction. Strain can be measured and the surface strain transverse first-order partial derivative can be effectively detected further.

The invention discloses a label, a system and an application method for measuring surface strain of a metal component. In order to break through active and wire limitations in the traditional strain sensor, an RFID (radio frequency identification) technology is used to provide a new idea for designing the strain sensor, and non-contact strain measurement without an external wire power supply can be realized. The RFID system used for measuring the surface strain of the metal component consists of a reader and the label used for measuring the surface strain of the metal component, wherein the label used for measuring the surface strain of the metal component is fixed to the to-be-measured metal component, and comprises an RFID antenna and a chip; the RFID antenna comprises an upper radiation paster, a lower radiation paster, a dielectric plate and a matching wire; the label is adhered to the metal surface of the to-be-measured metal component through the lower radiation paster of the RFID antenna; and the chip is connected with the upper radiation paster and the lower radiation paster through the matching wire.

The invention provides a method for improving the intensity of a metal material. The method comprises the following steps of: selecting the metal material, of which the plastic deformation is guided by twin crystal deformation or phase change; twisting the metal material, so that surface strain generated by the metal material meets predetermined conditions. According to the method provided by the invention, the intensity of the metal material can be improved observably without influences on the tension toughness of the metal material.

The invention provides a device for testing a three-dimensional strain state inside a soil mass. Six common strain gauges of the device are sequentially fixed onto strain gauge bases on six surfaces with uncorrelated normal vectors of a rhombic dodecahedron, and lead holes leading to the center of the rhombic dodecahedron are formed in centers of the six surfaces with the uncorrelated normal vectors of the rhombic dodecahedron and connected with a data acquisition system through measuring leads. Besides, the invention further provides a testing method of the device for testing the three-dimensional strain state inside the soil mass. The device has the advantages that the three-dimensional strain state of a certain position of the soil mass is more accurately tested, linear strain in a maximum main strain direction can be obtained, among six strain gauge testing values, testing precision of three main strain gauges is 1.22 rho, testing precision of three shearing strain gauges is 0.71 rho, average testing precision is 0.97 rho, strain gauge testing precision in a single direction is improved, and the limitation of only testing surface strain at inaccurate testing positions in the past is changed. The device visually reflects the deformation state inside the soil mass, and safety stock of engineering construction is improved.

The sugar quaternary ammonium salt positive ion surface active agent is made of C6-C18 long chain alkyl chain marked by R and halide marked by X. It has good surface activeness, effectively reduced in water surface strain, releasing the fiber surface charge effectively, particularly the lactin quaternary ammonium salt, being able to reduce the half-decay time of the friction static voltage of fabrics to 4s when the volume mass being 5g / L. It is novel in structure, with material getting from natural sugar.

The described embodiment relates generally to the field of press-fit technology. Press-fit technology results in deformation of one component to lock another component in place. This deformation commonly causes surface strain to occur on the deforming component. When a component is anodized surface strain can result in anodization cracking; this ruins the finished appearance of cosmetic surfaces, generally resulting in ghosting lines and splotches appearing on the surface of a component. The described embodiment achieves a careful balance between component deformation and surface strain. By utilizing specific press-fit geometries and assembly methods, surface strain can be sufficiently limited to eliminate anodization cracking while also achieving a durable press-fit joint.

A method of predicting sheet formability at a microscale level includes the steps of providing a grid pattern on a test sheet, bulging the test sheet to a hemispherical shape until a crack is initiated on the surface of the test sheet, detecting the initiation of the crack, acquiring two images of the surface adjacent to the crack and calculating surface strains on the test sheet.

A press-forming device has a punch (2), a die (7) which relatively moves with respect to the punch (2), a strain amount measuring means (8) which is provided inside a member to be controlled and measures a strain amount of the aforesaid member to be controlled which occurs in accordance with press-forming, when at least one of the punch (2) and the die (7) is made the aforesaid member to be controlled, and a strain amount control means (9) which is provided in the aforesaid member to be controlled and controls the strain amount of the aforesaid member to be controlled which occurs in accordance with press-forming. The strain amount control means (9) controls a drive amount of the aforesaid member to be controlled so that the strain amount measured by the strain amount measuring means (8) is in a predetermined range during forming. Thereby, reduction in a surface strain, improvement in shape fixability or the like of a press formed product can be achieved.

