Failure analysis of a field brittle fracture composite insulator: Characterization by FTIR analysis and fractography

Strength degradation and fractographic analysis of carbon fiber reinforced polymer composite laminates with square / circular hole using scanning electron microscope micrographs

“…[0] 8 laminate having 6 mm diameter circular hole failed via fiber pull‐out mechanism as observed from the SEM image (Figure 14c). A considerable amount of matrix debris were seen in the image that points to sliding abrasion, shearing and good fiber/matrix adhesion 39,40 …”

“…A considerable amount of matrix debris were seen in the image that points to sliding abrasion, shearing and good fiber/matrix adhesion. 39,40 Porosity/void in the laminate is the result of trapped volatiles or air bubble during the lay-up process or it may also be the cause of trapped moisture during crosslinking of the thermosetting matrix. 41,42 When tensile load is applied to the laminate, these porosities/voids coalescence and form cavities as observed in Figure 14d.…”

Failure analysis of a field brittle fracture composite insulator: characterisation by X‐ray photoelectron spectroscopy analysis

“…one or more smooth planar surfaces run perpendicular to the rod axis and may be accompanied by normal mechanical failure as well as axial delamination. As for the microscopic morphology of an individual glass fibre fracture surface responsible for brittle fracture, the appearance of mirror, mist and hackle zones was a common feature [6], in addition, the appearance of mirror and wedge (or wedges) zones is also a common feature of fracture surface of individual glass fibre in brittle fracture GFRP and can also be employed as an indication of brittle fracture at micro scale [10].…”

“…The chemical state change of GFRP occurs in the process of brittle fracture [15]; thus, the investigation of chemical properties of GFRP at fracture surface of brittle fracture GFRP rod can provide detailed and rich information reflecting the mechanism and process of brittle fracture. In the previous study [10,[16][17][18], the Fourier transform infrared (FTIR) analysis was the most common investigation method for detecting the chemical properties of GFRP at the fracture surface of brittle fracture. Through FTIR analysis of the GFRP at the fracture surface, the type of acid source responsible for brittle fracture can be confirmed, in general, the nitric acid was the most common type of acid medium responsible for brittle fracture due to the fact that an absorption band locating around 1384 cm −1 always can be detected on the FTIR spectra of GFRP at brittle fracture surface [10].…”

“…In the previous study [10,[16][17][18], the Fourier transform infrared (FTIR) analysis was the most common investigation method for detecting the chemical properties of GFRP at the fracture surface of brittle fracture. Through FTIR analysis of the GFRP at the fracture surface, the type of acid source responsible for brittle fracture can be confirmed, in general, the nitric acid was the most common type of acid medium responsible for brittle fracture due to the fact that an absorption band locating around 1384 cm −1 always can be detected on the FTIR spectra of GFRP at brittle fracture surface [10]. Furthermore, in FTIR spectra of a field brittle fracture GFRP presented in [16], the formation of carboxylic bands locating at 1734 cm −1 was identified, this was an evidence that oxidation of epoxy resin matrix at brittle fracture surface occurred in the process of brittle fracture.…”