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971 results about "Pressure stress" patented technology

Pressure is defined as force per unit area applied to an object in a direction perpendicular to the surface. And naturally pressure can cause stress inside an object. Whereas stress is the property of the body under load and is related to the internal forces.

Pedicle screw for intervertebral support elements

The pedicle screw (1) for intervertebral support elements (3) consists of a shaft (10) and a head (2) comprising at least two parts (20, 22). The head is formed as a securing means for at least one support element (3). Each support element consists of a piece of a cable-like band (31) and a cylindrical support body (30) with an axial lumen (31′) containing the band. The band is securable outside end surfaces (32) of the support body in the head. The head is formed with a contact surface (23) via which a pressure stress can be exerted on the support body in the band direction, and indeed using the band and in cooperation with a further pedicle screw. A part (20) of the head (2), which is firmly connected to the shaft (10) at the one end of the latter, contains a base groove (21) which is oriented transversally to the shaft and into which the part of the band (31) to be secured or a connecting piece (292) which contains the band can be introduced during the securing of the support element (3) by means of a translatory movement in the direction of the shaft and fixed there.
Owner:ZIMMER GMBH

Tunnel construction simulation plane strain model test device

The invention discloses a tunnel construction simulation plane strain model test device, which comprises a model rack, a loading system and a data acquisition system, wherein the model rack is used for providing a space for accommodating test models and providing a counter force for the loading system; the loading system comprises a plurality of load bodies and is used for synchronously controlling different load bodies to perform a test for loading at least one set of load body on the test models; and the data acquisition system is used for testing the real-time displacement and pressure stress of the test models in the process of the loading test. The tunnel construction simulation plane strain model test device which is based on a 'loading-first and hole digging-second' test method can synchronously perform similar model tests of three test models with different parameters and loading conditions, adopts an air bag loading mode, solves the problems of nondurable stability of loading in the traditional tests and can regulate lateral pressure flexibly.
Owner:BEIJING JIAOTONG UNIV

Laser shock and supersonic vibration extrusion co-strengthening device and method

The invention provides a laser shock and supersonic vibration extrusion co-strengthening device and method. The device comprises a laser assembly, a vibration assembly, a hydraulic assembly and a connecting assembly. The method comprises steps as follows: a hole formed on sheet metal is strengthened while laser shock strengthening and supersonic vibration extrusion strengthening are adopted, a mandrel forms clearance fit with the hole to constrain the hole, so that distortion of hole and a hole angle when the laser shock is performed on the outer surface of a workpiece is prevented, and the strengthening effect of the hole wall is improved; when the laser shock is performed on the outer surface of the sheet metal, supersonic vibration is applied to the mandrel in the hole, three-dimensional pressure stress distribution is formed nearby the hole wall at certain depth under the interaction produced by laser shock waves and power ultrasound at certain frequency, amplitude and modal, and higher anti-fatigue performance and smoother inner surface of the hole are obtained. With the adoption of the device and the method, defects of a traditional strengthening technology are overcome, and the problem that the hole is strengthened through either single laser shock or single supersonic vibration extrusion is solved.
Owner:JIANGSU UNIV

Information processing method and electronic equipment

ActiveCN104346050AAdd input methodAvoid the problem that one hand cannot complete the grip and input informationInput/output processes for data processingKey pressingInformation processing
The invention discloses an information processing method and electronic equipment. The information processing method is applied to the electronic equipment, and comprises the following steps: detecting to obtain a first pressure value of first pressure stressed on the surface of the electronic equipment; judging whether the first pressure value is greater than a preset threshold value to obtain a first judgment result; generating and executing a first control instruction when the first judgment result shows that the first pressure value is greater than the preset threshold value so as to enable the electronic equipment to realize a first function corresponding to the first control instruction. Through the method, a press input mode is provided for a user, so that the user can input information to the electronic equipment by pressing the surface of the electronic equipment; thus the technical problem of the electronic equipment that a third input mode apart from physical key input and touch input cannot be provided in the prior art is solved, and the technical effect of increasing the input mode of the electronic equipment is achieved.
Owner:LENOVO (BEIJING) CO LTD

