41 results about "Vertical Strain" patented technology

A quantum semiconductor device including quantum dots formed by S-K growth process taking place in a heteroepitaxial system wherein the relationship between the energy level of light holes and the energy level of heavy holes in the valence band is changed by optimizing the in-plane strain and the vertical strain accumulated in a quantum dot.

A testing method for one-time measurement of the tensile modulus and the compression modulus of rock comprises steps as follows: a horizontal strain gauge and a vertical strain gauge are pasted at centers of front and back sides of a disk sample respectively; the disk sample is placed on a press for a Brazilian disk test, the load force P is monitored by a pressure sensor, and the horizontal strain gauge and the vertical strain gauge monitor transverse strain epsilon x and vertical strain epsilon y of the centers of the disk sample respectively; the tensile modulus and the compression modulus of the rock are calculated as per the following formulas shown in the specification, wherein Ex and Ey represent the tensile modulus and the compression modulus of the rock respectively, P is the external load, D is the disk diameter, L is the disk thickness, vyx represents the x-direction transverse deformation coefficient caused by y-direction stress, and epsilon x and epsilon y represent the transverse strain and the vertical strain of the disk centers respectively. The tensile modulus and the compression modulus of the rock can be measured on the same rock sample through one test, the test method is simple and easy to implement, data are accurate and reliable, and results are more scientific.

The invention discloses a slope stability monitoring and landslide warning and forecasting method based on an all-optical fiber sensing network. A number of drill holes are drilled in a direction perpendicular to a potential sliding surface or a joint surface and a bedrock surface in the top and surface of a rocky soil slope. An all-optical fiber integrated gauging pipe is buried in each drill hole. All optical fibers are mutually welded to form the all-optical fiber sensing network which is connected with an optical fiber demodulator to measure the strain and temperature distribution of each optical fiber. On the basis of early monitoring results, the vertical strain eigenvalue of the slope is selected, and the safety factor of the slope is acquired. The empirical relationship between the vertical strain eigenvalue and the safety factor is acquired. According to the measured result of the vertical strain eigenvalue, the safety factor of the slope is estimated, and warning and forecasting of slope instability are realized. Based on the optical fiber monitoring data, the process of birth, occurrence and development of the potential sliding surface of the slope and the position of a multi-level potential sliding surface can be accurately identified.

The invention relates to a measuring system and method for a concrete non-load internal stress in a concrete structure. The system comprises a metal block sensor, a temperature compensation block, a temperature sensor, a temperature heating box and a strain tester, wherein the metal block sensor and the temperature sensor are buried in to-be-measured concrete; the temperature compensation block is placed in the temperature heating box and is located on the to-be-measured concrete; the metal block sensor comprises a metallic lumpish test block; at least three mutually vertical strain gages are adhered to the test block; the temperature compensation block comprises a metallic lumpish compensation block; one temperature strain gage is adhered to the compensation block; the strain gages and the temperature strain gage are connected with the strain tester in the manner of 1 / 4 bridging; the poisson ratio and coefficient of linear expansion of the test block and the compensation block are similar to those of the concrete; the temperature sensor is connected with the temperature heating box. According to the invention, the influences of inner temperature change of the concrete in early period of the concrete and different rebar reinforcement ratios on the internal concrete stress can be avoided and the test precision is higher.

The invention discloses a triaxial experiment instrument pressure chamber for measuring rock specimen volume strain and an operation method thereof. The triaxial experiment instrument pressure chambercomprises a base and a pressure cabin arranged on the base, wherein the pressure cabin is a confining pressure sealed accommodating cavity; a precise volume pressure controller and a pressure sensorconnected in the pressure cabin jointly act; the pressure in the cabin is enabled to be strictly invariant by regulating the water inlet and outlet quantity, so that the water outlet quantity is the volume strain of a rock specimen; finally, the conversion is performed with vertical strain to obtain Poisson's ratio. The condition that errors caused by subjective influence of operators during the position selection in a traditional strain gage pasting method is avoided; the phenomenon of liquid leakage caused by strain gauge conducting wires is also avoided; meanwhile, all parameters can be obtained through once experiment; the data non-unified errors caused by many time of experiments are avoided; the experiment operation process is greatly simplified; the experiment efficiency is improved; the confining pressure is provided through water injection from water inlet holes. Compared with traditional method using oil pressure, the method has the advantages that the water sources are wide;high economic performance is realized; the control is easy.

