45 results about "Static stretching" patented technology

The invention discloses a method for determining the large deformation uniaxial constitutive relation of a material based on the energy principle and a P-V curve obtained by stretching a central circular hole plate specimen. The method comprises the following steps: performing quasi-static tensile test on a central circular hole plate specimen to obtain a continuous P-V curve, and determining the elastic stiffness S, the feature load P* and the displacement index m by the curve so as to obtain the large deformation uniaxial constitutive relation of the material. The method disclosed by the invention is applicable to a ductile material with an isotropic strengthening and constitutive relation according with the power law, wherein the structure of the central circular hole plate specimen is special, namely during the tensile test, the circular hole edge center point material unit of the specimen is under uniaxial stress state before the occurrence of necking; compared with an equidistant specimen, the method disclosed by the invention is easier to implement, and the obtained uniaxial stress-strain relation is wider in range; the method has great significance on the engineering structure design and safety assessment work.

The invention discloses a uniform stress criterion-based bonding structure fracture failure analysis method, which is characterized by comprising the following steps of 1, carrying out the quasi-static tensile tests on the bonding joints with different tension-shear ratios to obtain the initial failure loads and the initial failure areas of the bonding joints with different tension-shear ratios, 2, establishing a finite element model of a bonding joint with the same test size and different tension-shear ratios, and applying the initial failure load to a position, corresponding to the initial failure area, in the finite element model to obtain an initial failure point and initial failure stress, 3, obtaining the equivalent forces of the bonding joints with different tension-shear ratios ina complex stress state, and 4, establishing a finite element model of the bonding joint needing to be subjected to fracture failure analysis, applying the one-way stress, when the stress is greater than or equal to the maximum equivalent stress, starting to fail the glue layer of the bonding joint, determining a failure unit, deleting the failure unit, and recording the corresponding failure stress.

The invention provides an ultrasound-assisted tensile test machine and a test method. The test machine comprises a base; a force value monitoring system with a force sensor; a lower clamp head fixed on the force sensor; a lifting device mounted on the base; an ultrasonic vibration system which comprises an ultrasonic controller and an ultrasonic vibration device, wherein the ultrasonic vibration device is mounted on the lifting device, the ultrasonic vibration device comprises an ultrasonic vibration generator and an ultrasonic horn, the ultrasonic horn is connected with the ultrasonic vibration generator, and a tested piece is connected and fixed between the ultrasonic horn and the lower clamp head; a strain monitoring system with an industrial camera; and a signal collection and processing system which is connected with the force value monitoring system, the lifting device, the ultrasonic vibration system and the strain monitoring system. According to the test machine and the test method, high frequency controllable vibration is provided through utilization of the ultrasonic vibration generator and a vibration direction is consistent with a static stretching direction of the tested piece, so an ultrasonic vibration load and static stretching load overlapped tensile test is realized.

The invention discloses a method for determining allowable amplitude of a turbine engine blade. The method comprises the following steps: correspondingly carrying out a normal-temperature quasi-statictensile test on a standard smooth test piece of the material for the blade and a high-temperature quasi-static tensile test on the standard smooth test piece of the material for the blade so as to obtain the attribute of the basic material of the material for the blade of the turbine engine; correspondingly carrying out a normal-temperature high-cycle fatigue test on a standard smooth test pieceof the material for the blade and a normal-temperature high-cycle fatigue test on the standard smooth test piece of the material for the blade to obtain an equal life curve of the material for the blade; carrying out an actual blade high cycle fatigue device to determine the blade fatigue limit at normal temperature; and introducing a relation between the fatigue life reserve coefficient and the amplitude of the monitoring point, and determining the allowable amplitude of the actual blade. The method is simple in design experiment and low in cost; the determined allowable amplitude result is more accurate, and the accuracy of the result is improved.

