293 results about "Load displacement" patented technology

The invention discloses a process for characterizing the elastoplasticity of a metal material by introducing an extra residual area through an indentation method, belonging to the field of researches on the mechanical properties of a material. Experiment devices required by the method mainly comprise an indentor, and an atomic force microscope or a three-dimensional optical imaging system. The method mainly comprises the following steps: indenting a material to be tested through the indentor to obtain an indention load displacement curve, extracting relevant parameters from the indention load displacement curve, substituting the extracted parameters to an established model, and calculating to obtain the elastoplasticity of the material. The method mainly has the following advantages: different materials having similar indention curves can be successfully separated, and the obtained solution is only; and the solution obtained through back-stepping has a high precision. So the only high-precision elastoplasticity of the indented material can be obtained through back-stepping by utilizing the theoretic model in the invention.

The invention discloses a test device and a test method for testing strength change of a soil body after occurrence of seepage deformation of dykes and dams. The test device includes a triaxial loading main machine, a confining pressure chamber pedestal, a specimen pedestal, a confining pressure chamber, a specimen, a heat shrinkable pipe, a covering cap, a porous steel plate, an axial pressing rod, a water outlet pipe, a vent hole, a hole pressure sensor, a load displacement sensor, a back pressure controller, a confining pressure controller, a water head control system, and a water-sand separation system. The device has novel design, can simulate influence of seepage deformation of the soil body under actual working conditions with different conditions on the soil body strength, and can realize data automatic recording and processing.

A portable type car outer cover component deforming stiffness test device which includes a carline and a beam of the first slid fixed on the cowl carline and it can drive the first slid moving up and down by the first screw stem so further drive the beam moving up and down and the second screw stem drives the second slid moving left and right; the load-on measuring mechanism connects with the second slid by the driving adjustment mechanism which includes the body, the electric engine set in it, the gear driving equipment, lead screw component, load-on light bar, and the displacement sensor, the pressure sensor. The test device of invention adopts the assemblage frame mechanism and it can adjust randomly for the experimental point of different cover component in the three-dimension space and it can measure the stiffness of cover component through applying the normal load to the experimental point also gives the load-displacement curve of the experimental point according it to judge the ability of outer cover component deforming stiffness, stability, and portable selection material of the car outer cover component.

The invention relates to a test method for a J-R resistance curve of a high-toughness material. The method comprises the steps of sample processing, three point bending test, determination of crack length, calculation of J-integration at every load, establishment of a difference function, recursive calculation of crack length and p-V data pairs and construction of the J-R resistance curve. According to the invention, an extensometer is not employed for testing opening displacement and unloading flexibility of a crack mouth; instead, a testing machine is used for direct acquisition of deformation of a three point bending sample and a load-displacement curve in the whole process of fracture; then, the J-R resistance curve of the material is obtained through a series of calculation; therefore, the problem of restriction of testing apparatuses caused by large deformation of a sample in the testing of high-toughness materials is overcome, a J-R resistance curve in the situation of expandedlong size crack is measured, and the test method is applicable to measuring of J-R resistance curves of samples at different temperature and with different dimension.

The invention provides a stress corrosion and hydrogen measuring electrochemical in-situ measurement device under a slow strain speed condition. The stress corrosion and hydrogen measuring electrochemical in-situ measurement device comprises an electrochemical work station, an auxiliary electrode, a working electrode, a reference electrode, a stretching test sample, a slow strain stretching machine, a computer, an isolation transformer, a corrosion device and a hydrogen measuring device. The stress corrosion and hydrogen measuring electrochemical in-situ measurement device has the effects that an electrochemical in-situ test can be carried out on stress corrosion and hydrogen permeation respectively under the slow strain speed condition through replacing a corrosion electrolytic tank; the device has the characteristics of adjustable test sample size, in-situ electrochemical measurement, accurate load-displacement readings, simple structure, convenience and flexibility in utilization, simplicity in operation and the like. The device can be used for simultaneously realizing in-situ electrochemical behavior detection of pull stress, corrosive liquid, corrosive gas and temperatures, and can be widely applied to researches of strain speeds, the pull stress, types and concentrations of corrosive media, pH values, temperatures, corrosive gas partial pressure and concentration and influences on corrosion of metal materials by hydrogen brittleness, and a damage evolution rule of materials can be analyzed through electrochemical data.