Method for growing non-crack III family nitride on silicon substrate

The invention is a method for growing crackles family-III nitride on a silicon substrate, using stress compensating buffer layer to grow crackles a family-III nitride film on the silicon substrate, and comprising the steps of: 1) firstly depositing an about 20 nanometer thick aluminized high-temperature aluminum nitride buffer layer on a monocrystalline silicon substrate and then depositing a layer of hexagonal-phase matter (such as low-temperature aluminum nitride, gallium aluminum nitride or boron nitride) whose lattice constant is far less than that of the family-III nitride and thus forming a buffer layer with stress compensating function; and 2) adding in an activating agent to make a stress compensating layer easy to form at low temperature and simultaneously the surface smooth and the crystal quality high; 3) because the lattice constant of the predeposited hexagonal-phase matter is less than that of the family-III nitride, able to introduce pressure stress into the family-III nitride film grown on the predeposited hexagonal-phase matter so as to compensate drawing stress caused by mismatching with the silicon substrate.
Owner:INST OF SEMICONDUCTORS - CHINESE ACAD OF SCI

Three-dimensional fluid stress sensor based on flexible MEMS (microelectromechanical system) technology and array thereof

The invention discloses a three-dimensional fluid stress sensor based on a flexible MEMS (microelectromechanical system) technology and an array thereof. The three-dimensional fluid stress sensor based on the flexible MEMS technology comprises a capacitive pressure stress sensor and a hot shearing stress sensor, wherein the capacitive pressure stress sensor comprises an upper electrode plate in an upper electrode layer, a pressure stress-sensitive film, and a lower electrode plate in a lower electrode layer; a cavity structure of the pressure stress sensor is formed in a supporting structurallayer; the hot shearing stress sensor consists of four groups of double hot-wire resistors which are in a square arrangement; and a hot-wire resistance signal is led from a flexible substrate into a detection circuit through a wire leading post. The three-dimensional fluid stress sensor is based on a flexible substrate technology and a back wire leading technology, and adopts an MEMS processing technology and a bonding technology; the magnitude of the pressure stress of a fluid is measured through the change of a capacitive signal; the magnitude and the direction of a two-dimensional shearingstress within a plane are measured through the change of the double hot-wire resistance; the capacitive signal and a shearing stress signal are led into the detection circuit and do not interfere with each other; and the three-dimensional fluid stress sensor based on the flexible MEMS technology has the advantages of relatively high resolution, small volume, and batch processing at low cost.
Owner:SHANGHAI JIAO TONG UNIV

Aluminum silicate glass and preparation method thereof

The invention relates to aluminum silicate glass. The toughness of the ultrathin glass is increased by adopting an ion exchange chemical reinforcing method in a subsequent process. The aluminum silicate glass comprises the following components in percentage by weight: 55 to 70 percent of SiO2, 10 to 20 percent of Al2O3, 8 to 25 percent of at least one alkali metal oxide and the balance of additive, wherein ions of chemical reinforcing ion exchange are from alkali metal ions in the alkali metal oxide. After ion exchange chemical reinforcing, the surface pressure value of the aluminum silicate glass can reach over 700MPa, and the depth of the pressure stress layer can reach over 50 microns, so cracks on the surface of the glass can be totally covered, and the safety of the glass in application is greatly promoted. The invention also relates to a method for preparing the aluminum silicate glass.
Owner:吴艺菲

Fast load testing device and method for chloride ion migration coefficient of concrete

InactiveCN102564916AAvoid compressive stress reductionSimple structurePermeability/surface area analysisSustained loadTest sample
The invention discloses a fast load testing device and method for a chloride ion migration coefficient of concrete. An elastic connecting piece in a state of compression is adopted for exerting a sustained load on a concrete sample and the concrete sample loaded with sustained stress is subjected to an electric accelerating chloride ion migration test to calculate the chloride ion migration coefficient of the concrete sample in the state. According to the invention, the fast load testing device and method for the chloride ion migration coefficient of the concrete aim at the problems that the conventional testing device for the chloride ion migration of the concrete can not exert a load on a tested sample and consequently can neither imitate the actual loaded state of in-service concrete nor determine the chloride ion migration coefficient of the concrete under sustained load; sustained and stable pressure is exerted on the concrete sample in longitudinal direction by the resilience of the elastic connecting piece; and the reduction of pressure stress caused by the creep of the concrete sample when a tensioning screw is used for exerting load can be avoided, so that the influence of the sustained load on the permeability of the chloride ions of the concrete can be researched.
Owner:HOHAI UNIV

