CN115326608A - Physical fatigue testing device and method for steel rail - Google Patents
Physical fatigue testing device and method for steel rail Download PDFInfo
- Publication number
- CN115326608A CN115326608A CN202210954835.5A CN202210954835A CN115326608A CN 115326608 A CN115326608 A CN 115326608A CN 202210954835 A CN202210954835 A CN 202210954835A CN 115326608 A CN115326608 A CN 115326608A
- Authority
- CN
- China
- Prior art keywords
- rail
- steel rail
- clamp
- steel
- connecting rod
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 207
- 239000010959 steel Substances 0.000 title claims abstract description 207
- 238000009661 fatigue test Methods 0.000 title claims abstract description 38
- 238000000034 method Methods 0.000 title claims abstract description 36
- 238000012360 testing method Methods 0.000 claims abstract description 62
- 230000007246 mechanism Effects 0.000 claims abstract description 24
- 230000008859 change Effects 0.000 claims description 7
- 230000008602 contraction Effects 0.000 claims description 6
- 230000009467 reduction Effects 0.000 claims description 6
- 238000004364 calculation method Methods 0.000 claims description 3
- 238000003466 welding Methods 0.000 description 7
- 125000004122 cyclic group Chemical group 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 230000009471 action Effects 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- 238000011160 research Methods 0.000 description 5
- 230000008569 process Effects 0.000 description 4
- 238000010998 test method Methods 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 238000011056 performance test Methods 0.000 description 3
- 238000013001 point bending Methods 0.000 description 3
- 241001391944 Commicarpus scandens Species 0.000 description 2
- 241001669679 Eleotris Species 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000014509 gene expression Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 229910001069 Ti alloy Inorganic materials 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- IXQWNVPHFNLUGD-UHFFFAOYSA-N iron titanium Chemical compound [Ti].[Fe] IXQWNVPHFNLUGD-UHFFFAOYSA-N 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/32—Investigating strength properties of solid materials by application of mechanical stress by applying repeated or pulsating forces
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/02—Details
- G01N3/04—Chucks
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/02—Details
- G01N3/06—Special adaptations of indicating or recording means
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0001—Type of application of the stress
- G01N2203/0005—Repeated or cyclic
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0058—Kind of property studied
- G01N2203/0069—Fatigue, creep, strain-stress relations or elastic constants
- G01N2203/0073—Fatigue
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/04—Chucks, fixtures, jaws, holders or anvils
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/06—Indicating or recording means; Sensing means
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The invention provides a steel rail physical fatigue testing device and a steel rail physical fatigue testing method, wherein the device comprises: the steel rail support group is used for supporting a steel rail and comprises a first support roller and a second support roller, and the distance between the first support roller and the second support roller is adjustable; the rail head clamping mechanism comprises a vertical loading clamp, a first longitudinal clamp and a second longitudinal clamp which are matched with each other, wherein the first longitudinal clamp and the second longitudinal clamp are used for longitudinally clamping the rail head of the steel rail, and a test connecting mechanism used for connecting the steel rail and the rail head clamping mechanism; the steel rail clamping device is provided with the steel rail supporting group and the rail head clamping mechanism, and the steel rail supporting group and the rail head clamping mechanism work in a matched mode, so that stable clamping and fixing of a steel rail to be tested are achieved, the steel rail clamping device is suitable for steel rails with different specifications, performance testing of the steel rail is facilitated, the service performance of the steel rail can be evaluated more accurately, and the steel rail clamping device is very suitable for researching the service performance of the steel rail.
Description
Technical Field
The invention relates to the technical field of testing, in particular to the technical field of steel rail testing, and particularly relates to a steel rail physical fatigue testing device and a steel rail physical fatigue testing method.
Background
As a key part for directly bearing the running of the train, the steel rail continuously receives the action of dynamic bending stress in the service process. In the process, the rail bottom of the steel rail is supported by the sleeper, and the rail head is repeatedly rolled by the wheels; the rail between two sleepers can be simplified to a three-point bending model that is subject to cyclic loading. In the three-point bending model, the rail bottom of the steel rail is under the action of cyclic tensile stress, once the rail bottom is damaged, cracks at the rail bottom of the steel rail are easy to grow and expand, and the steel rail is easy to break, particularly for a steel rail welding joint with weak performance, the damage is easy to occur under the action of cyclic load. Therefore, the steel rail physical fatigue performance test becomes an important index for evaluating the safety performance of the steel rail.