The invention discloses a crack propagation rate measurement method. The method comprises the steps of applying alternating load to a test piece with a single-side penetrated crack by a testing machine; measuring load-displacement curves at an interval of certain loading cycles and fitting a linear segment to obtain the non-dimensional flexibility value of the test piece; acquiring the length of the crack according to the relation of the non-dimensional flexibility value of the single-side penetrated crack and the length of the crack under a clamped boundary condition; recording the number of the current loading cycles to obtain a crack length-load cycle number curve, and determining the crack propagation rate; and calculating the corresponding stress intensity factor, acquiring discrete data and fitting to obtain the parameters of the crack propagation rate. The method has the advantages that the method is suitable for measuring the crack propagation rate under positive and negative stress ratios and can be used for measuring the crack length automatically; and the measurement system has wide application range and is particularly suitable for measuring the crack propagation rate of novel materials such as a metal laminated board, a metal/composite material laminated board, a ceramic matrix composite material, a welding material.

The invention provides a welding microcell performance test based residual stress detection method, which comprises the following steps of: carrying out a micro-compression-shear test on a welding microcell so as to obtain a load-displacement curve of the welding microcell, establishing a 3D (three-dimensional) finite element model of a micro-compression-shear test process, and carrying out a finite element reverse backstepping method based on an improved Gurson model so as to obtain a true stress-strain relation of the welding microcell; computing the welding residual stress, wherein in the process of carrying out computing on a welding temperature field, the influence of the mechanical property of the welding microcell on the change of the temperature field is not considered; and after the welding temperature field is obtained, in the process of carrying out computing on a welding stress field, taking normal-temperature mechanical property parameters (when the temperature of a weldment is reduced according to the true stress-strain relation of the welding microcell) into a welding computing model, and then obtaining the welding residual stress through computing. The accuracy of the method disclosed by the invention is higher than that of a result obtained by using a residual stress computing method which is implemented through not considering the mechanical property of the welding microcell.

The invention provides a method for testing elasticity moduli of coatings. Coatings are deposited on surfaces of matrix samples and are boned with dual samples by using high-strength glue; load displacement curves of boned samples are tested by using a tensile testing machine; and the curves are compared with a tensile testing result of a sample formed by bonding two matrix samples with deposition layers, so that elasticity modulus values perpendicular to the surface directions of the coatings during tensile processes of the coatings are obtained. The method makes up various disadvantages of a conventional surface coating testing technology. The advantages are as follows: a bending method can only be used for testing coating elasticity moduli parallel to the surface directions; and an indentation method is only can be used for testing local mechanical properties of the coatings and complexity of an ultrasonic testing method. The technical requirement for testing the elasticity moduli perpendicular to the surface directions of the coatings conveniently and reliably can be met. The method is applicable to measurement of indexes of elasticity moduli perpendicular to the surface directions of various surface coatings.

A method is provided for determining Young's modulus and, if desired, Poisson's ratio of a coating on a substrate wherein load-displacement indentation data in the elastic region (either elastic loading or unloading) generated using an indenter is analyzed to interpret the elastic repsonse of a coated material. The data analysis pursuant to the invention is based on an extended Hertzian analysis developed for thin-film coatings.

The invention discloses a construction method for a dynamic shear constitutive model of a fiber-reinforced composite material. The method comprises the steps of 1, completing shear tests of the fiber-reinforced composite material under various strain rate loading working conditions to obtain a load-displacement curve under each working condition; 2, combining a Weibull damage model with a viscoelastic model to deduce a to-be-fitted load-displacement relation containing Weibull damage distribution; 3, constructing a multi-curve least-square objective function according to the load-displacementcurves and the load-displacement relation; 4, obtaining an initial value of a to-be-fitted parameter by use of a genetic algorithm, searching in the vicinity of the obtained initial value of the parameter through a trust-region method to finally obtain a high-precision parameter value and the determined load-displacement relation containing the Weibull damage distribution; and 5, deducing the dynamic shear constitutive model of the composite material containing the Weibull damage distribution according to a load-stress relation, a displacement-strain relation and the load-displacement relation. According to the construction method for the dynamic shear constitutive model of the fiber-reinforced composite material, a reliable basis can be provided for numerical simulation calculation of thefiber-reinforced composite material under the dynamic working conditions.