The embodiment of the invention relates to a method and device for obtaining and verifying constitutive parameters and dynamic failure parameters. The method comprises the steps of: performing a quasi-static tensile experiment of an aluminium alloy material, and obtaining the quasi-static stress-strain curve of the aluminium alloy material; obtaining the dynamic stress-strain curve of the aluminium alloy material in different strain rates; obtaining the constitutive parameters of the aluminium alloy material by fitting according to the quasi-static stress-strain curve and the dynamic stress-strain curve; analyzing the fracture generated when the aluminium alloy material is tested, and determining the dynamic failure parameters of the aluminium alloy material; and, performing simulation calculation according to the constitutive parameters and the dynamic failure parameters, verifying the accuracy of the constitutive parameters and failure strain of the aluminium alloy material, simulating quasi-static stress-strain and dynamic stress-strain of the aluminium alloy material, then, obtaining the constitutive parameters and the dynamic failure parameters of the aluminium alloy material,and finally, verifying the constitutive parameters and the dynamic failure parameters.

The invention provides a system and a method for detecting the crimping quality of an end fitting of a composite insulator. The system comprises a horizontal lathe and a pull rod arranged in the horizontal lathe, wherein a tensile load device used for providing pull force for a to-be-detected composite insulator and a torsion load device for providing torsional force for the to-be-detected composite insulator are sequentially arranged on the pull rod in a sleeving manner; a sample end of the torsion load device is connected with one end of the to-be-detected composite insulator, and the other end of the to-be-detected composite insulator is connected with a mobile locking device; a testing device used for acquiring the deformation condition generated when a material of the to-be-detected composite insulator is damaged is further arranged at the sample end of the torsion load device; the output end of the testing device is connected with a computer. The system and the method are used for analyzing the crimping condition of the end fitting of the composite insulator by simulating the static tensile load and the dynamic torsional load borne by the composite insulator in the actual on-line operation process and by comprehensively utilizing the detecting device.

A structure for a semi-static tensile member and a method for producing the semi-static tensile member. A tensile member is prepared by attaching terminations to an assembly of synthetic filaments. The tensile member is then attached to a loading apparatus that subjects the tensile member to a pre-defined loading process. The tensile member is thereby conditioned to a stable length. A bend restricting device is attached to the cable assembly proximate the point where the synthetic strands exit the termination and enter the freely-flexing portion of the cable. The bend restricting device is configured to permit periodic inspection of the cable in the region it covers.

The invention discloses a multifunctional thin film three-axis tensile testing machine. The multifunctional thin film three-axis tensile testing machine comprises a horizontal double-axis testing device and a Z-axis tensile testing device, wherein the Z-axis tensile testing device is constructed above the horizontal double-axis testing device; the Z-axis tensile testing device comprises second stand columns, frameworks, a first fixed guide rail beam, a second fixed guide rail beam, a movable guide rail beam, a Z-axis platform, a first fixed plate, a movable rod, an electric cylinder, a second tension sensor and a second clamp. The invention further discloses a thin film three-axis tensile testing method which comprises a plurality of steps. The multifunctional thin film three-axis tensile testing machine and the testing method can realize multi-angle tension and have a multi-test function; the multi-angle tension comprises unidirectional static tension, low-cycle circulation back-and-forth tension, bidirectional static tension, low-cycle circulation back-and-forth tension with any double-axis stress ratio, three-dimensional connection part tension and low-cycle circulation back-and-forth tension with any three-axis stress ratio; the multifunctional thin film three-axis tensile testing machine is stable in operation, and the multifunctional thin film three-axis tensile testing machine and the testing method can be used for building membrane tests, airship skin tests and the like.

The invention provides a method used for obtaining stress-strain curve of metal materials at static tensile states. The method is invented through improvement of tensile experiment and experiment dataprocessing analysis based on strain control or displacement control states, and mainly comprises two steps: firstly, experiment data is obtained through improved tensile experiment, and then the experiment data is adopted in processing of the real stress-strain curve of an obtained material at limit slow tensile, i.e. static tensile states. According to the method, the real stress-strain curve ofa material at long period stretching process is obtained through experiments, so that effective evaluation of material real using performance is realized, and important guiding meaning on the metal material at long term stretching states is achieved.