Welding parts 1 on TB/T1632.1-2014 steel rails: the general technical conditions stipulate that a three-point bending type physical fatigue test must be carried out on a steel rail welding joint; the test load frequency is 5Hz +/-0.5 Hz, the load ratio is 0.2, and the test load is according to the formula
Calculating, wherein F is the load applied on the steel rail and the unit is N; sigma max The maximum fatigue stress is MPa, the maximum fatigue stress of a flash welding joint and a gas pressure welding joint is 297MPa, and the maximum fatigue stress of an aluminothermic welding joint is 217MPa; l is the sample offset, and the unit is m; w is the coefficient of section of the lower part of the rail, and the unit is mm 3 。
However, the above test method only simulates the support of the rail by the sleeper and the cyclic loading of the rail by the wheel. In practice, in the service process of the steel rail, besides the restraint and the loading in the two aspects, the steel rail is also subjected to the action of temperature force along the length direction of the steel rail, which is caused by the expansion caused by heat and the contraction caused by cold of the steel rail. For example, when the locking temperature of a 60kg/m steel rail of a certain line is 20 ℃, the winter air temperature is-10 ℃, the rail temperature is equivalent to the air temperature, the steel rail contracts, the formed temperature stress reaches 74.34MPa, and the formed temperature force of the whole steel rail section reaches 576kN; when the temperature in summer is 30 ℃, the rail temperature is 20 ℃ higher than the air temperature, the steel rail expands, the formed temperature stress reaches-74.34 MPa, and the formed temperature force of the whole steel rail section reaches-576 kN. Therefore, the actual service performance of the steel rail cannot be accurately evaluated by the currently used method for testing the physical fatigue of the steel rail, and the test result has limited reference value for the service of the steel rail line.
Therefore, aiming at the problems, a steel rail physical fatigue testing device and a steel rail physical fatigue testing method capable of evaluating the service performance of a steel rail more accurately are needed.
Disclosure of Invention
In view of this, the invention aims to provide an improved steel rail physical fatigue testing device and a testing method, so as to evaluate the service performance of a steel rail more effectively.
In view of the above, in one aspect, the present invention provides a steel rail physical fatigue testing apparatus, wherein the steel rail physical fatigue testing apparatus includes:
the steel rail support group is used for supporting a steel rail and comprises a first support roller and a second support roller, and the distance between the first support roller and the second support roller is adjustable;
a railhead fixture for centre gripping rail railhead, railhead fixture include vertical loading anchor clamps, first vertical anchor clamps and the vertical anchor clamps of second of mutually supporting, first vertical anchor clamps and the vertical anchor clamps of second are used for the vertical centre gripping of rail railhead, and
the test connection mechanism is used for connecting the steel rail and the rail head clamping mechanism.
In some embodiments of the physical rail fatigue testing apparatus according to the present invention, the test connection mechanism further comprises:
the first connecting rod is used for connecting the first longitudinal clamp and the steel rail head;
and the first connecting rod and the second connecting rod work in a matching way to clamp and fix the railhead on one side of the steel rail.
In some embodiments of the physical rail fatigue testing apparatus according to the invention, the test connection mechanism further comprises:
the third connecting rod is used for connecting the second longitudinal clamp and the steel rail head;
and the fourth connecting rod is matched with the third connecting rod to work and is also used for connecting the second longitudinal clamp and the steel rail head.
In some embodiments of the physical rail fatigue testing apparatus according to the present invention, the first longitudinal clamp is provided with a plurality of sets of first clamp holes, the first clamp holes are used for assisting the first longitudinal clamp to clamp the rail head and the rail web, and the plurality of sets of first clamp holes are respectively connected with the first rail head bolt and the first rail web bolt.
In some embodiments of the physical fatigue testing apparatus for a steel rail according to the present invention, a plurality of sets of second fixture holes are disposed on the second longitudinal fixture, the second fixture holes are used to assist the second longitudinal fixture to clamp the rail head and the rail web, and the plurality of sets of second fixture holes are respectively connected to the second rail head bolt and the second rail web bolt.
In some embodiments of the physical rail fatigue testing device according to the invention, the first clamp hole and the second clamp hole are both threaded holes, and the diameter of each threaded hole is 30mm.
