CN104764661A - Test device and test method for measuring mechanical properties of lap joint samples - Google Patents

Abstract

The invention relates to a test device and a test method for measuring the mechanical properties of lap joint samples. The test device includes two clamps for clamping the lap joint samples, and two clamps for fixing the lap joint samples on the clamps. A cover plate, two loading heads for connecting the test setup to the experimental equipment, four lap joint specimens and a set of connecting bolts and pins. The test method is to clamp the lap joint sample to be tested by two clamps, connect and load the test equipment through the loading head, and test the shear, bending, torsion or tensile mechanical properties of the sample. The present invention adopts the universal design concept, not only can realize the stretching, shearing, bending, torsion test and four-angle KSII test of lap joint samples, but also is suitable for lap joint samples of three different connection types, and has strong The versatility is beneficial to the reduction of the fixture cost.

Description

Test apparatus and test methods for measuring mechanical properties of lap joint specimens

technical field

The invention relates to a test device, in particular to a test device and a test method for measuring the mechanical properties of lap joint samples, which can be used to determine the failure of solder joints, structural glue and glue welding in tensile, bending, torsion and shear tests stress.

Background technique

Spot welding, glue bonding and glue welding are three commonly used lap joint methods, which have the characteristics of low cost and high efficiency. The lap joint structure has the advantages of low quality, high strength and high stability, and has been widely used in the field of industrial automation. Especially the connection of car body. Lap joint structures are mainly subjected to typical loads such as tensile force, shear force, bending moment, and torque. Under the action of a single load or multiple loads, the lap joint structure will be scrapped due to premature failure, and even cause serious accidents. With the continuous improvement of people's requirements for product quality and the increasingly harsh working conditions of products, the mechanical performance index of the lap joint structure is an important evaluation index for its safety and stability. Tensile, shear, bending and torsion tests are carried out on the lap joint samples. It is an important way to obtain the mechanical performance parameters of the lap joint structure, and the establishment of a reasonable test method and the design of a special test device are the keys to ensure the accuracy of the test results. Therefore, the design of an integrated test device with a simple structure, a wide range of applications, and high measurement accuracy imminent.

The publication number is CN 102645382A invention patent (test method for measuring spot welding shear strength and its special test device), which discloses a measurement method and special The test device, but the structure of the device is relatively complicated and difficult to realize. In the prior art, the method and device for measuring welding performance parameters of spot welding samples are only applicable to a certain type of load, and the operation method is relatively complicated and difficult to implement, and the test accuracy is limited to a certain extent.

Contents of the invention

The object of the present invention is to provide a test device and a test method for measuring the mechanical properties of lapped specimens in order to overcome the above-mentioned defects in the prior art. The following functions can be achieved by changing the installation positions of the loading head and the sample at both ends: (1) Determination of the shear performance of the lapped sample; (2) Determination of the bending performance of the lapped sample; (3) The measurement of the lapped sample Determination of torsional properties; (4) Tensile and KSII multi-angle mechanical properties of lapped specimens.

Technical scheme of the present invention is as follows:

A test device for measuring the mechanical properties of lapped samples, used to connect to experimental equipment to measure the mechanical properties of lapped samples, including:

Two clamps for clamping lap joint specimens, the two clamps are used in combination;

Two cover plates for securing the lap joint specimens to the fixture;

Two loading heads for connecting the test device with the experimental equipment;

Four kinds of lap joint samples, namely type I sample, type II sample, type III sample and type IV sample;

A set of connecting bolts and pins.

The two fixtures have the same symmetrical structure, the main body is fan-shaped, a rectangular wide groove is provided on the fan-shaped surface, an arc adjustment groove is arranged on the side close to the arc, and five semicircular connecting holes are connected to the outside of the arc adjustment groove. There are 90° connection hole, 60° connection hole, 45° connection hole, 30° connection hole and 0° connection hole in sequence. There is a right-angle notch at the central corner, and two pin holes are provided on the fan-shaped surface on one side of the notch. A through-slot is provided on the fan-shaped surface on the other side of the notch, and a pin hole vertically passes through the through-slot from one side of the fan-shaped surface.

The main body of the loading head is in the shape of a square groove, the bottom of the groove is provided with a connecting head for connecting with the experimental equipment, and the sides of the two grooves are provided with through pin holes.

The Type I sample is connected into a straight shape by two straight plates, the Type II sample is formed into an angular shape by connecting two straight plates, the Type III sample is connected into an H shape by two grooved plates, and the Type IV sample is formed by two The right-angled plates are connected into a ┴ shape; the connection methods include spot welding connection, glue joint or glue welding.

The test method of the above-mentioned test device for measuring the mechanical properties of the lap joint sample is to clamp the lap joint sample to be tested by two clamps, connect and load the test equipment through the loading head, and perform the shear resistance, Testing of mechanical properties against bending, torsion or tension.

Connect the loading head to the 0° position of the fixture to measure the tensile performance of the lap joint sample, connect the loading head to the 30° or 60° position of the fixture to test the tensile and shear performance of the lap joint sample , connect the loading head to the 90° position of the fixture to test the shear and torsion resistance of the lap joint specimen, and connect the loading head to the 45° position of the fixture to test the shear and bending resistance of the lap joint specimen .

