302 results about "Stress measures" patented technology

The invention discloses a system for testing a physical model for large-scale landslides under the action of multiple factors, which comprises a reservoir level fluctuation simulation unit, a landslide experiment slot section, an artificial rainfall simulation unit and a measuring unit, wherein the landslide experiment slot section comprises a horizontal slot section and a slope slot section, the horizontal slot section and the slope slot section are respectively paved with a slope body consisting of sand-soil mixtures, and the rear end of the horizontal slot section is hinged with the front end of the slope slot section; the slope slot section is composed of more than two slot sections which are sequentially hinged end to end, and the bottom of each slot section is provided with a lifting unit which can adjust the dip angle of the slot section; the rear end of the slope slot section is provided with a Malpighian-tube rear-edge water-replenishing unit; and the measuring unit comprises a deformation measuring part and a stress measuring part, wherein the deformation measuring part is used for measuring the deformation process of the slope body, and the stress measuring part is used for measuring the water pressure and water content of a pore of the slope body. By using the system disclosed by the invention, the changing regularity of each measurable physical quantity of a landslide in different development stages can be grasped accurately, thereby providing a possibility for better developing the studies on key parameters of landslides in different evolution stages.

Apparatuses and methods for measuring stress or strain in a conductive material without physical contact with the material are provided. The device comprises an inductor circuit configured to induce an alternating current into the material along a first path; and a detector configured to detect a signal representative of the stress in the material along the first path when current is induced in the material.

A method for preparing calibration test sample of X ray stress measurement includes removing phenomenon of crystal particle coarsening and crystal face preferred orientation, carrying out short blasting treatment for semiproduct of the sample, stripping layer by layer for portion with greater stress gradient by electrochemical corrosion, carrying out X ray stress measurement and calibrating out work surface of the sample by utilizing relation curve of stress to layer depth.

The invention provides a stress measuring device with higher precision, which can measure the size, direction and distribution of the stress of optical glass. The stress measuring device of the optical glass comprises a communicated light path interferometer and a stander, wherein the stander comprises a frame and a plane scanning test platform arranged on the frame; and a laser receiving unit and a laser emitting unit of the communicated light path interferometer are arranged on the stander, and can synchronously move front and back, and up and down. The stress measuring device achieves the quantitive measurement of the stress size and the stress uniformity of the optical glass; in addition, the precision is greatly improved, the resolution reaches 0.01nm, and the size of the measurable optical glass is greatly widened. The stress measuring device can better measure the stress optical coefficient of the optical glass; and compared with the other polarized stress meter measuring devices with weight application, the measuring precisions of the pressure and the stress of load are obviously improved, and the measuring precision of the stress optical coefficient can reach 0.03*10<-12>/Pa.

The invention discloses a testing device and a testing method for monitoring steel wire rope-friction pad dynamic micro-friction state. The testing device comprises a base frame, a loading system, a micro-slip system and a state monitoring system, wherein the loading system comprises a weight loading system, a hydraulic loading system and a steel wire rope; the micro-slip system comprises a support system, a drive system and a friction transmission system; the state monitoring system comprises a dynamic tension monitoring system, a pad stress measuring system, a friction force measuring system and a micro-slip monitoring system. By utilizing the testing device and the testing method, dynamic alternating tension can be applied to the steel wire rope and dynamic micro-friction can be applied between the steel wire rope and a friction pad simultaneously, and dynamic tension evolution of the steel wire ropes at both sides of the friction pad, micro-slip amplitudes of different sections of a contact arc of the steel wire rope and the friction pad, stress change of the friction pad near the contact zone of the steel wire rope and the friction pad and dynamic friction force between the steep wire rope and the friction pad can be measured in real time.

The invention relates to a riser stress measuring device and a measuring method. Four fiber Bragg grating stress sensors are arranged around the riser, namely the four fiber Bragg grating stress sensors are arranged around the axial direction of the riser 5, and the four sensors are positioned in the same circle on the outer wall of the riser at an interval of 90 DEG. When an external force is applied onto the riser, the four sensors arranged on the outer side of the riser are stretched and bent. In the invention, the circumferential and bending combined stress of the riser can be measured and calculated by the sensors. The device has a simple structure, low external environment sensitivity and high measurement structure accuracy, and can be widely used in measurement of stress of various risers.

