CN210665330U

CN210665330U - Bending fatigue test device of flat plate sample based on vibration table

Info

Publication number: CN210665330U
Application number: CN201921169211.2U
Authority: CN
Inventors: 石朝成
Original assignee: Shanghai Aeronautical Materials & Structures Testing Co ltd
Current assignee: Shanghai Aeronautical Materials & Structures Testing Co ltd
Priority date: 2019-07-23
Filing date: 2019-07-23
Publication date: 2020-06-02
Anticipated expiration: 2029-07-23

Abstract

The utility model discloses a bending fatigue test device of dull and stereotyped sample based on shaking table, including fixing the fixture on the fixed station, install the sample on this fixture, fix the fixed establishment on the shaking table, and: one end of the ejector rod is provided with an external thread for being connected and fixed with the fixing mechanism, and the other end of the ejector rod is provided with a first through hole; the adapter is provided with a pair of parallel lug parts on one side, a connecting column is arranged on the other side, an opening is formed between the parallel lug parts, a second through hole is formed in each lug part, one end of the ejector rod with the first through hole is inserted into the opening, and the ejector rod is connected with the adapter through a positioning pin penetrating through the second through hole of the lug part and the first through hole formed in one end of the ejector rod; and one end of the sensor is fixedly provided with a connecting piece, and the connecting piece is fixedly connected with the connecting column of the adapter and clamps one end of the sample between the connecting column and the connecting column.

Description

Bending fatigue test device of flat plate sample based on vibration table

Technical Field

The utility model belongs to bending fatigue test device field specifically is a bending fatigue test device of dull and stereotyped sample based on shaking table.

Background

Fatigue failure is one of the typical failure modes of mechanical products, and the parts can be subjected to certain alternating bending stress, so that the fatigue failure can occur.

In the bending fatigue test of the conventional flat plate specimen, the test is usually carried out on a conventional fatigue testing machine, the common frequency of the conventional fatigue testing machine is usually below 500Hz, and the cycle number is 1 × 10⁹The secondary bending fatigue performance test requires 55.6 hours and is longer.

Or the bending fatigue test of the flat plate sample is carried out on a vibration table, the flat plate sample is usually fixed on the table top of an electromagnetic vibration table through a clamp or a fixing device, the excitation frequency is selected to be close to the first-order resonance frequency of the blade by utilizing the resonance amplification principle, and the blade is forced to generate larger vibration response by small basic excitation. The vibration exciting frequency of the vibration table can reach more than 2000Hz, and the cycle number is 1 multiplied by 10⁹The secondary bending fatigue performance test only needs 14 hours, and the test efficiency is greatly improved.

However, in the conventional art, since the clamp or the fixing device clamps one end of the flat plate sample and the other end of the flat plate sample is a free end without external restraint, when the test is performed using the vibration table, the amplitude of the blade is greatly fluctuated due to resonance amplification, and thus, stable strain or stress response cannot be obtained, thereby reducing the reliability of the test result.

SUMMERY OF THE UTILITY MODEL

In order to overcome above-mentioned prior art time cost height or can't acquire stable meeting an emergency or stress response's defect in than bending test in low frequency bending test, the utility model provides a bending fatigue test device of dull and stereotyped sample based on shaking table.

The utility model provides a technical scheme that its technical problem adopted is: a bending fatigue test device for a flat plate sample based on a vibrating table comprises a clamping mechanism fixed on a fixed table, a fixing mechanism fixed on the vibrating table, and a clamping mechanism, wherein the clamping mechanism is used for clamping one end of the sample; further comprising:

one end of the ejector rod is provided with an external thread for being connected and fixed with the fixing mechanism, and the other end of the ejector rod is provided with a first through hole;

the adapter is provided with a pair of parallel lug parts on one side, a connecting column is arranged on the other side, an opening is formed between the parallel lug parts, a second through hole is formed in each lug part, one end of the ejector rod with the first through hole is inserted into the opening, and the ejector rod is connected with the adapter through a positioning pin penetrating through the second through hole of the lug part and the first through hole formed in one end of the ejector rod;

and one end of the sensor is fixedly provided with a connecting piece, and the connecting piece is fixedly connected with the connecting column of the adapter and clamps the other end of the sample between the connecting piece and the adapter.

