CN201876396U - Measuring device of static normal direction contact stiffness of junction plane - Google Patents

Abstract

The utility model discloses a measuring device suitable for the static normal contact stiffness of a joint surface. The measuring device comprises: a measuring bracket, a loading device, a measuring device, an adjusting device and a piece to be tested; the loading device is fixedly placed on the testing bracket The bottom of the bottom, directly above it is the measuring device, the piece to be tested and the adjusting device in sequence, and the loading device, the measuring device, the piece to be tested and the adjusting device are all located in the measuring bracket. The measuring device of the utility model has a simple structure. When loading different positive pressures, the measuring device of the utility model can compare the joint surface static method with respect to parameters such as different contact surface topography, different positive pressures, and different test piece material properties. The contact stiffness in the normal direction is measured, and the influence law of the contact surface morphology, normal pressure and test piece material on the normal contact stiffness is analyzed by using the experimental results.

Description

A joint surface static normal contact stiffness measurement device

Technical field:

The utility model belongs to the field of measurement, and relates to a normal contact stiffness measuring device, in particular to a joint surface static normal contact stiffness measuring device.

Background technique:

There are a large number of joint surfaces in complex mechanical systems such as machine tools and large aircrafts, which destroy the continuity of the mechanical system structure and greatly affect the overall performance of the mechanical system. The connection characteristics of the joint surface show discontinuity, and introducing the characteristic parameter model of the joint surface into the modeling process of the whole system can effectively improve the performance prediction ability of the whole machine in the product design stage. Therefore, the accurate construction of the joint surface characteristic parameter model will provide a theoretical basis for the optimal design of the joint surface of complex mechanical parts.

The contact stiffness of the joint surface is one of the important characteristic parameters of the joint surface, and its accuracy will directly affect the parameter characteristic model of the joint surface. The contact stiffness of the joint surface is related to the surface morphology and contact state of the two contact surfaces. Therefore, the study of the influence of the joint surface morphology and contact state on the contact stiffness of the joint surface will help to accurately determine the characteristic parameter model of the joint surface.

Utility model content:

The purpose of the utility model is to provide a static normal contact stiffness measuring device, which can obtain the stiffness by directly measuring the load and displacement between the joint surfaces.

The utility model is realized through the following technical solutions, a measuring device suitable for the static normal contact stiffness of the joint surface, the measuring device comprises: a measuring bracket, a loading device, a measuring device, an adjusting device and a piece to be tested; the loading The device is fixedly placed on the bottom of the test bracket, and directly above it are the measuring device, the piece to be tested and the adjustment device in sequence. The loading device, the measuring device, the piece to be tested and the adjustment device are all located in the measurement bracket.

The measuring device comprises a pressure sensor, a sensor top cap, a pressure sensor fixing ring and an axial extensometer; the pressure sensor is fixed directly above the jack, the pressure sensor top cap is set on the measuring top of the pressure sensor, and the pressure sensor fixing ring is fixed On the lower support plate, the pressure sensor and the top cap are fixed and guided, and the two blades of the axial extensometer are respectively clamped on the two test pieces during the measurement process.

The adjusting device includes an adjusting screw, a screw guide sleeve, a hollow guide sleeve, a first locking screw, a second locking screw, an aligning ball, a test piece fixing ring, and a steel ball fixing ring; wherein, the adjusting screw with a handle is located at Directly above the measuring bracket, the screw guide sleeve is tightly matched with the upper support plate, and is threadedly connected with the adjustment screw. The hollow guide sleeve is fixed on the upper support plate. Above, the first locking screw and the second locking screw are set in the threaded through hole on the hollow guide sleeve, which can be screwed in and out. The self-aligning ball is sealed in the test piece fixing ring through the steel ball fixing ring, which can be Free rotation within the retaining ring.

The test piece includes an upper test piece and a lower test piece, the lower test piece is located directly above the top cap of the pressure sensor, the upper test piece is located directly above the lower test piece, the top of the upper test piece has a ball socket, and the ball socket is directly above the top cap of the pressure sensor. The upper part is a self-aligning ball, which prevents partial contact of the joint surface during loading through the ball-socket fit, ensuring complete contact of the entire joint surface, and the axial extensometer near the joint surface is fixed on the upper and lower specimens by clamping blades .

The measurement bracket includes an upper support plate, a first column, a second column and a lower support plate, the three are assembled as one, and remain fixed during the measurement process.

The loading device includes a jack fixed in the lower support plate.

The principle of the utility model is to obtain the stiffness by directly measuring the load and deformation between the bonding surfaces, and the principle is relatively simple so the structure of the measuring device is simple. When loading different normal pressures, the measuring device of the present invention can measure the static normal contact stiffness of the bonding surface according to parameters such as different contact surface topography, different normal pressures, and different test piece material properties, and use the experimental Results The influence of contact surface morphology, normal pressure and test piece material on normal contact stiffness was analyzed.

