83 results about "Bending fatigue test" patented technology

The invention belongs to the technical field of coiled tubing life prediction, and particularly discloses a coiled tubing fatigue damage degree prediction method and a coiled tubing remaining life prediction method. The fatigue damage degree prediction method comprises the following steps: carrying out a bending fatigue test on a coiled tubing sample, and collecting a series of magnetic memory signals; preprocessing the series of magnetic memory signals and extracting a plurality of magnetic memory signal characteristic values from the magnetic memory signals; sequentially arranging the plurality of magnetic memory signal characteristic values according to the acquisition time to serve as an original data column, and establishing a grey prediction model; based on the grey prediction model and in combination with the Miner fatigue linear accumulation theory, a coiled tubing fatigue damage degree prediction model representing the relation between the magnetic memory signal characteristic value and the coiled tubing fatigue damage degree is established; and based on the established model, predicting the fatigue damage degree of the oil pipe to be detected according to the detected characteristic value of the magnetic memory signal. The fatigue damage degree prediction method can conveniently and efficiently predict the fatigue damage degree of the oil pipe to be detected.

The invention discloses a hydraulic concrete material bending fatigue test device, and belongs to the technical field of concrete tests.The hydraulic concrete material bending fatigue test device comprises a supporting and fixing plate, and a hydraulic device for applying pressure to a concrete material is arranged on the upper side of the supporting and fixing plate; the output end of the hydraulic device is provided with a pressing head used for directly loading the concrete material, one side of the pressing head is provided with a pressing and leveling assembly used for pressing and leveling the concrete material, and one side of the pressing and leveling assembly is provided with an opening and fastening unit used for fastening the two sides of the concrete material. The support fixing plate is provided with a balance adjusting assembly used for carrying out balance adjustment on a concrete material, and the dual effects improve the stability of placing the test piece, ensure that the test piece is kept in a stable posture in the whole test process, effectively avoid uneven stress caused by position deviation in the dynamic loading process of the test piece, and improve the stability of the test piece. Therefore, the accuracy and reliability of test data are remarkably improved.

The invention provides a metal plate bending fatigue testing device, and relates to the technical field of bending fatigue testing assistion.The metal plate bending fatigue testing device comprises a portal frame, a testing device support, a testing pressure applying assembly and two bearing assemblies, and the testing pressure applying assembly comprises a hydraulic push rod, a T-shaped plate, a rotating air cylinder, an adjustable pressure applying piece and a roller assembly; the two bearing assemblies each comprise a supporting round rod, a transverse rod base and a vertical plate base, two round rollers are arranged between the two supporting round rods, and ratchet wheel assemblies are arranged at the two ends of the two round rollers; according to the technical scheme, a T-shaped plate is controlled by a hydraulic push rod to drive an adjustable pressure applying piece and a roller assembly to move towards the bottom, and a rotary air cylinder drives the adjustable pressure applying piece to drive the roller assembly to rotate, so that a sample plate is supported by a supporting round rod and a round roller, and the roller assembly applies pressure when rolling at the center of the top of the sample plate; the effect of expanding the bending angle of the sample plate is achieved, and the basic requirement for simulating the working state is provided for data acquisition in the subsequent sample plate fatigue test.

The utility model relates to the technical field of test instruments, in particular to a high-low temperature cord thread bending fatigue testing machine which comprises a support body, a limiting groove is formed in the base face of the support body, a fixing rod is fixedly connected to the side, close to a fixing plate, of the base face of the support body, and one end of the fixing rod is connected with a first guide wheel through a bearing. The bottom end of the inner wall of the limiting groove is connected with a lead screw through a bearing, one end of the lead screw is connected with a motor through a coupler, the outer side of the lead screw is connected with a sliding block through an internal thread groove, the base face of the sliding block is fixedly connected with a movable rod, and the base face of the fixing plate is provided with scale marks. By arranging a first guide wheel, a lead screw, a motor, a sliding block, a movable rod, a control panel, a sliding groove and a second guide wheel, the test efficiency is improved, and the practicability is enhanced.

The present invention belongs to the technical field of material experiment, and discloses a sling tension-bending fatigue experiment device. The device includes a reaction frame, an axial force loading module, an anchoring module, a bending loading module, a clamping module and a protection module. Among them, the axial force loading module, the anchoring module and the protection module are arranged on the columns of the reaction frame, the bending loading module is arranged on the cross beam of the reaction frame, and the clamping module is anchored to the ground. The axial force loading module is used to apply axial load, the anchoring module is used to fix the specimen, the bending loading module is used to apply bending load for tension-bending, both the clamping module and the bending loading module can control the bending load received by the specimen, and the protection module is used to prevent injuries caused by specimen fracture; The present invention provides a fatigue experiment device capable of simultaneously performing axial tension and bending, and obtaining various fatigue performance indexes of steel strands or parallel steel wires through tension-bending fatigue experiments, which is applicable to sling tension-bending fatigue experiments.