Further, the both ends of shop bolt are equipped with the cotter hole respectively, all wear to be equipped with spacing pin in every cotter hole to spacing the shop bolt, prevent that it from following in the test process fall out in the second through-hole of adapter ear and the first through-hole of ejector pin.

The distance between two pin holes of dowel pin with the width phase-match of a pair of ear of adapter to make the dowel pin can not reciprocate in the experimentation.

Further, the spliced pole of adapter is equipped with the external screw thread, the connecting piece of sensor is the nut, and both pass through threaded connection.

The sample is provided with a perforation at one end and is sleeved on the connecting column of the connector through the perforation, so that the sample is allowed to be clamped between the adapter and the sensor.

According to the preferred embodiment of the present invention, the sensor is an acceleration sensor or a displacement sensor.

The utility model has the advantages that:

1. carry out bending fatigue test with the conventional fatigue testing machine who uses among the prior art and compare, the utility model discloses a bending fatigue testing device makes bending fatigue test can transfer to general shaking table and go on, the excitation frequency that the shaking table can provide can be higher than conventional fatigue testing machine's excitation frequency far away (the upper limit excitation frequency that present hyperfrequency fatigue testing machine can provide generally is less than 500Hz, and the upper limit excitation frequency that general shaking table can provide is higher than 2000Hz), test time can reduce by a wide margin.

2. With directly will in prior art the fixing device of sample and this sample of centre gripping is fixed and is compared on the shaking table by the experiment, the utility model discloses a scheme that bending fatigue test device carries out the experiment does: the test sample is fixed on a fixing table through a fixing device for clamping one end of the test sample (the end of the test sample fixed on the fixing device is called a fixed end, correspondingly, the other end of the test sample is called a free end), the free end of the test sample is connected with an ejector rod through an adapter, the other end of the ejector rod is connected with a vibration table, vibration is conducted to the test sample through the ejector rod, and the ejector rod forms external restraint on the free end of the test sample, so that the bending deformation of the test sample is realized, the instability of the test sample in response to high-frequency excitation vibration due to the existence of the free end without external restraint in the prior art is eliminated, the stability of strain or stress response of the test sample in the test process can be ensured, and the.

3. With the help of the utility model discloses a bending fatigue test device can be through changing the initial deformation of sample is the displacement size of the skew initial position of free end of sample, changes the stress ratio, realizes the test under the different stress ratios.

Drawings

Fig. 1 is an installation schematic diagram of the bending fatigue testing device of the present invention.

Fig. 2 is a schematic diagram of the connection of the carrier rod, the adapter and the test sample in fig. 1.

Fig. 3 is a schematic view of the jack of fig. 2.

Fig. 4 is a cross-sectional view of the transition joint of fig. 2.

Fig. 5 is a schematic view of the alignment pin of fig. 2.

Fig. 6 is a schematic view of the sensor of fig. 2.

FIG. 7 is a schematic representation of the sample of FIG. 2.

Description of the figure numbers:

1. a top rod, 10, a first through hole,

2. the adapter, 20, the connecting column, 21, the lug part, 210, the second through hole, 22, the opening,

3. a positioning pin, 30 pin holes, 4 limit pins, 5 sensors, 50 connecting pieces,

6. sample, 60 through holes, 7 clamping mechanisms, 70 metal frames, 71 cushion blocks, 73 bolts,

8. a fixed platform, 9 a vibration platform and 90 a fixing mechanism.

a. One end of the ejector rod is connected with the adapter, and b, one end of the ejector rod is connected with the fixing mechanism on the vibration table;

c. fixed end of sample, d.

Detailed Description

As shown in fig. 1 and 2, the bending fatigue test apparatus for a flat plate sample by a vibration table includes a holding mechanism 7 fixed to a fixed table 8, a sample 6 mounted on the holding mechanism 7, a fixing mechanism 90 fixed to a vibration table 9, and:

a top rod 1, one end of which is provided with an external thread (not shown in the figure) for connecting and fixing with the fixing mechanism 90, and the other end of which is provided with a first through hole 10 (figure 3);

as shown in fig. 4, the adapter 2 has a pair of parallel ears 21 on one side thereof, and a connecting post 20 on the other side thereof, an opening 22 is formed between the pair of parallel ears 21, and a second through hole 210 is formed in each of the two ears 21, one end of the ejector rod 1 with the first through hole 10 is inserted into the opening 22, and the ejector rod 1 is connected with the adapter 2 by passing a positioning pin 3 through the second through hole 210 of the ear 21 and the first through hole 10 formed in one end of the ejector rod 1;

as shown in fig. 6, the sensor 5 has a connector 50 fixed to one end thereof, and the connector 50 is fixedly connected to the connection post 20 of the adapter 2 to hold one end of the sample 6 therebetween.

