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CN-122016844-A - Engine attaching interface defect detection method based on weak grating array technology

CN122016844ACN 122016844 ACN122016844 ACN 122016844ACN-122016844-A

Abstract

The invention discloses an engine attaching interface defect detection method based on a weak grating array technology, which comprises the specific detection flow steps of designing a weak grating array optical fiber sensing network suitable for an engine interface according to geometrical characteristics of a solid rocket engine, manufacturing a solid engine equivalent physical model, establishing a finite element simulation model, carrying out solid rocket engine interface defect semi-physical simulation, constructing an engine interface defect knowledge base, establishing an interface defect intelligent mapping model, preprocessing measured data, acquiring data characteristics, identifying and classifying the data characteristics according to the interface defect intelligent mapping model, and confirming interface defect conditions. According to the defect detection method, the weak reflection grating sensing network is implanted into the contact interface between the engine shell and the heat insulation layer, the continuous physical interface is discretized into a plurality of independent monitoring areas, and the accurate judgment of defects is realized by carrying out deep analysis on actual measurement data acquired by the weak grating array optical fiber sensing network.

Inventors

  • XU JINLONG
  • Zhu Yashan
  • DUAN SHUJIE

Assignees

  • 湖北三江航天红峰控制有限公司

Dates

Publication Date
20260512
Application Date
20251216

Claims (9)

  1. 1. A method for detecting defects of an engine attaching interface based on a weak grating array technology is characterized by comprising the following specific detection processes: S1, designing a weak grating array optical fiber sensing network applicable to an engine interface according to the geometric characteristics of a solid rocket engine; S2, manufacturing a solid engine equivalent physical model, establishing a finite element simulation model, performing solid rocket engine interface defect semi-physical simulation, and constructing an engine interface defect knowledge base; S3, an intelligent mapping model of the interface defect is established, the actually measured data is preprocessed, data characteristics are obtained, the data characteristics are identified and classified according to the intelligent mapping model of the interface defect, and the condition of the interface defect is confirmed.
  2. 2. The method for detecting the defects of the engine attaching interface based on the weak grating array technology of claim 1, wherein in the step S1, the weak grating array optical fiber sensing network is arranged based on the optical frequency domain reflection demodulation technology, and the specific arrangement mode is that 4n weak grating array optical fiber sensors are arranged at the contact interface of a solid engine shell and a heat insulation layer along the axial direction of an engine bus or the winding direction of shell fiber, and the three-dimensional space position of a measuring point on each sensor at the engine interface is recorded as Adjacent sensors together define a monitoring area Wherein i=1, 2, ·4n.
  3. 3. The method for detecting the defects of the attaching interface of the engine based on the weak grating array technology of claim 2, wherein the continuous physical interface of the engine is discretized into a plurality of independent monitoring areas through a weak grating array optical fiber sensor network.
  4. 4. The method for detecting the defects of the bonding interface of the engine based on the weak grating array technology as set forth in claim 2, wherein the specific flow of the step S2 is as follows: s21, implanting a weak grating array optical fiber sensor into an engine interface according to an engine manufacturing process, selecting M representative working conditions from M working conditions to perform physical construction, and obtaining model strain data under each defect working condition of the physical ; S22, building a finite element model corresponding to m working conditions by using ABAQUS, and obtaining strain data of a corresponding simulation model ; S23, in order to By taking as a reference Checking a finite element simulation model; S24, acquiring strain curve data sets under M working conditions according to the verification result Strain field data set for each region ; S25, extracting Corresponding strain characteristics Strain characteristics extracted after correlation calculation with adjacent sensors under same working condition 、 For a pair of 、 、 And Normalized to obtain strain curve data set And strain field data sets , And Forming an interface defect strain knowledge base delta together; Wherein, the ; 。
  5. 5. The method for detecting the defects of the engine attaching interface based on the weak grating array technology as set forth in claim 4, wherein the simulation model is subjected to sample verification by introducing four key variables including a defect shape, a defect size, a defect position and an engine posture, specifically, the method is set for each type of variable 、 、 、 Typical state, constitution And (3) selecting M groups of representative key working conditions from the comprehensive simulation working conditions to perform physical manufacturing, checking and correcting the corresponding finite element simulation model based on the M groups of physical experimental data, and deducing and acquiring response data under all M experimental working conditions by the verified high-confidence simulation model.
  6. 6. The method for detecting the defects of the bonding interface of the engine based on the weak grating array technology of claim 4, wherein the sizes and the positions of the defects are calculated in a dimensionless manner through a formula a/A, wherein a is a defect related parameter, and A is a related parameter of a discretization monitoring area.
  7. 7. The method for detecting the bonding interface defect of the engine based on the weak grating array technology of claim 4, wherein the interface defect strain characteristics comprise strain data characteristics of a single optical cable and correlation characteristics between strain data of two adjacent optical cables.
  8. 8. The method for detecting the defects of the bonding interface of the engine based on the weak grating array technology of claim 4, wherein the specific flow of the step S3 is as follows: S31, establishing an intelligent mapping model for the defects of the engine interface based on an interface strain knowledge base; S32, acquiring test data of a sensor of the physical engine Engine attitude information, station position information Dividing and positioning data according to the position information of the measuring points and the engine structure; S33, pair of Preprocessing including outlier rejection, denoising and normalization, and extracting strain characteristics Strain features extracted after correlation calculation of adjacent sensors 、 ; S34, will 、 、 As input, outputting possible defect results based on the engine interface defect intelligent mapping model And corresponding weight coefficient ; S35, according to Obtaining the predicted value of the strain field of each region Image recognition algorithm pair predictive value And carrying out image recognition and obtaining the defect position and size.
  9. 9. The method for detecting the defects of the engine attaching interface based on the weak grating array technology as defined in claim 8, wherein the extracted strain data features comprise the strain data feature of a single optical cable and the correlation feature between the strain data of two adjacent optical cables.