The invention discloses a method and a device for judging optimal the time of stroke of a pumping unit. The method comprises the following steps of: obtaining a current load displacement indicator diagram according to data of load and displacement sensors; changing the time of stroke, re-collecting the load displacement data to obtain the changed load displacement indicator diagram after the changing of the time of stroke; calculating relative liquid yield according to the ground indicator diagram before and after the changing of the time of stroke, judging the variation situation of the ratio of; and continuously running the programs until the minimal time of stroke is obtained under the maximal daily liquid yield, i.e., the optimal time of stroke is obtained. The device mainly comprises the load sensor, the angular displacement sensor, an RTU (remote terminal unit), a frequency changer, and on the like. Due to the fact that the optimal time of stroke judging program adopts the relative variation value of the daily liquid yield instead of the absolute value of the daily liquid yield, so the program is low in computing amount and small in occupied internal memory, and is capable of directly running on the RTU, further, the pumping unit can finish the data collection, computation and control independently by self without depending on the computation and the control of a host computer, and the system is ensured to run more reliably.

The invention relates to a composite hydrodynamic reservoir bank slope stability prediction method, which belongs to the technical field of slope stability evaluation and landslide disaster monitoringand early warning. The method comprises the following steps of preliminary investigation of a reservoir-type landslide, selection of a displacement monitoring point, arrangement and installation of monitoring equipment, processing of monitored data, determination of landslide basic physical and mechanical property parameters and a slope slicing method, determination of overall residual downward thrust increment of the slope above a water line under effects of rainfall, determination of a slope saturation line during a reservoir water line decreasing process, determination of residual downwardthrust increment of the slope in a water line change range under effects of the reservoir water line, determination of reservoir-type landslide composite water loading and response parameters, determination of a composite hydrodynamic increased load displacement response ratio prediction model, and evaluation and monitoring and early warning of the composite hydrodynamic slope stability. The corresponding relationship between the reservoir-type landslide composite hydrodynamic increased load displacement response ratio parameters and the landslide stability is disclosed, and on the basis, a reservoir-type slope stability evolution law is analyzed and evaluated.

The invention discloses a determination method for predicting material uniaxial constitutive relation through circular ring radial compression energy. According to the method, quasi-static pressing loading is carried out on a size-variable circular ring by adopting a compression clamp with a limiting groove, after a continuous load P- displacement V curve is obtained, radial compressive stiffness S of the circular ring is marked though the elastic region data of the load-displacement curve, and the material uniaxial constitutive relation is predicted through post processing. By adopting the method, the defects that both time and labor are consumed since finite element iteration is required to be carried out for multiple times and astringency cannot be evaluated in advance in the prior art are overcome, obtaining of the material uniaxial constitutive relation can be realized simply, conveniently and efficiently and an ideal effect is realized. Particularly, the method has important significance in obtaining of the material uniaxial mechanical properties of important pipeline structures existing in aerospace, nuclear power, high-speed rail, oil and gas transportation and other key projects.

The invention discloses a method for measuring and representing microcosmic interface phases of asphalt concrete. According to the method, a small asphalt concrete piece is wrapped with epoxy resin AB glue and cured into a flat cylindrical test piece in a mold to prevent the small asphalt concrete piece from being stripped and deformed in the follow-up polishing process and improve the polishing flatness; the test piece is polished with metallographic abrasive paper, and then a final test piece meeting the requirements is obtained after ultrasonic cleaning is performed on the test piece when polishing is completed; the test piece enters a measuring step, all surface phases of the test piece are observed through amplification with a nanoindentation instrument, a measuring region containing all the phases is selected, equally-spaced dotting measuring is performed, and a load-displacement curve and a microscope image are recorded; after the test is finished, the Young modulus and hardness of all the points are computerized according to the load-displacement curve, and then the modulus and hardness indexes of all the phases are obtained by combining the phases where the measured points are located; finally, the size and the mechanical characteristics of a microcosmic interface transition area between asphalt and aggregates in the test piece can be analyzed and estimated according to the changing condition of the distance among the measured points and the mechanical indexes.

