High polymer material impact abrasion mechanism research experiment device and evaluation method

Abstract

The invention provides a high polymer material impact abrasion mechanism research experiment device and an evaluation method, and relates to the field of impact abrasion mechanisms. The high polymer material impact abrasion mechanism research experiment device comprises a base, a rack, an accelerating mechanism, a releasing mechanism and a measuring mechanism. The rack plays a role in fixing the pointed cone track, the acceleration mechanism is used for realizing high acceleration of the pointed cone, the release mechanism is used for releasing the pointed cone to scratch the high polymer material, and the measuring mechanism is used for measuring the speed, the load and the friction force when the pointed cone impacts and scratches the high polymer material. The high polymer material impact abrasion mechanism research experiment device and the evaluation method realize measurement of speed, load and friction force in the impact abrasion process, and can be used for impact abrasion mechanism research. Meanwhile, based on the measured mechanical parameters, the dynamic response characteristics of the high polymer material are fully considered, and the wear resistance of the material under the high-speed impact working condition can be scientifically evaluated.

Description

Technical Field

[0001] The invention belongs to the field of impact wear of polymer materials, and in particular relates to an experimental device for studying the impact wear mechanism of polymer materials and an evaluation method. Background Art

[0002] For impact wear of polymer materials such as rubber, traditional wear only evaluates the wear resistance of materials by the wear volume or wear mass of the materials. This single evaluation standard does not consider the influence of the dynamic mechanical parameters of the materials on the wear performance, and cannot accurately evaluate the wear resistance of materials under high-speed wear. The dynamic response of materials under high-speed impact conditions has a crucial influence on the wear resistance of materials, so it is necessary to propose a polymer wear resistance evaluation method that takes into account the dynamic response. Summary of the invention

[0003] In view of the shortcomings of existing impact wear evaluation methods for polymer materials, such as single evaluation parameters and failure to consider the dynamic response of polymer materials, the present invention proposes an experimental device and evaluation method for impact wear of polymer materials. The device realizes the precise measurement of mechanical parameters such as speed, load and friction during high-speed wear of materials, and can be used for the study of impact wear mechanism. At the same time, the present invention proposes an evaluation method matching the experiment. The method, based on the measured mechanical parameters, fully considers the dynamic response characteristics of polymer materials, and can scientifically evaluate the wear resistance of materials under high-speed impact conditions.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] An experimental device for studying the impact wear mechanism of polymer materials comprises a base, a frame, an acceleration mechanism, a release mechanism, and a measuring mechanism; the frame, the acceleration mechanism, the release mechanism, and the measuring mechanism are distributed on the base; the frame is used to fix a pointed cone track, and the pointed cone is located in the pointed cone track; the acceleration mechanism is used to achieve high acceleration of the pointed cone, the release mechanism is used to release the pointed cone to make it scratch on the polymer material, and the measuring mechanism is used to measure the speed, load and friction force when the pointed cone impacts and scratches the polymer material.

[0006] The present invention also provides a method for evaluating the impact wear of polymer materials, comprising the following steps:

[0007] Step 1: Make the polymer material sample into a rectangular sample, select a sample pad with a thickness of h and place it on the force sensor, then place the sample on the sample pad, and rotate the loading rod to clamp the sample and the sample pad;

[0008] Step 2: Calculate the first spring stiffness value k required when the cone reaches the speed V by using formula (1), install the first spring with the stiffness value k in the cone track, start the thruster to push the cone fixing block to the rear of the cone clamping block to realize energy storage of the cone;

[0009] (1)

[0010] Wherein, x is the compression of the first spring, v is the velocity of the cone, and m is the total mass of the cone and the cone fixing block;

[0011] Step 3: Push the release rod upward, the release rod drives the cone block to move upward, and the cone fixing block and the cone impact forward and scratch the sample;

[0012] Step 4: Measure and calculate the average speed V of the cone passing through the two laser sensors. The friction force f of the cone is obtained over time t through the force sensor under the specimen block. The normal load F of the cone is read through the lifting platform. The average speed of the cone passing through the two laser sensors is calculated by formula (2):

[0013] (2)

[0014] Where d is the distance between the two laser sensors, is the time it takes for the cone to pass through the two laser sensors;

[0015] The relative motion between the polymer material and the pointed cone is a stick-slip motion, which is divided into a sticking stage and a slipping stage.

