115 results about "Tensile fatigue" patented technology

The invention relates to a multilevel static-dynamic coupling mechanical loading device for a high-frequency fatigue test, and belongs to the fields of scientific instruments and mechanical property tests of materials. The device comprises a high-frequency fatigue loading unit, a low-frequency fatigue loading unit, a tensile loading and detection unit and a synchronous rotating unit. The device realizes tensile fatigue loading through a servo motor, a piezoelectric stack and an ultrasonic vibrator assembly, and simultaneously realizes detection of load and displacement through a mechanical sensor and an optical fiber displacement sensor. The motor drives a rotating mechanism by a motor to realize real-time dynamic crystal diffraction characterization performed on a sample by a synchronous radiation light source. Moreover, a dual-V gap feature defect sample can realize a composite load test mode of tensile-sheering or tensile-bending and the like close to the actual stress form of a material. The multilevel static-dynamic coupling mechanical loading device provided by the invention is compact in structure, and can integrate multiple test methods, thereby providing an effective test tool for the high-frequency fatigue test of the material.

The invention relates to a novel mechanical structure design scheme, which is used for testing test pieces made of various metal and alloy materials at room temperature and bearing tension fatigue characteristic, fatigue life and fatigue crack expansion test of mechanical parts (such as various mechanical connecting pieces). According to the scheme, a motor drives a speed reducer to rotate, the spring is subjected to energy storage by an eccentric shaft coupler and a crank connecting rod mechanism, the spring is controlled by four guide wheels to do vertical reciprocating motion, the potential energy of the spring is converted into moment through a lever, and extension and compression of the spring are reinforced by a lever mechanism, so that tension bars are separated vertically and the stretching effect is achieved; and force amplitude is changed through connecting points at different positions of the lever, so that fatigue tension tests of different frequency and different amplitude are realized. The invention is simple in structure and low in manufacturing cost, adopts a mechanical structure, can meet the basic performance requirement of the fatigue tension test, and can be applied to the tensile fatigue test under the lab environment.

The invention relates to a tensile fatigue and torsional fatigue testing machine for automobile parts. The tensile fatigue and torsional fatigue testing machine comprises a supporting platform, a motor, a test piece, a general fixture, an installing upright post, a base, an electronic control system, a signal generating system, a composite tension and torsion sensor and a transmission speed change system, wherein the motor and the transmission speed change system are arranged on the base; an input end of the transmission speed change system is fixedly connected with an output shaft of the motor; the composite tension and torsion sensor is arranged at an output end of the transmission speed change system; the composite tension and torsion sensor is connected with the electronic control system through a circuit; the signal generating system is sequentially connected with the electronic control system and the motor through a circuit. Compared with the prior art, the tensile fatigue and torsional fatigue testing machine has the advantages as follows: the tensile fatigue and torsional fatigue testing machine can conveniently perform a tensile fatigue test and a torsional fatigue test on the automobile parts, so that the periods for the fatigue tests are greatly shortened, and thus a basis for shortening the developing period of the whole automobile is provided.

The invention provides a test method for reciprocating tensile fatigue testing of safety break-away valves for oiling machines, which belongs to the technical field of assembly and testing of the safety break-away valves for the oiling machines. A two-way time relay is used for controlling the reciprocating motion of a piston rod of a cylinder with a valve, tensile force F born on the tested safety break-away valve can be gradually increased from 0N to the gravity of a heavy hammer via 3S-5S by utilizing the cushioning action of a spring, time is delayed for 3S-5S, and the tensile force F born on the tested safety break-away valve is gradually reduced from the gravity of the heavy hammer to 0N via 3S-5S, thereby constituting a reciprocating tensile fatigue test cycle, displaying 1 on a counter, and testing in such as way; when the repeated cycles reach 10000 and the tested safety break-away valves are not broken away, the batch of the safety break-away valves can be judged to be qualified; when the cycles are less than 10000 and any one of the tested safety break-away valves is broken away, the batch of the safety break-away valves can be judged to be unqualified. The test method has novel design and high working efficiency, and can find the quality hidden troubles of products in time and avoid the economic loss and the safety accidents.

A spring tensile fatigue test device is disclosed. The spring tensile fatigue test device comprises a support, a sliding bar, a first connecting bar, a circular disc and a supporting bar. The support is U-shaped, and is connected to the sliding bar in a sliding manner. Both ends of each spring to be tested are respectively connected to the support and the sliding bar. The first end of the first connecting bar is fixedly connected to the sliding bar, and the second end of the first connecting bar is fixedly connected to the edge of the circular disc. The circular disc rotates around a center shaft. The supporting bar is used for supporting the circular disc. The spring tensile fatigue test device can effectively test the tensile fatigue performance of the spring to be tested, and is simple in structure, high in testing efficiency and capable of largely reducing manual labor.

