Low velocity impact location identification method based on correlation dimension calculation and three-circle intersection principle

Abstract

Belonging to the technical field of impact monitoring of structural health monitoring, the invention discloses a low velocity impact location identification method based on correlation dimension calculation and three-circle intersection principle. The method includes the steps of: 1. sensor layout; 2. correlation dimension calculation of impact response signal time sequence; 3. processing of sensor response signal corresponding to a to-be-measured impact point and correlation dimension calculation of its time sequence; 4. determination of the area where the to-be-measured point is located, and calculation of the correlation dimension of sensor response signal time sequences corresponding to different sample impact points in the area; 5. building of a relational model between the length from a sample impact point to a sensor and the correlation dimension of sensor response signal time sequence in the area where the sample point is located; and 6. calculation of the specific coordinate location of a to-be-measured impact point based on three-circle intersection. The method provided by the invention has the characteristics of no need for a lot of prior knowledge and good transplantability, etc.

Description

Technical field [0001] The invention belongs to the technical field of impact monitoring of structural health monitoring, and particularly relates to a plate structure impact monitoring method based on the correlation dimension in a fractal theory system. Background technique [0002] Modern large structures such as space shuttles, high-rise structures, new bridges, long-span grid structures, etc. will be affected by design loads and various sudden external factors such as foreign object shocks and vibrations in complex service environments. Vibration or shock can cause different degrees of damage to the structure. These damages are highly concealed, the mechanism of damage and failure is complex, and the type and extent of damage are difficult to judge. However, if these damages are not detected in time and corresponding measures are taken, they will cause structural damage to accumulate, degrade its structural mechanical properties, and threaten structural safety. , Causing ca...

AI Technical Summary

Problems solved by technology

These damages are highly concealed, the mechanism of damage and failure is complicated, and the type and degree of damage are difficult to judge. However, if these damages are not discovered in time and corresponding measures are not taken, they will cause structural damage accumulation, degrade the mechanical properties of the structure, and threaten the safety of the structure. , with catastrophic consequences

[0003] At present, the research on the location and identification of impact loads is based on the Lamb wave excited by the impact in the plate structure. Usually, the triangular location based on the piezoelectric element, the quadrilateral location and the time difference location based on the wavelet transform are used, and a good impact is obtained. Position recognition results, but due to the dispersion phenomenon in the Lamb wave propagation process, the positioning accuracy is directly reduced

In addition, this type of method is susceptible to electromagnetic interference due to its data acquisition and transmission process, and its piezoelectric monitoring array requires a large number of transmission cables, which greatly increases the complexity of the system.

For the conventional low-speed sampling fiber grating sensing mode, in practical applications, due to the low sampling frequency of the demodulator, a large amount of effective information representing the characteristics of the impulse response will be lost, which cannot satisfy the principle of time difference positioning, resulting in a significant decrease in positioning accuracy

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