Furthermore, two ends of the positioning pin 3 are respectively provided with a pin hole 30 (see fig. 5), and each pin hole 30 is provided with a limiting pin 4 in a penetrating manner, so that the positioning pin 4 is limited, and the positioning pin is prevented from falling out of the second through hole 210 of the adapter ear 21 and the first through hole 10 of the ejector rod 1 in the test process.

The distance between two pin holes 30 of dowel 3 with the width phase-match of a pair of ear 21 of adapter 2 to make dowel 3 can not reciprocate in the experimentation.

Further, the connecting column 20 of the adapter 2 is provided with an external thread (not shown in the figure), and the connecting member 50 of the sensor 5 is a nut, and the two are connected through a thread.

As shown in fig. 7, the test piece 6 is provided with a through hole 60 at one end and is sleeved on the connecting column 20 of the connector 2 through the through hole 60, so as to be clamped between the adapter 2 and the sensor 5.

Preferably, the sensor 5 is an acceleration sensor or a displacement sensor.

As shown in fig. 7, the end of the test piece 6 provided with the through hole 60 is defined as a free end (d in the figure), and is connected with the connecting column 20 of the adapter 2; correspondingly, the other end of the sample 6 is defined as a fixed end (shown as c in the figure) and is fixed on a fixed table 8 through the clamping mechanism 7.

Referring back to fig. 1, the clamping mechanism 7 is a metal frame 70 fixed on the fixing table 8 by welding or bolts, clamps one end of the sample 6 by a pair of pads 71 and then nests in the metal frame 70, and fastens the pads 71 and the sample 6 by bolts screwed into screw holes on the side surface of the metal frame 70, thereby fixing the sample 6 on the fixing table 8; the clamping mechanism 7 may be simply bolted, for example, by providing a screw hole at the fixed end of the sample 6 and fixing the sample 6 to the fixed base 8 with a bolt. Fixture 7's function is used for the fixed mounting of sample 6 stiff end, consequently, can be applied to among the prior art the utility model discloses a centre gripping or mounting structure be simple equivalent replacement all should belong to the scope of the utility model.

The fixing mechanism 90 is used for connecting the ejector rod 1 and the vibrating table 9, and is a metal frame fixed on the vibrating table 9 by welding or bolts, and the metal frame is provided with a through hole (not shown in the figure) for allowing one end of the ejector rod 1 with external threads to pass through the through hole and screwing a nut (not shown in the figure) for fixing; the fixing mechanism 90 may also be a screw hole directly formed on the table top of the vibration table 9, and the end of the ejector rod 1 with the external thread is directly screwed into the screw hole on the vibration table 9 and is additionally provided with a locknut for further fastening. The function of the fixing mechanism 90 is to be used for the fixed mounting of the one end of the ejector pin connected with the vibration table, therefore, can be applied to the prior art the utility model discloses a fixed or mounting structure should all belong to the scope of the utility model, simple equivalent replacement promptly.

In the installation the utility model discloses a following installation procedure should be noted during bending fatigue test device:

1. the sample 6 is mounted and fixed on a fixed table 8 through the clamping mechanism 7, but not mounted on a vibration table 9;

2. the free end of the sample 6 is sleeved with the connecting column 20 of the adapter 2, and after a gasket is sleeved on the connecting column 20 of the adapter 2, the connecting column 20 passes through the through hole 60 on the free end of the sample 6 and is fixedly installed by using a nut, in the utility model, one end of the sensor 5 is provided with a connecting piece 50 which is matched with the connecting column 20 of the adapter 2, the connecting piece 50 is a nut, and the sensor 5 is used for replacing a common nut and is used for installing and fixing the adapter 2 and the free end of the sample 6 and simultaneously realizing the installation of the sensor 5; in this step, it should be noted that the opening 22 formed between the pair of ears 21 of the adapter 2 is horizontal, i.e. the positioning pin 3 inserted into the second through hole 210 of the pair of ears 21 is vertical.