Tensile prestress rubber earthquake isolation support

InactiveCN101806097ASimple structureSeismic isolation mechanism is clearBridge structural detailsShock proofingVulcanizationStressed state
The invention relates to a prestress rubber earthquake isolation support and belongs to the field of structural earthquake isolation control. The tensile prestress rubber earthquake isolation support consists of upper and lower connecting steel plates, an internal thin steel plate, an internal rubber layer, a prestress steel strand and an anchorage device. The internal thin steel plate and the internal rubber layer are alternately overlapped; and the internal thin steel plate, the internal rubber layer and an external rubber protective layer are connected with the upper and lower connecting steel plates by high-temperature and high-pressure vulcanization, and the internal prestress steel stand is connected with the upper and lower connecting plates by the anchorage device. In the prestress rubber support, the insufficient tensile strength is compensated by the large tensile pressure bearing capacity of the rubber support; and before the support bears a service load, a pressure stress is applied in advanced, so that the support, in high-level earthquake, maintains a pressed or low-tensile stress state for ensuring the safety of a earthquake isolation structure system. The support has a simple structure, applies a clear earthquake isolation mechanism and is suitable for earthquake isolation control of large structures with high earthquake-resistance requirements, such as high-rise buildings, tower structures and large-span bridges.
Owner:BEIJING UNIV OF TECH

Bolted steel filling plate-sleeve connection node for beam-post wood structure

The invention belongs to the field of civil engineering technology, and particularly relates to a bolted steel filling plate-sleeve connection node for a beam-post wood structure. The connection node comprises a wood beam, a wood post, a steel filling plate, a sleeve, a bolt, a gasket and a nut. The the beam-post connection node is formed by inserting steel filling plates in grooves of the wood beam and the wood post, the sleeve is embedded in the bolt hole on the beam-post connection node; after the bolt passes through the sleeve, the sleeve is pressed by the gasket through a stretch-draw bolt, so that the sleeve pushes against the steel filling plates to generate larger pressure, friction generated by pressure is utilized for shear resistance and the increasing and decreasing of pressure stress is utilized for bending resistance. The connection node is definite in force transfer and convenient for construction, and gaps at the nodes almost have no influence on the load-carrying property and rigidity of the structure; in addition, the introduction of the sleeve can also prevent the local bearing damage of the wood below the gasket and reduce the contact pressure stress at the bolt of the wood beam (post), thus being beneficial to the exertion of strength of the wood. Compared with the existing connection mode, the connection node of the beam-post wood frame has large and stable bending-resistant rigidity.
Owner:何敏娟 +1

Constructing method for shield entering into hole while passing through pipeline

The invention relates to a constructing method for a shield entering into a hole while passing through a pipeline. The constructing method comprises the following steps: (1) reinforcing an end shaft three-axe agitating pile entering into the hole and a rotary spraying pile, increasing a reinforcing area to 9 meters and keeping a reinforcing depth as 3 meters under a tunnel; (2) arranging a row of isolating piles between a sewage pipe and a station end shaft, isolating a lateral soil pressure of a soil body under the sewage pipe, and preventing pipeline settlement caused by a released soil pressure stress, wherein the isolating piles are three-axe agitating piles; (3) arranging four dewatering wells in a scope of entering the hole, dewatering and reducing a water level to 1 meter under a hole door; (4) except mounting a waterproof device around the hole door, mounting a double-layer spring steel plate, and filling sponge in the middle; (5) finishing an operation of chiseling the hole door within the shortest time; (6) adjusting all parameters, causing the shield to safely and quickly enter into the hole while passing through the pipeline; and (7) cleaning soil and turning a shielding machine. The constructing method provided by the invention has the advantages that the shielding machine successfully enters into the hole while passing through the pipeline, a successful construction case of a high-risk construction process of entering the hole of the shield under a complex condition is achieved, and abundant construction experiences for silt construction and close-range pipeline passing of the shield are provided.
Owner:SHANGHAI MECHANIZED CONSTR GRP