The invention discloses a device and a method for testing an ultrahigh-temperature indentation load-displacement curve. A to-be-tested ultrahigh-temperature material test piece is placed on a test piece loading platform in a high temperature furnace; one end of a loading rod is connected with a loading device located outside the high temperature furnace, a press head is arranged at the other end of the loading rod, and the other end of the loading rod stretches into the high temperature furnace and contacts the test piece; an ultrahigh-temperature extensometer for measuring displacement of the loading rod in the furnace is arranged on the high temperature furnace; a precise displacement sensor is used for measuring the displacement of the loading rod outside the high temperature furnace; and the test piece and the press head are heated to an experiment temperature by the high temperature furnace, after the temperature is stable, the test piece is loaded and unloaded by adopting the loading device, meanwhile, the ultrahigh-temperature extensometer close to the test piece and the precise displacement sensor away from the test piece are adopted to measure indentation displacement, and the ultrahigh-temperature extensometer and the precise displacement sensor are cooperated to measure the ultrahigh-temperature indentation load-displacement curve with high precision. According to the device and the method for testing the ultrahigh-temperature indentation load-displacement curve, measuring error of the extensometer caused by reverse motion idle running in the transforming process from loading to unloading is eliminated by two displacement sensors, and the measurement precision is improved.

The invention discloses a method for measuring a uniaxial tension large-strain-range hardening curve of a metal round bar specimen, and belongs to the field of mechanical property testing of metal materials. The method only needs to perform the following steps of: measuring the radius of the cross section of a round bar tension specimen, calculating the stress strain value at the time of fracture,and fitting the stress strain values before necking and at the time of fracture by adopting a hardening model to determine an initial value of hardening model parameters; and then, generating a plurality of hardening parameter combinations by adopting an experimental design method, inputting hardening curves determined by the parameters into finite element software for tension simulation, outputting the corresponding simulated load displacement curves, calculating the sum of the absolute area differences between the simulated and experimental load displacement curves, constructing a responsesurface model by taking the value as the response and the hardening parameters as independent variables, taking the minimization of a response surface function as an optimization objective, optimizingan objective function by adopting a quadratic programming method, and determining that an optimal solution is a large-strain-range hardening curve of an experimental material. The scheme of the invention has the advantages of small calculation amount and high measurement accuracy.

The invention discloses a method for obtaining the rock micrometer-scale elasticity modulus and yield strength. The method comprises the steps that a rock micrometer indentation experiment is carriedout through a micron-sized pressure head, a load-displacement curve in the loading process is obtained, and the rock elasticity modulus under different displacement conditions can be obtained by combining an indentation experiment formula; micro-CT scanning is carried out on a rock sample, and a finite element mesh model of a rock skeleton in an indentation area is built; the elasticity modulus obtained through the micrometer indentation experiment serves as an input parameter to simulate the rock uniaxial compression process, the model overall elasticity modulus is obtained and compared witha rock core uniaxial compression experiment, and the pressing depth RVE effectively representing the rock micrometer elasticity modulus is determined; and then, rock sample indentation experiment numerical simulation under different yield strength conditions is carried out, the simulated loading and unloading load-displacement curve is compared with the indentation experiment to be verified, and thus the rock micron-sized yield strength is determined.

The invention discloses a railroad sleeper detection system. The railroad sleeper detection system comprises a railroad sleeper detection data acquisition device and a data processing system. The railroad sleeper detection data acquisition device comprises a force exerting device, a pressure sensor (3), a displacement sensor (4) and a multi-channel data acquisition instrument (5). The pressure sensor (3) and the displacement sensor (4) conduct sleeper pressure measurement and sleeper displacement measurement and are connected with the multi-channel data acquisition instrument (5) through cables respectively. The multi-channel data acquisition instrument (5) is further connected with the data processing system. The data processing system comprises a digital processing device (61), a load displacement analyzing and processing module and a data output device. The load displacement analyzing and processing module is arranged in the data processing device (61). The railroad sleeper detection system can detect the load displacement of a rail and is high in detection speed, high in precision, high in stability, less in error, little in manual work, high in efficiency, safe and reliable.