The invention provides a battery fire early warning system and method. A first detector is used for detecting electrolyte or carbon cigarette pellets and the like released when battery cells are aboutto or already cause thermal runaway. A second detector is used for detecting shape change when multiple battery cells are about to or already cause thermal runaway. A third detector is used for detecting the vibration frequency of noise generated by air jet in the battery ejection process when the multiple battery cells are about to or already cause thermal runaway. Each of fourth detectors is used for detecting temperature or surface strain force on the surface of each battery cell, or extrusion force change between two adjacent battery cells. According to the battery fire early warning system, battery fire early warning can be realized from multiple aspects such as images, gas, sound, temperature, surface stress, extrusion force and the like, false alarm or missing alarm of fire is avoided, the safety of the battery in the fire early warning aspect is improved, and the losses of life and property are avoided.

The invention discloses a method of adopting a strain sensor to monitor the fatigue of nuclear grade pipelines. At first, a strain sensor (a strain sheet or a strain meter) is used to monitor the strain of the external surface of a nuclear grade pipeline; then according to the external surface strain of the nuclear grade pipeline, the properties of the material of the nuclear grade pipeline, and information of an existed monitoring device of the nuclear power plant, the strain of the internal wall of the nuclear grade pipeline can be determined; then alternation amplitude in strain circulations and corresponding circulation times can be determined; according to a preset epsilon-N curve, the fatigue use coefficient is calculated; then according to the pipeline strain history, the reasonable environmental influence coefficient (Fen) is determined, the fatigue use coefficient is corrected; finally, the fatigue use coefficient is output on the display terminal of the master-control room, and an accumulated fatigue use coefficient curve, which changes along the time, can be outputted and can be used to evaluate the change trend of accumulated fatigue use coefficient of a monitored position.

The invention discloses a final layer failure-based strength prediction method for a composite laminated plate with uncertain parameters. The method comprises the steps of (1) obtaining mechanical property distribution characteristic parameters and numeric simulation sample points of a single-layer plate according to a composite material mechanics test; (2) starting a loop, and calculating a stiffness conversion matrix of the single-layer plate by utilizing a stiffness matrix and a ply angle; (3) calculating stretching, coupling and bending stiffness of the laminated plate according to a laminated plate constitution form; (4) calculating a surface strain in the laminated plate and a main stress of the single-layer plate based on a constitutive equation; (5) substituting the main stress into a failure criterion to calculate a strength ratio, and performing performance degradation on a single-layer plate corresponding to a minimum strength ratio; (6) repeating the steps (2) to (5), stopping calculation until the strength ratio is less than 1, and outputting final layer failure strength; and (7) repeating the steps (2) to (6) until the loop is finished so as to obtain a strength distribution range of the laminated plate. According to the method, a final layer failure strength distribution characteristic of the laminated plate with the uncertain parameters can be effectively predicted.

The invention relates to an FLC (full-load current) testing method based on the variation of a strain rate. The method comprises the following steps: acquiring a surface strain distribution cloud chart of a test sample; exporting epsilon(t) of each location point; calculating a strain rate of the point-in-time on each location point epsilon(t) to form (described in the specification), calculating a first derivative value of the strain rate of each point-in-time on (described in the specification), and recording the point-in-time corresponding to the moment when a negative value or a maximum value first appears in the first derivative value as t1; repeating the steps to obtain t2 to tn; comparing the values of t1 to tn, adopting the point-in-time with the value being most repeated as a moment t0 when the test sample begins to be necked, finding out an epsilon major and a corresponding epsilon minor in the test sample necking area on the surface strain distribution cloud chart at the moment t-1, wherein the epsilon major and the corresponding epsilon minor are used as a limiting strain point of the material; repeating the steps to obtain 5 to 8 limiting strain points; marking the limiting strain points on a main / secondary strain plane, and connecting the limit strain points to obtain the FLC. By adopting the method, the influence caused by a cross-section strain distribution pattern can be effectively avoided, and the accurate and reliable FLC can be acquired.

The invention relates to a tunnel supporting structure stress monitoring device and method. The tunnel supporting structure stress monitoring device comprises a reinforcing steel bar strain gauge (11), a first soil pressure gauge (12), a first concrete strain gauge (13), a surface strain gauge (14), a second soil pressure gauge (21) and a second concrete strain gauge (22), wherein the reinforcing steel bar strain gauge (11) monitors anchor rod strain, the first soil pressure gauge (12) monitors the contact pressure between a primary supporting and surrounding rock, the first concrete strain gauge (13) monitors the annular strain of sprayed concrete, the surface strain gauge (14) monitors the axial strain of structural steel, the second soil pressure gauge (21) monitors the contact pressure between a secondary lining and the primary supporting, and the second concrete strain gauge (22) monitors the annular strain of secondary lining concrete. Compared with the prior art, the tunnel supporting structure stress monitoring device has the advantages that the device is reasonable in embedding position, measuring results can be mutually verified and corrected, and the accuracy and reliability of the measuring results are increased.