[0016] The viscous stage is: under the action of the normal load F, the sharp cone presses down the polymer material and scratches the polymer material at a speed V. Under the action of the friction force f, the polymer material and the sharp cone remain relatively still. At this time, the restoring force F generated by the deformation of the polymer material r Less than the friction force f;

[0017] Slip stage: As the cone continues to slide, the restoring force F generated by the deformation of the polymer material r When the friction force F is greater than the friction force F, the polymer material quickly passes through the sharp cone under the action of the restoring force, and the deformation and restoring force of the polymer material also decrease. r When it is smaller than the friction force again, the whole system enters the sticking stage again;

[0018] The relative motion between the polymer material and the pointed cone is carried out in a cycle of sticking, slipping, and sticking;

[0019] Step 5: Wear resistance index W r Indicates the wear resistance of the material, the wear resistance index W r It is expressed by formula (3):

[0020] (3)

[0021] Wherein, L is the length of polymer material cracking in a single stick-slip motion, and λ is the length of the stick-slip motion;

[0022] The length of the stick-slip motion is expressed by equation (4):

[0023] (4)

[0024] Among them, k1 is a parameter related to the shape of the tip cone, n is a parameter related to the speed of the tip cone, E is the elastic modulus of the polymer material, and f is the friction force;

[0025] The length L of a single stick-slip crack is expressed by formula (5):

[0026] (5)

[0027] Among them, k2 is a parameter related to the material and the shape of the cone;

[0028] The wear resistance index of different polymer materials under high-speed impact conditions is obtained by formula (3), and the wear resistance performance under high-speed impact conditions is evaluated by comparing the wear resistance indexes of different materials.

[0029] The present invention has the following beneficial effects:

[0030] The polymer material impact wear mechanism research experimental device and evaluation method of the present invention realizes the adjustment of different speeds and loads, and at the same time realizes the measurement of mechanical parameters such as friction, speed and load under high-speed impact conditions. The matching evaluation method is based on the measured mechanical parameters, fully considers the dynamic response characteristics of the polymer material under high-speed impact conditions, and can more accurately and quickly evaluate the wear resistance of the polymer material under high-speed impact conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 This is a general assembly diagram of an experimental device for studying the impact wear mechanism of polymer materials of the present invention;

[0033] Figure 2A schematic diagram of an accelerating mechanism of an experimental device for studying the impact wear mechanism of polymer materials according to the present invention;

[0034] Figure 3 A schematic diagram of a pointed cone and a pointed cone fixing block of an experimental device for studying the impact wear mechanism of a polymer material according to the present invention;

[0035] Figure 4 A schematic diagram of a release mechanism of an experimental device for studying the impact wear mechanism of polymer materials according to the present invention;

[0036] Figure 5 A schematic diagram of a release rod and a release knob of an experimental device for studying the impact wear mechanism of polymer materials of the present invention;

[0037] Figure 6 The present invention is a schematic diagram of the measuring mechanism of an experimental device for studying the impact wear mechanism of polymer materials.

[0038] Wherein, the accompanying drawings are marked as follows:

[0039] Base 1, first pointed cone track supporting mechanism 2, second pointed cone track supporting mechanism 3, crossbeam 4, pointed cone track 5, pointed cone fixing block 6, pointed cone 7, first spring 8, thruster 9, thruster fixing seat 10, positioning base 11, compression spring 12, pointed cone blocking block 13, release rod 14, release knob 15, laser speed measuring device 16, sample pad 17, force sensor 18, measuring base 19, loading rod 20, loading block 21. DETAILED DESCRIPTION

[0040] The following is a description of the implementation of the present invention by specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0042] In order to achieve the above object, the present invention provides the following technical solutions:

[0043] like Figure 1 As shown, an experimental device for studying the impact wear mechanism of polymer materials of the present invention is shown, and the experimental device for studying the impact wear mechanism of polymer materials comprises:

