A Survey of Scrutinizing Delaminated Composites via Various Categories of Sensing Apparatus

Abstract

Scrutinizing delaminated composites is extensively conducted based on measurements of various types of nondestructive sensing apparatus, classified herein as systems of thermographic inspection, piezoelectric inspection, optical interferometric inspection, electromagnetic testing, ultrasonic testing, and visual testing. The development of the subject has been reviewed during 2000–2017. Not only does the substantial corresponding literature strongly indicates numerous increasing industrial demand for composites, including carbon fiber-reinforced polymer, glass fiber-reinforced polymer, and fiber-reinforced metal laminate, but also the significant potential of composites to delaminate when subjected particularly to impact, machining operation or manufacturing imperfections. Conducting a study on the corresponding literature, the subject of delamination inspection within composites is found to be a dynamic, mature field, while lacking a thorough literature review. Therefore, the present study addresses the mentioned gap regarding various sensation systems utilized so as to detect internal anomalies in composites for the review arrangement. To that end, the literature inclusion in terms of citation times is electronically adopted associated with an appropriate combination of keywords. The study may be considered as a comprehensive, up-to-date review covering all delamination inspection techniques founded on sensation systems, thus benefiting the readers with information in an organized configuration.

Defect Detection in Aerospace Sandwich Composite Panels Using Conductive Thermography and Contact Sensors

“…However thermal energy is constantly being introduced to the delamination as a consequence of the capture method’s need to capture the temperature profile of the sample during both the ramp-up and steady state heating phases. While delaminations within laminate structures do introduce thermal resistance, this is concentrated at the boundary of the delamination and the homogeneous structure, resulting in the retention of heat for a measurably longer time within the edges of the delamination when compared to that of the surrounding non-delaminated structure during cooling which in turn yields a measurable contrast [ 23 , 24 , 25 ]. As such, this class of damage is best detected during the rapid introduction and removal of a heat source on the laminate surface.…”

Integrating Extended Non-destructive Testing in the Life Cycle Management of Bonded Products—Some Perspectives

“…Following SAE Standard ARP6461, SHM is defined as "the process of acquiring and analyzing data from on-board sensors to evaluate the health of a structure" [29]. To achieve this, SHM systems include three key elements [29] and three steps [32]. Following Güemes et al, these elements comprise first, a network of sensors that are permanently attached to the structure, which is essential for performing automated inspections; second, on-board data handling and computing facilities for processing data in real-time; and third, algorithms that compare recently acquired data with stored data on the pristine structure.…”

“…In this way, after correcting for environmental factors, a damage index may be calculated and information about damage existence, localization and type may be provided. Furthermore, damage severity may be quantified, and the residual life may be predicted [32]. Such prognosis is closely linked to diagnosis, or the evaluation of structural health, which is the main objective of SHM; prognosis and diagnosis conceptually differ in the tools they use: prognosis is mainly focused on statistical analysis, while diagnosis is more related to sensors, signal processing and algorithms for damage identification [29].…”

Conjugated Polymer/Graphene Oxide Nanocomposites—State-of-the-Art

“…The conjugated polymers have beneficial electronic, optical, durability, heat stability, and other physical properties [5,6]. These polymers shown wide ranging applications in supercapacitors, sensors, photovoltaics, light emitting diodes, and electronic devices [7][8][9]. The conducting polymers have also been used in the biomedical field [10,11].…”