2872 results about "Stressed state" patented technology

A branch vessel suture stent system and method including a branch vessel suture stent having a stent body having a first end, a second end, and a central axis, the first end having a first periphery; and shape memory hooks disposed about the first periphery, each of the shape memory hooks being attached to the first periphery at an attachment point, the shape memory hooks being elongated in a stressed state and looped in a parent state, each of the shape memory hooks defining a loop plane in the parent state. The shape memory hooks are substantially parallel to the central axis in the stressed state, and the first periphery at the attachment point for each of the shape memory hooks is substantially orthogonal to the loop plane for each of the shape memory hooks in the parent state. The delivery system allows the main body of the branch device to expand while maintaining the hooks in an undeployed configuration using individual hypotubes. Then once the body of the suture stent has expanded allowing the suture stent shape memory hooks to be released and engage the main graft body and / or surrounding tissue.

A method and apparatus for use in estimating stress fields in a geological formation are disclosed. The method includes ascertaining a perturbation of stress in the triaxial stress state in a reservoir and in a surrounding rock mass over time; and determining the change in a seismic attribute resulting from the perturbation in the stress. The apparatus includes a program storage medium encoded with instructions that, when executed by a computing device, perform such a method or a computing system programmed to perform such a method.

The invention discloses a true triaxial loading and unloading test device for large-size bedded pressure-bearing rock and a testing method. The device comprises a confining pressure loading module, a sample storage and water outlet module, a confined water loading module, a load loading module and a signal collecting and processing system, wherein the confining pressure loading module comprises two horizontal loading and unloading systems which are independent and perpendicular to each other and is used for performing horizontal load loading and unloading on the wrapped sample storage and water outlet module; the confined water loading module is located at the bottom of the sample storage and water outlet module and is used for performing confined water loading and unloading on the bottom of the bedded rock; the load loading module is located at the top of the sample storage and water outlet module and is used for performing vertical load loading and unloading on the top of the bedded rock; the signal collecting and processing system is used for collecting and analyzing signals in a test process. The test device realizes the true triaxial test of the bedded rock through four independent loading and unloading systems, truly simulates three-way anisobaric stress state of the coal-series bedded pressure-bearing rock and is more true and more reliable than a conventional triaxial test.

The invention provides a three-way loading mechanical property test system of a multifunctional lining segment joint, which mainly comprises a self-balancing frame sub-system, a loading sub-system, a test-piece support sub-system, a test-piece transporting sub-system, a loading control sub-system and a data acquisition sub-system. The loading sub-system adopts a modular design and can finish a shield tunneling lining segment inter-ring shearing test, a bending moment transferring test, a longitudinal joint corner rigidity test, a longitudinal joint radial shearing test and the like by different combinations. The system of the invention can preferably imitate three-way stress states of the shield tunneling lining segment joint in actual conditions and can finish various different loading modes to obtain mechanical parameters of the shield tunneling lining segment joint and mechanical properties of other similar structures.

The invention relates to a fatigue life prediction system for a vehicle body structure of a vehicle in the technical field of vehicle design. The prediction system adopts a road spectrum fitting module to establish a combined road spectrum suitable for a field test; a vehicle body loading spectrum acquisition module is adopted to establish an entire vehicle multi-body rigid-flexible coupled model so as to extract the load-time-history at a connecting passage of the vehicle body and a chassis as the input of vehicle body excitation; an automobile body structure dynamic response analysis module is adopted to establish a finite element model of the vehicle body so as to obtain the static stress history generated by gravity and the dynamic stress history generated by road surface excitation of the vehicle body when the vehicle is under the excitation of the combined road spectrum; a dangerous position identifying module of low fatigue life of the vehicle body is adopted to quickly search dangerous positions of low fatigue life through an S-N method and a Miner linear accumulated damage model, and determine the multiaxial stress state of the dangerous positions by using 'biaxiality' analysis; and a fatigue life prediction module of the vehicle body structure is adopted to predict the fatigue lives of the dangerous positions accurately. The fatigue life prediction system for the vehicle body structure can improve the speed and the precision of the fatigue life prediction for the vehicle body structure so as to provide a reference for a real vehicle test.