In another aspect of the present invention, a method for testing physical fatigue of a steel rail is further provided, where the method for testing physical fatigue of a steel rail includes:
step S1: preparing a test steel rail object;
step S2: assembling steel rails in a real object: placing the steel rail object prepared in the step 1 on a first support roller and a second support roller, wherein the center line of the steel rail object, the center line of a vertical loading clamp, the center line of the distance between the two support rollers are superposed by three lines;
and step S3: the first longitudinal clamp and the second longitudinal clamp are connected with the steel rail: calculating a test temperature force;
when the temperature reduction, steel rail contraction and temperature force of the simulated steel rail are tensile forces, one group of first clamp holes are connected with the first rail head through bolts by using the first connecting rod, the other group of first clamp holes are connected with the first rail web through bolts by using the second connecting rod, the first clamp holes are connected with the second rail head through bolts by using the third connecting rod, and the other group of first clamp holes are connected with the second rail web through bolts by using the fourth connecting rod.
When the temperature rise, the expansion and the temperature force of the simulated steel rail are pressure, the steel rail is connected with the first longitudinal clamp and the second longitudinal clamp without using a connecting rod, and the first longitudinal clamp and the second longitudinal clamp are only required to be attached to two ends of the steel rail.
When the simulated steel rail temperature is unchanged, the steel rail has no deformation, and the temperature force is 0, the first longitudinal clamp, the second longitudinal clamp, the first connecting rod, the second connecting rod, the third connecting rod and the fourth connecting rod are not needed to be used.
And step S4: physical fatigue test of steel rails: when the temperature reduction, steel rail contraction and temperature force of the simulated steel rail are tensile forces, the first longitudinal clamp and the second longitudinal clamp respectively move towards the direction far away from the steel rail, the tensile forces f2 and f3 are applied to the steel rail through the first connecting rod, the second connecting rod, the third connecting rod and the fourth connecting rod, wherein the magnitudes of f2 and f3 are equal, the directions are opposite, and the vertical loading clamp applies the circulating pressure f1 to the rail head of the steel rail;
when the simulated temperature rise, expansion and temperature force of the steel rail are pressures, the first longitudinal clamp and the second longitudinal clamp respectively move towards the direction pointing to the steel rail, the pressures f2 and f3 are applied to the steel rail, the magnitudes of the pressures f2 and f3 are equal, the directions are opposite, and the vertical loading clamp applies the circulating pressure f1 to the rail head of the steel rail;
and when the simulated steel rail temperature is unchanged, the steel rail is not deformed, and the temperature force is 0, applying the circulating pressure f1 to the steel rail head by the vertical loading clamp.
In some embodiments of the method for testing physical fatigue of a steel rail according to the present invention, in step S1, the method for preparing a test physical steel rail specifically includes:
according to actual requirements, a long steel rail object with the length of 450-1800mm is intercepted and used as a test object, and the length of the steel rail is at least 200mm longer than the distance between a first support roller and a second support roller; according to actual requirements, bolt holes with the diameter of 30mm are manufactured in the middle of the rail head and the rail web of the steel rail.
In some embodiments of the method for physical fatigue testing of steel rails according to the present invention, in step S3, the experimental temperature force calculation formula is:
temperature force = linear expansion coefficient of rail x elastic modulus of rail x temperature change of rail x cross-sectional area of rail.
In some embodiments of the method for physical fatigue testing of steel rails according to the present invention, the method further comprises step S5:
end of test and recording of test results: when the steel rail object is broken, stopping the test and recording the cycle of applying the circulating pressure to the steel rail head by the vertical loading fixture when the steel rail is broken, and stopping the test when the steel rail object is not broken after the circulating pressure applied to the steel rail head by the vertical loading fixture reaches the specified cycle.
The invention has at least the following beneficial technical effects: the embodiment of the invention is provided with the steel rail supporting group and the rail head clamping mechanism, and the steel rail supporting group and the rail head clamping mechanism work in a matching way, so that the steel rail to be tested is stably clamped and fixed, the steel rail clamping mechanism is suitable for steel rails with different specifications, the performance test of the steel rail is facilitated, the service performance of the steel rail can be more accurately evaluated, and the steel rail service performance research is very suitable for developing the steel rail service performance research.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the prior art descriptions will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other embodiments can be obtained according to the drawings without creative efforts.
In the figure:
FIG. 1 shows a schematic diagram of a physical rail fatigue testing apparatus according to the invention;
FIG. 2 is a schematic flow chart diagram illustrating an embodiment of a method for physical rail fatigue testing according to the present invention;
FIG. 3 is a schematic diagram illustrating a physical fatigue test method for a rail according to the present invention when a temperature of the rail is reduced;
FIG. 4 is a schematic diagram illustrating a physical fatigue test method for a rail according to the present invention when the temperature of the rail is simulated to increase;
FIG. 5 shows a schematic diagram of a real fatigue test method for a simulated steel rail when the temperature of the steel rail is unchanged.
