CN106442120A - Fatigue test clamp device for T-shaped corner joint - Google Patents

Abstract

A fatigue test fixture device for T-shaped corner joints, including a "T-shaped" connecting support, the connecting support is composed of a clamping end connected to the chuck of the fatigue testing machine at the lower part and a fixing end at the upper part. The connecting end of the T-shaped corner joint is composed of the connecting end; the specific structure of the connecting end is: the upper end surface of the connecting end is provided with a horizontal groove along the left and right direction with a length matching the wing plate size of the T-shaped corner joint. The left and right sides of the side are provided with support oblong holes, and the length direction of the support oblong holes is parallel to the horizontal groove; Two fixed pressing blocks are provided with pressing block oblong holes at positions corresponding to the oblong holes of the support; the fastening bolts pass through the oblong holes of the pressing block and the oblong holes of the support in turn to connect with the nuts. The device can connect the T-shaped corner joint with the existing fatigue testing machine, so as to realize fatigue loading on the T-shaped corner joint.

Description

A fatigue test fixture device for T-shaped corner joints

technical field

The invention relates to a fixture device for a fatigue test of a T-shaped corner joint, belonging to the technical fields of machinery and materials.

Background technique

As an important material joining technology, welding is widely used in modern manufacturing. Good welding quality is the prerequisite and guarantee for the safe service of welded structures. The methods for judging the quality of welded joints mainly include non-destructive testing and mechanical performance testing. However, in actual working conditions, due to the action of alternating stress, fatigue failure occurs in many components below the material static load limit σ _b , or even the material yield limit σ _s . Because there is no obvious plastic deformation before fatigue fracture, most of them are sudden brittle fracture, so it poses an extremely serious threat to the safe operation of welded structures. Therefore, how to correctly judge the fatigue strength of welded joints has become the focus of attention.

In traditional fatigue tests of welded joints, more attention is paid to common joints such as butt joints, cross-shaped corner joints, and reinforced cross-shaped corner joints, while fatigue tests on T-shaped corner joints are less involved. With the continuous development and application of welding technology in my country's rail transit, aerospace and other fields, and the further improvement of people's requirements for the quality of welded structures, the fatigue life evaluation of T-shaped fillet joints has become an urgent practical demand.

Due to the specificity of the T-shaped corner joint, fatigue loading cannot be performed directly on the fatigue testing machine, and it needs to be connected with the existing fatigue testing machine through a special fixture. However, there is no fatigue test fixture specially designed for T-shaped corner joints, which greatly hinders the fatigue performance test of T-shaped corner joints. Therefore, there is an urgent need for a special fatigue fixture for T-shaped corner joints, which can realize the fatigue test of T-shaped corner joints on the existing fatigue testing machine.

Contents of the invention

The object of the present invention is to provide a fatigue test fixture device for a useful T-shaped corner joint. The device can be connected with a T-shaped corner joint and an existing fatigue testing machine to realize fatigue loading on the T-shaped corner joint, and has low cost and simple operation, and is favorable for extensive application in fatigue tests.

The technical solution adopted by the present invention to realize the purpose of the invention is: a fatigue test fixture device for a T-shaped corner joint, including a "T-shaped" connecting support, the connecting support is located at the lower part and the fatigue testing machine The clamping end connected with the chuck and the connecting end located on the upper part for fixing the T-shaped corner joint; The length of the board size matches the horizontal groove along the left and right directions, and the left and right sides of the front and rear sides of the horizontal groove are respectively provided with a support oblong hole, and the length direction of the support oblong hole is parallel to the length direction of the horizontal groove; The fixture device also includes two left and right fixed pressing blocks for fixing the wing plate of the T-shaped corner joint in the horizontal groove, and there are pressing blocks on the two fixed pressing blocks corresponding to the long round holes of the support The oblong hole; the fastening bolt passes through the oblong hole of the pressing block and the oblong hole of the support in turn to connect with the nut.

Working principle and using method of the present invention are:

Put the wing plate side of the T-shaped corner joint (sample) into the horizontal groove on the upper end surface of the connecting end of the connecting support. Place the left and right fixed pressing blocks above the left and right wing plates of the T-shaped corner joint, and adjust the position of the fixed pressing blocks so that the fixed pressing blocks completely press the wing plates of the T-shaped corner joint. Pass the fastening bolt through the oblong hole of the pressing block and the oblong hole of the support, and tighten the fastening bolt, so that the fixed pressing block and the wing plate part of the T-shaped corner joint are fixed on the upper end surface of the connecting end. Then, according to the conventional fatigue sample clamping method, the other end of the T-shaped corner joint and the chuck of the fatigue testing machine are fixed on the fatigue testing machine together, and the fatigue test of the T-shaped corner joint can be carried out.

