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400results about "Material thermal coefficient of expansion" patented technology

Thermophysical property measuring device

The invention relates to a thermal physical property measuring device, which comprises a refrigerating machine (2) and a sealed vacuum cavity (1), wherein the refrigerating machine supplies cold energy to a sample to be measured so as to decrease the temperature of the sample to be measured to a measurement temperature, and the sealed vacuum cavity supplies a vacuum heat-insulating environment for measurement. The thermal physical property measuring device is characterized by further comprising a sealed sample chamber (8), a sample rack inserting pipe (6) and a sample rack (7), wherein the sealed sample chamber holds the sample to be measured; the sample rack inserting pipe is a tubular component; one end of the tubular component is a closed end; the other end of the tubular component is an open end; the closed end extends into the vacuum cavity (1); a first end of the sample rack is connected with the sample chamber (8); a second end of the sample rack is detachably and hermetically jointed with the open end of the sample rack inserting pipe (6); and the sample chamber (8) and the sample rack (7) which are connected mutually are suitable to be inserted into the sample rack inserting pipe (6). The device is mainly used for measuring the thermal physical property of the sample to be measured at a lower temperature, and compared with a conventional thermal physical property measuring device, the thermal physical property measuring device provided by the invention has the advantages that the sample is convenient and quick to replace, the test period is short, and the like.
Owner:北京中科富海低温科技有限公司

Testing method for anisotropic thermal-expansion coefficient of continuous-fiber-reinforced resin-based composite material

ActiveCN104677928ASolve poor shear resistance fromSolve fragile and fragile problemsMaterial thermal coefficient of expansionGratingThermostat
The invention relates to a testing method for the anisotropic thermal-expansion coefficient of a continuous-fiber-reinforced resin-based composite material. The testing method comprises the following steps: (1) preparation of a sample, namely laying a plurality of optical-fiber Bragg grating strings among layers of prepregs of the resin-based composite material along 0-degree direction and 90-degree direction respectively, embedding the grating area from top to bottom by using small prepregs on the grating strings laid in the 90-degree direction with the fiber direction of the small prepregs being same as the optical-fiber direction, formed a lead groove in a side-wall frame plate of a mold, coating the surfaces of the side-wall frame plate of the mold and the lead groove with high-temperature-resistant high-molecular thin films, curing the composite material and demolding; (2) testing, namely leading out leads of the optical-fiber Bragg grating strings from an opening of a high-low-temperature thermostat, connecting the leads to an optical-fiber and grating demodulator, sealing the thermostat, heating according to the testing specifications and acquiring data; and (3) data processing. The testing method has the advantages that the optical-fiber Bragg grating strings for detecting the thermal expansion coefficient of the continuous-fiber-reinforced resin-based composite material are well protected and the obtained data is comprehensive, accurate and reliable.
Owner:SHANDONG UNIV

Civil engineering material volume change test instrument and test method

The invention relates to a civil engineering material volume change test instrument and a test method, in particular to a material volume change test device and test method in civil engineering. According to the test instrument, a sealing rubber ring is arranged in an annular groove, a base is covered with an upper cover, an air intake and exhaust hole is formed in the top end of the upper cover, one end of a probe thermometer is arranged in the upper cover, the other end of the probe thermometer is arranged outside the upper cover, a plastic pipe is arranged on the upper end face of the upper cover and communicated with a cavity, and a graduated glass pipe is communicated with the plastic pipe. The test method comprises the steps that first, a civil engineering material test piece is prepared; second, the volume of the civil engineering test piece before a test is calculated; third, the civil engineering test piece is installed; fourth, liquid is injected into the cavity; fifth, the temperature of the civil engineering test piece is measured in an initial temperature environment; sixth, the temperature of the civil engineering test piece is measured in a measuring temperature environment; seventh, the initial temperature and the measuring temperature of the test piece are measured, and the number of division of the test piece is calibrated; eighth, the volume variation theta Vt of the civil engineering test piece is calculated; ninth, the volume expansion coefficient lambda of the civil engineering test piece is calculated. The civil engineering material volume change test instrument and the test method are used for measuring the volume change situation of the civil engineering material.
Owner:HARBIN INST OF TECH