A system and a method are disclosed for identifying and characterizing a stress state of a user based on features of blood flow identified from optical signals. One embodiment of a disclosed system (and method) includes an optical sensing system to detect features of blood flow and identify and characterize a stress state of a user based on those blood flow features. Light transmitted or reflected from tissue of the user is measured by an optical sensor. A processor analyzes the received optical signal to identify features of the blood flow. The stress state of the user is determined based on the identified features. The stress state is characterized according to a type of stress, a level of stress or both. Additionally stress events are identified.

The invention relates a procedure for the detection of stress state, wherein ambulatory heart beat signal is measured. In the first phase segments are defined from heart beat signal with a chosen rule for segmentation. Then at least one segment describing a physiological state with elevated cardiac activity due to physical workload and / or increased metabolic rate is identified and excluded, if exists, and segments other than the excluded segments are detected for a potential stress state, which is identified using a predetermined rule for the heart beat signal.

Various high-strength microwave antenna assemblies are described herein. The microwave antenna has a radiating portion connected by a feedline to a power generating source, e.g., a generator. The antenna is a dipole antenna with the distal end of the radiating portion being tapered and terminating at a tip to allow for direct insertion into tissue. Antenna rigidity comes from placing distal and proximal radiating portions in a pre-stressed state, assembling them via threaded or overlapping joints, or fixedly attaching an inner conductor to the distal portion. The inner conductor is affixed to the distal portion by, e.g., welding, brazing, soldering, or by adhesives. A junction member made from a hard dielectric material, e.g., ceramic, can be placed between the two portions and can have uniform or non-uniform shapes to accommodate varying antenna designs. Electrical chokes may also be used to contain returning currents to the distal end of the antenna.

The present invention provides an automatic keypad unlocking method and apparatus for mobile terminal, so as to automatically unlock a keypad when the mobile terminal is to be used. The apparatus includes: a state detecting unit configured to detect a stress state or a motion state of the mobile terminal, to recognize whether the mobile terminal is in a hand-held state based on the stress state or the motion state, and to generate a triggering signal when the mobile terminal is recognized as in the hand-held state; a camera configured to receive the triggering signal, and to capture image based on the triggering signal; a face detecting unit configured to detect a facial image from the image captured by the camera, and to generate an unlock control signal if the face detecting unit determines that a facial image of predetermined scale size is contained in the captured image; and an unlocking unit configured to receive the unlock control signal, and to automatically unlock a locked keypad based on the unlock control signal. The present invention automatically unlocks the keypad by recognizing the hand-held state of the mobile terminal.

The invention relates to a rock true triaxial test system with a CT (Computed Tomography) real-time scanning system and a method. The rock true triaxial test system with the CT real-time scanning system comprises a triaxial pressure box, a triaxial host frame, a loading device and a CT scanning device, wherein the triaxial host frame comprises a bottom plate, a top plate and a stand column supported on the bottom plate; the loading device comprises a reversed force device, a jack and a measuring device; the pressure box, the stand column, and the reversed force device located in a scanning area of the CT scanning device are respectively made of carbon fiber materials. The rock true triaxial test system adopts the horizontal loading device, a carbon fiber force transfer plate and the stand column with special designs for a CT scanning area; solves the difficult problem that an X ray cannot penetrate through a traditional triaxial tester; overcomes the defect that in the traditional test, a rock sample needs to be unloaded and taken down from a true triaxial test bed and is then tested through CT scanning; realizes real-time coordination of rock true triaxial and CT scanning test; has significance on researching real-time extension and evolution law of microfissuring and microvoid in rocks under the triaxial stress state.

The invention provides a penetration and corrosion triaxial testing apparatus for gravel soil. The penetration and corrosion triaxial testing apparatus comprises a pressure control system, a penetration and corrosion triaxial testing system and a sand-water separation system, wherein the penetration and corrosion triaxial testing system is used for containing gravel soil samples and can form a penetration and corrosion environment with a multistage water head and complex stress condition through self-loaded axial pressure as well as confining pressure and water pressure, provided by a pressure supplying system; the contained gravel soil samples can flow out of the penetration and corrosion triaxial testing system in the penetration and corrosion environment and then enter the sand-water separation system. The invention also provides a testing method of the triaxial testing apparatus. According to the triaxial testing apparatus, the samples are placed in a pressure chamber with confining pressure to be saturated, so that the multistage water head can realize penetration, corrosion and strength testing under a condition that the real environment stress state is simulated; corroded particles are discharged through a porous chassis of the pressure chamber, the mass of the corroded particle can be weighed in real time after sand-soil separation, and the penetration and corrosion triaxial testing process with the multistage water head and the complex stress condition can be effectively carried out.