In the present invention, the left-right direction is the X direction, and the front-back direction is the Y direction.

Compared with prior art, the beneficial effect of the present invention is:

1. The T-shaped corner joint and the fatigue testing machine are connected through a special connecting support, so that the fatigue test of the T-shaped corner joint on the existing conventional fatigue testing machine is realized.

2. The horizontal groove on the upper end surface of the connecting end can not only limit the movement of the T-shaped corner joint in the front and rear direction, but also conveniently adjust the position of the T-shaped corner joint, reducing the number of specimens, fixtures, and fatigue testing machine chucks. The test results will be affected by mismatching. The design of the oblong hole of the pressing block and the oblong hole of the support can quickly adjust the position of the fixing pressing block and install the fastening bolt.

3. The fixture device is simple in design, low in cost, and easy to operate, which is conducive to a large number of applications in fatigue testing.

Further, the front sides of the two fixed pressing blocks in the present invention are all provided with front positioning blocks, and the rear sides are all provided with rear positioning blocks. Paste the rear face of the connected end.

The front positioning block and the rear positioning block can limit the movement of the fixed pressing block in the Y direction, and at the same time play a guiding role in fine-tuning the X direction of the fixed pressing block.

Further, in the middle of the front and rear end faces of the connecting end of the present invention, an X-face center score line is provided, and the middle part of the left and right end faces of the connection end is provided with a Y-face center score line.

The center line on the X face and the center line on the Y face can be used for the precise alignment of the T-shaped corner joint and the connecting support, avoiding the asymmetric loading of the fatigue sample due to the misalignment of the sample, and reducing its impact on the test results. Impact.

Further, in the present invention, a pressure sensor is provided on the part of the lower end surface of the two fixed pressure blocks in contact with the wing plate of the T-shaped corner joint, and the output end of the pressure sensor is electrically connected to the force value digital display.

In this way, the tightening pressure when the fixture device clamps the T-shaped corner joint can be measured, and the clamping force of the fixture on the sample can be checked according to the force value digital display before the test, and the tightening bolt can be adjusted to make the force value reach an appropriate value to ensure The sample has been fully clamped to ensure the normal vibration of the fatigue testing machine.

Further, a pair of opposite fine-tuning screws in the Y direction are provided in the middle of the front and rear sides of the horizontal groove in the present invention.

Furthermore, in the middle of the left and right sides of the horizontal groove of the present invention, a pair of opposite X-direction fine-tuning screws are provided.

When installing the sample, by turning the fine-tuning screw in the X direction and the fine-tuning screw in the Y direction, the sample coincides with the center line on the X face and the center line on the Y face, which can be used to precisely adjust the position of the T-shaped corner joint sample. Location.

Further, according to the present invention, there are two fastening bolts passing through each oblong hole of the pressing block and the oblong hole of the support.

In this way, on the one hand, the position of the pressing block can be adjusted conveniently, on the other hand, it can ensure the stable clamping of the sample by the clamp, and avoid the failure of the fatigue testing machine to vibrate due to insufficient clamping.

The sub-invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

The descriptions of directions such as front and rear, left and right, and up and down in the present invention are only used to indicate the positional relationship between various parts, and are not used to limit the protection scope of the present invention.

Description of drawings

FIG. 1 is a schematic diagram of a complete three-dimensional structure of an embodiment of the present invention.

Fig. 2 is an enlarged schematic view of the connection support parts of the embodiment of the present invention.