3. Inserting one end of the ejector rod 1 connected with the adapter 2 into the opening 22 of the adapter 2, and installing the other end of the ejector rod 1 on the fixing mechanism 90 on the vibrating table 9, during installation, sleeving the gasket on the corresponding end part of the ejector rod 1, and screwing the nut, wherein at the moment, the nut is only required to be screwed until the first gasket is attached to the fixing mechanism 90 on the vibrating table 9;

4. simultaneously inserting the positioning pin 3 into the second through holes 210 of the pair of ears 21 of the adapter 2 and the first through hole 10 on the ejector rod 1, and inserting the limiting pin 4 into the pin holes 30 at the two ends of the positioning pin 3 to complete the connection between the ejector rod 1 and the adapter 2;

5. finally, the nut of the fixing mechanism 90 for fixing the carrier rod 1 to the vibration table 9 in step 3 is further tightened, and an appropriate torque is set for the nut, but it should be noted that the torque is set according to the material and the dimensional specification of the component, and the magnitude of the torque is generally 0.01 to 5N · m according to experience.

In the above installation step, it is a common practice in mechanical connection to provide a gasket at the joint of the bolt and the nut, and therefore the present invention does not describe it in detail.

Different with directly fixing sample 6 through fixing device and carrying out the test on shaking table 9, use the utility model discloses a bending fatigue test device is tested, need will sample 6 passes through fixing device and fixes it on fixed station 8, this sample 6 the free end with adapter 2's spliced pole 20 is connected, with the ejector pin 1's that adapter 2's ear 21 is connected the other end is fixed on shaking table 9, will vibrate conduction to sample 6 and form external restraint to sample 6's free end through ejector pin 1 to this bending deformation who realizes sample 6, this in-process, has eliminated the instability of sample 6 to high frequency excitation vibration response. Meanwhile, the stress ratio of the test is changed by adjusting the initial deformation of the test sample 6, and the stress ratio is set according to the material and the dimension specification of the part, and is generally-1-0.1 according to experience.

It should be understood that, in the technical solution of the present invention, the value ranges are given for the torque magnitude set for the nut used for the connection between the ejector rod 1 and the fixing mechanism 90 on the vibration table 9 and the test stress ratio of the sample 6, but these two ranges should not be regarded as limitations of the present invention, because these two values are set depending on the material and specification of the component and according to experience, the ranges described in the present invention are only suggested value ranges under general conditions; sensor 5 be used for obtaining the response acceleration of sample 6 is the acceleration sensor who directly acquires the acceleration parameter, perhaps can indirectly acquire the sensor of acceleration parameter after handling like other accessible data such as displacement sensor, consequently should not regard as right according to theory of operation (voltage, electric current, resistance, electric capacity etc.) to the classification of sensor the utility model discloses a restriction and belong to the utility model discloses a scope.

Claims

1. The utility model provides a bending fatigue test device of dull and stereotyped sample based on shaking table, is including fixing the fixture on the fixed station, fixture is used for the one end of centre gripping sample, fixes the fixed establishment on the shaking table, and its characterized in that still includes:

2. The bending fatigue test device according to claim 1, wherein pin holes are respectively formed at two ends of the positioning pin, and a limiting pin is arranged in each pin hole in a penetrating manner, so that the positioning pin is limited and prevented from falling out of the second through hole of the adapter ear and the first through hole of the ejector rod in the test process.

3. The bending fatigue testing apparatus of claim 2, wherein the distance between the two pin holes of the positioning pin is matched with the width of the pair of ears of the adapter, so that the positioning pin does not move up and down during the test.

4. The bending fatigue testing device of claim 1, wherein the connecting column of the adapter is provided with an external thread, and the connecting member of the sensor is a nut, and the connecting member and the nut are connected through a thread.

5. The bending fatigue testing apparatus of claim 1, wherein the test piece is provided with a through hole at one end and is sleeved on the connecting column of the connector through the through hole, thereby allowing to be clamped between the adapter and the sensor.

6. The bending fatigue testing apparatus of claim 1, wherein the sensor is an acceleration sensor or a displacement sensor.