In the figure: the device comprises a steel rail support group 1, a first support roller 11, a second support roller 12, a rail head clamping mechanism 2, a first longitudinal clamp 21, a first clamp hole 211, a second longitudinal clamp 22, a second clamp hole 221, a vertical loading clamp 23, a test connection mechanism 3, a first connection rod 31, a second connection rod 32, a third connection rod 33 and a fourth connection rod 34.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the following embodiments of the present invention are described in further detail with reference to the accompanying drawings.
It should be noted that all expressions using "first" and "second" in the embodiments of the present invention are used for distinguishing two non-identical entities with the same name or different parameters, and it is understood that "first" and "second" are only used for convenience of expression and should not be construed as limiting the embodiments of the present invention. Furthermore, the terms "comprises" and "comprising," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements does not include all of the other steps or elements inherent in the list.
Briefly, the present invention provides a physical rail fatigue testing apparatus, as shown in fig. 1, the physical rail fatigue testing apparatus includes:
the steel rail support group 1 is used for supporting a steel rail, the steel rail support group 1 comprises a first support roller 11 and a second support roller 12, and the distance between the first support roller 11 and the second support roller 12 is adjustable;
a railhead clamping mechanism 2 for clamping a rail head of a rail, the railhead clamping mechanism 2 comprising a vertical loading clamp 23, a first longitudinal clamp 21 and a second longitudinal clamp 22 cooperating with each other, the first longitudinal clamp 21 and the second longitudinal clamp 22 being for longitudinal clamping of the rail head of the rail, and
and the test connecting mechanism 3 is used for connecting the steel rail and the rail head clamping mechanism 2.
In this embodiment, set up rail support group 1 and railhead fixture 2, rail support group 1 and railhead fixture 2 cooperation work have realized the stable centre gripping and the fixing of rail to be tested, and are adapted to the rail of different specifications, do benefit to the capability test of rail, can more accurately evaluate the service performance of rail, and especially adapted developing rail service performance research.
Specifically, the distance between the first support roller 11 and the second support roller 12 is adjustable, the distance between the first support roller 11 and the second support roller 12 is set to be 250-1600mm, and the vertical loading clamp 23 can realize 0-2000kN cyclic loading.
In a preferred embodiment, the first longitudinal gripper 21 and the second longitudinal gripper 22 can achieve a loading of 0- ± 1000 kN.
In a preferred embodiment, the test connection mechanism 3 further comprises:
a first connecting rod 31 for connecting the first longitudinal clamp 21 and the rail head;
the second connecting rod 32 is arranged on one side of the first connecting rod 31, and the first connecting rod 31 and the second connecting rod 32 are matched to work and are used for clamping and fixing railheads on one side of the steel rail.
Simultaneously, as the setting of cooperation work, test coupling mechanism 3 still includes:
a third connecting rod 33 for connecting the second longitudinal clamp 22 and the rail head;
a fourth connecting rod 34 co-operating with the third connecting rod 33, the fourth connecting rod 34 also serving to connect the second longitudinal clamp 22 and the rail head.
In this embodiment, the first connecting rod 31, the second connecting rod 32, the third connecting rod 33 and the fourth connecting rod 34 are specifically round rods or square rods, and the first connecting rod 31, the second connecting rod 32, the third connecting rod 33 and the fourth connecting rod 34 are made of stainless steel or iron-titanium alloy, so that the strength and hardness of the testing device are ensured, and the smooth performance of the testing work is ensured.
In a preferred embodiment, a plurality of first clamp holes 211 are disposed on the first longitudinal clamp 21, the first clamp holes 211 are used to assist the first longitudinal clamp 21 to clamp the rail head and the rail web, and the first clamp holes 211 are respectively connected with the first head bolt and the first web bolt.
Illustratively, a plurality of sets of first clamp holes 211 are longitudinally arranged, the first clamp holes 211 are respectively arranged at the head and web positions of the steel rail, and the first clamp holes 211 are threaded holes with a diameter of 30mm.
In a preferred embodiment, a plurality of sets of second clamp holes 221 are disposed on the second longitudinal clamp 22, the second clamp holes 221 are used for assisting the second longitudinal clamp 22 to clamp the rail head and the rail web, and the plurality of sets of second clamp holes 221 are respectively connected with a second rail head bolt and a second rail web bolt.