Fig. 3 is an enlarged schematic view of the fixed pressing block part of the embodiment of the present invention.

detailed description:

Example

Figure 1 shows that a specific embodiment of the present invention is: a fatigue test fixture device for a T-shaped corner joint, including a "T-shaped" connecting support 1, as shown in Figure 2, the connecting support The seat 1 is composed of the clamping end connected with the chuck of the fatigue testing machine at the lower part and the connecting end for fixing the T-shaped corner joint at the upper part; the specific structure of the connecting end is: the upper end surface of the connecting end is provided with The length matched with the size of the wing plate of the T-shaped corner joint is along the horizontal groove 1e in the left and right direction, and the left and right sides of the front and rear sides of the horizontal groove 1e are respectively provided with a support oblong hole 1f, and the support is oblong The length direction of the hole 1f is parallel to the length direction of the horizontal groove 1e; the clamp device also includes two left and right fixed pressing blocks 2 for fixing the wing plate of the T-shaped corner joint in the horizontal groove 1e, as shown in Figure 3 As shown, two fixed pressing blocks 2 are provided with pressing block oblong holes 2b at positions corresponding to the support oblong holes 1f; connect.

The front sides of the two fixed pressing blocks 2 described in this example are all provided with a front positioning block 2c, and the rear sides are all provided with a rear positioning block 2d. The 2d internal test is close to the rear end face of the connecting end.

In this example, the middle part of the front and rear end surfaces of the connecting end is provided with an X-facing engraved line 1a, and the middle part of the left and right end surfaces of the connecting end is provided with a Y-facing engraved line 1b.

In this example, a pressure sensor 2a is provided at the part where the two fixed pressing blocks 2 are in contact with the wings of the T-shaped corner joint, and the output end of the pressure sensor 2a is electrically connected to the force value digital display 6 .

In this example, the middle of the front and rear sides of the horizontal groove 1e is provided with a pair of opposing fine-tuning screws 1c in the Y direction.

In this example, a pair of opposite X-direction fine-tuning screws 1d are provided in the middle of the left and right sides of the horizontal groove 1e.

In this example, there are two fastening bolts 4 passing through each pressing block oblong hole 2b and the support oblong hole 1f.

Claims (7)

1. a kind of fatigue test clamper device of T-shaped corner joint, including the connects bearing (1) in " T-shaped ", the connects bearing (1) by being located at the bare terminal end connected with the chuck of fatigue machine of bottom and superposed for fixing T-shaped corner joint Connection end composition；The concrete structure of the connection end is：It is provided with the upper surface of connection end and the T-shaped corner joint The length that wing plate size matches horizontal groove (1e) in left-right direction, before and after horizontal groove (1e), the right and left of both sides is each A bearing slotted hole (1f) is provided with, bearing slotted hole (1f) length direction is flat with horizontal groove (1e) length direction OK；The grip device also includes that the left and right two for the wing plate of T-shaped corner joint is fixed in horizontal groove (1e) is consolidated Level pressure block (2), all has briquetting slotted hole with bearing slotted hole (1f) corresponding position on two fixing briquettings (2) (2b)；Fastening bolt (4) sequentially passes through briquetting slotted hole (2b) and bearing slotted hole (1f) is connected with nut (3).

2. the fatigue test clamper device of a kind of T-shaped corner joint according to claim 1, it is characterised in that：Described two The front side of individual fixing briquetting (2) is provided with pre-positioning block (2c), and rear side is provided with post-positioning block (2d), the pre-positioning block (2c) front end face for being close to connection end is surveyed in, surveys the rear end face for being close to connection end in post-positioning block (2d).

3. the fatigue test clamper device of a kind of T-shaped corner joint according to claim 1, it is characterised in that：The company The middle part for connecing end front/rear end is provided with X in the face of middle groove (1a), and the middle part of described connection end or so end face is provided with during Y faces Groove (1b).

4. the fatigue test clamper device of a kind of T-shaped corner joint according to claim 1, it is characterised in that：Described two The part that individual fixing briquetting (2) are contacted with the wing plate of T-shaped corner joint is provided with pressure transducer (2a), pressure transducer (2a) Outfan electrically connect with force value device for digit-displaying (6).

5. the fatigue test clamper device of a kind of T-shaped corner joint according to claim 3, it is characterised in that：The water Before and after flat grooves (1e), the middle part of both sides is provided with a pair of relative Y-direction fine setting screw rod (1c).

6. the fatigue test clamper device of a kind of T-shaped corner joint according to claim 3 or 5, it is characterised in that：Described The middle part of the left and right sides of horizontal groove (1e) is provided with a pair of relative X-direction fine setting screw rod (1d).

7. the fatigue test clamper device of a kind of T-shaped corner joint according to claim 1, it is characterised in that：Described wear The fastening bolt (4) for crossing each briquetting slotted hole (2b) and bearing slotted hole (1f) is two.