Fatigue crack three-dimensional measurement system and method based on multi-camera shooting

Abstract

The invention discloses a multi-camera shooting fatigue crack three-dimensional measurement system and method. The system comprises a mobile measurement support, a high-brightness LED illumination band, an illumination band annular support, a plurality of high-definition cameras, a camera annular support, a camera lens distortion correction plate, a space camera calibration object and a data processing system. The device has the advantages of being flexible to assemble, easy and convenient to operate, suitable for complex use environments and the like, and fatigue cracks and fatigue life of an object can be intelligently measured with low cost, high precision and multiple scales.

Description

technical field [0001] The invention belongs to the field of non-contact measurement, and in particular relates to a fatigue crack detection system and method. Background technique [0002] In the field of engineering structures, most bridges, tracks, and factory buildings are usually subjected to long-term cyclic loads (including earthquake loads, vehicle-induced vibrations, and wind-induced vibrations, etc.) Damage, which in turn leads to cracking and failure of the metal without warning, which is fatigue failure. Due to brittle failure, fatigue failure will pose a great threat to structural safety and durability. However, this kind of disaster is unavoidable in the engineering field, and we must pay attention to it in order to grasp the fatigue-inducing factors, damage mechanism and preventive measures. Among them, the key to understanding the fatigue damage mechanism is how to quickly and effectively identify and measure fatigue cracks. Existing fatigue crack detection...

AI Technical Summary

Problems solved by technology

[0003] First, although direct detection technologies such as penetrant testing and magnetic particle testing can identify fatigue cracks, they cannot quickly and reliably measure the size of crack development, and thus cannot predict fatigue life; indirect nondestructive testing technologies such as ultrasonic testing and infrared testing are complex and cumbersome to implement. Automation and intelligence of detection system

[0004] Second, most of the existing detection methods are used in the mechanical field. The fatigue measurement of large structures in the field of civil engineering requires a lot of manpower and material resources, especially for fatigue cracks in long-span bridges and high-rise buildings, which cannot be simple, fast, cheap and reliable. detection

[0005] Third, the current identification and measurement of fatigue cracks only stays in the two-dimensional plane, and the three-dimensional fatigue cracks of complex structures or pipe string components (such as bolts, suspenders, etc.) cannot be accurately measured

[0006] Digital image correlation technology has been applied in the detection of strain field and displacement field in the engineering field. However, the relevant commercial products at home and abroad only use one or two camera positions to shoot objects, which cannot effectively capture fatigue cracks on a spatial scale. At the same time, existing products do not The system functions such as measurement of fatigue cracks and prediction of fatigue life have not really been realized

In addition, expensive commercial equipment and complex professional operating procedures further limit the popularity of related measurement systems, making it difficult to achieve full promotion in the field of engineering structures

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