Method for determining effective coefficient of thermal expansion

A method for determining an “effective” thermal coefficient of a machine comprises the steps of installing one or more temperature sensors (110) at various locations on the machine, positioning a first machine member (60) at a “known” reference location, relative to a second machine member (42), installing a linear position measuring device (120) to detect changes in position of the first machine member (60) relative to the second machine member (42) along a first axis of movement, periodically acquiring readings from each of the temperature sensors (110) and from the linear position measuring device (120) during a test cycle and compiling the temperature and linear position data into a table. A statistical correlation analysis is performed to determine which of the temperature sensors (110) experiencing changes in temperature are most linearly related to changes in the linear position of the first machine member (60) relative to the second machine member (42) and an “effective” coefficient of thermal expansion is thereafter determined as the rate of change of position, i.e. length, relative to change in temperature. The present method includes using the machine's “effective” thermal coefficient the calibrate the motion of the machine to compensate for the thermal characteristics thereof.
Owner:FIVES MACHINING SYST +1

Method of detecting amount of axis displacement in power transmission device using automatic self-aligning engagement clutch

An object is to provide a method of detecting an amount of an axis displacement in a power transmission device using an automatic self-aligning engagement clutch, the method being capable of accurately detecting the amount of the axis displacement in the automatic self-aligning engagement clutch during an operation with a simple configuration. In a power transmission device configured to transmit a driving force to a driven body by allowing a rotary shaft of a first drive source to engage with a rotary shaft of a second drive source through an automatic self-aligning engagement clutch, an amount of an axis position variation of each of the rotary shaft of the first drive source and the rotary shaft of the second drive source are measured by non-contact sensors, and an amount of a relative axis displacement of the rotary shaft of the second drive source relative to the rotary shaft of the first drive source is detected on the basis of the measurement result of the amount of the axis position variation of each rotary shaft when the rotary shaft of the first drive source engages with the rotary shaft of the second drive source through the automatic self-aligning engagement clutch.
Owner:MITSUBISHI HITACHIPOWER SYST LTD

Measuring method and device for coefficients of thermal expansion

The invention discloses a measuring method and a measuring device for coefficients of thermal expansion. The measuring method comprises the following steps of: plating a layer of membrane which transmits light partially and reflects the light partially on upper and lower surfaces of a light transmission material to be measured respectively; heating the light transmission material; allowing a beamof monochromatic light to be incident to the light transmission material to be measured in the heating process, and reflecting the monochromatic light on the upper and lower surfaces of the light transmission material respectively, so that two beams of reflected light are interfered with each other; detecting the power of the interfered reflected light, finding a temperature value corresponding to the maximum value of the power of the reflected light, and determining the change period of the power of the reflected light in preset temperature intervals of the light transmission material; and calculating according to the change period to obtain the coefficients of thermal expansion of the light transmission material to be measured in the temperature intervals. By the measured method, the coefficients of thermal expansion of the light transmission material can be measured accurately, the test accuracy is relatively high, and system error caused by thermal expansion of sample frames and the like can be eliminated effectively; and due to the adoption of a single light source, a light path is simple, the cost is low, and the thermal expansion condition of each temperature interval can be reflected visually.
Owner:WUHAN SCHWAB INSTR TECH