Description of drawings:

Fig. 1 is the structural representation of measuring device of the present utility model;

Among them: 1 is the adjusting screw; 2 is the upper support plate; 3-1 is the first locking screw; 3-2 is the second locking screw; 4 is the test piece fixing ring; 5 is the upper test piece; 6 is the pressure sensor Fixed ring; 7-1 is the first column; 7-2 is the second column; 8 is the lower support plate; 9 is the jack; 10 is the pressure sensor; 11 is the top cap of the pressure sensor; 12 is the lower test piece; 13 is the shaft 14 is a steel ball fixing ring; 15 is a self-aligning ball; 16 is a hollow guide sleeve; 17 is a screw guide sleeve.

Detailed ways:

Below in conjunction with accompanying drawing, the utility model is described in further detail:

As shown in Figure 1, the utility model is a measuring device suitable for the static normal contact stiffness of the joint surface, which includes: a measuring bracket, a loading device, a measuring device, an adjusting device and a piece to be tested.

The measurement support includes an upper support plate 2, a first column 7-1, a second column 7-2 and a lower support plate 8, the three are assembled as one, and remain fixed during the measurement process.

The loading device includes a jack 9 fixed in the lower support plate 8 .

The measuring device includes a pressure sensor 10 , a pressure sensor top cap 11 , a pressure sensor fixing ring 6 and an axial extensometer 13 . Wherein: the pressure sensor 10 is fixed directly above the jack 9, the pressure sensor top cap 11 is set on the measuring top of the pressure sensor 10, the pressure sensor fixing ring 6 is fixed on the lower support plate 8, and the pressure sensor 10 and the top cap 11 are fixed. and guiding function, the two blades of the axial extensometer 13 are respectively clamped on the two test pieces during the measurement process.

The adjustment device includes adjusting screw 1, screw guide sleeve 17, hollow guide sleeve 16, first locking screw 3-1 and second locking screw 3-2, self-aligning ball 15, specimen fixing ring 4, steel ball fixing ring 14. Among them, the adjusting screw 1 with a handle is located directly above the measuring bracket, the screw guide sleeve 17 is tightly matched with the upper supporting plate 2, and is threadedly connected with the adjusting screw 1, the hollow guiding sleeve 16 is fixed on the upper supporting plate 2, and the test piece is fixed. The ring 4 is arranged in the hollow guide sleeve 16 and is located directly above the test piece. The first locking screw 3-1 and the second locking screw 3-2 are arranged in the threaded through hole on the hollow guide sleeve 16, which can be rotated. In and out, the self-aligning ball 15 is sealed in the test piece fixing ring 4 by the steel ball fixing ring 14, and can freely rotate in the test piece fixing ring 4.

The test piece to be tested includes an upper test piece 5 and a lower test piece 12, the lower test piece 12 is located directly above the top cap 11 of the pressure sensor, the upper test piece 5 is located directly above the lower test piece 12, and the top of the upper test piece 5 has a ball socket , directly above the ball socket is the self-aligning ball 15, through the ball-socket cooperation, it can prevent partial contact of the joint surface during loading, and ensure the complete contact of the entire joint surface, and the axial extensometer 13 is fixed by clamping the blade near the joint surface On the upper test piece 5 and the lower test piece 12.

When the utility model is used to measure the static normal contact stiffness of the joint surface, the specific implementation process includes the following steps:

1) Adjust the adjustment screw 1, so that the test piece fixing ring 4 can slide up and down in the hollow guide sleeve 16, adjust the first locking screw 3-1 and the second locking screw 3-2, so that the test piece fixing ring 4 is fixed on the A suitable location for placing the test piece;

2) Place the lower test piece 12 with a specific surface roughness directly above the top cap 11 of the pressure sensor, place the upper test piece 5 directly above the lower test piece 12, and adjust the adjusting screw 1 and the first locking screw 3- 1 and the second locking screw 3-2 to embed the self-aligning ball 15 into the ball socket to fix the test piece;

3) The jack 9 applies force evenly until the predetermined maximum pressure is reached. The pressure between the joint surfaces and the deformation of the test piece are respectively measured by the pressure sensor 10 and the axial extensometer 13, and the data of force and deformation are uniformly collected

4) After a group of experiments is completed, repeat the above steps and replace the next group of test pieces. In this way, multiple sets of measurement data of different types of bonding surfaces can be obtained

5) In each group of test pieces, after obtaining multiple sets of pressure and displacement data, the data is post-processed to obtain the pressure-displacement curve of the joint surface of each set of test specimens, so as to obtain the static normal contact stiffness between the joint surfaces.