Method for testing concrete performance under pressure stress-chemical coupling effect and device thereof

The invention discloses a method for testing concrete performance under pressure stress-chemical coupling effect and a device thereof. The method applies a pressure stress to a test piece through a prestressing mode, and provides specific chemical corrosion action through a matched sealing device so as to apply a pull force to concrete and apply common chemical action at the same time. The internal stress of the concrete is monitored through a pressure sensor, the pressure stress is kept constant through secondary tension prestressing force, and the sealing device is arranged on the middle part of the concrete test piece to provide the chemical action, so the corrosion action of the chemical medium on a loading device is avoided; and a sealed box can provide one or more chemical erosion environments of carbonization, sulfate erosion, alkali-aggregate reaction, chloride ion erosion and corrosion. The device has a string structure, and can conveniently apply the pressure stress-chemical coupling effects of different conditions to a plurality of concrete test pieces.
Owner:SOUTHEAST UNIV

Pulsed high magnetic field auxiliary laser welding method and device

The invention discloses a pulsed high magnetic field auxiliary laser welding method and device. The method and device can be applied to laser spot welding and seam welding. According to the method, in the overall welding process, laser beams are emitted to a workpiece to form a welding connector, a high pulsed magnetic field is exerted to the welding connector which is just solidified and the surrounding area, the pulsed magnetic field generates pressure stress on the surface of the workpiece to enable the connector area to have plastic deformation, residual stress is released to lower the degree of stress concentration and the degree of structural deformation of the welding connector, and the fatigue strength of the welding connector is improved. The device comprises a laser, a pulsed magnetic field generator, a numerical control system, an optical transmission system and a laser pulsed magnetic field composite processing head. The processing head is used for integrating the laser beams and the high pulsed magnetic field, and regulating the perpendicular distance between an electromagnetic conversion device and the surface of the workpiece and the horizontal distance between the electromagnetic conversion device and the laser beams. By means of the pulsed high magnetic field auxiliary laser welding method and device, structural deformation can be lowered, welding quality and processing efficiency are improved, and the processing effect which is superior to that of an existing laser welding process is achieved.
Owner:武汉飞能达激光技术有限公司

Gas turbine blade thermal barrier coating bonding layer and preparation method thereof

A gas turbine blade thermal barrier coating bonding layer is composed of powdery Co, Ni, Cr, Al and Y. The optimal range of the powder particle size is 10-50 micrometers. A preparation method comprises the steps that 1, oil removal, washing and drying are performed on the surface of a matrix before spraying is performed, 40-80-mesh corundum is used for sand-blasting roughening, and floating dust is removed to form the rough surface; 2, the powder forming the bonding layer is kept at the temperature of 200-300 DEG C for 4 h before spraying is performed, and the powder is sufficiently softened; 3, a cold spraying method is adopted for preparing the bonding layer on the surface of the matrix; 4, the surface of the bonding layer is sprayed through the plasma technology to obtain an 8YSZ ceramic surface layer; 5, a complete thermal barrier coating is kept at the temperature of 900-1100 DEG C in a vacuum heat treatment furnace for 4 h, and the vacuum degree is lower than 10<-3>Pa. The technology is simple and low in cost; the porosity of the bonding layer is controlled to be smaller than 1%, and the structure is compact; pressure stress exists inside the coating, and the thermal expansion matching in the coating service process can be relieved; the bonding strength of the coating is improved, and the oxidation resistance of the coating is improved.
Owner:ELECTRIC POWER RES INST OF GUANGDONG POWER GRID

