CN111122315B - Method for assessing aging performance for eliminating residual stress of aerospace metal parts - Google Patents

Abstract

The invention proposes a method for evaluating the aging performance for eliminating the residual stress of aerospace metal parts, comprising the following steps: preparing a test device; machining the test metal parts to form a plate with a preset curvature; The plate is covered with a vacuum bag film (5) and placed in the flat mold (1); the flat mold (1) with the metal parts for testing is placed in the vacuum autoclave (6); in the vacuum autoclave (6) , perform an aging process to eliminate residual stress on the test metal parts, and use the vacuum bag film (5) to press the test metal parts into a flat plate; use a static test platform to statically or shear the flat plate. Check the test to obtain the failure strength parameters; confirm the failure strength parameters of the flat plate as the failure strength parameters of the metal parts to be checked. The method is not only accurate and reliable, but also does not damage the mechanical properties of the metal parts to be examined.

Description

Method for assessing aging performance for eliminating residual stress of aerospace metal parts

technical field

The invention relates to the technical field of aviation, in particular to a method for evaluating the aging performance for eliminating residual stress of aviation metal parts.

Background technique

The aerospace industry uses a large number of metal materials for the manufacture of large and complex cross-section parts. In the manufacturing process of such parts, residual stress that is difficult to eliminate will be generated, resulting in deformation of the parts. In order to eliminate the residual stress in the manufacturing process of large and complex cross-section parts, aging can be carried out in an autoclave, and pressure is introduced in the process to make the part creep, and the final part achieves the target performance and eliminates the residual stress.

However, after the residual stress-relieving aging in the autoclave, the parts generally show a final shape with curvature, and the parts with curvature cannot be subjected to static or shear tests commonly used in engineering.

SUMMARY OF THE INVENTION

In view of this, in order to solve at least one technical problem in the prior art, the present invention provides a method for testing airborne display control software. The method includes:

Technical scheme of the present invention:

A method for evaluating the aging performance of aerospace metal parts for eliminating residual stress, wherein the metal part to be evaluated is a plate with a preset curvature after an aging process for eliminating residual stress, comprising the following steps:

S1, prepare a test device, the test device includes: a flat die (1), a fixed platform (2), and a bolt (3), wherein: the flat die (1) is arranged above the fixed platform (2) and passes through the bolt (3) connected with the fixed platform (2);

S2, the test metal part is machined to form a plate with a preset curvature, wherein the test metal part is a plate with a preset curvature formed by machining; S2, the plate with a preset curvature is clad A vacuum bag film (5) is placed on the flat mold (1);

S3, put the flat mold (1) with the test metal parts into the vacuum autoclave (6);

S4, in the vacuum autoclave (6), carry out an aging process to eliminate residual stress on the test metal parts, and use the vacuum bag film (5) to press the test metal parts into a flat plate;

S5, use a static test platform to perform a static or shear assessment test on the flat plate to obtain the failure strength parameters;

S6, confirming the failure strength parameter of the plate pressed into a plane as the failure strength parameter of the metal part to be examined.

The advantages of the present invention may be:

The performance of the metal part to be tested is determined by the performance of the test metal part 4 . First, the test metal part 4 is a plate with a preset curvature formed by machining. The test metal part 4 is pressed into a flat test piece in order to test the final performance level after the aging to relieve the residual stress. Use the static test platform to perform static or shear assessment tests on the flat-pressed plates to obtain the failure strength parameters, and confirm the failure strength parameters of the flat-pressed plates as the failure strength parameters of the metal parts to be checked. The device is not only accurate and reliable, but also will not damage the mechanical properties of the metal parts to be tested.

Description of drawings

In order to explain the technical solutions of the embodiments of the present invention more clearly, the following will briefly introduce the drawings that need to be used in the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained from these drawings without any creative effort.

FIG. 1 is a schematic diagram of a device for evaluating the aging performance for eliminating residual stress of aerospace metal parts according to an embodiment of the present invention;

FIG. 2 is an isometric view of a device for evaluating the aging performance for eliminating residual stress of aerospace metal parts according to an embodiment of the present invention;

FIG. 3 is an isometric view of a device for evaluating the aging performance for eliminating residual stress of aerospace metal parts according to another embodiment of the present invention;

4 is a side view of a test piece tooling for relieving metal residual stress by aging according to an embodiment of the present invention.

