Nonlinear guided wave composite material damage positioning method based on trapezoidal array

Abstract

The invention discloses a nonlinear guided wave composite material damage positioning method based on a trapezoidal array, and belongs to the technical field of damage monitoring. The method comprises the following steps of: arranging a sensor array on a structure; selecting an optimal excitation frequency; acquiring the fundamental wave amplitude and the second harmonic amplitude of a signal through the frequency spectrum; calculating nonlinear characteristic parameters of each path before and after damage; and performing two-dimensional positioning on the damage of a composite material according to the change of the nonlinear characteristic parameters before and after damage. According to the monitoring method provided by the invention, a trapezoidal sensor array is used for collecting signals of each path before and after damage, the damage on the structure is positioned according to the change of nonlinear characteristic parameters, the influence of the structure and the material of the structural part is avoided, the requirements of people for monitoring various complex conditions are met, remedial measures can be taken in time after monitoring, so that further deterioration of the material is prevented, and accident risks caused by further deterioration are reduced.

Description

technical field [0001] The invention relates to a trapezoidal array-based damage location method for nonlinear guided wave composite materials, which belongs to the technical field. Background technique [0002] With the development of aerospace, machinery manufacturing, construction and other fields, composite materials have been widely used in various industries. Although composite materials have many advantages such as high strength and rigidity, good fatigue resistance and flexible design, due to their sensitivity to the impact of foreign objects, composite materials may suffer from various forms of invisible damage in improper use or harsh environments. Or hard-to-identify damage, such as low-velocity impact, tool drops during manufacturing or repair, can cause composites to have impact damage that is not visible on the outside. All of these require an accurate understanding of damage in composite materials and timely remedial measures to prevent further deterioration ...

AI Technical Summary

Problems solved by technology

With the discovery and application of various new materials, people pay more and more attention to the small damage in the structure, and various projects have also increased the requirements for monitoring technology, such as the detection of micro cracks / micro defects, the monitoring of complex shape parts, Various needs such as long-distance monitoring of large-scale structures are continuously generated. Due to the limitation of the principle, the traditional linear Lamb wave monitoring technology can no longer meet people's requirements for monitoring.

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