The invention discloses a bending fatigue test method for interface failure of a bonding layer. The method comprises the following steps: preparing a sample; under the preset temperature condition, periodically changing external force is applied to the sample according to the preset external force condition, so that bending deformation testing is conducted on the sample; the final surface appearance of the sample at the bonding boundary is observed, and crack parameters of cracks on the bonding boundary are recorded; according to the crack parameters of the cracks on the bonding boundary line, the interface failure risk grade of the sample is judged. The thermal load and the force load are applied to the sample at the same time, so that the test environment is closer to the actual working environment of the chip, and the accuracy of failure risk judgment is improved. On the basis of thermal load, periodically changing external force is applied to the sample, so that the sample is deformed and bent, and through the double-field coupling rapid failure mechanism, the test period of the sample can be effectively shortened, and the test efficiency is improved.

The invention relates to the technical field of mechanical fatigue testing, in particular to rotary bending fatigue testing equipment for a rotor shaft, which comprises a base, a rotary driving module, a loading module, a dynamic balance module, a crack monitoring module and an adjusting module, and is characterized in that the rotary driving module drives the rotor shaft to rotate through a belt transmission assembly; the loading module adopts a lever type force reversing mechanism to realize accurate bending moment loading; the dynamic balance module automatically counteracts eccentric vibration through a free disc and a symmetrical bearing seat; the crack monitoring module captures vibration abnormity and internal crack initiation in real time; and the adjusting module is automatically adapted to different shaft lengths by driving a threaded screw rod through a motor. Anti-slip lines are arranged on the inner sides of the clamps at the two ends to ensure stable clamping; the levers are symmetrically arranged and matched with the locking nuts, so that switching of translation force or bending force applied by the levers is facilitated, the equipment realizes high-precision and full-period fatigue test, and the device is suitable for reliability evaluation of key rotor parts of aero-engines and steam turbines.

This disclosure relates to the field of fatigue testing, specifically to a bending fatigue testing apparatus and a bending fatigue testing system. The bending fatigue testing apparatus includes a test bench, a fixing fixture, and a loading fixture. The fixing fixture has two limiting ends spaced apart along a first direction, and the two limiting ends are connected to the test bench. The fixing fixture is movable relative to the test bench along a second direction to adjust the distance between the fixing fixture and the test bench. The test bench and the loading fixture are arranged sequentially along a third direction, and the loading fixture is movably arranged in the second direction, used to move the test piece along the second direction. The first direction is perpendicular to the second direction, and the third direction is perpendicular to both the first and second directions. By implementing the bending fatigue testing apparatus and system of the exemplary embodiments of this disclosure, cantilever bending fatigue tests can be performed on test pieces to test their bending fatigue performance.

The utility model belongs to the technical field of metal material fatigue tests, and particularly relates to a testing device for diaphragm compressor research and development, which comprises a support and a testing assembly, the support is a rectangular frame-shaped support, clamping assemblies are arranged in the middle of the inner side of a left frame and the middle of the inner side of a right frame of the support, and the testing assembly comprises a hydraulic cylinder and a testing mold. The fixed end of the hydraulic cylinder is connected with the inner side of an upper side frame of the support, the telescopic end of the hydraulic cylinder is connected with the upper side of the test mold, the test mold comprises an upper mold, a lower mold and a connecting plate, and the connecting plate is fixedly connected with the rear sides of the upper mold and the lower mold. And a periodic load test is carried out, and the stress state of the compressor in actual service is simulated to the greatest extent, so that the data of the symmetric bending fatigue test of the metal diaphragm is true and credible.