Among them, the flat die 1 , the fixed platform 2 , the bolts 3 , the metal parts for testing 4 , the vacuum bag film 5 , and the vacuum autoclave 6 .

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

Features and illustrative embodiments of various aspects of the invention are described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that the present invention may be practiced without some of these specific details. The following description of the embodiments is only intended to provide a better understanding of the present invention by illustrating examples of the invention. The present invention is in no way limited to any specific arrangements and methods set forth below, but covers any improvements, substitutions, and alterations in structures, methods, and devices without departing from the spirit of the present invention. In the drawings and the following description, well-known structures and techniques are not shown in order to avoid unnecessarily obscuring the present invention.

It should be noted that, in the case of no conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other, and the various embodiments may refer to and cite each other. The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

FIG. 1 is a schematic diagram of an apparatus for evaluating the aging performance of aerospace metal parts for eliminating residual stress according to an embodiment of the present invention; FIG. 2 is an isometric view of the device for evaluating aging performance for eliminating residual stress in aerospace metal parts according to an embodiment of the present invention; 3 is an isometric view of an apparatus for evaluating the aging performance of aerospace metal parts residual stress according to another embodiment of the present invention; FIG. 4 is a side view of a test piece tooling for aging metal residual stress relief according to an embodiment of the present invention.

Referring to Figures 1 to 4, a method for evaluating the aging performance of aerospace metal parts for eliminating residual stress, wherein the metal part to be evaluated is a plate with a preset curvature after an aging process for eliminating residual stress, the method includes: The following steps:

S1, prepare a test device, the test device includes: a flat die (1), a fixed platform (2), and a bolt (3), wherein: the flat die (1) is arranged above the fixed platform (2) and passes through the bolt (3) connected with the fixed platform (2);

S2, the test metal part is machined to form a plate with a preset curvature, wherein the test metal part is a plate with a preset curvature formed by machining; S2, the plate with a preset curvature is clad A vacuum bag film (5) is placed on the flat mold (1);

S3, put the flat mold (1) with the test metal parts into the vacuum autoclave (6);

S4, in the vacuum autoclave (6), carry out an aging process to eliminate residual stress on the test metal parts, and use the vacuum bag film (5) to press the test metal parts into a flat plate;

S5, use a static test platform to perform a static or shear assessment test on the flat plate to obtain the failure strength parameters;

S6, confirming the failure strength parameter of the plate pressed into a plane as the failure strength parameter of the metal part to be examined.

In some embodiments, the concave surface of the pre-curved sheet is ribbed.

In some embodiments, the test metal part (4) has the same curvature as the metal part to be tested.

In some embodiments, the flat mold (1) has grooves corresponding to the ribs.

In some embodiments, the aging process determines a predetermined pressure, a predetermined temperature, to be applied to the metal part to be verified.

In some embodiments, the flat plate mold (1) is sealed at the junction of the flat plate mold (1).

In some embodiments, the method further comprises: using a vacuum autoclave (6) to remove residual stress on the test metal part (4) carried on the flat mold (1) and covered with the vacuum bag film (5) The aging process is adopted, and the test metal part (4) is creeped into a flat plate.

In some embodiments, the method further includes: taking out the flat plate from the vacuum autoclave (6), and then using a static test platform to perform a static or shear assessment test on the flat plate, to obtain The failure strength parameter is determined, and the failure strength parameter of the flat plate is confirmed as the failure strength parameter of the metal part to be examined.

The design method of an assessment and verification test for eliminating metal residual stress by aging, which meets the requirements of a static or shear assessment test commonly used in the aerospace industry according to the embodiment of the present invention, follows the following principles:

Principle 1 Flat test piece:

In order to carry out the static or shear verification test commonly used in the aerospace industry, it is necessary to ensure that the test piece for the test must not have curvature and must be a flat test piece.