Determinator for thermal expansion coefficients of concrete

The invention discloses a determinator for thermal expansion coefficients of concrete. The determinator can be used for determining the thermal expansion coefficients of newly stirred concrete in the whole process from introduction of the concrete into a mould to coagulation and hardening of the concrete. The determinator comprises a movable container structure which is composed of polyformaldehyde plastic slabs and an insulation material, is assembled by four surfaces and facilitates dismounting of a concrete test piece after testing; the six polyformaldehyde plastic slabs, the insulation material and upper and lower aluminum plates form a cuboid enclosed space which is used for accommodating a newly stirred concrete test piece; sides of the upper and lower aluminum plates opposite to the contact sides of the upper and lower aluminum plates and the test piece are all full of semiconductor chilling chips, and metallic cooling fins are used to evacuate heat of the semiconductor chilling chips; the upper and lower aluminum plates and upper and lower plastic slabs respectively form an enclosed cavity which encapsulates the metallic cooling fins; the upper and lower enclosed cavities are connected with a circulating pump through water pipes and are filled with water so as to form water circulation loops; furthermore, a temperature sensor is placed in the concrete test piece to measure the temperature of the concrete test piece, and high precision displacement sensors are installed at the center of the polyformaldehyde plastic slabs and the insulation material at the left and right sides to measure expansion shrinkage deformation of the concrete when the temperature of the concrete changes.
Owner:SHENZHEN FANHUA ENG GRP +1

One-dimensional soil column frost heave deformation tester

PendingCN107024499AAchieve frost heave deformationMonitor temperature fieldMaterial thermal coefficient of expansionSoil sciencePore water pressure
The invention discloses a one-dimensional soil column frost heave deformation tester, the one-dimensional soil column frost heave deformation tester comprises an organic glass mould for containing a one-dimensional cylindrical soil column, a circulator for soil column frost heaving through refrigeration, a test device for soil column frost heave deformation in the frost heaving process, a monitoring device for real-time monitoring of internal temperature change of a soil sample along the soil column height change in the refrigeration process, a water replenishing device for simulation of replenishing groundwater into the soil column from bottom to up, a drainage device, a testing device for testing the pore water pressure of the soil column in the process of frost heaving, and a data acquisition system; the one-dimensional soil column is a cylindrical soil sample, the mould for containing the one-dimensional cylindrical soil column is vertically-arranged cylindrical double-layer transparent organic glass, and the water replenishing device is connected with the bottom of the one-dimensional cylindrical soil column by a water replenishing pipe. The one-dimensional soil column frost heave deformation tester has the advantages of simple structure, reasonable design, practical operation and good practical effect, can simulate the indoor soil frost heave deformation process, and can effectively test soil body internal temperature, pore water pressure, vertical frost-heave capacity, vertical volume deformation and frost heaving force.
Owner:TARIM UNIV

Solid-liquid phase change material normal pressure thermal expansion rate and work volume digital measuring device

The invention discloses a digital measuring device for a heat expansion rate and working quantity of solid-liquid phase transformation materials under normal pressure, which belongs to the physical measuring field. The invention comprises an inner container, an outer container, an air discharging lock, a pressure sensing device, a water level gauge, a water valve, a sampling control unit, a heat electric couple, and an automatic electric heater. The inner container is arranged crosswise inside the outer container, an emulsion film is arranged on one end of the inner container through a compression ring and an O-shaped rubber ring, the inner container is filled fully with measuring working fluid, the outer container is filled fully with water, the rubber ring is expanded out due to an expansion of the working fluid along water temperature rising inside the outer container, and water level inside the water gauge rises. The heat expansion rate and the working quantity of the solid-liquid phase transformation materials under normal pressure can be calculated out according to liquid levels as volume expansion signal, temperature and pressure signal, which provides a convenient and reliable approach for performance measurement of the solid-liquid phase transformation materials. The invention is applicable to materials as n-pentadecane, n-hexadecane, heptadecane, sodium acetate trihydrate, storing thermal paraffin RT 54 which is produced by a German company, and the similar materials.
Owner:SHANGHAI JIAO TONG UNIV

Device and method for testing early thermal expansion coefficient of concrete based on suspension method