Artificial half pelvic prosthesis with support structure

InactiveCN102048598ALong-term steady decreasePrevent looseningJoint implantsAcetabular cupsNeurovascular injuryProsthesis
The invention discloses an artificial half pelvic prosthesis with a support structure, comprising an ilium side prosthesis and an acetabulum side prosthesis which are provided with a plurality of bolt holes, and a hook-like support structure arranged at the sacrum part justly is arranged at the edge end of the ilium side prosthesis; the ilium side prosthesis is hemispherical, an extension arm is arranged inwards, and a hook-like support structure arranged below the public rami at the same side or the opposite side is arranged at the tail end below the arm. In the invention, by adopting the support structure, interfacial stress between the prosthesis and the residual pelvis is converted into pressure stress from shearing or tensile stress, so as to improve the stability of the prosthesis. Moreover, a special inserted support structure or an inserted intramedullary stem structure is adopted at the connecting part of the prosthesis and a horizontal ramus of pubis, more femoral blood vessels and nerves on the surface are not needed to be exposed in the operation, the inserted type support structure or the intramedullary stem is directly inserted in the stump of the horizontal ramus of pubis, so as to simplify the operation and reduce risks of bleeding and injuring vital nerves and blood vessels.
Owner:SHANGHAI NINTH PEOPLES HOSPITAL AFFILIATED TO SHANGHAI JIAO TONG UNIV SCHOOL OF MEDICINE

Vortex-excitation piezoelectric energy harvester for monitoring wind power gear box

The invention relates to a vortex-excitation piezoelectric energy harvester for monitoring a wind power gear box, and belongs to the field of piezoelectric power generation. A main shaft is sequentially sleeved with a left wall plate, a left shaft sleeve, a rim, a right shaft sleeve and a right wall plate from left to right; a baffle plate is arranged at the end part; the left side of an inner ring of a bearing on the left wall plate abuts on a shaft shoulder; the right side of the inner ring of the bearing on the right wall plate abuts on the baffle plate; a certain included angle exists between a blade and a bus of the rim; two ends of the shell are connected with the left wall plate and the right wall plate respectively; a balancing weight is arranged on the outer wall of the shell; a limiting frame and a piezoelectric vibrator are arranged at the left end and the right end of the shell; the length and the width of a piezoelectric wafer are smaller than those of a hollow cavity of the limiting frame respectively; and the length and the width of a metal substrate are greater than those of the hollow cavity of the limiting frame respectively. The vortex-excitation piezoelectric energy harvester has the advantages and characteristics that the piezoelectric vibrator is excited by fluid motion caused by rotation to generate electricity; rigid shock and electromagnetic interference are avoided; the piezoelectric wafer only bears pressure stress with a controllable range; the reliability is high; fixed support is not needed; and the vortex-excitation piezoelectric energy harvester can be applied to cantilever gear shaft and multi-gear coaxial occasions.
Owner:ZHEJIANG NORMAL UNIVERSITY

Rock three-way pressure stress sensor based on optical fiber grating sensing

The invention discloses a rock three-way pressure stress sensor based on optical fiber grating sensing. The rock three-way pressure stress sensor comprises a cubic box body, wherein the box body is provided with six surfaces; three of the six surfaces which share a vertex are stress surfaces; each of the other three surfaces which share the vertex is provided with a recessed disc and serves as a recessed disc surface; fastening screw holes which have the same size and are uniformly distributed are formed at the periphery of each recessed disc; an optical fiber channel is formed in the center of each recessed disc; a sensing film is connected to each recessed disc; a small circular thin plate in the middle of each sensing film is an effective pressure bearing surface, and an optical fiber grating is adhered to an inner surface of the small circular thin plate; a sensing film supporting end is arranged at the periphery of the effective pressure bearing surface; screw holes which have the same size and are uniformly distributed are formed at the periphery of the supporting end; a box body penetration hole is formed at each vertex of the stress surfaces and the recessed disc surfaces;and the optical fiber channels are connected with two box body penetration holes. The rock three-way pressure stress sensor is intrinsically safe, free from electromagnetic interference, high in long-term stability, large in range, high in accuracy, high in sealing performance, pressure-resistant, corrosion-resistant and the like.
Owner:INST OF ROCK AND SOIL MECHANICS - CHINESE ACAD OF SCI +1