The invention discloses a multi-node fatigue failure test device for steel beam columns and concrete beam columns. The device comprises a steel frame system, an electro-hydraulic servo actuator, a test beam column and a test furnace, wherein the test beam column is arranged in the test furnace; the steel frame system is arranged on the periphery of the test furnace; a horizontal fatigue load device, a vertical fatigue load device and a torsional fatigue load device are sequentially arranged between the steel frame system and the test beam column, the horizontal fatigue load device is arrangedin the horizontal direction of the test beam column, the vertical fatigue load device is arranged in the vertical direction of the test beam column, and the torsional fatigue load device is arranged above the test beam column. The eccentric tensile fatigue load to the steel beam columns and the concrete beam columns can be met, the eccentric size can be set according to experimental requirements,and all that is required is to change the relative position of a column head and the test beam column; the fatigue failure test device can also meet requirements of nodes such as cross type, T type, Ltype and the like of the steel beam columns and the concrete beam columns.

The invention relates to the technical field of a fatigue test device, in particular to a tensile fatigue test machine. The tensile fatigue test machine comprises a bracket, a vibration exciter, a lower clamping head, an upper clamping head and a force sensor; the vibration exciter and the force sensor are arranged on the bracket; the lower clamping head is connected with a top rod of the vibration exciter and can synchronous move along with the top; the upper clamping head is connected with the force sensor and used for conducting the stress condition to the force sensor; the lower clamping head and the upper clamping head are arranged at intervals in the axial direction of the top rod. The tensile fatigue test machine solves the problem that the tensile fatigue test device for monofilaments does not exist in the prior art; the test machine is small in volume and high in flexibility; each accessory can be replaced according to the requirement, is high in matching property and wide in application range, and has high stability and reusability.

The invention relates to a tensile fatigue-four-point flexural fatigue in-situ mechanical testing device which comprises a tensile-fatigue pre-load loading unit, a tensile fatigue loading unit, a four-point flexural fatigue pre-load loading unit and a four-point flexural fatigue loading unit, wherein the tensile fatigue loading unit is used for driving a first-stage worm and gear component to drive a bidirectional screw rod nut pair to achieve quasi-static loading through a motor; a flexible chain is driven by piezoelectric ceramic to achieve medium-low frequency reciprocation movement of a test part in an axial tensile direction; the four-point flexural fatigue loading unit is used for driving a worm and gear to drive a one-way screw rod nut pair to achieve four-point flexural pressure head loading through another motor, four-point flexural pressure head loading is achieved with the combination of piezoelectric stack and a flexible hinge mechanism, and under a certain flexural load, a pressure head is driven through piezoelectric stack to output micro alternating displacement, and thus low-frequency fatigue loading under a flexural load. The tensile fatigue-four-point flexural fatigue in-situ mechanical testing device is compact in structure and reliable in principle, and in-situ testing on micro deformation, damage and cracking process of a material under flexural fatigue and four-point flexural fatigue stress can be implemented under observation of various imaging instruments.

The invention discloses an experimental device used for evaluation of water stability of a bituminous mixture and an experimental method. The experimental device comprises dynamic load loading equipment, a working box, an indirect tensile test device, a temperature control device and fixed equipment. The experimental device can simulate an external environment of the bituminous mixture in the practical use condition. By adopting a method of conducting an indirect tensile fatigue test in the experimental device, the evaluation of water stability performance of the bituminous mixture under multi-field coupling of stress field, temperature field, waterpower field and dynamic change is achieved, and a fatigue life is used to evaluate the water stability performance of the bituminous mixture in different use environments. The experimental device and the experimental method can be used for studying the water stability performance of the bituminous mixture in the practical use environment, and have very good evaluating effectiveness.

The invention provides a three point bending fatigue testing apparatus, which can enrich the functions of a tensile fatigue testing machine so that the tensile fatigue testing machine can carry out three point bending fatigue tests. A rotatable clamping mechanism design is adopted; the bending fatigue tests with a negative stress ratio can be carried out effectively, the boundary conditions of a three point bending experiment can be satisfied, the experiment range is enlarged; a conventional three point clamp is optimized, the apparatus cost is reduced, and the sample positioning problem is solved. The adopted clamping structure can prevent a test piece from sliding during the long term fatigue experiment process; the upper clamping structure of the clamping structure is adjustable so as to clamp test pieces with different thicknesses; the clamping structure is composed of a roller and a trapezoidal block; the roller is in line contact with a test piece during the experiment process and is convenient to replace so as to guarantee the experiment accuracy; the trapezoidal block can prevent the interference on the test piece during the experiment process; and a load can be effectively applied on the test piece during the bending fatigue experiment process (with a negative stress ratio) through the combination of an upper press head and a lower press head.