Compared with the prior art, the present invention adopts the universal design concept, which not only can realize the tensile, shear, bending, torsion test and four-angle KSII test of lap joint specimens, but also is applicable to three different connection types (spot welding , Glue and glue welding) lap joint specimens have strong versatility and are conducive to reducing the cost of fixtures. The structure of the fixture body is mainly connected by pins and holes, which is conducive to the simplification of operation; the wide groove can make the sample firmly fixed on the fixture body, and the position will not change during the test; the arc adjustment groove can greatly simplify the loading The head position adjustment program improves the test efficiency.

Description of drawings

Fig. 1 is the structural representation of fixture among the present invention;

Fig. 2a, Fig. 2b are the structural representations of the loading head in the present invention;

Fig. 3a, Fig. 3b, Fig. 3c, Fig. 3d are structural representations of samples in the present invention, wherein Fig. 3a is a type I sample, Fig. 3b is a type II sample, Fig. 3c is a type III sample, and Fig. 3d is Type IV sample;

Figure 4 is a schematic diagram of type I sample clamping;

Figure 5 is a schematic diagram of Type II sample clamping;

Figure 6 is a schematic diagram of Type III sample clamping;

Fig. 7 is a schematic diagram of type IV sample clamping.

Detailed ways

The device of the present invention is further described below in conjunction with examples: the present embodiment is implemented under the premise of the technical solution of the present invention, and detailed implementation and specific operation process are provided, but the protection scope of the present invention is not limited to the following examples .

As shown in Figures 1 to 5, the test device for measuring the mechanical properties of lapped samples in the present invention is used to be connected to experimental equipment to measure the mechanical properties of lapped samples, which includes two clamps 1, two Cover plate 2, two loading heads 3 and four lap joint specimens 4, 5, 6, 7.

Two clamps 1 are used in combination to clamp the lapped specimen. The two clamps have the same symmetrical structure. The main body is fan-shaped. There is a rectangular wide groove 11 on the fan-shaped surface, and an arc adjustment groove 12 is arranged on the side close to the arc. There are five semicircular connection holes connected to the outside of the arc adjustment groove. It is a 90° connecting hole, a 60° connecting hole, a 45° connecting hole, a 30° connecting hole and a 0° connecting hole, a right-angled notch is provided at the central corner, and two pin holes 13 are provided on the fan-shaped surface on one side of the notch. A through-slot 14 is provided on the fan-shaped surface on the other side of the gap, and a pin hole 15 vertically passes through the through-slot from one side of the fan-shaped surface.

The two cover plates 2 have the same structure and are used to fix the overlapping specimen on the fixture.

The two loading heads 3 have the same structure and are used to connect the test device and the experimental equipment; the main body of the loading head is in the shape of a square groove, and the bottom of the groove is provided with a connecting head 31 for connecting with the experimental equipment, and the sides of the two grooves are provided with through pin holes 32.

Four kinds of lap joint samples are Type I sample 4, Type II sample 5, Type III sample 6 and Type IV sample 7.

A set of connecting bolts and pins is used to connect the lap joint specimen with the clamp, connect the cover plate 2 to the lap joint specimen and the clamp, or connect the loading head to the clamp.

Referring to Fig. 3, type I sample 4 in the present invention is connected into a straight shape by two straight plates, type II sample 5 is connected into an angle by two straight plates, and type III sample 6 is connected into an H shape by two grooved plates , IV sample 7 is connected by two right-angled plates into a ┴ shape; the connection methods include spot welding connection, glue joint or glue welding.

The test method of the above-mentioned test device for measuring the mechanical properties of the lap joint sample is to clamp the lap joint sample to be tested by two clamps, connect and load the test equipment through the loading head, and perform the shear resistance, Testing of mechanical properties against bending, torsion or tension. The specific method is to connect the loading head to the 0° position of the fixture to measure the tensile performance of the lapped specimen, and connect the loading head to the 30° or 60° position of the fixture to measure the tensile and shear resistance of the lapped specimen. For the shear performance test, the loading head is connected to the 90° position of the fixture to perform the shear and torsion resistance test of the lap joint sample, and the load head is connected to the 45° position of the fixture to perform the shear resistance and torsion resistance test of the lap joint sample. Bend performance test.

The specific implementation method of I-type sample 4 clamping in the present invention cooperates Fig. 4 to illustrate as follows:

Place the two clamping ends of the Type I sample 4 in the wide grooves 11 of the two fixtures 1 respectively, place the two cover plates 2 on the two clamping ends of the Type I sample 4, and fasten the Type I test The sample 4 is fixed on the fixture 1, and the two loading heads 3 are respectively placed at the 45° connection holes of the two fixtures, and the loading head is fixedly connected with the fixture through the connecting pin 9, and then the loading head 3 is installed on the experimental equipment. That is, the clamping of type I sample 4 is completed.

