CN113916406A

CN113916406A - Method for reflecting structural stress range

Info

Publication number: CN113916406A
Application number: CN202111292503.7A
Authority: CN
Inventors: 王焜; 余林衡; 王刚化; 张超; 陈炜; 姚旭; 曾俊; 张伟
Original assignee: Guizhou Guifei Aircraft Design And Research Institute Co ltd
Current assignee: AVIC Guizhou Aircraft Co Ltd
Priority date: 2021-11-03
Filing date: 2021-11-03
Publication date: 2022-01-11

Abstract

The invention provides a method for reflecting the structural stress range, which is characterized in that a pre-damage sheet is pasted at a key part of a structure, one or more pre-damage sheets are pasted according to the requirement of measurement precision, the pre-damage sheet is broken in a smaller range of specific strain, after pasting, the pre-damage sheet and a structure body have the same strain, and after the structure is loaded, the structural stress range is judged by observing whether the pre-damage sheet is damaged; the invention provides a structure monitoring method which can measure the structural stress level of an airplane and does not need to arrange a circuit and install a signal receiving device on the premise of ensuring a certain precision range; the method is quick, simple to operate, free of professional staff and professional equipment and capable of reflecting whether the stress of the key part is smaller than an expected value or not when the structure body is loaded.

Description

Method for reflecting structural stress range

Technical Field

The invention belongs to the field of stress detection, and particularly relates to a method for reflecting the structural stress range.

Background

Depending on the aircraft application, the aircraft structure is often subjected to complex, long-term fatigue and impact loads, and therefore the stress levels and stress concentration areas of the aircraft structure need to be examined to provide early warning of possible fractures and other forms of damage to prevent irreparable damage.

The general method is that strain gauges are pasted on key areas of the airplane structure and connected with a detector through cables, and the stress level of the airplane is calculated according to the change situation of strain-pressure-voltage of the airplane in the use process, so that the method has the advantage of higher precision; however, usually, the aircraft needs internal traction and series circuits, professional personnel and professional equipment are needed, the workload is huge, the period is long, the cost is high, holes are required to be formed in the structure sometimes for passing through cables, certain influence is caused on the aircraft structure, and the burden of maintenance, guarantee and the like in the future is increased.

Disclosure of Invention

In view of the above problems, the present invention provides a method for rapidly detecting a stress concentration area of an aircraft, which is fast and simple to operate, and does not require professional personnel or professional equipment.

The invention is realized by the following technical scheme:

a method for reflecting the structural stress range is characterized in that a pre-damage sheet is pasted on a key part of a structure, one or more pre-damage sheets with different strength limits are pasted according to the requirement of measurement precision, the pre-damage sheet is broken in a smaller range of specific strain, after pasting, the pre-damage sheet and a structure body have the same strain, and after the structure is loaded, the stress range of the structure body is judged by reflecting the strain condition of the structure body through whether the pre-damage sheet is damaged; when the structure body area is measured, a plurality of pre-damage pieces with different strength limits are stacked and adhered in the area to be measured, each pre-damage piece corresponds to one strain when being broken and damaged, and the stress range of the area to be measured is judged by observing the breakage of the pre-damage pieces; when the measuring range needs relatively accurate numerical values, a plurality of pre-damage pieces with different strength limits are arranged and stuck in the range to be measured, each pre-damage piece corresponds to one strain when being broken and damaged, and the stress range of the area to be measured is judged by observing the breakage of the pre-damage pieces.

The invention has the beneficial effects that:

the invention provides a structure monitoring method which can measure the structural stress level of an airplane and does not need to arrange a circuit and install a signal receiving device on the premise of ensuring a certain precision range; the method is quick, simple to operate, free of professional staff and professional equipment and capable of reflecting whether the stress of the key part is smaller than an expected value or not when the structure body is loaded.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings.

FIG. 1 is a first schematic diagram of a method of reflecting the stress range of a structure according to the present invention.

FIG. 2 is a second schematic diagram of a method of reflecting the stress range of a structure according to the present invention.

FIG. 3 is a third schematic diagram of a method of reflecting the stress range of a structure according to the present invention.

FIG. 4 is an enlarged view A of a method of reflecting the stress range of a structure according to the present invention.

Shown in the figure: 1-a structural body; 2-pre-damage slice one; 3-pre-damage slice II; 4-pre-damage slice III; 5-pre-damage slice four; 6-pre-damage slice five; 7-pre-damaged slice six.

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

Example 1: paste on the structure body 1 and decrease piece one 2 in advance, when loading, decrease piece one 2 in advance and paste the department and will lead to decreasing piece one 2 in advance and produce the strain the same with this department structure body 1 because structure body 1 warp, reach the intensity limit sigma of decreasing piece one 2 in advance when the strain_bWhen the pre-damage piece 2 is damaged, the strain of the structure body 1 at the position can be reversely pushed out by observing whether the pre-damage piece is damaged or not, and thenFrom the strain, the minimum stress σ of the structural body 1 can be estimated_b1，When the structural body 1 is loaded to cause the breakage and the damage of the pre-damaged sheet-2, the stress borne by the structural body 1 is positioned at sigma_b1To sigma_bmax (sigma)_bmax is the strength limit of the structural body).

Embodiment 2, paste a plurality of different intensity limit on the structural body 1 within the scope of awaiting measuring side by side in advance decrease piece two 3, in advance decrease piece three 4, in advance decrease piece four 5, in advance decrease piece five 6, in advance decrease piece six 7, wherein in advance decrease the piece crack when breaking the strain relation as follows: pre-damaged slice (3) < pre-damaged slice (4) < pre-damaged slice (5) < pre-damaged slice (6) < pre-damaged slice (7); the structural stress of each strain corresponding to the structural body during damage can be controlled, if under a certain working condition, the two pre-damage pieces 3, the three pre-damage pieces 4 and the four pre-damage pieces 5 are damaged, and then the load bearing range of the structural body 1 can be judged to be between the stress of the structural body 1 corresponding to the strain when the four pre-damage pieces 5 are damaged and the stress of the structural body corresponding to the five non-damaged pre-damage pieces 6.

Example 3: the principle of the method is the same as that of the embodiment 2, and the only difference is that a plurality of pre-damaged sheets two 3, three 4 and four 5 with different strength limits are stacked and stuck in the range to be measured on the structural body 1.

The scope of the present invention is not limited to the technical solutions disclosed in the embodiments, and any modifications, equivalent substitutions, improvements, etc. made to the above embodiments according to the technical spirit of the present invention fall within the scope of the present invention.

Claims

1. A method for reflecting the structural stress range is characterized in that a pre-damage sheet is pasted at a key part of a structure body, one or more pre-damage sheets are pasted according to the requirement of measurement precision, after pasting, the pre-damage sheets and the structure body have the same strain, and after the structure is loaded, the structural stress range is judged by observing whether the pre-damage sheets are damaged or not.

2. The method for reflecting the structural stress range according to claim 1, wherein when the structural body region is measured, a plurality of pre-damage pieces are stacked and stuck in the region to be measured, each pre-damage piece corresponds to a strain when being broken and damaged, and the stress range of the region to be measured is judged by observing the breakage of the pre-damage pieces.

3. The method for reflecting the structural stress range according to claim 1, wherein when the measurement range requires relatively accurate numerical values, a plurality of pre-damaged pieces are arranged and stuck in the range to be measured, each pre-damaged piece is corresponding to a strain when being broken and damaged, and the stress range of the area to be measured is judged by observing the breakage of the pre-damaged pieces.