A chip with resistive, metallic strain gauges distributed on surfaces on and buried within the chip. Also, vertically arranged vias and vertical thin film resistive strain gauges are described. The resistive strain gauges can be multiplexed wherein strain can be measured across the topology of the chip in each of the top, bottom and buried layers and any vertical strain. The resistive strain gauges may be in serpentine patterns and may be arranged on via or on vertical edges of grooves that extend from an upper or lower surface of the chip to buried layers. In this fashion, the distributed strain gauges may be used to map the strain throughout the body of a chip. A Kelvin bridge may be used to measure the strain, but other such measuring techniques and devices may be used.

The invention relates to a device and a method for monitoring deformation and stress of a cement-based material in a steaming and maintaining process and belongs to the technical field of test of civil engineering materials. The device comprises a water bath temperature control heating system, a steel ring restraint system, a swelling deformation test system and a stress test system; the water bath temperature control heating system is composed of a rectangular double-layer heat preservation box and a water temperature control system; the swelling deformation test system is composed of a laserdisplacement sensor and a displacement data acquisition instrument; the laser displacement sensor is fixed on a bracket and directly above a test piece; the internal stress test system is composed ofa strain gauge and a strain data acquisition instrument; the strain gauge is attached to the middle of the outer side of a steel ring; and the strain gauge is connected with the strain acquisition system. According to the device and the method for monitoring deformation and stress of a cement-based material in the steaming and maintaining process in the invention, based on volume deformation characteristic of the steamed concrete in the steaming and maintaining process, the swollen steamed cement-based material is restrained through the external steel ring; the internal stress of the concretein the steaming and maintaining process is obtained through calculation by testing strain of the steel ring; and vertical strain is obtained by testing the change in vertical displacement.

It is a micro pressure sensor, which comprises fiber Brag grating and pressure deformation. Its process method is as following: according to the conditions to design the deformation size; to compute the flexible gemel and elastic design parameters; to process deformation; to fix the grating on the side of deformation. When the elastic plate of the invention suffers transverse force, the PEG generates vertical strain force with its two ends fixed on the rigid thin plate to convert the transverse force into vertical pressure direction. The force is exerted in the PBG to generate vertical strain force to cause the reflection wavelength change to make the transverse pressure and reflect wavelength react together to achieve the measurement.

The invention relates to the field of civil engineering, and discloses a method for acquiring dynamic resilience mechanical characteristic parameters of aggregates, which comprises the following steps: 1) deriving a stress increment constitutive equation of the aggregates, and determining a stress loading sequence according to the equation; 2) performing a dynamic triaxial test on the granules according to the stress loading sequence, recording the stress level, the stress increment, the corresponding horizontal deformation and the corresponding vertical deformation of the test, and calculating the horizontal strain increment and the vertical strain increment; 3) introducing a stress dependence model of dynamic resilience mechanical characteristic parameters; and 4) performing parameter regression analysis, and determining model parameters to obtain a nonlinear dynamic resilience mechanical characteristic parameter prediction model including dynamic resilience modulus, Poisson's ratioand orthotropic parameters. According to the method, the model for predicting the dynamic resilience mechanical characteristic parameters of the aggregate under different stress states can be established, the dynamic resilience mechanical characteristic parameters under various stress states can be conveniently and accurately obtained, and the requirements of engineering construction are met.

The invention provides a method for detecting vertical force of a linear motor based on vertical strain of bolts. The method includes the following steps: manufacturing force measuring bolts, and calibrating the force measuring bolts through a mechanical testing machine; on a sensing steel plate, fixing the force measuring bolts on steel plate on a concrete substrate through a pinch plate, and respectively arranging measuring points on each bolt; grinding each measuring point and the corresponding position, and wiping up by using alcohol; setting four strain gauges symmetrically on the same circumferential side surface of each bolt, wherein the adjacent two strain gauges are perpendicular to each other, and the strain gauges are tightly closed by silica gel; performing assembling of a testbridge circuit on the attached strain gauges; accessing the bridge circuit assembled at each measuring point to a strain collector system, and collecting the strain of the bolts when a train passes through the area; and inverting the vertical force of the linear motor by using the relationship between the force and the strain obtained through calibration by a laboratory. The method for detectingvertical force of a linear motor based on vertical strain of bolts is a non-destructive testing method, and the detecting process does not affect the stability of the track structure, and more accurate vertical force of the linear motor can be obtained through the field test.