Illustratively, the plurality of sets of second fixture holes 221 are longitudinally arranged, and the second fixture holes 221 are threaded holes having a diameter of 30mm.
In order to realize the performance test of the steel rail, the invention provides a steel rail physical fatigue test method. Fig. 2 shows a schematic implementation flow diagram of the steel rail physical fatigue testing method according to the invention. In the embodiment shown in fig. 2, the method comprises:
step S1: the method for preparing the test steel rail object comprises the following steps:
according to actual requirements, a long steel rail object with the length of 450-1800mm is cut out to be used as a test object, and the length of the steel rail is at least 200mm longer than the distance between the first support roller 11 and the second support roller 12; according to actual requirements, bolt holes with the diameter of 30mm are manufactured in the middle of the rail head and the rail web of the steel rail;
step S2: assembling steel rails in a real object: placing the steel rail object prepared in the step 1 on a first support roller 11 and a second support roller 12, and superposing the central line of the steel rail object, the central line of a vertical loading clamp 23 and the central line of the distance between the two support rollers by three lines;
and step S3: the first longitudinal clamp 21 and the second longitudinal clamp 22 are connected with the steel rail: calculating a test temperature force;
in step S3, the test temperature force calculation formula is:
temperature force = linear expansion coefficient of rail x elastic modulus of rail x temperature change of rail x cross-sectional area of rail.
When the simulated temperature reduction, the contraction and the temperature force of the steel rail are tensile forces, the first clamp holes 211 of one group are connected with the first rail head bolt through the first connecting rods 31, the first clamp holes 211 of the other group are connected with the first rail web bolt through the second connecting rods 32, the first clamp holes 211 are connected with the second rail head bolt through the third connecting rods 33, and the first clamp holes 211 of the other group are connected with the second rail web bolt through the fourth connecting rods 34.
When the temperature rise, the expansion and the temperature force of the simulated steel rail are pressure, the steel rail is connected with the first longitudinal clamp 21 and the second longitudinal clamp 22 without using a connecting rod, and only the first longitudinal clamp 21 and the second longitudinal clamp 22 are required to be attached to two ends of the steel rail.
When the simulated steel rail temperature is unchanged, the steel rail has no deformation, and the temperature force is 0, the first longitudinal clamp 21, the second longitudinal clamp 22, the first connecting rod 31, the second connecting rod 32, the third connecting rod 33, and the fourth connecting rod 34 are not needed.
And step S4: physical fatigue test of steel rails: when the simulated steel rail temperature reduction, steel rail contraction and temperature force are tensile forces, the first longitudinal clamp 21 and the second longitudinal clamp 22 respectively move towards the direction far away from the steel rail, the tensile forces f2 and f3 are applied to the steel rail through the first connecting rod 31, the second connecting rod 32, the third connecting rod 33 and the fourth connecting rod 34, wherein the magnitudes of f2 and f3 are equal, the directions are opposite, and f2+ f3= the temperature force vertical loading clamp 23 applies the circulating pressure f1 to the steel rail head;
when the simulated temperature rise, expansion and pressure of the steel rail are pressures, the first longitudinal clamp 21 and the second longitudinal clamp 22 respectively move towards the direction pointing to the steel rail, the pressures f2 and f3 are applied to the steel rail, the magnitudes of the f2 and f3 are equal and the directions are opposite, and f2+ f3= the temperature force vertical loading clamp 23 applies a cyclic pressure f1 to the rail head of the steel rail;
when the simulated steel rail temperature is unchanged, the steel rail is not deformed, and the temperature force is 0, the vertical loading fixture 23 applies the circulating pressure f1 to the steel rail head.
Step S5: end of test and recording of test results: when the steel rail object is broken, stopping the test and recording the cycle of applying the circulating pressure to the steel rail head by the vertical loading clamp 23 when the steel rail is broken, and stopping the test when the steel rail object is not broken after the circulating pressure applied to the steel rail head by the vertical loading clamp 23 reaches the specified cycle.
Illustratively, 5 60kg/m and 5 75kg/m steel rails with artificially prefabricated defects at the rail bottoms of the steel rails are selected to carry out the test according to the physical fatigue test method for the steel rails provided by the invention; simultaneously selecting 160 kg/m and 1 75kg/m steel rails with the artificially prefabricated defects at the rail bottoms of the steel rails, and welding the No. 1 steel rail according to TB/T1632.1-2014 steel rail: the method specified in general technical Condition "was tested on a conventional test apparatus for comparison.