The specific implementation method of II-type sample 5 clamping among the present invention cooperates Fig. 5 to illustrate as follows:

Place the two ends of the Type II sample 5 in the through grooves 14 of the two fixtures 1 respectively, and fix the Type II sample 5 on the two fixtures 1 by inserting the pin 10 into the pin hole 15 at the through groove 14. The two loading heads 3 are respectively placed at the 90° connection holes of the two fixtures 1, and the loading heads 3 are fixedly connected to the fixture 1 through the connecting pin 9, and then the loading heads 3 are installed on the experimental equipment, and the type II sample is completed. 5 for card loading.

The specific implementation method of III type sample 6 clamping in the present invention cooperates Fig. 6 to illustrate as follows:

Place the two ends of the type III sample 6 on the two fixtures 1 respectively, fix the type III sample 6 on the fixture 1 through the pin 11, and place the two loading heads 3 in the 0° connection holes of the two fixtures respectively , the loading head is fixedly connected to the fixture through the connecting pin 9, and then the loading head 3 is installed on the experimental equipment, that is, the KSII 0° clamping of the Type III sample 6 is completed. The position of the above-mentioned loading head 3 can be adjusted through the arc adjustment groove 12 on the fixture, and moved to the 30°, 60° or 90° connecting hole on the fixture to realize KSII 30° and KSII 60° of Type III sample 6 respectively. Or KSII 90° test.

The specific implementation method of the IV type sample 7 clamping in the present invention cooperates Fig. 7 to illustrate as follows:

Place the two clamping ends of the IV-type sample 7 in the wide grooves 11 of the two fixtures 1 respectively, place the two cover plates 2 on the two clamping ends of the IV-type sample 7 respectively, and fasten the bolts 8 Fix the Type IV sample 7 on the fixture 1, place the two loading heads 3 at the 45° connection holes of the two fixtures respectively, fix the loading head and the fixture through the connecting pin 9, and then install the loading head 3 on the On the experimental equipment, the KSII 0° clamping of Type IV sample 7 is completed.

In the above-mentioned embodiment, when the position of the loading head 3 needs to be adjusted, it is not necessary to remove the loading head, only need to lift the loading head to enter the arc adjustment groove, and adjust the loading head to the required position by rotating the fixture 1 . Adjusting to 0°, 30°, 60° or 90° connecting hole can carry out KSII 0° pure tensile test, KSII 30° tensile + shear test, KSII 60° tensile + shear test, KSII 90° pure shear test, adjust to 90° connecting hole for torsion test of type II sample, adjust to 45° connecting hole to realize shear test and bending test of type I sample and type IV sample respectively.

Claims (6)

1., for measuring a test unit for overlap joint sample mechanical property, for being connected on experimental facilities, the mechanical property of overlap joint sample being measured, it is characterized in that comprising:

For clamping two fixtures of overlap joint sample, two fixture combinations use;

For overlap joint sample being fixed on two cover plates on fixture;

For two loading heads of joint test device and experimental facilities;

Four kinds of overlap joint samples, are respectively I type sample, II type sample, type III sample and IV type sample;

A set of coupling bolt and pin.

2. the test unit for measuring overlap joint sample mechanical property according to claim 1, it is characterized in that, two described clamp structure symmetries are identical, main body is fan-shaped, sector is provided with a rectangle sipes, circular arc regulating tank is provided with near circular arc side, five semicircle connecting holes are communicated with outside circular arc regulating tank, be followed successively by 90 ° of connecting holes, 60 ° of connecting holes, 45 ° of connecting holes, 30 ° of connecting holes and 0 ° of connecting hole, central angle place is provided with square breach, the sector of breach side is provided with two pin-and-holes, the sector of breach opposite side is provided with through slot, one pin-and-hole passes perpendicularly through this through slot from a side of sector.

3. the test unit for measuring overlap joint sample mechanical property according to claim 1, it is characterized in that, described loading head main body is square groove shape, and its trench bottom is provided with the connector for being connected with experimental facilities, and two trough rims are provided with through pin-and-hole.

4. the test unit for measuring overlap joint sample mechanical property according to claim 1, it is characterized in that, described I type sample connects into straight shape by two blocks of straight plates, II type sample connects into dihedral by two blocks of straight plates, type III sample connects into H-shaped by two pieces of trough plates, and IV type sample connects into ┴ type by two blocks of square plates; Its connected mode comprises spot welding and connects, glueds joint or glue weldering.

5. the test method of the test unit for measuring overlap joint sample mechanical property according to claim 1, it is characterized in that: overlap joint sample to be measured is coordinated clamping by two fixtures, to be connected with testing equipment by loading head and to load, carrying out that sample is anti-shearing, counter-bending, the test of anti-torsion or stretch-proof mechanical property.

6. test method according to claim 5, it is characterized in that: the stretch-proof performance measurement of sample is carried out overlapping in 0 ° of position loading head being connected to fixture, loading head is connected to stretch-proof, anti-shear performance test that sample is carried out overlapping in 30 ° of fixture or 60 ° of positions, anti-shearing, the anti-torsion performance test of sample is carried out overlapping in 90 ° of positions loading head being connected to fixture, and anti-shearing, the bending resistance test of sample is carried out overlapping in 45 ° of positions loading head being connected to fixture.