Semi-pelvic prosthesis

The invention belongs to the technical field of designing and manufacturing of prosthesis and relates to semi-pelvic prosthesis. The semi-pelvic prosthesis is characterized by being formed by connecting an ilium fixing part, acetabulum prosthesis, and a pubis connection part, wherein the ilium fixing part is used for being connected and fixed with a residual iliac wing and sacrum; the pubis connection part is used for being connected and fixed with the residual pubis on the same side or pubis on an opposite side; the ilium fixing part and the acetabulum prosthesis are connected by a tapered rotation prevention clamp port; and the acetabulum prosthesis and the pubis connection part are fixed and connected by a bolt. The semi-pelvic prosthesis has the advantages that (1) compared with assembled prosthesis, hot bending forming integrated prosthesis is disperse in stress; (2) the semi-pelvic prosthesis and the residual iliac wing are fixed by a self-locking nail, and the sacrum and the residual pubis are fixed by a self-locking nail, so that loosening of the bolt can be effectively prevented; and (3) the semi-pelvic prosthesis is provided with a flat supporting structure, so that the interfacial stress between the prosthesis and the sacrum, and between the prosthesis and the pubis can be converted from shear force or tensile stress into pressure stress, the loosening or displacement of the prosthesis is prevented, the long-term stability of the prosthesis is facilitated, and the prosthesis cannot be broken easily when complex force is applied to a human body for a long time.
Owner:THYTEC SHANGHAI

Self-healing environmental barrier coating on member surface and preparation method thereof

The invention relates to a self-healing environmental barrier coating on the member surface and a preparation method thereof. The theory basis is that: when silicide is added into present EBC, if cracks appear in coating used in a combustion gas environment, silicide on the crack surface or near the crack will be rapidly oxidized to generate silicon dioxide (SiO2) or another oxide, thus the SiO2 can be used as a mobile phase to seal the cracks; furthermore, the volume expansion caused by the oxidation reactions and the high expansion coefficient of the silicide generate pressure stress on the cracks to accelerate the healing of the cracks; so the prepared environmental barrier coating has a good self-healing ability.
Owner:NORTHWESTERN POLYTECHNICAL UNIV

Flange assembly, a coupling flange and an assembly method tehreof

ActiveUS20100117353A1Reliable bonding strengthEnsures anti-fatigue performancePipe supportsFlanged jointsCouplingUltimate tensile strength
A flange assembly, a coupling flange, and its assembling method thereof are disclosed. Stiffening plates (2) are located on the front side of the flange plate (1). Equilibrium contact surfaces (211) are set up on the front end surfaces of stiffening plates. The pressure stress bending moment created by the equilibrium contact surfaces offsets the pulling stress on the steel pipe wall and reduces the hoop stress of the steel pipe. This provides reliable bonding strength and ensures that the tensile rigidity remains unchanged under circulating dynamic load. This coupling flange is especially suitable for the connection of large-scale steel pipes such as the cylindrical pylons of large-scale wind power generators. The coupling flange can save steel consumption, reduce machining difficulty, and thus greatly reduce the manufacturing and assembling costs.
Owner:INNER MONGOLIA GOLDEN OCEAN NEW ENERGY TECH

Multi-laser polishing and reinforcing method for surfaces of additive manufacturing metal parts

InactiveCN104109860AAchieving Surface Quality Polishing IssuesQuick polishSurface stressLaser scanning
The invention discloses a multi-laser polishing and reinforcing method for surfaces of additive manufacturing metal parts, and the polishing on the surfaces of the additive manufacturing metal parts can be realized by repeatedly scanning and processing the surfaces of the additive manufacturing metal parts through utilizing millisecond pulse laser and nanosecond pulse laser; during the multi-laser scanning polishing process, the additive manufacturing metal parts are subjected to thermal preservation treatment, so that the stress on the surfaces of the additive manufacturing metal parts can be evenly distributed; laser scanning reinforcement is carried out on the surfaces of the laser-polished additive manufacturing metal parts, so that the stress state on the surfaces of the additive manufacturing metal parts can be changed into pressure stress from tensile stress, the anti-fatigue property of the additive manufacturing metal parts can be enhanced, and the usage performance of the metal parts can be met; compared with a manual polishing method, the multi-laser polishing and reinforcement efficiency of the additive manufacturing metal parts is high and is as 20 times as that of the manual polishing, the non-contact rapid polishing of the additive manufacturing metal parts can be realized, the tensile stress, caused by the laser polishing, of the additive manufacturing metal parts can be eliminated, and the anti-fatigue property of the additive manufacturing metal parts can be enhanced.
Owner:XI AN JIAOTONG UNIV