The present invention relates to the technical field of medical devices, and relates to a dynamic bending fatigue test device and test method for a lamina fixing plate. The present invention includes: a base, a bracket test block, a connecting block, and a fatigue testing machine. A sliding groove for the movement of the bracket test block is provided inside the base, and a locking bolt for fixing the bracket test block is provided on the base; Two groups of bracket test blocks are symmetrically arranged and slidably arranged in the sliding groove. There is an intermediate groove between the bracket test blocks. Two groups of lamina fixing plates are symmetrically arranged in the intermediate groove. The lower end of the lamina fixing plate is fixed to the upper end of the bracket test block, and a groove is provided inside the lamina fixing plate; The connecting block is fitted in the groove and the upper end surface of the connecting block is fixedly connected to the lamina fixing plate. A loading hole is provided on the upper surface of the connecting block; The loading block of the fatigue testing machine is fixedly connected to the loading hole, and the connecting plate of the fatigue testing machine is fixedly connected to the base. By applying a dynamic load to simulate the situation of the postoperative opening lamina being squeezed, the service life and corresponding fatigue performance of the lamina fixing plate are measured.

The invention discloses a method for evaluating the fatigue performance of a pipe joint, which comprises the following steps of: establishing an equivalent calculation model of a pipe joint forming process and an equivalent calculation model of a rotating bending fatigue process, simulating the rotating bending fatigue process, and identifying to obtain the stress level Ai of a guide pipe and the pipe joint at 0 moment; and identifying the position of the maximum stress change point of the conduit and the pipe joint and the stress amplitude Bi of the point. According to the material equal-life curve and the S-N curve, obtaining a relation curve of stress levels and stress amplitudes of the guide pipe and the pipe joint with the fatigue life of the pipe joint within 10 million times, and extracting a stress amplitude Ci corresponding to the stress level Ai in the relation curve; if so; ci, evaluating that the pipe joint meets the fatigue life requirement; and if Bi is greater than or equal to Ci, evaluating that the pipe joint does not meet the fatigue life requirement. The bending fatigue performance can be simulated and predicted, the verification period of the rotating bending fatigue test is remarkably shortened, and the method has good practicability.

The application discloses a kind of asphalt mixture fatigue life prediction methods, comprising the following steps: S1, making the standard test piece of asphalt mixture;S2, the three-point bending fatigue test of asphalt mixture under different stress levels is carried out to the standard test piece made under the setting parameter;S3, according to the stress-strain hysteresis curve of asphalt mixture is fitted to test data;S4, the accuracy of the stress-strain hysteresis curve obtained is verified;S5, based on the hysteresis curve, the fatigue damage variable of asphalt mixture is constructed;S6, the fatigue life prediction model of asphalt mixture is constructed.The method of the application avoids the defect that the relative change rate of dissipation energy is the discrete index data of prediction fatigue life, so as to improve the prediction accuracy of asphalt mixture fatigue life, the model construction step is less, form is simple, and has higher practical value.

The present invention relates to a testing device, and in particular to a high-frequency bending fatigue testing device for steel fibers used in concrete. It is necessary to design a high-frequency bending fatigue testing device for steel fibers used in concrete that can fix the steel fibers before the test without the need for additional human operations to fix them, which is relatively convenient. A high-frequency bending fatigue testing device for steel fibers used in concrete, including a support frame, a mounting frame, and a placement frame, etc. The front and rear sides of the top of the support frame are both symmetrically and slidingly connected with placement frames for placing steel fibers. A groove is formed between the placement frames on the left and right sides, and a mounting frame is fixed to the bottom of the support frame. The present invention places the steel fibers into the placement frame, starts the bending hydraulic cylinder so that the trigger mechanism limits the steel fibers, and the fixing mechanism also limits the steel fibers. The bending roller moves downward and then bends the limited steel fibers, thereby performing a bending fatigue test on the steel fibers. In this way, no additional human operations are required to fix the steel fibers, which is relatively convenient.

The application discloses a kind of based on initial modulus index asphalt mixture fatigue life prediction method, the present application includes the following steps: S1, the standard test piece of asphalt mixture is made;S2, the three-point bending fatigue test of asphalt mixture under different stress levels is carried out to the standard test piece made under setting parameter;S3, according to test data fitting asphalt mixture stress strain hysteresis curve;S4, based on the stress strain hysteresis curve obtains the initial modulus and failure modulus of asphalt mixture;S5, based on the initial modulus and failure modulus described above constructs the fatigue damage factor model of asphalt mixture based on initial modulus;S6, based on the fatigue damage factor model constructed predicts the fatigue life of asphalt mixture in use.The present application is more reasonable by introducing failure modulus and constructing damage factor model, so that the residual life of asphalt mixture can be more accurately and quickly predicted.

This invention provides a high-temperature three-point bending ultrasonic fatigue testing device and its usage method, which can be used to conduct high-temperature and ultra-high-temperature three-point bending fatigue tests on materials. This invention overcomes the limitation of traditional three-point bending ultrasonic fatigue tests, which can only be performed at room temperature, bringing a novel fatigue testing method. Furthermore, the combined fixture device adopts a modular design, making it simple to process and operate, and easy to replace.

