19 results about "Pure shear" patented technology

The invention provides an improved Arcan disc complex stress metal fatigue test method. The method specifically comprises the following steps: (1) designing clamps for stretching, stretching-shearing and pure shearing fatigue tests; (2) designing a clamp for compression, compression-shear and pure shear fatigue tests; (3) designing a stretching-shearing or compression-shearing sample, and connecting the clamps designed in the step (1) and the step (2) to a clamping rod and a pin required by a fatigue testing machine; and (4) assembling the clamps designed in the step (1) and the step (2) and the sample designed in the step (3), and connecting to a fatigue testing machine by using a clamping rod and a pin. The metal fatigue performance test under different stress states such as stretching / compression, stretching-shearing / compression-shearing, pure shearing and the like can be realized, the fatigue test result difference caused by different stress states can be quantified, optical and high-resolution scanning electron microscope observation under in-situ conditions can be compatible, and the fatigue failure mechanism analysis is facilitated.

The invention relates to the technical field of mechanical property testing, in particular to a laminated plate mechanical property evaluation method and system based on strain data. The method comprises the following steps: performing a biaxial tensile experiment on a laminated plate sample, synchronously acquiring load time-history data and a full-field speckle image, constructing a full-field strain matrix through a mapping algorithm, dispersing the full-field strain matrix into nodes, dividing a core pure shear region and a stress diffusion region, and then obtaining first principal strain through principal component analysis; a load transmission efficiency attenuation spectrum and full-field strain energy entropy density are calculated respectively, a dynamic correction model is constructed in combination with weighted coupling of preset shape characteristic parameters, and a real constitutive curve is obtained by using the model to calculate correction coefficient inversion nominal stress; the thermodynamic entropy characteristic is introduced, so that the problem that the stress field distortion at the nonlinear damage stage of the material is difficult to sense by a traditional method is solved, and the biaxial mechanical property test precision of the laminated plate is effectively improved.

This application discloses a creep testing device for a fiber composite-steel interface. The device horizontally supports the specimen using a first support and a second support. A first loading mechanism applies a downward vertical force to the specimen, with the point of application located between the first end and a pre-fabricated crack. A second loading mechanism applies a downward vertical force to the specimen, with the point of application located between the second end and the pre-fabricated crack. The fiber composite-steel beam interface of the specimen primarily bears Type II interfacial shear stress caused by bending deformation, while the Type I peel stress approaches zero. This avoids the combined stress-shear + peel stress generated by direct tension in traditional lap joints, enabling the test results to accurately reflect the interface's durability under pure shear.

The invention belongs to the technical field of material analysis, and relates to a tire rubber fatigue crack propagation test method which comprises the following steps: preparing a sample wafer of a rubber product; determining the direction of the crack propagation test according to the rolling direction of the rubber sample sheet, and cutting to obtain a pure shear fatigue crack propagation test sample with a notch on a single side; performing a critical tearing energy test under the temperature condition of 0-70 DEG C to obtain a relationship between the critical tearing energy and the temperature; determining R = 0 and 0lt; rlt; 1, the relationship among the crack propagation rate, the crack propagation length and the temperature under different temperature conditions. The invention provides a test method and a parameter determination method aiming at a rubber material with a strain crystallization characteristic and considering the influence of the strain crystallization characteristic on a fatigue crack propagation characteristic, and the strain crystallization rubber at 0lt can be obtained through the parameters of the invention; rlt; 1, and makes up the blank of no research on strain crystallization fatigue crack propagation rate and crack propagation length in the prior art.

The present application relates to the technical field of mechanical property testing, and more particularly to a method and system for evaluating the mechanical properties of a laminate based on strain data. The method comprises the following steps: performing a biaxial tensile test on a laminate sample, simultaneously collecting load time history data and full-field speckle images, constructing a full-field strain matrix and discretizing it into nodes using a mapping algorithm, dividing the core pure shear zone and stress diffusion zone, obtaining the first principal strain through principal component analysis, calculating the load transfer efficiency attenuation spectrum and the full-field strain energy entropy density, respectively, combining the preset shape feature parameters to construct a dynamic correction model, and using the model to calculate the correction coefficient to obtain the true constitutive curve by inverting the nominal stress. The introduction of thermodynamic entropy characteristics solves the problem of stress field distortion in the nonlinear damage stage that is difficult to perceive by traditional methods, effectively improving the accuracy of biaxial mechanical property testing of laminates.

The invention provides a method for characterizing a fatigue crack growth rate without digital image processing, and belongs to the field of fatigue crack testing of rubber materials. The method comprises the following steps: firstly, carrying out a tensile test on an unprefabricated crack sample by utilizing a prefabricated crack annular sample (RS), calculating a node tensile force f0 under a pure shear working condition according to a test result, and simulating a quasi-static tensile test of the prefabricated crack sample; according to a simulation result, further calculating to obtain a drawing force scale factor and a distribution function of the drawing force scale factor, the function being determined by two variables of a circumferential radian theta and a crack length c, and the function being integrated to obtain the total drawing force F (c) of the annular sample; and further introducing a force arm value gc as a characteristic value, correcting the characteristic value to obtain corrected values gc and c0, performing a fatigue crack propagation test on the annular sample of the precrack to establish a relationship between gc, c0 and the cycle index N, and finally establishing a relationship between the cycle index N and the crack length c by using gc and c0 to obtain the fatigue crack propagation rate.