The experimental parameters of the examples and comparative examples are shown in Table 1.
TABLE 1 test parameters for the examples and comparative examples
When the rail type, the test frequency, the maximum vertical load, the load ratio and other test parameters are the same, the test result of the embodiment is closely related to the simulation temperature change; when the simulated temperature changes from low to high, the vertical load loading cycle of the broken steel rail also changes from low to high, even when the temperature changes to 20 ℃, the steel rail does not break after 200 ten thousand vertical load loads, and the test result is consistent with the actual condition that the line steel rail is more easy to break in winter. The comparative example adopting the traditional test method can not simulate the temperature change condition, the test result is single, and meanwhile, the test result of simulating the temperature change of 0 ℃ in the embodiment is close to the comparative example test result, which shows that the steel rail physical fatigue test method provided by the invention can accurately simulate the service performance difference of the steel rail caused by the temperature change and can completely cover the traditional test method.
TABLE 2 test results of examples and comparative examples
Through comparison, the steel rail physical test method can be used for more accurately evaluating the service performance of the steel rail, and is very suitable for carrying out the research on the service performance of the steel rail.
In this embodiment, set up rail support group 1 and railhead fixture 2, rail support group 1 and railhead fixture 2 cooperation work have realized the stable centre gripping and the fixing of rail to be tested, and are adapted to the rail of different specifications, do benefit to the capability test of rail, can more accurately evaluate the service performance of rail, and especially adapted developing rail service performance research.
The foregoing is an exemplary embodiment of the present disclosure, but it should be noted that various changes and modifications could be made herein without departing from the scope of the present disclosure as defined by the appended claims. The functions, steps and/or actions of the method claims in accordance with the disclosed embodiments described herein need not be performed in any particular order. Furthermore, although elements of the disclosed embodiments of the invention may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated.
It should be understood that, as used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly supports the exception. It should also be understood that "and/or" as used herein is meant to include any and all possible combinations of one or more of the associated listed items. The numbers of the embodiments disclosed in the embodiments of the present invention are merely for description, and do not represent the merits of the embodiments.
Those of ordinary skill in the art will understand that: the discussion of any embodiment above is meant to be exemplary only, and is not intended to intimate that the scope of the disclosure, including the claims, of embodiments of the invention is limited to these examples; within the idea of an embodiment of the invention, also combinations between technical features in the above embodiments or in different embodiments are possible, and there are many other variations of the different aspects of the embodiments of the invention as described above, which are not provided in detail for the sake of brevity. Therefore, any omissions, modifications, substitutions, improvements and the like that may be made without departing from the spirit or scope of the embodiments of the present invention are intended to be included within the scope of the embodiments of the present invention.
Claims (10)
1. A kind of physical fatigue testing device of rail, used in physical fatigue test of rail, characterized by that, said physical fatigue testing device of rail includes:
the steel rail support group is used for supporting a steel rail and comprises a first support roller and a second support roller, and the distance between the first support roller and the second support roller is adjustable;
a railhead fixture for centre gripping rail railhead, railhead fixture includes vertical loading anchor clamps, the first vertical anchor clamps and the vertical anchor clamps of second of mutually supporting, the vertical centre gripping that first vertical anchor clamps and second are used for the rail railhead, and
the test connection mechanism is used for connecting the steel rail and the rail head clamping mechanism.
2. The apparatus of claim 1, wherein the test connection mechanism further comprises:
the first connecting rod is used for connecting the first longitudinal clamp and the steel rail head;
and the first connecting rod and the second connecting rod are matched to work and are used for clamping and fixing the railhead on one side of the steel rail.
3. The apparatus of claim 2, wherein the test connection mechanism further comprises:
the third connecting rod is used for connecting the second longitudinal clamp and the steel rail head;
and the fourth connecting rod is matched with the third connecting rod to work, and is also used for connecting the second longitudinal clamp and the steel rail head.
4. The apparatus according to any one of claims 1 to 3, wherein the first longitudinal clamp is provided with a plurality of sets of first clamp holes, the first clamp holes are used for assisting the first longitudinal clamp to clamp the rail head and the rail web, and the plurality of sets of first clamp holes are respectively connected with the first rail head bolt and the first rail web bolt.
