Real world application of angular scan pulse-echo ultrasonic propagation imager for damage tolerance evaluation of full-scale composite fuselage

Abstract

Composite structures are assertively used for new airframe designs and manufacturing in military aircrafts because of superior strength-to-weight ratios and fatigue resistance. Because the composites have different fatigue failure characteristics compared with metals, it is necessary to develop different approaches for the composite fatigue design and testing. In this study, we propose an in situ damage evaluation technology with high spatial resolution during full-scale fatigue testing of composite aircraft structures. For real composite structure development considering composite fatigue characteristics, full-scale fatigue and damage tolerance tests of the composite fuselage structure were conducted to evaluate the structural characteristics. In the meantime, the laser ultrasonic nondestructive inspection method, called an angular scan pulse-echo ultrasonic propagation imager, which is fully noncontact, real-time, and portable to position it in between the complex test rigs, is used to observe in situ damage growth of the composite. Finally, the verification procedure assisted by the angular scan pulse-echo ultrasonic propagation imager assures no growth of the initial impact damages after lifetime operation and proves the damage tolerance capability of the developed composite fuselage structure.

Understanding System Complexity in the Non-Destructive Testing of Advanced Composite Products

“…In recent years, there has been a rapid increase in the use of arrays over conventional transducers, attributed to greater flexibility, imaging performance, and signal stability [34]. Applications of UT have been reported in evaluating the effects of fatigue and damage tolerance on aircraft fuselage structures, detecting cracks, and detecting disbonds in wind turbine blades [35][36][37]. The two conventional approaches to UT are chosen dependent on the specific application, with careful consideration given to the material and geometry specification and quality control requirements [38][39][40]:…”

Investigation of manufacturing defects in 3D-printed CFRP using laser ultrasonic testing and x-ray micro-computed tomography

“…Therefore, micro-CT cannot be applied to the large structures typically used in industries. Laser ultrasonic testing (LUT) is an alternative method, and it can be applied to various structures, regardless of their size [15][16][17]. Given the large components manufactured using 3D-printed CFRP for applications in the aerospace and automobile industries, it is necessary to verify whether the manufacturing defects of 3D-printed CFRP can be detected via the LUT method.…”