[0044] Base 1;

[0045] Test specimens;

[0046] Frame: It is composed of a first pointed cone track support mechanism 2, a second pointed cone track support mechanism 3 and a crossbeam 4, wherein the first pointed cone track support mechanism 2 and the second pointed cone track support mechanism 3 are both fixed on the base 1, and upper rectangular holes and lower rectangular holes are respectively distributed on the first pointed cone track support mechanism 2 and the second pointed cone track support mechanism 3, wherein two ends of the crossbeam 4 are respectively embedded in the two upper rectangular holes, and the pointed cone track 5 is distributed in the lower rectangular hole; wherein the crossbeam 4 plays a role in resisting the lateral force of the structure.

[0047] Acceleration mechanism: Figure 2 As shown, the acceleration mechanism is composed of a pointed cone track 5, a pointed cone fixing block 6, a pointed cone 7, a first spring 8, a propeller 9 and a propeller fixing seat 10, wherein the pointed cone fixing block 6 and the first spring 8 are located inside the pointed cone track 5, and the pointed cone 7 is connected to the pointed cone fixing block 6 by a thread, as shown in FIG. Figure 3 As shown, the thruster fixing base 10 is connected to the base 1 by bolts, and the thruster 9 is located on the upper part of the thruster base 10. The thruster 9 is used to compress the first spring 8 to realize the energy storage of the pointed cone fixing block 6 and the pointed cone 7.

[0048] Release mechanism; Figure 4 As shown, the release mechanism consists of a locking base 11, a compression spring 12, a pointed cone block 13, a release rod 14 and a release knob 15, wherein the locking base 11 is connected to the base 1 through a thread, a crossbeam rectangular hole is distributed above the locking base 11, a rectangular slot is distributed inside the locking base 11, the compression spring 12 and the pointed cone block 13 are embedded in the rectangular slot from above the rectangular slot, a circular through hole is distributed on the pointed cone block 13, and the release rod 14 passes through the circular through hole and is connected to the release knob 14 through a thread, as shown in FIG. Figure 5 shown.

[0049] Measuring institutions; such as Figure 6 As shown, the measuring mechanism consists of a laser speed measuring device 16, a sample pad 17, a force sensor 18, a measuring base 19, a loading rod 20 and a loading block 21, wherein the loading rod 20 passes through a hole on the upper part of the measuring base 19 and is connected to the loading block 21 by threads, the force sensor 18 is located on the upper part of the measuring base 19, the sample pad 17 is located on the upper part of the measuring base 19, the force sensor 18, the measuring base 19 and the sample pad 17 are connected by bolts, and the laser speed measuring device 16 is connected to the upper part of the measuring base 19 by bolts.

[0050] The experimental device for studying the impact wear mechanism of polymer materials provided by the present invention has a wide range of configurable cone speeds. The cone speed can be adjusted by replacing the first spring 8 in the cone track 5. The adjustable cone speed range is from 0.001 m / s to 100 m / s. The stiffness of the replacement spring can be calculated according to formula (1):

[0051] (1)

[0052] Wherein, x is the compression amount of the first spring 8 , v is the velocity of the pointed cone 7 , and m is the total mass of the pointed cone 7 and the pointed cone fixing block 6 .

[0053] In the experimental device for studying the impact wear mechanism of polymer materials provided by the present invention, the load control of the pointed cone 7 is achieved by changing the thickness of the loading block 21. The friction force f of the pointed cone 7 during the impact wear process is controlled by the force sensor 18 below the loading block 21.

[0054] In the experimental device for studying the impact wear mechanism of polymer materials provided by the present invention, a propeller 9 is used to push the pointed cone fixing block 6 to compress the first spring 8. When the pointed cone fixing block 6 slides to the rear of the pointed cone clamping block 13, the pointed cone clamping block 13 moves upward and pushes the compression spring 12. At this time, the pointed cone fixing block 6 is fixed to the rear of the pointed cone clamping block 13, and the pointed cone fixing block 6 and the pointed cone 7 realize energy storage. The acceleration of the pointed cone fixing block 6 and the pointed cone 7 is achieved by moving the release rod 14 upward.