The invention discloses a biaxial tensile fatigue test piece with conic curve transition and a test method thereof. The whole test piece is in a cross shape and is provided with four loading arms; theends of the four loading arms are integrated into a central area, the other ends of the four loading arms are integrated into a clamping area, a transition area formed by a conic curve is arranged between roots of every two adjacent loading arms, the axis of symmetry of the conical curves at least coincides with one axis of symmetry of the test piece, and a thickness reducing area is arranged between the transition area and the central area and thinned by adopting double arcs or a spline curve or a single arc. The test piece has the advantages that by adopting a conic curve transition mode, the stress strain in the central area is more uniform, and the influence between every two adjacent loading arms is reduced as much as possible; through the design of smooth transition and central areathinning, breakage and cracking of the test piece in the test process occur in the central area at first.

The invention discloses an in-situ centering clamping device and method for a plate specimen of a tensile fatigue tester. The device comprises upper flat clamping blocks and lower flat clamping blockswhich are used for clamping the upper and lower ends of the plate specimen, a side clamping mechanism used for clamping the two sides of the plate specimen and a clamping driving mechanism used for driving the side clamping mechanism are arranged between the upper flat clamping blocks and the lower flat clamping blocks, one side of the side clamping mechanism is fixedly connected with a height and transverse direction adjustment mechanism used for adjusting the side clamping mechanism vertically and transversely, and the lower part of the height and transverse direction adjustment mechanism is fixed to the middle plane of a clamping head of the tensile fatigue tester through a switch-type magnetic base. By means of the device, the coaxiality of the plate specimen on a clamp is guaranteed,the centering accuracy purpose during plate specimen installation of the tensile fatigue tester is achieved, and the consistency and the accuracy of a test result are ensured; moreover, based on thepremise that same functions are achieved, the device is conciser, the production cost is greatly reduced, and the reliability of the device is greatly improved.

The invention relates to a damage quantitative evaluation method of a reinforced concrete test piece. The damage quantitative evaluation method comprises the following steps: step I: pouring a test piece; step II: performing the pretreatment before the test; step III: connecting an induction system to a dynamic strain gauge, and performing pre-loading; step IV: applying the load according to a predetermined repeated loading rule, recording stress-strain data, reading residual strain on the surface of the concrete after a unloading standing target time after the test is ended, and calculating the residual strain (shown in description) of the concrete at the initial tensile fatigue damage state, accumulated residual strain sigma rc of the concrete at an initial state of the tensile fatigue damage corresponding to the tensile damage of the concrete and the residual strain sigma r of the concrete after N times of circulation of the tensile fatigue load; and step V: quantifying the damage quantitative of the single-axis tensile concrete by adopting a residual strain method according to the consistence of a damage development rule and a fatigue deformation rule of the concrete. The damage quantitative evaluation method of the reinforced concrete test piece is simple in operation and high in test stability.

The invention relates to a material mechanical property testing apparatus and provides a composite material low temperature performance test fixture assembly. The fixture assembly comprises two fixtures having the same structures. The fixture comprises a clamping sliding block for clamping a sample, a driven sliding block for transmission of the vertical displacement, a transition sliding block for transmission of the horizontal displacement, a braking bolt for producing a braking force and a forced clamping bolt for forcibly clamping the sample. The two sides of the clamping sliding block are provided with teeth and bosses. The teeth of the two clamping sliding blocks are opposite. The driven sliding block is a raised part having a smooth slope as the top end. The transition sliding block is provided with a smooth slope fitting to the transition sliding block so that a friction pair is formed. The fixture assembly is suitable for low temperature tension and tensile fatigue mechanical tests on the fiber-reinforced composite material sample, can prevent slipping of the composite material at a low temperature and can prevent clamped section damage. In the experiment, along with increasing of test tension, the resistance to the fixture teeth is increased and the clamping force is improved so that the effect of clamping is further guaranteed.

The invention discloses a preparation method of a polyurethane fiber with tensile fatigue resistance. According to the method, a screw-type nanotube is added to the polyurethane fiber for the first time. The method specifically comprises the following steps of firstly, using a high molecular surfactant and sonic oscillation treatment to do surface modification and dispersion processing on the screw-type nanotube, so as to prepare uniform and stable screw-type nanotube dispersion liquid; then uniformly mixing the dispersion liquid and other auxiliaries with a polyurethane solution; finally, forming the polyurethane fiber through a high-temperature channel evaporation solvent. According to the technical method, spring-effect of the screw-type nanotube is utilized to build a firmer elastic network structural system, so the tensile fatigue resistance of the polyurethane fiber is obviously promoted.