The invention discloses an optical fiber interference water level sensor. The optical fiber interference water level sensor is composed of a semiconductor laser device, a 3dB coupling device, a sensitive element, a Faraday polariscope, a light guide optical fiber, a photoelectric detector and a computer, wherein the sensitive element is a key part of the water level sensor and is used for converting the change of a water level into vertical strain and radial strain of the optical fiber so that the phase difference of two interference arms is changed; finally, the change of the water level is inverted by using the change of the phase difference. By the aid of the optical fiber interference water level sensor, the high-precision water level measurement can be realized, and the optical fiber interference water level sensor has the advantages of reliability, electromagnetic interference resistance, corrosion resistance, high sensitivity, simple and exquisite structure and the like, and is suitable for the environment needing high-precision water level monitoring.

The invention discloses a method for detecting the vertical structure load of an existing building by intercepting a concrete structure test piece. The longitudinal strain can be used to calculate the vertical load carried by the vertical structure of the building. The invention intercepts the concrete structure test piece from the side of the vertical structure of the existing building, measures the strain of the concrete structure test piece in the vertical direction through the vibrating wire strain gauge, and calculates the existing building structure through the elastic modulus formula The vertical load is less destructive to the building structure, and it is easy to implement, the result is reliable, and it has good use value in the engineering field. At the same time, the invention provides important data support for building reinforcement design, especially plays an extremely important role in building pile foundation deviation correction and reinforcement engineering.

The invention discloses an underground sensor network used for expressway life monitoring and a deployment method thereof. The underground sensor network comprises sensing measuring devices, a raster demodulating device, fiber-optic connecting devices, and communication and storage devices. The sensing measuring devices mainly comprise a horizontal strain sensor, a vertical strain sensor, a temperature sensor, and a soil pressure gage. The raster demodulating device comprises a fiber bragg grating demodulation instrument. The fiber-optic connecting devices comprise a fiber junction box, a fiber terminal box, and outdoor optical cables. The communication and storage devices comprise a computer, and a GPRS module. Through embedding fiber bragg grating sensors inside each structural layer of a road, road structure is monitored in a dynamic manner in real time, so that problems that dynamic response of each structural layer of the road on traffic load are solved, difficulties of former monitoring are overcome, and real-time monitoring of road structural information is realized.

The invention discloses a method for calibrating a hydraulic jack in the technical field of civil engineering structure testing, which comprises the following implementation steps: making two short steel pipes with completely identical parameters; pasting vertical strain gauges in the middle of the steel pipes; on a long-axis testing machine, Carry out the axial compression test of a steel pipe to measure the force and strain of the steel pipe in the elastic stage; carry out the axial compression test of another steel pipe on the hydraulic jack to measure the force and strain of the steel pipe in the elastic stage; The correction coefficient of the hydraulic jack can be obtained by comparing the force of the steel pipe under the same strain in the elastic stage. This method uses the existing instruments and equipment to calibrate the hydraulic jack. This method utilizes the force characteristics of the steel pipe in the elastic stage, has the advantages of high measurement accuracy and accurate correction coefficient, and can meet the measurement requirements of building structure tests and actual engineering.

A test method for one-time measurement of rock tensile modulus and compressive modulus, comprising sticking horizontal strain gauges and vertical strain gauges respectively at the center of the front and back of a disc sample; placing the disc sample on a press, Carry out the Brazilian disk test, use the pressure sensor to monitor the loading force P, and use the horizontal strain gauge and vertical strain gauge to monitor the transverse strain εx and vertical strain εy in the center of the disc sample respectively; the tensile modulus of the rock can be calculated by the following formula and compression modulus: E y = 2 P πDL 3 + ν yx ε y - - - ( 1 ) E x = 2 P πDL 3 + ν yx ( 3 + ν yx ) ε x + 3 ν yx ε y - - - ( 2 ) where Ex and Ey represent the tensile modulus and compressive modulus of the rock, respectively, P is the external load, D is the diameter of the disk, L is the thickness of the disk, νyx represents the lateral deformation coefficient in the x direction caused by the stress in the y direction, εx and εy denote the transverse strain and vertical strain at the center of the disc, respectively. The tensile modulus and compressive modulus of the rock can be measured on the same rock sample through one test. The test method is simple and feasible, the data is accurate and reliable, and the result is more scientific.