Ultrasonic guided wave scattering due to delamination in curved composite structures

2020 ◽  
Vol 239 ◽  
pp. 111987 ◽  
Author(s):  
Rajendra Kumar Munian ◽  
D. Roy Mahapatra ◽  
S. Gopalakrishnan
Author(s):  
Scott M. Bland ◽  
Shiv P. Joshi

This paper discusses the development and testing of an automated robotic ultrasonic guided wave based inspection system developed to provide an efficient, accurate and reliable method for performing nondestructive evaluation and longer term structural health monitoring in advanced composite structures. The development process and challenges in the design of the automated robotic system are described. A number of tests were performed using the developed robotic ultrasonic inspection system on composite honeycomb core sandwich materials. Experiments showed that the developed automated ultrasonic guided wave inspection system was successful at locating disbonds between the core and the facesheets. Environmental sensitivity testing was also performed to characterize the effect of changing temperature and humidity on system performance. These tests indicate that approach was relatively insensitive to environmental changes, so that this approach could be used in service environment without a significant reduction in performance. Current system testing indicates that the described robotic ultrasonic inspection approach offers an accurate and robust method for inspection and long term tracking of advanced structural system health.


Author(s):  
Hashen Jin ◽  
Jun Li ◽  
Weibin Li ◽  
Xinlin Qing

Due to the complicacy of geometry and structure in the arched composite structure, it is difficult to monitor various kinds of defects accurately. The developed damage probabilistic diagnostic imaging approach based on ultrasonic guided wave energy signal characteristics is very feasible for the structural health monitoring in the arched composite structures. However, the conventional probabilistic diagnostic imaging (PDI) approaches united with the signal energy damage indices ( DIs) have some limitations in the identification of the number, location and specific size information of multi-defects. Thus, the damage shape factor from the single damage-impaired path imminently demands to be majorized to raise the precision and stability of PDI approach in the damage recognition. A corrected probabilistic diagnostic imaging (CPDI) approach integrated with the damage shape factor [Formula: see text] needs to be recommended to precisely inspect the expansion of defect zones and different multi-defects in the arched composite structure. The availability and feasibility of the proposed methods has been validated by the experiments in the tested specimen. The results show that the fused frequency-domain energy DIs can be applied to indicate the expansion of defect zones quantitatively. It is proved that the defect identification accuracy of multi-defects from the CPDI approach can be improved by the majorization of damage shape factor, effectively. It is also clearly observed that the number, location and specific size information of different conditions of multi-defects can be distinguished by using the CPDI algorithm, availably.


Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5291
Author(s):  
Gerardo Aranguren ◽  
Josu Etxaniz ◽  
Sergio Cantero-Chinchilla ◽  
Jose M. Gil-Garcia ◽  
Muhammad Khalid Malik

Structural health monitoring comprises a set of techniques to detect defects appearing in structures. One of the most viable techniques is based on the guided ultrasonic wave test (UGWT), which consists of emitting waves throughout the structure, acquiring the emitted waves with various sensors, and processing the waves to detect changes in the structure. The UGWT of layered composite structures is challenging due to the anisotropic wave propagation characteristics of such structures and to the high signal attenuation that the waves experience. Hence, very low amplitude signals that are hard to distinguish from noise are typically recovered. This paper analyzes the propagation of guided waves along a cross-ply composite laminate following an empirical methodology. The research compares several implementations for UGWT with piezoelectric wafer active sensors. The reference for comparison is set on a basic mode, which considers the application of nominal voltage to a single sensor. The attenuation and spreading of the waves in several directions are compared when more energy is applied to the monitored structure. In addition, delayed multiple emission is also considered in multisensor tests. The goal of all the UGWT configurations is to transmit more energy to the structure such that the echoes of the emission are of greater amplitude and they ease the signal processing. The study is focused on the realization of viable monitoring systems for aeronautical composite made structures.


Author(s):  
W.-J. Song ◽  
J.L. Rose ◽  
J.M. Galan ◽  
R. Abascal

Sign in / Sign up

Export Citation Format

Share Document