[0055] The present invention provides a method for evaluating the impact wear of polymer materials, comprising the following steps:

[0056] Step 1: Make a polymer material sample such as rubber into a rectangular sample, select a sample pad 17 with a thickness of h and place it above the force sensor 18, then place the sample above the sample pad 17, and rotate the loading rod to clamp the sample and the sample pad 17.

[0057] Step 2: Calculate the first spring stiffness value k required when the cone 7 reaches the speed V by using formula (1), and install the first spring with the stiffness value k in the cone track 5, start the thruster 9 to push the cone fixing block 6 to the rear of the cone clamping block 13 to realize the energy storage of the cone.

[0058] Step 3: Push the release rod 14 upward, the release rod 14 drives the pointed cone block 13 to move upward, and the pointed cone fixing block 6 and the pointed cone 5 impact forward and scratch the sample.

[0059] Step 4: Measure and calculate the average speed V of the cone 7 passing through the two laser sensors 16, and obtain the curve of the friction force f of the cone 7 changing with time t through the force sensor 18 under the sample block. By reading the normal load F of the cone 7 through the lifting platform, the average speed of the cone 7 passing through the two laser sensors 16 can be calculated by formula (2):

[0060] (2)

[0061] Wherein, d is the distance between two laser sensors 16, is the time it takes for the tip cone 7 to pass through the two laser sensors 16.

[0062] The relative motion between the polymer material and the pointed cone is a stick-slip motion, which is divided into a sticking stage and a slipping stage.

[0063] The sticking stage is: under the action of the normal load F, the sharp cone 7 presses down the polymer material and scratches the polymer material at a speed V. Under the action of the friction force f, the polymer material and the sharp cone 7 remain relatively still. At this time, the restoring force F generated by the deformation of the polymer material r is smaller than the friction force f.

[0064] Sliding stage: As the pointed cone 7 continues to slide, the restoring force F generated by the deformation of the polymer material r When the friction force F is greater than the friction force F, the polymer material quickly passes through the sharp cone 7 under the action of the restoring force, and the deformation and restoring force of the polymer material also decrease. r When it is smaller than the friction force again, the entire system enters the sticky stage again.

[0065] The relative movement between the polymer material and the pointed cone proceeds in a cycle of "viscosity" - "slippage" - "viscosity"...

[0066] Step 5: The present invention uses the wear resistance index W r Indicates the wear resistance of the material, the wear resistance index W r It can be expressed by formula (3):

[0067] (3)

[0068] Among them, L is the length of the polymer material cracking in a single stick-slip motion, and λ is the length of the stick-slip motion.

[0069] The length of stick-slip motion can be expressed by equation (4):

[0070] (4)

[0071] Among them, k1 is a parameter related to the shape of the pointed cone 7, n is a parameter related to the speed of the pointed cone 7, E is the elastic modulus of the polymer material, and f is the friction force;

[0072] The length L of a single stick-slip crack can be expressed by formula (5):

[0073] (5)

[0074] Among them, k2 is a parameter related to the material and the cone shape.

[0075] The wear volume of different polymer materials under high-speed impact conditions can be obtained by formula (3), and the wear resistance under high-speed impact conditions can be evaluated by comparing the wear volumes of different materials.

[0076] In a specific embodiment, a certain type and size of rubber is taken as an example to perform wear resistance analysis.

[0077] Step 1: As a preferred solution of the present invention, the rubber is made into a rectangular sample with a length, width and height of 30mm×60mm×10mm, a sample pad with a thickness of 10mm is selected and placed above the force sensor, and then the rectangular rubber sample is placed above the sample pad, and the loading rod is rotated to clamp the sample and the sample block.

[0078] Step 2: As a preferred solution of the present invention, the speed of the sharp cone impacting and scratching the rubber is selected to be 1 m / s. The compression amount x of the spring is selected to be 100 mm, and the total mass m of the sharp cone and the sharp cone fixing block is selected to be 30 g. The required spring stiffness is calculated to be 2 N / m by formula (1). Then, the thruster is started to push the sharp cone fixing block to the rear of the sharp cone clamping block to realize energy storage of the sharp cone.