The utility model discloses a horizontal high-speed rotating bending fatigue testing device, which belongs to the technical field of bending fatigue testing equipment and comprises a rotating bending fatigue testing machine body and a moving mechanism fixedly mounted outside the rotating bending fatigue testing machine body. The moving mechanism comprises a U-shaped shell fixedly installed on the outer wall of the rotary bending fatigue testing machine body, a U-shaped frame is slidably installed in the U-shaped shell, four supporting columns distributed in a matrix mode are fixedly connected to the bottom of the U-shaped frame, rolling wheels are rotatably installed at the lower ends of the supporting columns, and the rolling wheels are movably installed on the U-shaped frame. A screw rod is rotationally mounted on one side of the interior of the U-shaped shell, and the U-shaped frame is connected to the screw rod in a sleeving manner and is in threaded connection with the screw rod; through the arrangement of the moving mechanism, the moving mechanism can be additionally arranged outside the rotating bending fatigue testing machine body, the rotating bending fatigue testing machine can be conveniently moved, manual carrying is not needed, and time and labor are saved.

The invention belongs to the technical field of material fatigue strength testing, and particularly relates to a composite material bending fatigue testing machine and method.The composite material bending fatigue testing machine comprises a frame body, a first linear mover and a second linear mover are arranged on the front side wall of the frame body, and the moving path of the first linear mover is located on the lower left portion of the moving path of the second linear mover; the moving path of the first linear mover is transverse, the moving path of the second linear mover is longitudinal, a rotating disc is arranged on the front side wall of the frame body through a rotating device, the rotating disc is located over the second linear mover, and a plurality of positioning holes are formed in the position, away from the center of the rotating disc, of the rotating disc. The distance between each positioning hole and the center of the rotating disc is not equal, and the face, back on to the front side wall of the frame body, of the second linear mover is rotationally connected with one end of a connecting rod, and the problem of how to achieve displacement adjustment in a fatigue test through a mechanical means is solved.

The invention discloses a load loading device of a rope belt bending fatigue testing machine and the testing machine, the load loading device comprises a base, a slide rail and an adjusting loading device, the base is provided with the adjusting loading device and the slide rail, the slide rail is slidably provided with two test wheels which are staggered up and down, and the two test wheels are used for sleeving a test rope belt; the adjusting and loading device comprises a mounting stand column, a telescopic rod and a vertical displacement mechanism, the mounting stand column is mounted on the rear side of the sliding rail, the vertical displacement mechanism is arranged on the mounting stand column, the moving end of the vertical displacement mechanism is used for being connected with the telescopic rod and driving the telescopic rod to vertically move, and the telescopic end of the telescopic rod is hinged to one ends of two driving rods; the other ends of the two driving rods are hinged to the side ends, extending out of the sliding rail, of the center shafts of the two test wheels respectively, and the telescopic rod is used for extending forwards or retracting backwards and driving the two test wheels to get away from or get close to each other in the vertical direction. According to the invention, the telescopic rod can be controlled to stretch out and draw back and drive the two test wheels to be far away from or close to each other in the vertical direction, so that tension adjustment of the test rope belt is realized, and the loading efficiency can be improved.

The application discloses a kind of asphalt pavement asphalt mixture layer fatigue life prediction method, belong to data processing technical field, including preparation asphalt pavement structure fatigue life calculation layer asphalt mixture sample;Using beam four-point bending testing machine to carry out bending fatigue test to asphalt mixture, test the fatigue life of asphalt mixture under different test temperatures and strain levels, in combination with fatigue life test results, take the average of each test temperature and strain level combination, deduce fatigue life prediction model based on different each type asphalt mixture;According to the parameters of fatigue life prediction model based on different types of asphalt mixture, determine asphalt mixture layer fatigue cracking life model.The application constructs the fatigue life prediction model of pavement structure asphalt layer based on different types of asphalt mixture, and can realize the fatigue life prediction of asphalt pavement asphalt mixture layer for more than 30 years, is favorable for the accurate design and maintenance of long-life asphalt pavement structure.

