135 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 utility model relates to a cantilever type flat plate reciprocating bending fatigue testing machine which comprises a rack, a heating system is arranged on a top plate of the rack, and a fixing assembly used for fixing the fixed end of a horizontally arranged flat plate sample is arranged in the heating system. The right side of the fixing assembly is provided with a loading assembly used for being connected with the free end of the flat plate sample; a power assembly is arranged on a bottom plate of the machine frame, the power output end of the power assembly is connected with a loading assembly through a conjugate transmission assembly capable of vertically moving in a reciprocating mode, the power assembly drives the loading assembly to swing up and down through the conjugate transmission assembly, and reciprocating bending of a flat plate sample is achieved. The device is reasonable in design, can realize reciprocating bending fatigue test of a flat sample in a high-temperature environment, is beneficial to material fatigue life research in the high-temperature environment, and is high in reliability, accurate in loading and low in cost.

To provide a vibration unit for thin plate bending fatigue test and a thin plate bending fatigue test device that allow fine adjustment of a frequency and enable high-accuracy testing.SOLUTION: A vibration unit for thin plate bending fatigue test comprises a track-shaped drive coil 2, a magnet 3a, a magnet 3b, a drive arm 4, a specimen holder 5, a drive coil tray 6, a bearing 7, a yoke 8a and a yoke 8b. The track-shaped drive coil 2, the drive coil tray 6 as a holding part, the magnet 3a and the magnet 3b constitute the drive part. The bearing 7 constitutes a rotation part, and the drive arm 4 and the specimen holder 5 constitute the arm part. The bearing 7 comprises a pivot bearing 70 and a boss 71. One end of the bearing 7 is connected to one end of the drive arm 4 using a fastener 9c, and to the other end of the drive arm 4 the specimen holder 5 is attached with a fastener 9d. The other end of the bearing 7 is connected to the drive coil tray 6 using a fastener 9b. The track-shaped drive coil 2 is fixed to the drive coil tray 6.SELECTED DRAWING: Figure 2

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 aviation conduit fatigue tests, and provides an aviation conduit rotation bending test flexural disc, which is provided with a self-aligning bearing, a basic disc and a bearing seat, a joint at one end of an aviation conduit is inserted into an inner hole of the self-aligning bearing, and a joint at the other end of the aviation conduit is mounted on an aviation conduit rotation bending fatigue test mounting device. The aviation conduit rotation bending fatigue test installation device is installed on a workbench, a basic disc is fixedly installed at one end of a rotating shaft through an installation hole, the rotating shaft is connected with a synchronous belt, the synchronous belt is connected with a motor, the motor is arranged in a headstock, the headstock is installed on the workbench, and a bearing seat is assembled with the outer diameter of a self-aligning bearing. The bearing seat is arranged on one side of the basic disc in a position-adjustable mode and can move relative to the basic disc to generate eccentricity during position adjustment, so that the aviation conduit is subjected to bending force, and the reasonability, reliability and safety of the flexure disc structure are improved.

The utility model provides an eight-point bending fatigue test tool based on tension-compression load action, which comprises an upper loading assembly, a lower loading assembly and a support assembly, a first support roller is arranged on the upper loading assembly, a second support roller is arranged on the lower loading assembly, and a third support roller is arranged on the support assembly; at least two sets of supporting assemblies are arranged, at least one set of supporting assemblies is the first supporting assembly, and the other sets of supporting assemblies are at least one set of second supporting assemblies. The first supporting assembly is connected with the upper loading assembly, the first supporting roller and the third supporting roller are oppositely arranged, and the first supporting roller and the third supporting roller clamp a to-be-tested piece; the second supporting assembly is connected with the lower loading assembly, the second supporting roller and the third supporting roller are oppositely arranged, and meanwhile the second supporting roller and the third supporting roller clamp a to-be-tested piece. The supporting roller is designed, so that even if the to-be-tested piece deforms in the test process, the supporting roller is cylindrical, and the loading point of the supporting roller and the test piece can be kept unchanged all the time.

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.