[0079] Step 3: Push the release rod upward, the release rod drives the pointed cone block to move upward, and the pointed cone fixing block and the pointed cone impact forward and scratch the rubber sample.

[0080] Step 4: As a preferred solution of the present invention, the distance between the two laser sensors is 50 mm, and the time of the two laser sensors is read respectively, and the time difference between the two laser sensors is 0.05 s. The speed V of the sharp cone is calculated by formula (2) to be 1 m / s. When the sharp cone scratches the rubber, the friction force between the rubber and the sharp cone is 2 N. The normal load of the sharp cone is read by the lifting platform and is 1.5 N.

[0081] Step 5: Calculate the stick-slip distance of rubber by formula (4) to be 8×10 -5 m, and the crack length of the rubber is calculated by formula (5) to be 10 -5 m. The wear resistance index of rubber calculated by formula (5) is 0.125.

[0082] As a preferred solution, when the wear resistance index of the material is greater than 1, the material is a low wear resistance material, and when the wear resistance index of the material is less than 1, the material is a high wear resistance material. According to step five, the wear resistance index of the rubber is less than 1, so this type of rubber is a high wear resistance material.

[0083] Although the present invention has been described in detail above by general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. An experimental device for studying the impact wear mechanism of polymer materials, characterized in that: The experimental device includes a base, a frame, an acceleration mechanism, a release mechanism, and a measuring mechanism; the frame, the acceleration mechanism, the release mechanism, and the measuring mechanism are distributed on the base; the frame is used to fix the pointed cone track, and the pointed cone is located in the pointed cone track; the acceleration mechanism is used to achieve high acceleration of the pointed cone, the release mechanism is used to release the pointed cone to make it scratch on the polymer material, and the measuring mechanism is used to measure the speed, load and friction force when the pointed cone impacts and scratches the polymer material.

2. The polymer material impact wear mechanism research experimental device according to claim 1, characterized in that: The frame consists of a first pointed cone rail support mechanism, a second pointed cone rail support mechanism and a crossbeam, wherein the first pointed cone rail support mechanism and the second pointed cone rail support mechanism are both fixed on a base, and upper rectangular holes and lower rectangular holes are respectively distributed on the first pointed cone rail support mechanism and the second pointed cone rail support mechanism, wherein two ends of the crossbeam are respectively embedded in the two upper rectangular holes, and the pointed cone rail is embedded in the lower rectangular hole.

3. The polymer material impact wear mechanism research experimental device according to claim 1, characterized in that: The acceleration mechanism consists of a pointed cone track, a pointed cone fixing block, a pointed cone, a first spring, a thruster and a thruster fixing seat, wherein the pointed cone fixing block and the first spring are located inside the pointed cone track, the pointed cone is connected to the pointed cone fixing block through a thread, the thruster fixing base is connected to the base through bolts, and the thruster is located on the upper part of the thruster base; the thruster is used to compress the first spring to realize energy storage of the pointed cone fixing block and the pointed cone.

4. The polymer material impact wear mechanism research experimental device according to claim 3, characterized in that: The release mechanism consists of a locking base, a compression spring, a conical block, a release rod and a release knob, wherein the locking base is connected to the base through threads, a rectangular hole of a crossbeam is arranged above the locking base, a rectangular slot is arranged inside the locking base, the compression spring and the conical block are embedded into the rectangular slot from above, a circular through hole is distributed on the conical block, and the release rod passes through the circular through hole and is connected to the release knob through threads.

5. The polymer material impact wear mechanism research experimental device according to claim 1, characterized in that: The measuring mechanism consists of a laser speed measuring device, a sample pad, a force sensor, a measuring base, a loading rod and a loading block, wherein the loading rod passes through a hole on the upper part of the measuring base and is connected to the loading block by a thread, the force sensor is located on the upper part of the measuring base, the sample pad is located on the upper part of the measuring base, the force sensor, the measuring base and the sample pad are connected by bolts, and the laser speed measuring device is connected to the upper part of the measuring base by bolts.