The invention relates to a visual natural gas hydrate sediment mechanical property testing apparatus, belonging to the field of the measurement of basic natural gas hydrate physical properties. The visual natural gas hydrate sediment mechanical property testing apparatus mainly comprises an automatic-pressing triaxial apparatus main machine, an axial loading system, a confining pressure control system, a backpressure control system, a temperature control system, a data collection system and an X-ray CT (computed tomography) imaging system. The low-temperature high-pressure hydrate triaxial apparatus is organically combined with the X-ray CT imaging system, so that the testing on macro and micro mechanical properties of natural gas hydrate sediments can be synchronously carried out. The visual natural gas hydrate sediment mechanical property testing apparatus can simulate a stress state of a real reservoir stratum, macro and micro mechanical property data of the natural gas hydrate sediments can be acquired, the important significance on disclosing a deformation mechanism of the natural gas hydrate reservoir stratum and a triggering mechanism of geological hazards such as submarine landslide caused by the decomposition of natural gas hydrate can be realized, and an important guiding function for safely and high efficiently exploiting the natural gas hydrate can be realized.

Information display medium (1) having at least two display faces, one on each of two blank parts (2, 3) made of a substantially rigid and foldable material, the blank parts (2, 3) being arranged so that, when the medium is unfolded, they are stressed so as to stress the display faces, a plurality of holding inserts, which act at various different points along said display faces, being provided to keep the display faces stressed. The blank parts (2, 3) of the display faces are joined together by their edges (14, 19), each holding insert (21) is mounted between the blank parts (2, 3) in a variable position that can switch between a position in which the medium is collapsed and a position in which the display faces of the blank parts (2, 3) of the medium are kept in the stressed state, each insert (21) being associated with a mechanism for locking it in its holding position.

An integrated device for in-situ generation and decomposition of hydrate sediments and permeability measurement thereof belongs to the field of measuring the basic physical properties of natural gas hydrates. The device mainly comprises a reaction kettle, a cold store, a scavenging leakage detection system, a temperature control system, a gas supply system, a water supply system, a permeability measurement system and a computer data acquisition system. A compression type design is adopted for the reaction kettle so that different stress states can be simulated. The device has the following advantages that: the cold store and a constant temperature bath are capable of realizing quick and accurate control of temperatures; the gas supply system is quick and convenient to increase and preserve pressures; the data acquisition system has the functions of data storage and real-time analysis; the temperatures, pressures, historical sedimentary conditions and stress states of different hydratesediment reservoirs can be simulated; and a hydrate sediment sample can be integrally taken out in a relatively convenient manner, and can be directly put in a low-temperature high-pressure three-axis tester for the mechanical characteristic testing research. Besides, the device plays an important role in guiding the drilling and safe mining of natural gas hydrates.

The invention belongs to the technical field of strength tests in aviation, and particularly relates to a test device capable of evenly applying an axial compression load and a shearing load. The test device comprises a shearing load applying component 1, an axial compression load applying component 2, a lower platform component 3 and a rib-adding flat plate component 4. According to the technology for independently loading the compression load and the shearing load, adopted by the device, the device not only is suitable for the flat plate, but also is suitable for a rib-adding flat plate. Furthermore, the test debugging of the single axial compression load and the single shearing load under the condition that the rib-adding flat plate is invariable in an installing posture can be realized, so that the reference can be provided for the analysis of the stress state of a lower wall plate under the joint action of the compression load and the shearing load. The device applies shearing force by the self-balance principle of a whole frame and a 'load balancer', so that the shearing force can be evenly applied, the axial rigidity of the rib-adding flat plate can not be enhanced due to an adopted segmental shearing reinforcement block, a compression load applying effect can not be influenced, and a 'side frame effect' can be avoided.