The invention provides a simple, flexible and reliable thin-film stress measuring system and a measuring method. The invention adopts shape-measuring equipment to measure the deformation of a thin-film material caused by thin-film stress, and expresses the deformation as the deflection or the cross-section corner of the thin-film material. The invention adopts a plate structural finite element to discrete the geometric model of a detected object, so as to give all or part of measuring values of the nodal freedom degree of the finite element in a direct measurement or indirect interpolation mode, when data are measured and processed, the influence of external force on deformation measurement is modified. The least-squares fitting condition between the deformation generated by the thin-film stress at the nodes and the deformation given by measurement is established to reversely calculate the thin-film stress by regularization process. In the condition of irregular plane form, uneven thickness of a sample and the thin-film, uncertain parameters of the thin-film material, the invention can be used for identifying anisotropic and non-uniformly distributed thin-film stress.

The invention provides a structure safety evaluation method under the action of environmental loads of a space steel structure. The structure safety evaluation method under the action of the environmental loads of the space steel structure comprises the steps that S1, environmental load partitioning is conducted on the structure on the basis of existing monitoring data; S2, a method for determining values of non-uniform distributed loads on structure partitions is determined; S3, a structural stress monitoring data evaluation threshold is set; S4, simulation analysis of structural stress field distribution under the action of the actual environmental loads is conducted through operation of finite element software and combination between the existing structure partitions and partition load values; S5, stress response data of the structure are extracted to be evaluated. According to the structure safety evaluation method under the action of the environmental loads of the space steel structure, good simulation of non-uniform distribution of actual temperature loads and actual wind loads of the space steel structure is achieved through utilization of existing temperature measured data and wind speed and pressure monitoring data of a health monitoring system, and therefore identification of a whole stress field under the action of the environmental loads of the structure is achieved; meanwhile, due to the fact that stress of rod pieces at measuring points and rod pieces which are not arranged at the measuring points is evaluated, the problems which can be caused in the process that whole stress safety of the structure is evaluated only through the finite stress measuring points are solved.

The invention discloses a three-dimensional in-situ stress testing method by acoustic emission method, comprising the following steps: 1) sampling and processing; 2) uniaxial acoustic emission test; 3) drawing a stress-accumulated acoustic emission ringing count-time curve; 4) Quickly discriminate the Kaiser effect points; 5) Calculate the three-dimensional stress state of the in-situ stress measuring points. The rock specimen sampling direction angle of the invention is flexible, the Kaiser effect point identification is quick and easy, the error in the calculation result of the in-situ stress caused by the deviation of the sampling angle is reduced, and the accuracy of the original rock stress test is also ensured.

The present invention relates to a stress-measuring system for determining a level of stress of a user, in particular for monitoring an upcoming burnout, the system (10) comprising: an alarm clock (12) for initiating an alarm at an arbitrary preset time, wherein the system (10) comprises an interface (14) for switching off the alarm; a vital sign sensor (16) for measuring a first vital sign of the user while the user operates the interface (14); and a processing unit (18) for determining the level of stress of the user based on the sensed first vital sign.

The invention belongs to the field of power system overhead transmission line tower safety monitoring, and provides a transmission tower online safety monitoring system and method for stress measuring. Firstly, stress sensors are installed on the key parts of a tower, and installation points can be obtained through finite element analysis and load application. Measurement values of the stress sensors are transmitted to a background server through the internet, the background server works out the reliability of each section of main material in real time according to each group of data together with the mean value and the variance of the strength of steel materials, and therefore the overall reliability of the tower can be obtained. The transmission tower online safety monitoring system and method have the following advantages that the problem of real-time tower stress monitoring is solved, and the stress distribution situations of the key parts can be monitored in real time; the safety state of the tower can be estimated in real time and serious accidents such as collapse can be effectively prevented under severe working conditions; research results are wide in application and can be directly applied to various tower shapes.

The invention discloses an excavator's boom fatigue test program spectrum managing and test loading method. The method comprises the concrete processes of 1, preparing basic data for compiling a load spectrum; 2, determining an excavator's boom fatigue test loading scheme; 3, taking the maximum bending moment of the boom as the load equivalent basis, and calculating the equivalent vertical load; 4, compiling the equivalent vertical force-time history into a boom calculation load spectrum; and 5, adopting the damage consistence principle at the fatigue key part stress measuring point to correct the calculation load spectrum, and finally obtaining the boom fatigue test program spectrum. The method is based on the actually-measured load, simplifies the fatigue test and represents the actual stress state of the boom to the greatest extent.