The invention relates to a device and a method for testing an early thermal expansion coefficient of concrete based on a suspension method. The device comprises a corrugated pipe test mould for pouring concrete to be tested to form a concrete corrugated pipe test piece, a plurality of rope rings for suspending the concrete corrugated pipe test piece, a device base for suspending the rope rings, a temperature measurement device used for measuring the temperature change of the concrete in the corrugated pipe test mould and having the measurement end of a first thermocouple wire buried in the corrugated pipe test mould, a deformation measurement device for measuring the deformation amount of the concrete corrugated pipe test piece, and a temperature control box used for adjusting the temperature of a test environment and in which a suspension position of the concrete corrugated pipe test piece is located. According to the method, the concrete corrugated pipe test piece is suspended by adopting the device to measure the early thermal expansion coefficient of the concrete. According to the test device and the test method, the friction between the test piece and the test device is effectively reduced, the test precision is improved, the operation is simple, and the using effect is good.
Owner:FUJIAN TONGLI BUILDING MATERIALS SCI & TECH

Noncontact-type test method of early-period thermal expansion coefficient of concrete dam and equipment thereof

ActiveCN101865865ACoefficient of thermal expansion neglectedMaterial thermal coefficient of expansionUsing optical meansWater bathsThermal expansion
The invention relates to a noncontact-type test method of an early-period thermal expansion coefficient of a concrete dam and equipment thereof. The test method comprises the following steps of: (1) loading a piece to be tested in a culture test barrel; (2) arranging a metal test terminal at the top of the piece to be tested and immediately putting the tested piece in a constant-temperature water bath to culture; (3) stabilizing for a period of time, slightly increasing the temperature, confirming a test end point when the internal temperature of the piece to be tested is constant with the water temperature, then decreasing the temperature to a start temperature and circulating; (4) testing the displacement values of the bottom and the top of the piece to be tested with a noncontact-type laser displacement sensor; and (5) calculating the early-period thermal expansion coefficient of the piece to be tested according to tested displacement change data. The equipment comprises the culture test barrel containing the piece to be tested, a constant-temperature water bath case is arranged outside the barrel, the culture test barrel is internally provided with the metal test terminal which is pre-buried at the top end of the piece to be tested, and the noncontact-type laser displacement sensor is arranged on the culture test barrel. The invention overcomes the defects of the prior art and provides a noncontact-type in-situ displacement test to acquire the early-period thermal expansion coefficient of the concrete dam.
Owner:NANJING HYDRAULIC RES INST

Dilatometer for measuring expansive force by constant volume method

The invention discloses a dilatometer for measuring the expansive force by a constant volume method, and relates to geotechnical test apparatuses. According to the structure of the dilatometer, a fixing system is connected with a measuring system, the fixing system comprises a fixing base, circular steel columns, a square crossbeam with a hole, a knob, a lower permeable stone, an upper permeable stone, a cutting ring fixing cylinder, a cutting ring, a nut, and a gasket, and the measuring system comprises a pressure sensor, a data display meter, a computer, and a dial gauge. The dilatometer is advantageous in that 1) constant volume: the volume of a soil sample in the whole test process is invariable; 2) high precision: the pressure sensor is advantaged by high precision and large measuring range, and the precision of test results is improved; 3) wide range: the dilatometer is applicable to measurement of the change of the expansive force in the soaking process of the soil sample and with the change of the environmental humidity condition and the test of the expansive force under the temperature control; and 4) the structure is good, the installation is convenient, the operation is simple, and the data display is visual.
Owner:GUILIN UNIVERSITY OF TECHNOLOGY

Asphalt volume expansion and shrinkage coefficient determinator and method

ActiveCN103278526ASolve the problem of linear expansion coefficientReduce low temperature crackingMaterial thermal coefficient of expansionAsphaltComputer science
The invention discloses an asphalt volume expansion and shrinkage coefficient determinator and method, and relates to a volume expansion and shrinkage coefficient determinator and method of a material, in order to solve the problems that when an existing device determines the asphalt volume expansion and shrinkage coefficient, the determined result accuracy cannot be ensured because of the influences by asphalt adhesion and the creep property, and only the linear coefficient of asphalt can be determined. The asphalt volume expansion and shrinkage coefficient determinator comprises a top cover, a base and a glass tube, wherein the base comprises a connector and a base plate; the connector is inserted and installed in a first groove, and the connector and the first groove are detachably connected with each other; the upper end surface of the connector and the bottom surface of the first groove are sealed; and a second groove forms an enclosed chamber. The determining method mainly comprises the following steps of: step 1, assembling the determinator; step 2, determining the volume expansion or shrinkage coefficient of an indicator; step 3, manufacturing an asphalt test element and determining the volume of the asphalt test element; step 4, determining the volume expansion or shrinkage coefficient of the asphalt test element; and step 5, calculating the volume expansion or shrinkage coefficient of the asphalt test element. The asphalt volume expansion and shrinkage coefficient determinator and method provided by the invention are used for determining the asphalt volume expansion and shrinkage coefficient.
Owner:HARBIN INST OF TECH

