A multi-camera 3D measurement system and method for fatigue cracks

Abstract

The invention discloses a multi-camera fatigue crack three-dimensional measurement system and method. The system includes a mobile measurement bracket, a high-brightness LED lighting strip, a lighting strip ring bracket, several high-definition cameras, a camera ring bracket, and a twisted camera lens. Correction plate, space camera calibration object and data processing system. The invention has the advantages of flexible assembly, easy operation, adaptability to complex use environments, etc., and can measure fatigue cracks and fatigue life of objects with low cost, high precision, multi-scale, and intelligence.

Description

technical field [0001] The invention belongs to the field of non-contact measurement, and particularly relates to a fatigue crack detection system and method. Background technique [0002] In the field of engineering structures, most bridges, tracks and workshops usually bear long-term cyclic loads (including seismic loads, vehicle-induced vibration and wind-induced vibration, etc.) during their life cycles, and structural materials will be affected by these millions of dynamic cyclic loads. The damage, which in turn causes the metal to crack and fail without warning, is called fatigue failure. Due to brittle failure, fatigue failure poses a great threat to structural safety and durability. However, this kind of disaster is unavoidable in the engineering field, and it must be paid attention to in order to grasp the fatigue-inducing factors, damage mechanism and preventive measures. Among them, the key to mastering the fatigue failure mechanism is how to quickly and effecti...

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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