The invention discloses a brittle material crack initiation stress measurement system and a brittle material crack initiation stress measurement method. The brittle material crack initiation stress measurement system comprises a loading device, a CCD camera, a synchronizer trigger, a load-time signal receiving device and a digital image signal receiving device. The brittle material crack initiation stress measurement method includes synchronously triggering the loading device and the CCD camera by the synchronizer trigger, loading a sample and outputting a load-time signal; shooting sample surface images by the CCD camera in real time; not stopping shooting until the sample is destroyed; selecting a first frame of images shot by the CCD camera, marking 2 measurement points on the circumference of a through hole, continuously measuring tensile strain-time curves of the 2 measurement points in a whole loading process, and determining stress values, namely crack initiation stress sigmaci,on the stress-time curves corresponding to tensile crack initiation time T. The brittle material crack initiation stress measurement system and the brittle material crack initiation stress measurement method have the advantages that the position and the expansion direction of brittle material crack initiation can be controlled, the crack initiation time and the crack initiation stress can be determined objectively, precisely and quantitatively, authenticity and reliability of brittle material crack initiation stress measurement are improved effectively, and the method simple to operate, reliable in result and objective in quantization is provided for measuring crack initiation stress of rock-like brittle materials with prefabricated holes under uniaxial compression.

Apparatus for providing support to, and/or measuring the stress present in a potentially unstable structure, such as the roof of a coal or other underground mine, or a rock mass. The apparatus is an instrumented cable that has a center wire having a plurality of stress measuring devices attached along its length. Forming material is placed around the center wire and the stress measuring devices in order to provide protection and support. A plurality of noncenter wires extend generally longitudinally around the center wire, the stress measuring devices, and the forming material. Advantageously, the apparatus measures the stress placed thereon when inserted into the potentially unstable structure at more than one location along the length thereof, may be spun into a rock mass without damaging the stress measuring devices (or other components of the apparatus) and may be grouted into the potentially unstable structure with a variety of different grouts.

The invention relates to a non-contact ground stress testing device and method based on drilling microscopy digital photography and belongs to ground stress measuring device and method of geotechnical engineering. The device comprises an electronic microscopy camera, a signal processing and control module, a signal transmission module, a gyroscope, a signal collecting module, a portable power source and a device shell. The method includes: fixing the testing device in a device mounting hole, using the electronic microscopy camera to collect the hole wall digital images of the hole during a whole stress relieving process, selecting the representative images before and after the stress relieving, acquiring sub-pixel images through image interpolation, optimizing sub-pixel image analyzing areas and points, setting analyzing traces, calculating to obtain strain values, and calculating the ground stress values and the azimuth angles thereof by the hole partial wall surface stress relieving method theory. The non-contact ground stress testing device and method has the advantages that simple operation and high adaptability are achieved, testing precision can reach one micro strain, strain measuring mark points and analyzing traces are optimized, influence of temperature, rock viscosity and electromagnetic interference is avoided, a probe can be reused, and low cost is achieved.

The invention provides a crossed coupling synchronous control system of multiple motors, which is used for realizing synchronous control of two servo control units. The two servo control units are respectively used for controlling different servo motors to rotate, and each servo control unit comprises a position control subunit, a speed control subunit and a current control subunit; the crossed coupling synchronous control system comprises a stress detection unit and a stress crossed-coupling control unit; the stress detection unit is used for detecting the stresses at two rotating shafts on a gantry crossbeam; and the stress crossed-coupling control unit is used for carrying out current compensation on the current control subunits of the two servo control units according to the two stressed measured by the stress detection unit. The invention also provides a corresponding method. According to the crossed coupling synchronous control system and method provided by the invention, the torque adjustment is carried by stress detection of the gantry crossbeam, and the deflection of absolute positions between shafts in the synchronous control can be reduced.

After a probe control means causes a longitudinal wave probe to carry out transmission and reception, it slides a shear wave probe to the same position. The probe control means rotates the shear wave probe at each predetermined angle and rotates it 180° while causing it to carry out the transmission and the reception at each rotating position. A measured data analyzer 16 calculates the constant of texture induced anisotropy in a test piece from echo data when both the probes carry out the transmission and the reception. With this arrangement, it is possible to measure the residual stress of a material, in which both texture induced anisotropy and residual stress induced anisotropy mixedly exist with pinpoint accuracy by separating only the texture induced anisotropy from the material.