The invention relates to a high-strength long-service-life rack steel. After the steel is subjected to quenching and low-temperature tempering treatment, the tensile strength Rm is larger than or equal to 1650 MPa, and the symmetric tensile fatigue strength Sigma-1 is larger than or equal to 750 MPa. A great amount of data regression analysis is carried out through testing the contribution of the chemical elements to tensile strength and impact toughness, the chemical components are redesigned, so that the tensile strength and the fatigue strength of the rack steel are obviously improved, and the rack steel comprises the following components of, in percentage by mass, 0.22%-0.32% of C, 0.17%-0.37% of Si, 0.55%-1.55% of Mn, less than or equal to 0.015% of P, less than or equal to 0.030% of S, 0.60%-1.65% of Cr, 0.15%-0.45% of Mo, 0.65%-1.65% of Ni, 0.02%-0.25% of Cu, 0.02%-0.035% of Al, 0.01%-0.06% of Nb, 0.0003%-0.0006% of B.

The invention discloses a tensile high-speed data cable, which comprises eight copper conductor pairs, a second insulating layer, a polyester tape layer, a second aluminum composite layer and a braided shielding layer, wherein the second insulating layer coats two copper conductor pairs of the eight copper conductor pairs; the other six copper conductor pairs in the eight copper conductor pairs are adhered to the second insulating layer; the polyester tape layer is coated on the other six copper conductor pairs in the eight copper conductor pairs; the second aluminum composite layer is coated on the polyester tape layer and consists of a polyester film layer and an aluminum film layer which is coated on the surface of the polyester film layer; the braided shielding layer is coated on an aluminum foil layer and comprises a plurality of strands of aramid fibers of which the sections are circular; a flat copper wire of which the section is rectangular and which is coated with a tin layer is lapped on the aramid fibers; and the braided shielding layer is braided by the plurality of strands of aramid fibers. By the high-speed data cable, the tensile fatigue resistance is improved, and the shielding performance of the cable is improved.

The invention relates to the technical field of detection equipment, in particular to a tensile fatigue tester. The tensile fatigue tester comprises a worktable, at least one fixed seat arranged on the worktable, at least one sliding seat movably arranged on the worktable and a sliding seat lifting driving mechanism for driving the sliding seat to reciprocate up and down relative to the fixed seat, wherein the fixed seat is provided with a plurality of lower clamps and a limiting plate for preventing the lower clamps from moving upward; the sliding seat is provided with a plurality of upper clamps, the upper clamps and the lower clamps are arranged correspondingly, and a stop test touch block is arranged below each lower clamp. The tensile fatigue tester provided by the invention is simpleand compact in structure and high in testing efficiency, and can detect and test a plurality of samples simultaneously and can detect rejected products from the samples so as to remedy defects of anexisting tensile device, so that the detection efficiency of samples of large batches is improved effectively.

The invention relates to a high-temperature tensile-fatigue mechanical property tester and method based on electric cylinder drive and belongs to the field of mechanical property testing. The high-temperature tensile-fatigue mechanical property tester and method based on electric cylinder drive comprises a mobile platform, a high-temperature module and a test module, the test module is directly driven by an electric cylinder; the intermediate transmission links are few to achieve tensile and fatigue single load and tensile fatigue composite loading. The high-temperature module adopts a double-cavity high-temperature heating furnace, and the clamping specific unit of the test module can be driven by the movable platform after reaching the specified temperature by the double-cavity high-temperature heating furnace and enters the heating cavity to perform relevant mechanical property tests so as to meet the test requirements of the specific materials. The high-temperature tensile-fatiguemechanical property tester had the advantages that the structure is simple, the transmission link is small, the measuring precision is high, and effectively solves the problem of the influence of thethermal deformation on the mechanical property test during the temperature loading process and provides. a new method to reveal the mechanical properties of materials under the coupling of temperaturefield and composite load and has great practical significance to guide future resource exploration, aerospace and so on.

The invention discloses a microstructure unidirectional bending fatigue test device, which is characterized by the following: the driving comb couple is set on one side of hung vibration block and the test comb couple is set to detect the vibration amplitude on the other side; the outside wall of driving and test comb couples is fixed on the silicon base through anchor fixing layer, which connects the driving electrode to generate periodic electrostatic force and test electrode of sensing circuit; the end of hung vibration block connects one end of sample to produce alternating stress; the other end connects the ground electrode; the sample integrates with the driving and detecting device; the driving electrode connects the output probe of power amplifier; the test electrode is leaded by probe to connect the input end of terminal control equipment after the probe is switched in the amplitude measuring circuit. The device adapts the research based on micronanometer technique on the MEMS system.