5. The apparatus of claim 4, wherein the second longitudinal clamp has a plurality of second clamp holes formed therein, the second clamp holes being adapted to assist the second longitudinal clamp in clamping the rail head and the rail web, and the plurality of second clamp holes being adapted to receive respective second head bolts and second web bolts.
6. The apparatus of claim 5, wherein the first and second clamp holes are threaded holes having a diameter of 30mm.
7. A steel rail physical fatigue testing method is used for steel rail physical fatigue testing, and is characterized by comprising the following steps:
step S1: preparing a test steel rail object;
step S2: assembling steel rails in a real object: placing the steel rail object prepared in the step 1 on a first support roller and a second support roller, wherein the center line of the steel rail object, the center line of a vertical loading clamp, the center line of the distance between the two support rollers are superposed by three lines;
and step S3: the first longitudinal clamp and the second longitudinal clamp are connected with the steel rail: calculating a test temperature force;
when the temperature reduction, the shrinkage and the temperature force of the simulated steel rail are tensile forces, one group of first clamp holes are connected with a first rail head bolt by a first connecting rod, the other group of first clamp holes are connected with a first rail web bolt by a second connecting rod, the first clamp holes are connected with a second rail head bolt by a third connecting rod, and the other group of first clamp holes are connected with a second rail web bolt by a fourth connecting rod;
when the temperature rise, the expansion and the temperature force of the simulated steel rail are pressure, the steel rail is connected with the first longitudinal clamp and the second longitudinal clamp without using a connecting rod, and only the first longitudinal clamp and the second longitudinal clamp are attached to two ends of the steel rail;
when the simulated steel rail temperature is unchanged, the steel rail has no deformation, and the temperature force is 0, the first longitudinal clamp, the second longitudinal clamp, the first connecting rod, the second connecting rod, the third connecting rod and the fourth connecting rod are not needed to be used;
and step S4: physical fatigue test of steel rails: when the temperature reduction, steel rail contraction and temperature force of the simulated steel rail are tensile forces, the first longitudinal clamp and the second longitudinal clamp respectively move towards the direction far away from the steel rail, the tensile forces f2 and f3 are applied to the steel rail through the first connecting rod, the second connecting rod, the third connecting rod and the fourth connecting rod, wherein the magnitudes of f2 and f3 are equal, the directions are opposite, and the vertical loading clamp applies the circulating pressure f1 to the rail head of the steel rail;
when the simulated temperature rise, expansion and temperature force of the steel rail are pressures, the first longitudinal clamp and the second longitudinal clamp respectively move towards the direction pointing to the steel rail, the pressures f2 and f3 are applied to the steel rail, the magnitudes of the pressures f2 and f3 are equal, the directions are opposite, and the vertical loading clamp applies the circulating pressure f1 to the rail head of the steel rail;
and when the simulated steel rail temperature is unchanged, the steel rail is not deformed, and the temperature force is 0, applying the circulating pressure f1 to the steel rail head by the vertical loading clamp.
8. The method according to claim 7, wherein in step S1, the method for preparing the test rail object specifically comprises:
a long steel rail object with the length of 450-1800mm is intercepted and used as a test object, and the length of the steel rail is at least 200mm longer than the distance between the first support roller and the second support roller; bolt holes with the diameter of 30mm are manufactured in the middle of the rail head and the rail web of the steel rail.
9. The method of claim 8, wherein in step S3, the test temperature force calculation formula is:
temperature force = linear expansion coefficient of rail x elastic modulus of rail x temperature change of rail x cross-sectional area of rail.