Provided are a stress analysis method and stress analysis equipment that enable a detailed stress measurement, by using both a photoelasticity measurement method and a stress measurement (mechanoluminescence measurement) which utilizes a mechanoluminescent substance to measure a stress state of an object. Physical quantities that are measurable include individual principal stress component and a principal stress direction. The photoelasticity measurement method alone cannot measure individual principal stress component values.

The invention relates to lateral compression performance measuring method and device of fibrous material, comprising the parts of fiber lateral cimpression element using pressure head on cantilever beam to lateral compress filament and overlapping fiber sample in multiangular tray, fiber deformation observing parts using two objectives with different direction finish stereo-observation and measurement to compressed fiber, compressive stress measuring elements with deflection correction to put in real time change of stress of pressure head in computer and the deflection correction is to correct vertical compressed displacement by small deflection deflection of cantilever beam when laser reflects measuring compression. By using multiple measurement of stress and conformational change and compact and novel design, lateral compression shape measurement is fast, accurate, overall, its measurement error has decreased greatly and the method is suitable for various kinds of fibrous material.

The invention relates to a stress measuring method based on a dynamic photoelastic system. The method comprises that dark-field imaging is carried out, and a first light intensity value of a stress measuring point is obtained; bright field imaging is carried out, and a second light intensity value of the stress measuring point is obtained; dark compensation field imaging is carried out to obtain a third light intensity value of the stress measuring point; the phase difference of birefringence caused by stress is obtained on the basis of the first, second and third light intensity values; and on the basis of the phase difference, different stress values of the stress measuring point are calculated. A laser vibration meter is used to verify the accuracy of a result measured via the method; the measuring method which is a new rotation polarizer method is characterized by a simple optical system, simple operation and the accurate result; and the measuring method can serve as a brand new method to measure the internal stress of a transparent solid, and can be applied to small stress measurement.

A method (10) for performing stress-based topology optimization of a structure (2, 102, 202) on a computational device (302) is provided. Upon receiving a problem definition of the structure (2, 102, 202) from an input device (304) coupled to an input of the computational device (302), the method (10) may generate a density filter, interpolation schemes for stiffness, volume and stress, a global stress measure, an adaptive normalization scheme and a regional stress measure, to determine an optimized stress-based solution to the problem defined. The method (10) may further enable the optimized solution to be rendered for display at an output device (306) coupled to an output of the computational device (302).

The invention discloses a quick surrounding rock stress measuring method applicable to buried circular tunnels. The method includes: setting each circle of spallation blastholes, buffering blastholes and smooth blasting blastholes to be detonated in two sections, determining main stress on a tunnel face to determine axial stress of the tunnel according to the maximum main stress on the tunnel face. The quick surrounding rock stress measuring method applicable to the buried circular tunnels has the advantages that conventional blasting operations and vibration monitoring are utilized, no extra equipment is needed, operation is convenient, and real-time and dynamic estimation of the surrounding rock stress close to the tunnel face during blasting construction can be realized. The quick surrounding rock stress measuring method applicable to the buried circular tunnels is mainly applicable to quick measuring of the surrounding rock stress of the deep buried underground constructions in the field of hydropower, communication, mines and the like.

The invention relates to a device and a method for detecting a force thermal magnetic coupling action of a ferromagnetic thin film, and belongs to the technical fields of engineering materials, structure deformation and mechanical experiments. The device comprises a ferromagnetic thin film uneven stress measuring optical circuit, a film magnetic hystersis loop measuring optical circuit, a Helmholtz coil and a power supply thereof, a test piece heating table, a thermocoupler, a force loading structure and an adjusting bracket. The film uneven stress measuring optical circuit comprises a laser, a beam expander, a spectroscope, a reflector, a raster, a lens, a filtering screen and a CCD camera; and the film magnetic hystersis loop measuring optical circuit comprises a laser, a beam expander, a reflector, a polarizer, a polarization analyzer and a photodetector. The method utilizes the Helmholtz coil to provide an even magnetic field for the ferromagnetic thin film, utilizes the test piece heating table to heat the film, utilizes the force loading structure to carry out force loading on the film, utilizes shearing interference to measure uneven curvature of the surface of the film and further obtain the stress of the film through the curvature, and utilizes Kerr magnetooptical effect on the surface of the ferromagnetic thin film to measure a magnetic hystersis loop of the film.