The invention discloses a tissue engineering lymph node model and a construction method thereof and belongs to the technical field of tissue engineering and regenerative medicine. The tissue engineering lymph node model comprises lymphocytes separated from lymphoid tissues and a collagen-Matrigel scaffold. The construction method for the tissue engineering lymph node model comprises the following steps of: preparing lymphocyte suspension and primary generation mouse fibroblast cell suspension; and compounding mixed cell suspension and the collagen-Matrigel scaffold, and culturing in a mold subjected to static stretching to obtain the tissue engineering lymph node model. The scaffold system subjected to static stretching can better simulate in-vivo environment and support the growth and proliferation of the lymphocytes, secretion of cell factors and the expression of surface markers, and has important significance for applying the tissue engineering lymph node model to immunotoxicity evaluation of biological materials, immune medicine screening and the like. The construction method has the advantages of simple operating process and mild implementation conditions.

The invention relates to a sample clamping device for a high-temperature high-frequency complicated load loading test, and belongs to the technical field of material testing. The sample clamping device is composed of a left clamp and a right clamp which are same in structure; in the left clamp or the right clamp, an outer ring of a sleeve is matched with an inner ring of a knuckle bearing or a clamping part of a standard plate-shaped sample, is fixed through a quick-change baffle ring and is mounted on a supporting seat; an inner ring of the sleeve is provided with a thread, and is screwed with an outer thread section of a high-temperature high-frequency complicated load sample to realize the fixation of the high-temperature high-frequency complicated load sample; the bottom of the supporting seat is provided with four through holes, and is mounted on a tensile bending composite fatigue testing machine through bolts; and a tensile loading device on the testing machine is connected withthe supporting seat through bolts to realize the static tensile loading of the high-temperature high-frequency complicated load sample. The sample clamping device has the advantages as follows: the sample clamping device can be applicable to a material testing machine with loading functions of high temperature, tension, bending, ultrasonic vibration and the like; the sample clamping device is simple in structure and convenient in operation; and a powerful guarantee is provided for testing the mechanical properties of key structure materials in the fields of aviation, spaceflight and the like.

A calf-stretching device enables a user to conduct stretching exercises of the gastrocnemius muscles of the leg. The calf-stretching device includes a support base positionable on a floor surface and left and right surfaces immovably attached to the support base. Each of the left and right surfaces present a convex curved surface from a front side to a back side to receive respective feet of the user, the convex curved surface having a greater radial dimension on an inner portion than an outer portion to correspond to a foot arch of the user.

The invention provides an intermittent hypoxia training device. The intermittent hypoxia training device comprises a hypoxia training system, a muscle stretching training instrument and a control module, the hypoxia training system is used for providing hypoxia air and normal oxygen content air required by intermittent hypoxia training, a valve control module arranged in the hypoxia training system is connected with the control module, and the muscle stretching training instrument is used for enabling a trainee to keep a training posture to carry out intermittent hypoxia training. An instruction input module arranged on the muscle stretching training instrument is connected with the control module. The invention further provides a control method of the intermittent hypoxia training device.By combining muscle static stretching training and intermittent hypoxia training, the auxiliary treatment of allergic respiratory diseases, the improvement of cardiovascular functions, the preventionof sudden cardiac death, the improvement of endogenous testosterone level and the improvement of whole-body microcirculation ability are facilitated, the training intensity is low, and the device andmethod are suitable for common trainees to use.