A method for measuring the bending fatigue life of a forged aluminum alloy hub belongs to the technical field of automobile hub manufacturing, and is characterized by comprising the following steps: 1) under the condition of not considering the influence of other external forces, according to a hub bending fatigue test, only the acting force of a bending load on a hub connecting rod; and (2) according to the fatigue damage accumulation theory, the maximum stress Smax and the minimum stress Smin of the forged aluminum alloy hub under the action of the bending moment, the average stress S and the fatigue damage D of the hub are calculated, and the relation among the average stress S, the fatigue damage D and the bending fatigue life N of the forged aluminum alloy hub is directly designed. The method has the advantages that the relationship with the bending fatigue life of the hub can be determined through the average stress and fatigue damage of the hub, the fatigue life of the hub is rapidly measured, and the actual experiment cost is saved.

The utility model relates to the technical field of rubber conveying belt detection, in particular to a pipe belt bending fatigue testing machine which comprises a machine frame, vertical sliding rails in the vertical direction are arranged on the two sides of the machine frame, a first moving frame, a second moving frame and a third moving frame are arranged on the vertical sliding rails from top to bottom, and a bottom pressure sensor is arranged at the upper end of a bottom supporting frame. A first supporting frame is arranged on the first moving frame on the two sides of the bottom supporting frame, a first pressure sensor is arranged on the first supporting frame, a second pressure sensor is arranged on the second supporting frame, a vertical moving mechanism is arranged in the middle of the top of the rack, and a top pressure sensor is arranged at the lower end of the vertical moving mechanism. The tubular conveying belt is curled into a tubular shape, the pressure applied to the sensors by the tubular conveying belt is detected in real time through the sensors, finally the bending fatigue performance of the tubular conveying belt can be obtained through computer analysis, the detection process is automatically completed, and the device is simple, convenient, safe and reliable.

The present application relates to a kind of cantilever flat plate reciprocating bending fatigue testing machine and its working method, including rack, heating system is arranged on the top plate of the rack, the inside of the heating system is provided with the fixed end of the fixed component for fixing the horizontally arranged flat plate sample, the right side of the fixed component is provided with the loading component for being connected with the free end of flat plate sample;Power component is arranged on the bottom plate of the rack, the power output end of the power component is connected with loading component via the vertically reciprocating movable conjugate transmission component, power component drives loading component up and down swing, realizes the reciprocating bending of flat plate sample.The present application is reasonable in design, can be carried out in high temperature environment flat plate sample reciprocating bending fatigue test, it is helpful to the fatigue life research of material in high temperature environment, and high reliability, loading accurate and low cost.

This invention relates to the field of material fatigue testing technology, and more particularly to a high-temperature rotary bending fatigue testing device capable of simulating different salt spray environments. Addressing the problem of existing equipment providing only a single environmental simulation, the high-temperature rotary bending fatigue testing device proposed in this invention includes an environmental cabinet with a shock-absorbing wooden block at the top; it also includes an environmental simulation mechanism, a salt spray supply and control mechanism, and a rotary bending loading mechanism. The environmental simulation mechanism is located on top of the shock-absorbing wooden block; the salt spray supply and control mechanism is located inside the environmental cabinet and communicates with the interior of the environmental simulation mechanism, used to control the concentration and flow rate of the salt spray supplied to the environmental simulation mechanism; the rotary bending loading mechanism is located on top of the shock-absorbing wooden block and coaxially connected to the environmental simulation mechanism, used for rotary bending of the test specimen. The high-temperature rotary bending fatigue testing device of this invention can closely simulate real service environments.

The invention provides a bending-torsional fatigue testing device, relates to the technical field of bending-torsional fatigue testing, and is used for solving the technical problem that a rotary bending fatigue testing device is complex in structure. The bending-torsional fatigue testing device comprises a base, two loading assemblies and a tested piece, and the base is provided with two arc-shaped rails; the two arc-shaped rails are symmetrically arranged on the base in the first direction. The two loading assemblies are movably connected with the two arc-shaped rails respectively, and one loading assembly is connected with one arc-shaped rail; each loading assembly comprises two loading pieces, and the two loading pieces move along the corresponding arc-shaped rails in the direction close to each other or away from each other; the tested piece is located between the two loading assemblies, and each loading piece is in direct contact with the tested piece. The testing device is used for detecting and evaluating the bending-torsional fatigue life of the tested piece, and the testing device is simple in structure.

The application discloses a flexible beam bending fatigue test load monitoring method of unmanned helicopter, which comprises the following steps: pasting strain gauges on a test piece and a test piece fixing joint, checking the effectiveness of the strain gauges; calibrating all specified sections of the test piece and the test piece fixing joint; performing load debugging before the test to obtain load values of monitoring sections meeting test task requirements; performing a flexible beam bending fatigue test, monitoring the flexible beam bending load in the test process by using a strain monitoring load mode; and performing test monitoring by means of test load drop and upgrade according to strain output load values and edgewise forces on the test piece fixing joint after all the strain gauges on the test piece are damaged. The technical scheme of the application solves the problems of prolonged test period, low test efficiency, increased labor cost, wasted test resources, and difficulty in completing the test task within a specified time.