直接计算得到，其中，F为结合面间的法向正压力，A为结合面的名义接触面积，L为试件结合面端距离轴向引伸计夹持刀刃的距离。因此，结合面在法向正压力F的作用下所产生的法向变形：δ＝W-ΔL₁-ΔL₂，其中，W是轴向引伸计测得的变形，ΔL₁、ΔL₂是理论计算得到的材料的弹性变形。这样，在多次加载下通过压力传感器测量正压力、轴向引伸计测量变形就可以得到结合面的力-位移曲线，从而求得结合面的静态法向接触刚度。The measurement principle of the utility model is that when a normal positive pressure is applied at both ends of the joint surface, the deformation measured by the axial extensometer includes two parts: one is the normal deformation of the joint surface, and the other is the two parts of the axial extensometer. Elastic deformation of the material held between the blades. The elastic deformation of materials can be determined by Hooke's law

It is directly calculated, where F is the normal positive pressure between the joint surfaces, A is the nominal contact area of the joint surface, and L is the distance between the joint surface end of the specimen and the clamping blade of the axial extensometer. Therefore, the normal deformation of the bonding surface under the action of the normal positive pressure F: δ=W-ΔL ₁ -ΔL ₂ , where W is the deformation measured by the axial extensometer, and ΔL ₁ and ΔL ₂ are the theoretical The calculated elastic deformation of the material. In this way, the force-displacement curve of the joint surface can be obtained by measuring the normal pressure with the pressure sensor and the deformation with the axial extensometer under multiple loadings, so as to obtain the static normal contact stiffness of the joint surface.

The above content is a further detailed description of the utility model in conjunction with specific preferred embodiments. It cannot be determined that the specific embodiment of the utility model is limited to this. Under the premise of the new concept, some simple deduction or replacement can also be made, which should be regarded as belonging to the utility model and the patent protection scope is determined by the submitted claims.

Claims (6)

1. A measuring device applicable to the static normal contact stiffness of joint surfaces, characterized in that: the measuring device comprises: a measuring bracket, a loading device, a measuring device, an adjusting device and a test piece; the loading device is fixedly placed on the test The bottom of the bracket and directly above it are the measuring device, the piece to be tested and the adjusting device in sequence, and the loading device, the measuring device, the piece to be tested and the adjusting device are all located in the measuring bracket. 2. A kind of measuring device applicable to the static normal contact stiffness of joint surface as claimed in claim 1, characterized in that: said measuring device comprises a pressure sensor, a sensor top cap, a pressure sensor retaining ring and an axial extensometer ;The pressure sensor is fixed directly above the jack, the top cap of the pressure sensor is set on the top of the pressure sensor, the fixing ring of the pressure sensor is fixed on the lower support plate, which plays a role of fixing and guiding the pressure sensor and the top cap, and the axial extensometer is in the During the measurement, the two blades are respectively clamped on the two test pieces. 3. A measuring device suitable for static normal contact stiffness of joint surfaces as claimed in claim 1, characterized in that: said adjusting device comprises an adjusting screw, a screw guide sleeve, a hollow guide sleeve, a first locking screw, a second Two locking screws, self-aligning balls, test piece fixing ring, and steel ball fixing ring; among them, the adjusting screw with handle is located directly above the measuring bracket, the screw guide sleeve is tightly matched with the upper support plate, and is threadedly connected with the adjusting screw, The hollow guide sleeve is fixed on the upper support plate, the specimen fixing ring is set in the hollow guide sleeve, and is located directly above the test piece, and the first locking screw and the second locking screw are arranged in the threaded through hole on the hollow guide sleeve Inside, it can be screwed in and out. The self-aligning ball is sealed in the test piece fixing ring through the steel ball fixing ring, and can rotate freely in the test piece fixing ring. 4. A kind of measuring device applicable to the static normal contact stiffness of the bonding surface as claimed in claim 1, wherein the test piece includes an upper test piece and a lower test piece, and the lower test piece is located at the top of the pressure sensor cap. Directly above, the upper test piece is located directly above the lower test piece, the top of the upper test piece has a ball socket, directly above the ball socket is a self-aligning ball, through the ball-socket cooperation to prevent partial contact of the joint surface during loading, to ensure that the entire The joint surface is in full contact, and the axial extensometer near the joint surface is fixed on the upper and lower specimens by clamping the blade. 5. A kind of measuring device applicable to the static normal contact stiffness of joint surface as claimed in claim 1, characterized in that: said measuring bracket comprises an upper support plate, a first column and a second column and a lower support plate, three The latter is assembled as a whole and remains fixed throughout the measurement process. 6 . A measuring device suitable for static normal contact stiffness of joint surfaces as claimed in claim 1 , wherein the loading device comprises a jack, and the jack is fixed in the lower support plate. 7 .

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