CN107884149A - Shake test structure in one kind top destroys recognition methods - Google Patents

Abstract

The invention provides a method for identifying structural damage in a shaking test, comprising: installing an acceleration sensor on a test piece of the shaking test, the measurement direction of the acceleration sensor is the same as the shaking direction; acquiring the acceleration signal collected by the acceleration sensor, And calculate the shock response spectrum of the acceleration signal; calculate the tolerance between the shock response spectrum and the reference shock response spectrum, and judge whether the test piece is damaged and the time of damage according to the tolerance; solve the problem of traditional artificial The detection method and data judgment are not standardized, and it is difficult to determine the problem of destruction time.

Description

A damage identification method for shaking test structures

technical field

The invention relates to the technical field of environmental testing, in particular to a structural damage identification method for a jolting test.

Background technique

The detection of structural damage in the shaking test is a relatively cumbersome and complicated technology in the shaking test. Whether the test piece is damaged is an important parameter to measure whether the test piece is normal, and it has important reference value in the evaluation of the product's adaptability to the shaking environment .

At present, the method of determining whether the structure of the test piece is damaged after the test in engineering is firstly to carry out manual inspection before the test to ensure that it is intact before the test, and then carry out manual inspection after the test to confirm whether it is intact. This method has some shortcomings, such as test Structural integrity checks are completely manual, and the efficiency is relatively low. At the same time, the time of structural damage cannot be judged during the test, and it can only be judged by whether the acceleration peak value is abnormal. This traditional method is difficult to accurately locate the time of damage.

Contents of the invention

A brief overview of the invention is given below in order to provide a basic understanding of some aspects of the invention. It should be understood that this summary is not an exhaustive overview of the invention. It is not intended to identify key or critical parts of the invention nor to delineate the scope of the invention. Its purpose is merely to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later.

In order to solve the above problems, the present invention proposes a damage identification method for a shaking test structure.

A damage identification method for a shaking test structure, comprising:

An acceleration sensor is installed on the test piece of the jolt test, and the measurement direction of the acceleration sensor is the same as the jolt direction;

Obtain the acceleration signal collected by the acceleration sensor, and perform shock response spectrum calculation on the acceleration signal;

Calculating the tolerance between the shock response spectrum and the reference shock response spectrum, and judging whether the test piece is destroyed and the time of destruction according to the tolerance.

The damage identification method of the shaking test structure provided by the invention solves the problem that the traditional manual detection method and data judgment are not standardized, and it is difficult to judge the damage time.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a flow chart of an embodiment of a method for identifying damage of a shaking test structure provided by the present invention.

Fig. 2 is a flow chart of a second embodiment of a method for identifying damage to a structure in a jolt test provided by the present invention.

Detailed ways

Embodiments of the present invention will be described below with reference to the drawings. Elements and features described in one drawing or one embodiment of the present invention may be combined with elements and features shown in one or more other drawings or embodiments. It should be noted that representation and description of components and processes that are not relevant to the present invention and known to those of ordinary skill in the art are omitted from the drawings and descriptions for the purpose of clarity.

Referring to Fig. 1, the present embodiment provides a method for identifying damage of a shaking test structure, including:

Step S101, installing an acceleration sensor on the test piece for the jolt test, the measurement direction of the acceleration sensor is the same as the jolt direction;

Step S102, acquiring the acceleration signal collected by the acceleration sensor, and performing shock response spectrum calculation on the acceleration signal;

Step S103 , calculating the tolerance between the shock response spectrum and the reference shock response spectrum, and judging whether the test piece is damaged and the time of failure according to the tolerance.

Specifically, before the start of the jolt test, an acceleration sensor is arranged on the test piece. For the selection and use requirements of the acceleration sensor, refer to the "Shock and Vibration Handbook". Similarly, the installation position of the acceleration sensor is preferably the vulnerable position of the test piece, and the connection method between the acceleration sensor and the test piece is glued.

Use a general-purpose data acquisition system to collect acceleration signals throughout the test process, and the sampling frequency is not less than 10KHz. For the selection and use requirements of the data acquisition system, please refer to the Shock and Vibration Manual.

In the vibration test, the number of vibrations is generally 1000 times. First, the acceleration signals of the vibrations are separated to form independent acceleration signals. The sequence of each acceleration signal remains unchanged, and the shock response spectrum is performed on each acceleration signal Calculation, see the Shock and Vibration Handbook for the calculation method of the shock response spectrum.