The invention provides an annular sample, a clamp and an axial tension pure shear test method, belongs to the field of material mechanical property test, and aims to thoroughly solve the problem of non-uniform pure shear stress field caused by necking phenomenon. Under axial tension, a sample global uniform pure shear stress field is achieved, the pure shear stress-strain relation of the hyperelastic material is directly solved according to force and displacement data of the sample, and the influence of tension displacement and strain is avoided. The mechanical property of the rubber material can be better evaluated. Through verification, an annular sample tensile test has good substitutability for a plane tensile test.

The invention relates to a support structure for components subjected to large loads and torques. The invention particularly relates to a novel elastic bearing which connects large, heavy and moving components of a wind power installation, such as a transmission or a generator, to the power train or the rotor shaft, wherein the active torsional forces can be transmitted by pure shear deformation of the elastic element.

The embodiment of the application discloses a kind of crack parameter determination method, device and computer storage medium, belong to the technical field of seismic exploration.The method comprises: when receiving the multi-wave seismic data including pure shear wave seismic data, PSV converted wave seismic data and SVP converted wave seismic data by geophone, due to the reverse direction of shear wave source excitation direction caused by the back and forth of seismic source vehicle, therefore, the polarity adjustment processing can be carried out to the shear wave source seismic data therein;Then, according to the seismic data imaging profile corresponding to the multi-wave seismic data, the shear wave splitting analysis time window corresponding to the multi-wave seismic data in each target layer is determined, and the crack parameter of each target layer is determined by the shear wave splitting analysis time window corresponding to the multi-wave seismic data in each target layer.The embodiment of the application carries out shear wave splitting analysis by converted wave and pure shear wave, which guarantees the uniqueness and reliability of crack parameter.

The application discloses a dielectric elastomer film multi-mode stretching device and a stretching method. The dielectric elastomer film multi-mode stretching device comprises a base guide rail, a pure shear stretching module, an equal biaxial stretching module, a uniaxial stretching module and a film fixing module. One of the pure shear stretching module, the equal biaxial stretching module or the uniaxial stretching module is installed on the base guide rail. The film fixing module is assembled on one of the pure shear stretching module, the equal biaxial stretching module or the uniaxial stretching module. The uniaxial stretching module, the pure shear stretching module and the equal biaxial stretching module all comprise a film shearing type stretching assembly. The film shearing type stretching assembly is connected by a shearing type clamping unit. The application realizes effective clamping and uniform stretching of the dielectric elastomer film through the design of the film shearing type stretching assembly, can accurately control the film stretching multiple, and can meet the demand of different stretching modes by replacing different stretching modules.

The invention belongs to the technical field of physical and chemical testing, and relates to a high-brittleness random fiber network thermal protection material shear experiment device and method.The method comprises the steps that firstly, after a sample is wrapped with an isolation pad, the sample is placed in a fixed clamp assembly and a sliding clamp assembly, and an initial gap between the fixed clamp assembly and the sliding clamp assembly is accurately set through a gap gasket; then, the load applying end of the testing machine control box pushes the sliding clamp assembly to generate displacement, shear load is applied to the sample, and the whole process is monitored in real time by the computer terminal and shear force and displacement data are recorded. Stress concentration generated during clamping of the clamp is effectively buffered through the isolation pad, and a sample is prevented from being damaged in advance in a non-shearing area; the clearance gasket is matched with the relative movement of the fixed / sliding clamp assembly, so that the load is ensured to act on the sample in a pure shearing form; the modularized clamp design is compatible with different sample shapes and shearing modes, so that the universality of the method and the accuracy and reliability of a test result are remarkably improved.

The invention relates to a clamp for testing the adhesive property of a rubber roller interface under a calendaring working condition and a testing method. The clamp comprises a base, a supporting structure, a heating and clamping structure, a water supply structure and a driving structure, the supporting structures are arranged on the two sides of the base and provided with a rotatable rubber roller to be detected. The heating and clamping structure is provided with a plurality of pairs of arc-shaped clamping jaws with a heating function, containing grooves are formed in the inner sides of each pair of clamping jaws, and the clamping jaws can move in opposite directions to clamp a rubber roller; the rubber roller comprises a metal pipe with a cooling flow channel and an outer rubber layer, the rubber layer is matched with the containing groove, the water supply structure introduces cooling liquid into the cooling flow channel, and the driving structure is connected with the rubber roller through the torque detection unit and detects a torque peak value. The interface shearing process is simulated more truly; meanwhile, a heating clamping jaw and internal cooling are adopted for cooperative temperature control, the temperature gradient under the calendaring working condition is accurately simulated, and the test accuracy and the working condition simulation authenticity are improved.