Principle 2 Process reproducibility:

To carry out the verification test of the aging process for eliminating residual stress, it must be ensured that the process characteristics used in the manufacture of the test piece are completely consistent with the aging process characteristics for eliminating residual stress. Process characteristics include: temperature, pressure, time, and part deflection. Therefore, it is designed to machine the metal verification test piece into a test piece with the same curvature as the part production, and then use the same aging process characteristics to eliminate residual stress to carry out the same aging process for the test piece with curvature to eliminate residual stress. , the final creep deformation to the flat plate verification test piece.

Principle 3 Comparability:

According to the above principles, after the flat plate examination and verification test piece that can completely reproduce the aging process characteristics of eliminating residual stress is manufactured, the static or shear examination test commonly used in the aerospace industry should be carried out. The test results are consistent with other similar tests at home and abroad. Contrast.

In some embodiments, a method for designing a test piece for evaluation and verification of aging to eliminate residual stress in metals, comprising the following steps:

Step 1, use the metal material to manufacture the curved wall panel parts by machining method;

Step 2, place the flat plate forming tool in the vacuum autoclave;

Step 3, place the parts obtained in step 1 on the tooling in step 2;

Step 4, use vacuum bag film to wrap the parts and tooling of Step 3;

Step 5, performing aging forming to eliminate residual stress on the metal parts;

Step 6, after the aging of the metal residual stress is eliminated in step 5, the curved part of step 1 creeps into a flat part;

Step 7, take out the flat part of step 6 from the autoclave;

Step 8: Carry out the test according to the static or shear test method commonly used in aerospace.

It should be noted that the above process operations can be combined and applied to different degrees. For the sake of brevity, the implementation modes of various combinations will not be repeated. Those skilled in the art can flexibly adjust the order of the above operation steps according to actual needs, or The above steps are flexibly combined and other operations.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited to this. Various equivalent modifications or substitutions should be included within the protection scope of the present invention.

Claims (7)

1. A method for evaluating the residual stress of aviation metal parts by eliminating the aging performance of the residual stress, wherein the metal parts to be evaluated are plates with preset curvature after the aging process for eliminating the residual stress, the metal parts for testing are plates which are taken out from a vacuum autoclave (6) and creep into a plane, a static test platform is used for carrying out static or shearing evaluation tests on the plates pressed into the plane to obtain failure strength parameters, and the failure strength parameters of the plates pressed into the plane are confirmed as the failure strength parameters of the metal parts to be evaluated, and the method is characterized by comprising the following steps:

s1, preparing a test device, the test device comprising: dull and stereotyped mould (1), fixed platform (2), bolt (3), wherein: the flat plate die (1) is arranged above the fixed platform (2) and is connected with the fixed platform (2) through a bolt (3);

s2, machining the metal part for testing to form a plate with a preset curvature, wherein the metal part for testing is the plate with the preset curvature formed by machining; s2, covering a plate with a preset curvature with a vacuum bag film (5) and placing the plate on a flat plate mould (1);

s3, placing the flat plate mould (1) with the metal parts for testing into a vacuum autoclave (6);

S4, in the vacuum autoclave (6), the aging process for eliminating residual stress is carried out on the metal parts for testing, and the metal parts for testing are pressed into a plane plate by using the vacuum bag film (5);

s5, performing a static or shear examination test on the plate pressed into the plane by using a static test platform to obtain a failure strength parameter;

and S6, confirming the failure strength parameter of the plate pressed into the plane as the failure strength parameter of the metal part to be checked.

2. The method of claim 1, wherein:

the concave surface of the plate with the preset curvature is provided with ribs.

3. The method of claim 1, wherein:

the test metal part (4) has the same curvature as the metal part to be examined.

4. The method of claim 1, wherein:

the flat plate die (1) is provided with grooves corresponding to the ribs.

5. The method of claim 1, wherein:

the aging process determines a preset pressure and a preset temperature applied to the metal part to be verified.

6. The method of claim 1, wherein:

the joint of the flat plate mould (1) and the flat plate mould (1) is sealed.

7. The method of any one of claims 1-6, further comprising:

the aging process for eliminating residual stress is carried out on the test metal part (4) coated with the vacuum bag film (5) and carried on the flat mold (1) by utilizing a vacuum autoclave (6), and the test metal part (4) is creeping into a plane plate.

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