High-accuracy method for testing thermal interface material

ActiveCN102768225AEliminate Uncertainty ErrorsMaterial heat developmentHeat fluxEngineering
The invention discloses a high-accuracy method for testing a thermal interface material. The high-accuracy method comprises step one, preparing testing devices and selecting a test point of a testing thermal flow meter; step two, loading pressure stress and heating the thermal flow meter in a forward direction; step three, collecting the temperature of the test point and calculating forward contact thermal resistance R'; step four, loading pressure stress and reversely loading heat flux and collecting temperature of the test point; step five, calculating reverse contact thermal resistance R''; step six, calculating contact thermal resistance of the thermal interface material; and step seven, measuring the thickness L of the thermal interface material and calculating equivalent heat conductivity of the thermal interface material. According to the method, a symmetrical test structure capable of achieving vertical two-way heat flux is utilized to perform measurement, so that uncertainty errors of temperature measurement caused by a plurality of temperature sensors distributed on the testing thermal flow meter and different contact conditions of the testing thermal flow meter are basically eliminated, and then the contact resistance and effective equivalent heat conductivity of the thermal interface material can be measured in high accuracy mode under the premise that the heat flux accuracy is ensured.
Owner:NANJING UNIV OF SCI & TECH

Equal-channel extrusion mold for forming powder superalloy blank

The invention discloses an equal-channel extrusion mold for forming a powder superalloy blank, which is specifically used for improving the organizational characteristics of a powder superalloy blank. After a forging blank enters the mold, the round section of the forging blank is twisted to be elliptical and then to be round again, the deformation is combination of twisting and shearing deformation and extruding deformation, and thus the combination of multiple deformation modes in one-pass extruding process is realized. At the transitional section of deformation and twisting, due to the twisting deformation of the elliptical twisting surface, the blank rotates and is subjected to shearing strain under the action of shearing stress so as to realize shearing and crushing of crystal grains and further achieve the effect of refining the grains; simultaneously, since the blank is limited by a mold cavity, the intracrystalline deformation of the blank in the state of pressure stress is difficult, and thus the development of various original microscopic defects in a deformed body can be inhibited; since the refining effect of the grains in the extruding process is obvious, original grain boundaries are eliminated thoroughly, and the comprehensive mechanical property of the powder superalloy blank is obviously improved.
Owner:NORTHWESTERN POLYTECHNICAL UNIV

Pulse laser synchronous riveting and welding method and device of ultrathin plates

The invention relates to a pulse laser synchronous riveting and welding method and a device of ultrathin plates. An upper layer of plate and a lower layer of plate are stacked and positioned on a concave mold having mold holes; a bottom mold is arranged on the concave mold; a pulse laser beam is used for acting on the upper layer of plate or an energy absorbing layer coated on the surface of the upper layer of plate to form an explosive plasma; the lower layer of plate is collided by the upper layer of plate; the upper layer of plate and the lower layer of plate generate high-strain-rate plastic flow coupling; and under the restraint of the bottom mold, the upper layer of plate and the lower layer of plate are plasticized to form rivet button shapes so as to generate mechanical interlocking for riveting. In the plastic deformation process, the pressure stress exists on the contact interfaces of the upper layer of plate and the lower layer of plate, and the high-speed sliding and the shearing deformation are generated, so that the interfaces generate the melting and the atomic diffusion, and the upper layer of plate and the lower layer of plate are welded when colliding the bottom mold. The method and the device synchronously realize the riveting and the welding of the upper layer of plate and the lower layer of plate; and joints formed by the method and the device have higher connecting strength and fatigue resistance through the compounding effect characteristic of the mechanical bonding and the metallurgic bonding.
Owner:SHANDONG UNIV