The invention discloses a method for positioning transverse cracks of a carbon fiber composite material by using a chirp grating, which comprises the following steps of: (1) manufacturing a carbon fiber composite material cross-ply laminate with the stacking sequence of [0-degree 2/90-degree 4/0-degree 2], and embedding a chirp grating sensor into a 0-degree layer the carbon fiber composite material cross-ply laminate, wherein the chirp grating sensor is adjacent to a 90-degree layer; (2) under a condition with a constant temperature, using an optical fiber sensing analyzer to monitor a chirp grating reflection spectrum of a carbon fiber composite material test piece in a quasistatic tensile test; and (3) adjusting the length of the chirp grating to be accordant with a bandwidth phase of the chirp grating reflection spectrum before embedding in a coordinate system to ensure that a wavelength position corresponding to a point with decreased light intensity and a grating position corresponding to the wavelength in the chirp grating reflection spectrum are the positions where the transverse cracks are generated in the 90-degre layer of the composite material at that time. The method is simple, has a low cost, and can detect the transverse cracks in the carbon fiber composite material in real time.

The invention provides a method for designing the optimal back zone draft ratio of a drawing frame. The method comprises the steps that an upper chuck and a lower chuck of a drawing tester clamp the two ends of a fiber fringe to conduct drawing, the fringe between the upper chuck and the lower chuck is drafted and drawn to be thin and long till the middle of the fringe is completely separated along with the process of drawing, and when the drawing force is the largest, the corresponding draft ratio is the optimal back zone draft ratio of the drawing frame. According to the method for designing the optimal back zone draft ratio of the drawing frame, static drawing of the drawing tester is adopted to simulate dynamic drawing, according to a relation curve of simulated drawing force and extension, the extension is converted into the draft ratio through a formula, the extension corresponding to the maximum value of the drawing force can have the maximum drawing force, evenness of sliver is minimum at this time, and therefore the draft ratio corresponding to the maximum value of the drawing force is the optimal draft ratio of a back draft zone. The method for designing the optimal back zone draft ratio of the drawing frame is simple, practical and capable of saving time, labor and raw materials, and the simple, effective and accurate method is provided for design of the back zone draft ratio of the drawing process.

The invention relates to a method for manufacturing a static stretching thin film reflecting mirror. The periphery of a thin film in the thin film reflecting mirror is fixed on a circular ring fixing device. Electrodes are arranged under the thin film. The electrodes comprise a central circular electrode and annular electrodes with the equal radial width, wherein the annular electrodes are distributed in a concentric-circle mode. The radius of the central circular electrode is 1.5-1.7 time the radial width of the annular electrodes. The number of the annular electrodes is 3-10. The pressure of the central position of the radius of the central electrode is used as the pressure of the central electrode area. The pressures of radial central points of the annular electrodes are used as the pressure of the annular electrode area. The pressures are converted into voltage signals to be input to the corresponding electrodes. The static stretching thin film reflecting mirror can be obtained through machine-shaping. Compared with a standard paraboloid, the three-dimensional surface shape of the thin film reflecting mirror obtained by adopting the static shaping control method is small in error. Compared with the prior art, the static stretching thin film reflecting mirror has the advantage that the surface shape precision is remarkably improved.

The invention discloses an improved type breakage failure stress testing method of an adhesion test piece. The improved type breakage failure stress testing method comprises the following steps: 1, performing quasi-tensile test on n adhesion abutting joints with different adhesive layer thicknesses to acquire initial breakage failure loads and initial breakage failure points of the n adhesion abutting joints; 2, building finite element models of the adhesion abutting joints of which the test sizes are identical and the adhesive layer thicknesses are different, applying the initial failure loads into the finite element models to ensure that an application position corresponds to the quasi-tensile test to acquire the breakage failure stresses of the unit corresponding to the initial breakagefailure points, wherein the failure stress comprises components, including sigma 1, sigma 2 and sigma 3, of three main stresses; and 3, acquiring the breakage equivalent stresses of the adhesion abutting joints with different adhesive layer thicknesses under complicated stress states. According to the improved type breakage failure stress testing method disclosed by the invention, the initial failure stresses of the adhesion abutting joints can be determined, the breakage equivalent stresses is determined, a real failure process is approached relatively, and the correctness of a breakage failure analysis process of an adhesion structure is improved.