The application provides a pre-stack fast-slow pure transverse wave separation method and device, and belongs to the technical field of seismic exploration. A first kind of observation pre-stack pure transverse wave four-component seismic data is rotated in a direction, then separated-azimuth stacking or separated-azimuth migration stacking is performed, a second kind of observation separated-azimuth stacking pure transverse wave four-component seismic data which is convenient for analyzing transverse wave splitting characteristics is formed, then a target crack direction is obtained, fast-slow transverse wave separation is performed on the second kind of observation separated-azimuth stacking pure transverse wave four-component seismic data according to the target crack direction, a judging matrix is combined, whether the target crack direction changes with depth is judged, then fast-slow transverse wave separation is performed on seismic data, so that the pre-stack fast-slow pure transverse wave separation of transverse wave data is performed, the precision of fast-slow wave separation is improved, the pre-stack migration calculation amount of two-component seismic data except fast transverse wave and slow transverse wave is reduced, and the velocity of fast transverse wave and the velocity of slow transverse wave are conveniently adjusted subsequently.

The application discloses a kind of in-situ testing methods of material shear stress under double-beam system, it is related to shear stress testing technical field, comprising the following steps: step one, with electron beam perspective analysis sample block, with ion beam imaging to determine processing area;Step two, ion beam processing microblock topography;Step three, mechanical hand assisted microblock extraction and finishing;Step four, with ion beam deposition microblock;Step five, ion beam processing shear sample;Step six, with electron beam perspective carries out pure shear test.The application provides a kind of method for determining critical shear stress on micro-nano scale to specific structure metal material, provides important support for regulating metal material plastic deformation.

The invention relates to the technical field of tire computer aided design, in particular to a rubber fatigue crack propagation rate prediction method and system, a storage medium and a program product. According to the method, rubber samples with different crosslinking densities are constructed by adjusting the dosage of a sulfur donor, the crack growth rate and tearing energy data are rapidly obtained by adopting a gradient loading pure shear fatigue test, and a crack growth rate aesthetic model in a segmented index-power law form is constructed by combining energy dissipation analysis and a strain induced crystallization mechanism. According to the method, the optimal crosslinking density enabling the crack growth rate to be minimum can be effectively recognized, quantitative prediction and formula optimization of the fatigue resistance of natural rubber are achieved, and the service life of high-strain rubber components such as aircraft tires is remarkably prolonged.

The utility model relates to a kind of device for testing the bonding performance of fiber reinforced polymer (FRP) and concrete, including fixture assembly and FRP support and concrete fixed module.The device is used to evaluate the bonding performance of FRP-concrete structure under pure shear mode and mixed mode failure, and the sample used can be deployed with any servo hydraulic load test frame.The device can test the bonding performance of FRP-concrete by changing the debonding angle under pure shear mode or mixed mode, thereby characterizing the shear / debonding properties of bonded joints.The utility model can solve the inconvenience of existing FRP-concrete bonding performance testing, and different debonding angles need to be tested by respectively designing test devices and different test modules in pure shear mode and mixed mode testing, thereby reducing test efficiency, poor repeatability, and unable or difficult to compare the performance test results obtained horizontally.

The invention relates to a concrete joint surface repeated shear test device, which comprises a counter-force support system, which comprises a first counter-force column, a second counter-force column and a test bed for supporting a concrete test piece from the bottom and providing a moving plane; the clamping and connecting system comprises a first clamping and connecting mechanism used for clamping and fixing the first concrete and a second clamping and connecting mechanism used for clamping and fixing the second concrete; the loading system comprises a servo actuator with an adjustable horizontal posture, one end of the servo actuator is fixed on the first counter-force column, and the other end of the servo actuator is connected with the first clamping connection mechanism; the auxiliary installation system comprises a jack support and a mechanical jack installed on the jack support, and the output end of the mechanical jack is connected with the second clamping connection mechanism. Compared with the prior art, installation is easy and convenient, the force transmission mechanism is clear, and it can be guaranteed that the joint face is in a pure shear state.

This specification provides a method and apparatus for determining fracture density based on pure shear wave reflection amplitude domain information. The method involves acquiring first and second shear wave data, as well as logging data, for the target area; preprocessing the first and second shear wave data and logging data to determine the first and second shear wave amplitude gathers, seismic wavelets, and stratigraphic interpretation information; simultaneously inverting the first and second shear wave amplitude gathers, seismic wavelets, and stratigraphic interpretation information using a pre-defined pre-stack joint inversion objective function to determine the shear wave splitting parameters; the pre-defined pre-stack joint inversion objective function is constructed based on a linearized reconstruction reflection coefficient equation; and determining the fracture density of the target area based on the shear wave splitting parameters and the pre-defined mapping relationship between the shear wave splitting parameters and fracture density. This method effectively solves the problem of weak capture and low resolution of fracture details by time-difference attributes in existing technologies.