The invention discloses a true triaxial rock loading and unloading disturbance test device. The device comprises a vertical loading device and a horizontal loading device, which are orthogonally distributed, wherein the vertical loading device is hollow; load cylinders are arranged on, below, in the front of and at the rear of the vertical loading device; pressure transfer pillars are arranged at the left and right ends of the horizontal loading device and are driven by the load cylinders to achieve six-side stress loading simulation of a specimen. The device has the beneficial effects that an unloading rockburst experimental method for suddenly unloading the single-side stress of the rock specimen and a loading rockburst experimental method for increasing the vertical load after single-side sudden unloading are obtained on the basis of the true triaxial three-direction six-side stress state.

Methods are disclosed for producing architectural preforms and high-temperature composite structures containing high-strength ceramic fibers with reduced preforming stresses within each fiber, with an in-situ grown coating on each fiber surface, with reduced boron within the bulk of each fiber, and with improved tensile creep and rupture resistance properties for each fiber. The methods include the steps of preparing an original sample of a preform formed from a pre-selected high-strength silicon carbide ceramic fiber type, placing the original sample in a processing furnace under a pre-selected preforming stress state and thermally treating the sample in the processing furnace at a pre-selected processing temperature and hold time in a processing gas having a pre-selected composition, pressure, and flow rate. For the high-temperature composite structures, the method includes additional steps of depositing a thin interphase coating on the surface of each fiber and forming a ceramic or carbon-based matrix within the sample.

Provided is a coating layer for cutting tools, as a hard coating layer stacked and formed in the sequence of a TiN layer, a TiCN layer, a bonding layer, an alumina (Al2O3) layer, and a cover layer from the bottom by using a chemical vapor deposition (CVD) method on a parent material, able to improve cutting performance, because surface residual stress of the coating layer may be maintained in a compressive stress state by adjusting a composition of the cover layer without using a separate additional process, such as a blasting operation, or a mixed process of CVD and physical vapor deposition (PVD), and simultaneously the cover layer may also be used as a wear-resistant layer.The coating layer according to present invention is formed on a surface of a parent material by using a CVD method, in which the coating layer includes an alumina layer formed of an α-phase, disposed on the parent material and composed of a composite structure having a columnar crystal structure and an equiaxed crystal structure mixed therein, and a cover layer formed of AlxTiySizCrwN (herein, x+y+z+w=1, x≧0.75, y≧0.2, 0≦z≦0.06, 0≦w≦0.08) and disposed on the alumina layer.

The invention discloses an experiment testing method and device to test stressed state of product when falling on the ground. It has a clamping device to hang the object, and a piezoelectricity sensing platform is set under it. A CCD camera is set outside the platform. Impact accelerometer is set on the testing point of the testing object. Using a monitoring program to start clamping device to drop the object in free falling state, recording the process until the object knocking at the piezoelectricity sensing platform trigger circuit, starting CCD camera to capture the process, calculating falling angle, taking simulation test, and comparing simulation G value and accelerometer testing G value, the accurate testing value would be gained. It would effectively improve economic benefit.

The invention relates to a pumping stop sand setting fracture-height-controlling acid fracturing process method applicable to a carbonate reservoir. The method comprises the following work procedures that before the normal fracturing, low-viscosity slickwater is adopted for fracture making, and the initial fracture height is controlled; then, after the slickwater enters the stratum in a way of carrying support agent sand, the pumping stop is adopted for prompting the support agent sand to be settled near a fracture opening, so that each stage of support agent sand shields the back section in advance, a high-intensity artificial separation layer is formed, the stress state is changed, and the goal of effectively controlling the lower fracture height extending to prevent the communication with the lower part water body is achieved; low-viscosity fracturing fluid is injected for fracture making at a stable discharge capacity; after the fracturing fluid enters the stratum, acid liquid is injected for etching the stratum, and high-flow-guide capability artificial fractures are formed; after the acid liquid is extruded into the stratum, the pumping is stopped for measuring the pressure drop, and the construction is completed. The process has the advantages that the artificial separation layer can be formed, the fracture height vertical direction extending can be controlled, the stress state is changed, and the goals of effectively controlling the lower fracture height extending and preventing the communication with the lower part water body are achieved.