6. The polymer material impact wear mechanism research experimental device according to claim 3, characterized in that: The speed of the pointed cone is adjusted by replacing the first spring in the pointed cone track. The speed of the pointed cone is adjusted within the range of 0.001 m / s to 100 m / s. The stiffness of the first spring is calculated according to formula (1): （1） Wherein, x is the compression amount of the first spring, v is the velocity of the pointed cone, and m is the total mass of the pointed cone and the pointed cone fixing block.

7. The polymer material impact wear mechanism research experimental device according to claim 5, characterized in that: The load control of the pointed cone is achieved by changing the thickness of the loading block, and the friction force f during the impact wear of the pointed cone is controlled by the force sensor under the loading block.

8. The polymer material impact wear mechanism research experimental device according to claim 4, characterized in that: A thruster is used to push the pointed cone fixing block to compress the first spring. When the pointed cone fixing block slides to the rear of the pointed cone clamping block, the pointed cone clamping block moves upward and pushes the compression spring. At this time, the pointed cone fixing block is fixed to the rear of the pointed cone clamping block, and the pointed cone fixing block and the pointed cone store energy. The release rod is moved upward to accelerate the pointed cone fixing block and the pointed cone.

9. A method for evaluating impact wear of polymer materials, characterized in that: The following steps are involved: Step 1: Make the polymer material sample into a rectangular sample, select a sample pad with a thickness of h and place it on the force sensor, then place the sample on the sample pad, and rotate the loading rod to clamp the sample and the sample pad; Step 2: Calculate the first spring stiffness value k required when the cone reaches the speed V by using formula (1), install the first spring with the stiffness value k in the cone track, start the thruster to push the cone fixing block to the rear of the cone clamping block to realize energy storage of the cone; （1） Wherein, x is the compression of the first spring, v is the velocity of the cone, and m is the total mass of the cone and the cone fixing block; Step 3: Push the release rod upward, the release rod drives the cone block to move upward, and the cone fixing block and the cone impact forward and scratch the sample; Step 4: Measure and calculate the average speed V of the cone passing through the two laser sensors. The friction force f of the cone is obtained over time t through the force sensor under the specimen block. The normal load F of the cone is read through the lifting platform. The average speed of the cone passing through the two laser sensors is calculated by formula (2): （2） Where d is the distance between the two laser sensors, is the time it takes for the cone to pass through the two laser sensors; The relative motion between the polymer material and the pointed cone is a stick-slip motion, which is divided into a sticking stage and a slipping stage. The viscous stage is: under the action of the normal load F, the sharp cone presses down the polymer material and scratches the polymer material at a speed V. Under the action of the friction force f, the polymer material and the sharp cone remain relatively still. At this time, the restoring force F generated by the deformation of the polymer material r Less than the friction force f; Slip stage: As the cone continues to slide, the restoring force F generated by the deformation of the polymer material r When the friction force F is greater than the friction force F, the polymer material quickly passes through the sharp cone under the action of the restoring force, and the deformation and restoring force of the polymer material also decrease. r When it is smaller than the friction force again, the whole system enters the sticking stage again; The relative motion between the polymer material and the pointed cone is carried out in a cycle of sticking, slipping, and sticking; Step 5: Wear resistance index W r Indicates the wear resistance of the material, the wear resistance index W r It is expressed by formula (3): （3） Wherein, L is the length of polymer material cracking in a single stick-slip motion, and λ is the length of the stick-slip motion; The length of the stick-slip motion is expressed by equation (4): （4） Among them, k1 is a parameter related to the shape of the tip cone, n is a parameter related to the speed of the tip cone, E is the elastic modulus of the polymer material, and f is the friction force; The length L of a single stick-slip crack is expressed by formula (5): （5） Among them, k2 is a parameter related to the material and the shape of the cone; The wear resistance index of different polymer materials under high-speed impact conditions is obtained by formula (3), and the wear resistance performance under high-speed impact conditions is evaluated by comparing the wear resistance indexes of different materials.

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