The invention discloses a bending fatigue test device and method for testing a metal composite pipe, the device comprises a main body, a driving mechanism, a pipe rotating mechanism, a first adjusting mechanism, a second adjusting mechanism and a pipe pressing mechanism, the main body comprises a mounting frame, and two groups of parallel first sliding rails are arranged in the center of the top of the inner side of the mounting frame; the two ends of the two first sliding rails are fixedly connected with the inner walls of the two sides of the mounting frame correspondingly, the tops of the two first sliding rails are slidably connected with first sliding blocks, the tops of the two first sliding blocks are jointly and fixedly connected with a supporting plate, a clamping assembly used for clamping a composite pipe is arranged above the supporting plate, and the bottom of the supporting plate is fixedly connected with a connecting column. The device has the beneficial effects that the driving mechanism is arranged to be matched with the pipe rotating mechanism, so that the device not only can bend the composite pipe in a reciprocating manner, but also can rotate the composite pipe by a certain angle when the composite pipe is bent back to the midpoint in the reciprocating manner every time, and further simulates the possible multi-dimensional compounding condition in an actual working environment.

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 invention discloses a method for establishing an inclusion-containing metal rotation bending fatigue life prediction model. A certain metal is selected, a fatigue life model directly related to the actual width or diameter of the inclusion is established through metallographic sample preparation, electrolytic corrosion, SEM / EDS detection, a rotating bending fatigue test and the like, and gaps which are neglected by a traditional metallographic inclusion detection method all the time and are formed around the inclusion and are also unfavorable for the fatigue performance of the metal are considered. By adopting the model, the actual width or diameter of the inclusion obtained by a traditional metallographic inclusion detection method can be used for directly predicting the rotating bending fatigue life of the metal, so that more convenient and accurate guidance is provided for selection of a smelting process in a metal production process and control of the inclusion.

The invention discloses a device and a method for testing the bending fatigue performance of a circular thin plate test piece. A device body is composed of a pressing head 2, a support 7 and a bottom plate 10. The testing method comprises the following steps: firstly, mounting the pressure head 2 and the bottom plate 10 on a loading rod and a load sensor of a material testing machine through a thread 1 and a thread 11 respectively, and embedding the support 7 into the positioning groove 9; a strain gauge is adhered to the center of the bottom of the test piece 4 and is horizontally placed on the top plate 5 of the support 7; the testing machine is controlled to repeatedly load the middle of the test piece 4 through the pressure head 2, the load and strain values in the loading process are collected until the test piece 4 is broken, and the loading frequency at the moment is the fatigue life of the test piece. The method has the beneficial effects that compared with a one-way tension state of the bottom of a test piece in a traditional fatigue test, the bottom of the test piece in the method is in a radial tension state which is consistent with a stress state of an actual pavement structure under the action of a wheel load, and the performance of a material in the actual pavement structure can be reflected more truly.

The utility model relates to a water flow indicator blade bending test device which comprises a test bench, a clamping seat used for clamping a water flow indicator blade, a V-shaped swing frame and a rotating shaft used for driving the V-shaped swing frame to swing are arranged on the test bench, and the clamping seat is located on one side of the V-shaped opening direction of the V-shaped swing frame. And the water flow indicator blade on the clamping seat extends into the V-shaped opening of the V-shaped swing frame. The V-shaped swing frame is driven by the rotating shaft to swing back and forth, so that the water flow indicator blade is driven to bend along the central axis in the positive and negative directions to meet the bending fatigue test of the blade, and the bending fatigue test device has the characteristics of simple structure, low manufacturing cost, convenience in use, high test efficiency and the like.

The present invention relates to a fixed mold for a front fork bending fatigue test, comprising a support frame, a force-applying mechanism, a vertical rod fixing mechanism, a locking block and a pushing assembly, wherein the force-applying mechanism and the vertical rod fixing mechanism are installed on the support frame, the force-applying mechanism is used to drive the front fork to move up and down, the vertical rod is rotatably installed in the vertical rod fixing mechanism, the pushing assembly is used to push the locking block tightly against the vertical rod fixing mechanism, and the locking block is used to lock the vertical rod to prevent the vertical rod from shaking. During the test of the present invention, the vertical rod can rotate 360° in the vertical rod fixing mechanism to fully simulate the actual stress condition, and the locking block can be used to firmly lock the front fork to avoid abnormal phenomena such as loosening and shaking of the front fork during the test.

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.