Description

Engine attaching interface defect detection method based on weak grating array technology Technical Field The invention relates to the technical field of solid rocket engine detection, in particular to an engine attaching interface defect detection method based on a weak grating array technology. Background The engine is a key power device of a spacecraft, the structural integrity of the engine is directly related to the flight safety, the engine combustion chamber is usually formed by bonding a plurality of layers of materials of a shell, a heat insulation layer, a lining layer and a propellant, and during the production and use process, the defects of debonding, creep, cracking and the like of multiple interfaces possibly occur due to poor technology, aging or overload, and the defects can change the combustion surface rule of the engine, influence the engine performance and even cause catastrophic accidents. At present, the interface defect detection of the solid engine mainly adopts ultrasonic detection, ray detection and traditional optical fiber sensing technology. The ultrasonic detection needs coupling and has poor adaptability to complex results, the radiation detection has the safety protection problem and is difficult to monitor in real time, the traditional fiber bragg grating sensor has strong reflectivity, large crosstalk and limited spatial resolution, and the distributed accurate measurement is difficult to realize. The weak grating array technology is used as an emerging distributed optical fiber sensing technology, the reflectivity of the weak grating array technology is as low as 1%, thousands of sensing units can be multiplexed by a single optical fiber, the weak grating array technology has the advantages of high precision, electromagnetic interference resistance, distributed measurement and the like, and a brand new solution is provided for dynamic monitoring of the interface defects of an engine. However, the existing research focus detection means have few studies on the accurate correlation of strain data collected by the optical fiber sensor and the defects of the engine interface. The invention constructs the strain knowledge base through the semi-physical object and combines the artificial intelligent algorithm to provide technical support for the identification of the defects of the engine interface. Disclosure of Invention Aiming at the technical problems, the invention provides an engine attaching interface defect detection method based on a weak grating array technology, which is characterized in that a weak reflection grating sensing network is implanted into a contact interface between an engine shell and a heat insulation layer, a continuous physical interface is discretized into a plurality of independent monitoring areas, the response of various defects such as interface debonding, weak adhesion, cracks and the like under different working conditions is systematically simulated by utilizing a semi-physical simulation technology, and the accurate discrimination of the defects is realized by carrying out deep analysis on actual measurement data acquired by the weak grating array optical fiber sensing network. A method for detecting defects of an engine attaching interface based on a weak grating array technology comprises the following specific detection processes: S1, designing a weak grating array optical fiber sensing network applicable to an engine interface according to the geometric characteristics of a solid rocket engine; S2, manufacturing a solid engine equivalent physical model, establishing a finite element simulation model, performing solid rocket engine interface defect semi-physical simulation, and constructing an engine interface defect knowledge base; S3, an intelligent mapping model of the interface defect is established, the actually measured data is preprocessed, data characteristics are obtained, the data characteristics are identified and classified according to the intelligent mapping model of the interface defect, and the condition of the interface defect is confirmed. As the optimization of the technical scheme, in the step S1, the weak grating array optical fiber sensing network layout is carried out based on the optical frequency domain reflection demodulation technology, and the specific layout mode is that 4n weak grating array optical fiber sensors are arranged at the contact interface of a solid engine shell and a heat insulation layer along the axial direction of an engine bus or the winding direction of shell fiber, and the three-dimensional space position of a measuring point on each sensor at the engine interface is recorded as followsAdjacent sensors together define a monitoring areaWherein i=1, 2, ·4n. As a preferable mode of the technical scheme, the continuous physical interface of the engine is discretized into a plurality of independent monitoring areas through the weak grating array optical fiber sensor network. As a preferable mode