The reference shock response spectrum SRS ₀ (f) refers to the shock response spectrum when the test piece is intact, which can generally be obtained during test debugging. As a preferred implementation, the reference shock response spectrum is obtained from the first jolt in the test Shock Response Spectrum.

Further, the tolerance is calculated by the following formula:

Among them, f is the sampling frequency, SRS ₀ is the reference shock response spectrum, SRS _i is the shock response spectrum of the i-th jolt, and δ _i is the tolerance of the i-th jolt.

Further, referring to FIG. 2, judging whether the test piece is damaged according to the tolerance includes:

The tolerance is compared with a preset threshold, and if the tolerance is greater than or equal to the preset threshold, it is determined that the test piece has been damaged; otherwise, if it is smaller than the preset threshold, it indicates that the test piece is normal.

As a preferred implementation manner, the preset threshold is 6dB.

Further, according to the number of vibrations when the test piece is damaged, determine the time when the test piece is damaged, and when the tolerance is greater than or equal to the preset threshold, record the number of vibrations at this time, that is, start from the i-th vibration Destruction, thereby determining the time of destruction.

The damage identification method of the shaking test structure provided by the invention solves the problems of manual detection and difficulty in determining the failure time in the traditional shaking test, and has the advantages of simple principle and clear physical meaning after being tested in engineering practice.

Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not limited to the specific embodiments of the procedures, devices, means, methods and steps described in the specification. Those of ordinary skill in the art will readily appreciate from the disclosure of the present invention that existing and future devices that perform substantially the same function or obtain substantially the same results as the corresponding embodiments described herein can be used in accordance with the present invention. The developed process, device, means, method or steps. Accordingly, the appended claims are intended to include within their scope such processes, means, means, methods or steps.

Claims (5)

1. shake test structure in one kind top destroys recognition methods, it is characterised in that including：

Acceleration transducer, measurement direction and the top shake direction of the acceleration transducer are set on the testpieces of top shake experiment It is identical；

The acceleration signal of the acceleration transducer collection is obtained, and shock response spectrum meter is carried out to the acceleration signal Calculate；

The tolerance between shock response spectrum and the standardized impact response spectra is calculated, judges that the testpieces is according to the tolerance The time of no destruction and destruction.

2. shake test structure in top according to claim 1 destroys recognition methods, it is characterised in that the standardized impact response Compose and rung for the shock response spectrum that top shake for the first time obtains in experiment or the impact that equal state testpieces obtains in the shake experiment of top Ying Pu.

3. shake test structure in top according to claim 1 destroys recognition methods, it is characterised in that the tolerance passes through following Formula is calculated：

<mrow> <msub> <mi>&amp;delta;</mi> <mi>i</mi> </msub> <mrow> <mo>(</mo> <mi>f</mi> <mo>)</mo> </mrow> <mo>=</mo> <mn>20</mn> <msub> <mi>log</mi> <mn>10</mn> </msub> <mrow> <mo>(</mo> <mfrac> <mrow> <msub> <mi>SRS</mi> <mi>i</mi> </msub> <mrow> <mo>(</mo> <mi>f</mi> <mo>)</mo> </mrow> </mrow> <mrow> <msub> <mi>SRS</mi> <mn>0</mn> </msub> <mrow> <mo>(</mo> <mi>f</mi> <mo>)</mo> </mrow> </mrow> </mfrac> <mo>)</mo> </mrow> <mo>,</mo> <mi>i</mi> <mo>=</mo> <mn>1</mn> <mo>,</mo> <mn>2</mn> <mo>,</mo> <mo>...</mo> <mo>,</mo> <mi>N</mi> </mrow>

Wherein, f is sample frequency, SRS₀On the basis of shock response spectrum, SRS_iFor the shock response spectrum of ith top shake, δ_iFor i-th The tolerance of secondary top shake.

4. shake test structure in top according to claim 3 destroys recognition methods, it is characterised in that is judged according to the tolerance Whether the testpieces destroys, including：

By the tolerance compared with predetermined threshold value, if the tolerance is more than or equal to predetermined threshold value, it is determined that the experiment Part has destroyed.

5. shake test structure in top according to claim 4 destroys recognition methods, it is characterised in that when being destroyed according to testpieces Top shake number, determine the time that the testpieces destroys.