The invention belongs to the technical field of ferrule joint detection, and particularly relates to a ferrule joint bending fatigue test device which comprises a base, a U-shaped seat is fixed to the top of the base, a transverse plate is slidably mounted in the U-shaped seat, a box is fixed to the top of the transverse plate, and a counterweight plate is slidably inserted into the box. The box body is provided with a limiting assembly used for limiting the balance weight plate, two connecting blocks are symmetrically fixed to the top of the box body, and clamping holes are formed in the side walls of the two connecting blocks. Through the arrangement of the base, the U-shaped seat, the transverse plate, the box body, the counterweight plate, a limiting assembly, a connecting block, a clamping hole, a clamping assembly, an air cylinder, an impact block and a clamping assembly, a to-be-detected clamping sleeve joint can be conveniently and rapidly clamped and fixed, and reciprocating pressure application operation can be performed on the to-be-detected clamping sleeve joint. And the magnitude of acting force applied to the clamping sleeve connector can be conveniently adjusted, so that the overall using effect is good.

The invention discloses a dexterous hand bionic finger bending fatigue testing machine and a testing method thereof, and relates to the technical field of bionic finger tests.The dexterous hand bionic finger bending fatigue testing machine comprises a bottom box, a platform plate is fixedly connected to the top of the bottom box, a mounting interface base is fixedly connected to the upper surface of the platform plate, a bionic dexterous hand is inserted into the mounting interface base, and a plurality of lifting boxes are slidably connected into the bottom box; balancing weights are detachably stacked in the lifting boxes, and stabilizing wheels corresponding to the lifting boxes are rotationally connected to the platform plate. The bending fatigue test of the bionic dexterous hand can be performed in different degrees by increasing different numbers of balancing weights, so that fingers of the bionic dexterous hand can be bent and circulated under different external loads, light-load life verification can be performed, heavy-load accelerated fatigue test can also be performed, and the application range is wider; different bionic dexterous hands have different finger rigidities, sizes and materials, and required test loads are different; the balance weight can be increased or decreased, so that the device can adapt to multiple models and multiple schemes without replacing the main mechanism, and the universality is improved.

The invention discloses a temperature control device and a temperature control method for a rotary bending fatigue test. The rotating bending fatigue test temperature control device comprises a test platform, the upper surface of the test platform is fixedly connected with a testing machine, the testing machine is provided with a voltage transmission module, the voltage transmission module is wirelessly connected with a voltage reduction device, the voltage reduction device is connected with a temperature control device through a second compensation wire, and the temperature control device is connected with a resistance furnace through a resistance furnace control wire. A through hole is formed in the resistance furnace, the resistance furnace is connected to the testing machine in a sleeving mode, and according to the temperature control method for the rotary bending fatigue test, the temperature is controlled through the temperature control device for the rotary bending fatigue test. The thermocouple can be in direct contact with the sample, and the problems that a rotating bending test thermocouple cannot be in contact with the sample, and accurate temperature control on the test sample is difficult are solved.

The method for predicting the service life of the coiled tubing under the cooperation of plasticity and damage is characterized in that the fatigue service life and the strain amplitude under the specific curvature radius are obtained through a full-size bending fatigue test, and the fatigue service life and the strain amplitude are substituted into a Manson-Coffin model to invert an unknown coefficient; the method comprises the following steps: determining mechanical parameters of a material in combination with a uniaxial tensile test, constructing a finite element mechanical model, carrying out finite element simulation on bending working conditions of a damaged coiled tubing on a roller and a guider, extracting strain amplitudes, and further establishing strain amplitude calculation models under different working conditions by adopting a Levenberg-Marquardt algorithm; coupling the model with a Manson-Coffin equation, and respectively constructing fatigue life prediction models of the roller and the guider; and on the basis of the Miner theory, three times of bending cycles with different curvatures in one trip are regarded as complete load cycles, an accumulated damage value is calculated, a correction coefficient is determined through low-cycle fatigue finite element simulation, a calculation model of the number of remaining trip times is established, and quantitative prediction of the remaining life is achieved. The method is suitable for the technical field of petroleum and natural gas drilling engineering.