Rear casing assembly manufacturing method capable of solving problems of deformation and cracking

InactiveCN104439926AAvoid deformationReduce stress concentration stress stateAircraft componentsStress concentrationManufacturing technology
The invention provides a rear casing assembly manufacturing method capable of solving the problems of deformation and cracking and belongs to the technical field of aero-engine part manufacture. When webs and supporting board heads are preassembled, welding joint shrinkage deformation is considered in the preassembly size aspect, it is guaranteed that the size generated after welding operation is identical to the design size of an outer casing, shrinkage stress can not be generated on welding joints, stress concentration is avoided, and cracks are prevented from being generated. Due to the fact that shrinkage stress can not be generated on the welding joints, the situation that a front installation edge and a rear installation edge are deformed due to the shrinkage stress effect is avoided; an inner ring and a flat supporting board pipe are preassembled and welded, the flat supporting board pipe with the inner ring and the supporting board heads of the outer casing are assembled and welded in a butt joint mode, the welded flat supporting board pipe bears tensile stress, the tensile stress exactly counteracts pressure stress borne by the flat supporting board pipe in the operation process of an engine, the stress concentration force receiving state is reduced, and cracks and deformation are avoided. In the thermal treatment process, structural stress is distributed in a balanced mode through a thermal treatment clamp and the situation that a rear casing assembly is deformed due to stress release is avoided.
Owner:SHENYANG LIMING AERO-ENGINE GROUP CORPORATION

Chemical tempered glass with combined stress advantage as well as preparation method and application thereof

ActiveCN110040982AHigh mechanical strengthComposite stress advantageDielectric lossIon exchange
The invention discloses chemical tempered glass with a combined stress advantage as well as a preparation method and application thereof. When the chemical tempered glass is 0.4-1.5mm in thickness specification, and the planar pressure stress CS_F at an area which is 50 mu m below a surface depth meets: CS_F is greater than or equal to 215.24-230.61 / (1+EXP((T-0.715) / 0.203)). The chemical temperedglass disclosed by the invention has high-level deep layer stress and high drop-resistant strength, and is high in mechanical strength. The chemical tempered glass further has relatively low dielectric constant and dielectric loss. As the chemical tempered glass has the advantages, the application of the chemical tempered glass is effectively expanded. The chemical tempered glass is obtained by adopting a single binary ion exchange processing method, the chemical reinforcing method of the chemical tempered glass can effectively save the usage amount of salt bath, the reinforcing treatment process is simplified, the stability of chemical tempered glass performance is guaranteed, and the cost of production is lowered.
Owner:CHONGQING XINJING SPECIAL GLASS CO LTD

Manufacture method for prestress steel-concrete combined bridge

The invention relates to a manufacture method for a prestress steel-concrete combined bridge, comprising the steps of: computing a position most disadvantageous to live load and the size of the live load at the position according to a positive bending moment influence line of fulcrum of a steel girder; casting positive bending moment area concrete in the positive bending moment area of the steel girder; placing pre-compression counterweight on the positive bending moment area concrete, wherein position and size of the pre-compression counterweight are same as those of the live load at the most disadvantageous position; casting steel fiber expansion concrete at the negative bending moment area; and detaching the pre-compression counterweight after the steel fiber expansion concrete reacheshardening strength. A connecting piece at the top of the steel girder comprises a rigid combination connecting piece, a flexible combination connecting piece or a non-combination connecting piece, and an elastic combination connecting piece. According to the manufacture method for the prestress steel-concrete combined bridge, disclosed by the invention, the pre-compression counterweight is quantitatively and accurately distributed on the positive bending moment area concrete according to the most disadvantageous position and the size of the live load, the positive bending moment is obtained at the fulcrum; pressure stress is obtained by the concrete on the steel girder, so that the storage of the bridge can counteract the pre-load of the live load.
Owner:SHENZHEN UNIV +1
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