The invention discloses a high-pressure water burst and CO2 fracturing combined coal bed gas displacement extraction technology. The high-pressure water burst and CO2 fracturing combined coal bed gas displacement extraction technology comprises the following steps: ground stress state determination, hole sealing section drilling and sealing, hole drilling and slitting, charging, water injection hole sealing, high-pressure water burst crack starting, supercritical or liquid CO2 fracturing and gas extraction. A ceramsite proppant is mixed in the supercritical or liquid CO2, in a continuous fracturing process of the liquid CO2, extension conditions of burst cracks can be monitored in real time by a microseism monitoring instrument, and fracturing is stopped after an expected effect of extension in a set range is achieved. During guided slitting, slitting can be carried out step by step after holes are drilled according to the number of slits and a set distance between each two adjacent slits, and a mode of drilling holes and slitting alternately can also be adopted. The high-pressure water burst and CO2 fracturing combined coal bed gas displacement extraction technology has the advantages that the permeability of a low-permeability coal bed gas reservoir can be increased effectively, construction amount is reduced, and coal bed gas extraction efficiency is high.

A creep-damage lifetime forecast method of a material under a multi-axial stress state belongs to the field of material lifetime forecast. The method of the material under the multi-axial stress state is characterized by comprising the following steps of (1) building a creep-damage constitutive model which can represent different temperatures under the multi-axial stress state; (2) building a creep constitutive equation describing different temperatures under the multi-axial stress state; (3) building a damage equation of the material during the creep process; (4) embedding the creep-damage equations in the steps (2) and (3) into a finite element for lifetime analysis; and (5) forecasting creep lifetime of the material under the multi-axial stress state according to an analysis result of the infinite element. By the method of the material under the multi-axial stress state, the lifetime forecast of the material under a high-temperature condition can be achieved better, the forecast process is simple, and a result is accurate.

The invention provides a shrinkage creep and prestress loss computation method of a concrete bridge. According to the invention, the shrinkage creep and prestress loss computation method of the concrete bridge, in which the time variation and the uncertainty are simultaneously considered, is obtained by analyzing the time variation of concrete through utilizing an age-adjusted effective modulus method (AEMM) and analyzing the uncertainty of the concrete through utilizing an accurate and rapidly-sampled Latin hypercube sampling (LHS) method; a prestress loss computation formula in which the time variation and the uncertainty of shrinkage creep and the interaction between the shrinkage creep and reinforcement stress relaxation are simultaneously considered is deduced according to a prestressed reinforcing steel and concrete stress balance equation and deformation coordination conditions and on the basis of the AEEM method and the LHS method; and a prestress loss computation method of the concrete bridge, in which the shrinkage creep and the stress relaxation are considered, is formed. In the structural internal force value field interval computed according to the shrinkage creep and prestress loss computation method disclosed by the invention, the unfavorable stress state of the bridge structure can be considered from multiple aspects in the designing process, so that the reliability of structure computation result is higher and the structure safety is better.

The invention relates to a rock shearing seepage coupling true triaxial test system, which comprises a loading assembly, a test box, a seepage assembly, a detection assembly and a control assembly. The whole system is high in rigid, safe and reliable in high-pressure water injection and sealability, good in sealing reliability, high in loading stability and protection strength and capable of effectively reducing the end-part friction effect and the corner effect and realizing the uniform triaxial stress state as far as possible; a loading test device and a mainshaft loading mechanism are designed in a split manner, and safe high-pressure water injection is achieved; a safety valve and a pressure-stabilizing control device are arranged on a water outlet; and the rock shearing seepage coupling true triaxial test system is stable to control.

Determination of in-situ rock yield stress state of a geological formation surrounding a borehole includes determining a profile for each of an axial effective, a radial effective, and a hoop effective stress within at least one axial plane containing a borehole axis. A predicted radial shear response radial profile is calculated from the effective stresses within the at least one axial plane. A measurement-based estimate of a shear response radial profile within the at least one axial plane is determined from measured data. A maximum radial distance at which a difference between the predicted and measurement-based shear response radial profiles is identified within the at least one axial plane as being greater than a difference threshold. The respective axial, radial, and hoop stresses, are determined at the identified maximum radial distance. The identified stresses are indicative of an in-situ yield stress state of the rock.

The invention relates to a method of producing a complex microelectronic structure, in which two basic microelectronic structures (1, 3) are assembled at the two respective connecting faces (3) thereof. The invention is characterised in that, before assembly, a difference is created in the tangential stress state between the two faces to be assembled, said difference being selected such as to produce a pre-determined stress state within the assembled structure under given conditions in relation to the assembly conditions.