Method and device for measuring decrepitation, expansion and shrinkage performance of lump coal

ActiveCN102156149AImprove featuresImprove understanding of coal coke morphology changesMaterial thermal coefficient of expansionMaterial exposibilityExpansion rateCoal
The invention provides a method and a device for measuring decrepitation, expansion and shrinkage performance of a lump coal. The device comprises a heating system, a camera, a computer, a light source adjustment system and an atmosphere system, wherein the heating system comprises a furnace tube, a quartz window, a sample substrate, a sample and a temperature measuring thermocouple, wherein the top of the thermocouple contacts the sample substrate closely; the lens of the camera is a long-focus charge coupled device (CCD) lens; and the heating system is arranged right ahead of the CCD lens. The method comprises the following steps: heating a lump coal sample in the device; selecting a proper temperature point to collect an image when the image is clear; calculating the expansion rate and shrinkage rate of the volume. The pyrolyzation and degassing processes of the lump coal can be visually observed at different temperatures through providing a visual device and the measurement method; the expansion and shrinkage behavior and the decrepitation of the lump coal can be indirectly measured through image collecting, thus providing guidance basis for the use of the lump coal in a melting gasification furnace.
Owner:XINJIANG BAYI IRON & STEEL

Method for measuring thermal expansion coefficient of concrete

The invention discloses a method for measuring the thermal expansion coefficient of concrete, which comprises the steps of: proportioning each concrete to form into 3 test pieces; previously embedding 4 copper heads which are taken as ends for measuring the length on the surface of the each test piece when forming the each test piece; removing modules after 1 day of forming the test pieces; putting the test pieces into a standard curing room to cure; when reaching a preset curing age, putting the concrete test pieces into water with temperature of T0 to immerse, and measuring the length 1 (T0) among each two corresponding copper heads on the surface of the each test piece; moving the concrete test pieces into a thermostatic water tank with temperature of T to immerse, measuring the length 1 (T) among each two corresponding copper heads on the surface of the each test piece, and recording; measuring the distance among the same pair of the copper heads on the surface of the same test piece under each temperature for many times, taking the average value as effective data; and according to the measured length among the two copper heads on the surface of the each test piece under the different temperatures, counting the thermal expansion coefficient of concrete according to formula (1).
Owner:SOUTHEAST UNIV

Method for measuring rock thermal coefficient of linear expansion by utilizing pressure tester

The invention relates to a method for measuring rock thermal coefficient of linear expansion by utilizing a pressure tester. The method comprises the following steps of selecting a rock sample, drilling a circular hole and engraving a wire leading groove; installing a silica gel heating element heating device; wrapping a heat preservation and insulation layer; installing an electric couple; placing the assembled rock sample onto a uniaxial pressure tester, putting heat preservation and insulation mats on the top surface and the bottom surface of the rock sample; starting the uniaxial pressure tester to apply an initial load on the rock sample; setting finishing temperature required to be applied, recording a finishing load value and axis finishing temperature after a system is stabilized; finally, calculating the thermal coefficient of linear expansion. The invention utilizes the common pressure tester to measure the rock thermal coefficient of linear expansion, so that compared with other existing methods, the time required for single measuring can be well shortened, the problem of cooling of heating equipment does not need to be considered, the measurement of the next sample can be carried out directly, and high-efficient measurement of the rock thermal coefficient of linear expansion in engineering design is realized.
Owner:GUANGXI UNIV
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