10. The method according to any of claims 7 to 9, characterized in that the method further comprises a step S5:
end of test and recording of test results: when the steel rail object is broken, stopping the test and recording the cycle of applying the circulating pressure to the steel rail head by the vertical loading fixture when the steel rail is broken, and stopping the test when the steel rail object is not broken after the circulating pressure applied to the steel rail head by the vertical loading fixture reaches the specified cycle.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210954835.5A CN115326608A (en) | 2022-08-10 | 2022-08-10 | Physical fatigue testing device and method for steel rail |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210954835.5A CN115326608A (en) | 2022-08-10 | 2022-08-10 | Physical fatigue testing device and method for steel rail |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115326608A true CN115326608A (en) | 2022-11-11 |
Family
ID=83922580
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210954835.5A Pending CN115326608A (en) | 2022-08-10 | 2022-08-10 | Physical fatigue testing device and method for steel rail |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115326608A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118130288A (en) * | 2024-05-10 | 2024-06-04 | 西南交通大学 | Evaluation method for rolling contact fatigue test of wheel-rail material |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU1758493A1 (en) * | 1990-06-07 | 1992-08-30 | Московский Институт Инженеров Железнодорожного Транспорта | Method of fatigue testing of full-scale specimens of rails |
| CN1442679A (en) * | 2002-03-05 | 2003-09-17 | 王建文 | Jointless track temperature force and locking rail temperature test method |
| CN102721501A (en) * | 2012-06-15 | 2012-10-10 | 大连理工大学 | Experimental method for measuring distribution of breaking longitudinal force of steel rail of railway |
| CN105784269A (en) * | 2016-04-21 | 2016-07-20 | 温州大学 | Laser ultrasonic method-based steel rail temperature stress calibration platform |
| CN110441138A (en) * | 2019-07-09 | 2019-11-12 | 武汉理工大学 | Adjustable Biaxial stress fatigue rig |
-
2022
- 2022-08-10 CN CN202210954835.5A patent/CN115326608A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU1758493A1 (en) * | 1990-06-07 | 1992-08-30 | Московский Институт Инженеров Железнодорожного Транспорта | Method of fatigue testing of full-scale specimens of rails |
| CN1442679A (en) * | 2002-03-05 | 2003-09-17 | 王建文 | Jointless track temperature force and locking rail temperature test method |
| CN102721501A (en) * | 2012-06-15 | 2012-10-10 | 大连理工大学 | Experimental method for measuring distribution of breaking longitudinal force of steel rail of railway |
| CN105784269A (en) * | 2016-04-21 | 2016-07-20 | 温州大学 | Laser ultrasonic method-based steel rail temperature stress calibration platform |
| CN110441138A (en) * | 2019-07-09 | 2019-11-12 | 武汉理工大学 | Adjustable Biaxial stress fatigue rig |
Non-Patent Citations (1)
| Title |
|---|
| 王彪;谢铠泽;肖杰灵;王平;: "应用电阻应变计的无缝线路纵向力测试原理及方案", 西南交通大学学报, no. 01, 15 February 2016 (2016-02-15), pages 43 - 49 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118130288A (en) * | 2024-05-10 | 2024-06-04 | 西南交通大学 | Evaluation method for rolling contact fatigue test of wheel-rail material |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP3187761B1 (en) | Fastening-type pipe supporting apparatus for curved pipe | |
| CN115326608A (en) | Physical fatigue testing device and method for steel rail | |
| Jiao et al. | Section slenderness limits of very high strength circular steel tubes in bending | |
| Lee et al. | Static test until structural collapse after fatigue testing of a full-scale wind turbine blade | |
| Chiew et al. | Fatigue performance of cracked tubular T joints under combined loads. I: Experimental | |
| CN114323956A (en) | Four-way composite loading fatigue test device for rubber elastic element | |
| CN1007999B (en) | Installing process of pipe in steam generator | |
| CN108760469B (en) | Test device and test method for high-temperature strength of ceramic matrix composite material tenon connection structure | |
| Schneider et al. | Inelastic behavior of bolted flange plate connections | |
| Wei et al. | Investigation of welded structures on mechanical properties of 304L welded tube-to-tubesheet joints | |
| Wehsener et al. | Advancements for the structural application of fiber-reinforced moulded wooden tubes | |
| Lacalle et al. | On the analysis of the causes of cracking in a wind tower | |
| Turvey et al. | Shear failure strength of web–flange junctions in pultruded GRP WF profiles | |
| CN103471840A (en) | Box beam vertical moment test mechanism | |
| CN109520838B (en) | Tensile property test device for shield tunnel bolt joint | |
| CN113252439A (en) | Composite laminate fatigue test clamping device | |
| CN115655865A (en) | Test device for simulating local load mechanical property of concrete segment | |
| CN112082865B (en) | Novel device for buckling test of inclined strut | |
| Talei-Faz et al. | Residual static strength of high strength steel cracked tubular joints | |
| GB2549080A (en) | Tethering apparatus and method | |
| CN212275470U (en) | Testing device for pipeline welding tensile stress | |
| Botros et al. | Behavior of free and connected double-tee flanges reinforced with carbon-fiber-reinforced polymer | |
| Herion et al. | Multiaxial loading of RHS by wheel loads | |
| CN117388058A (en) | Pipe joint fatigue test clamp for bearing single-shaft load | |
| CN220018915U (en) | Durable test bench of bush |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |