Experimental and analytical study on fiber-kinking failure mode of laminated composites

This work presents a comparison of various combinations of patch and parent laminates with different orientations and stacking sequence, on the performance of adhesively bonded external patch-repaired carbon/epoxy laminates under quasi-static compressive loading. The compressive behaviour and failure modes of pristine, damaged and repaired specimens of four different parent laminates ([0]6, [45]6, [0/45/45]s, [45/45/0]s) are discussed. The repair of each parent laminate is carried out by bonding patches of four configurations ([0]2, [45]2, [45/0], [0/45]) having two plies on each side of the parent laminates. Real-time digital image correlation technique was employed to capture the development of the strain field with the increasing load. The results reveal the development of distinctive strain contours associated with different patch–parent configurations. The inspection of damaged specimens revealed the fiber micro-buckling as the dominant mode of failure. The orientation of plies influences the overall failure mode of the laminates. The clustering of 0° plies results in laminate possessing higher strength. The less stiff [45]2 patch shows higher compliance with the increasing load.

Section: Introductionmentioning

confidence: 99%

Experimental investigation on compressive behaviour of different patch–parent layup configurations for repaired carbon/epoxy composites

Bhatia

Andrew

Arockiarajan

2019

“…This case can be interpreted as fiber kinging. 39 It should be noted that other fiber orientations and strain rates of the composite laminates, which do not differ greatly in the damaged areas, are not given here for sake of brevity.…”

Section: Resultsmentioning

confidence: 99%

Determination of flexural properties of hybrid composite using Cowper-Symonds rate-dependent material model

Erbayrak

2021

This study addressed to determine the flexural properties of hybrid composite laminates (HCAFRE) under the strain rate sensitivity. The hybrid composite laminate was formed as consecutive stacking of a sequence of plain woven carbon fiber reinforced epoxy (CFRE) and a plain-woven aramid fiber reinforced epoxy (AFRE) laminates. The flexural tests were carried out at four different strain rates (0.01, 0.11, 0.55, 1.1 s−1) to determine the strain rate sensitivity of the HCAFRE. Moreover, the strain rate sensitivity of CFRE and AFRE was also determined individually. The effect of different fiber orientations (0°, 45°, and 90°) on the flexural properties of the composite laminates were also investigated at the scope of this study. In numerical analysis, composite laminates (CFRE, AFRE, and HCAFRE) were constituted in LS-DYNA finite element program using the Cowper-Symonds material model (MAT 112) which includes strain rate dependency. Consequently, it was seen that the experimental and numerical results were indicated a similar tendency to each other. Therefore, it was understood that the Cowper-Symonds material model is suited for the flexural behavior model of composite laminates under different strain rates.

“…11–13 Kinking is the predominant failure mechanism for fiber-reinforced composite laminates under longitudinal compression. 14,15 Moreover, the kink-band formation combined with splitting in fiber-reinforced laminated composites leads to the catastrophic failure. 16…”

Section: Introductionmentioning

confidence: 99%

“…[11][12][13] Kinking is the predominant failure mechanism for fiber-reinforced composite laminates under longitudinal compression. 14,15 Moreover, the kink-band formation combined with splitting in fiber-reinforced laminated composites leads to the catastrophic failure. 16 Although the CF reinforcement is almost impervious to the temperature and time, the matrix resin in CFRPs exhibits time-dependent and temperature-dependent behaviors.…”

Section: Introductionmentioning

confidence: 99%

Time-and temperature-dependent compressive behavior of woven carbon fabric reinforced polyamide composite laminate

Nam

Goto

Tobata

et al. 2022

Plain woven carbon fabric reinforced polyamide (CF/PA) composite laminate was developed using hot-pressed processing with a vacuum-assisted system. Temperature-dependent mechanical properties of the CF/PA composite laminate under longitudinal compressive loading were examined. The compressive mechanical properties of the composite laminate decreased considerably with increasing the temperature to 120°C. The compressive strength and strain at maximal stress reduced rapidly below 80°C, while the compressive modulus declined slightly underneath 50°C. The glass transition temperature of the CF/PA composite was found to be about 50°C by the differential scanning calorimetry, which almost corresponded to the slight reduction of the elastic modulus at temperatures below 50°C. The time-dependent creep behavior of the CF/PA laminate under compressive loading at isotherms between 25°C and 50°C was studied. Creep strains of the CF/PA composite samples increased with rising temperature. The smooth creep compliance master curve of the CF/PA composite was obtained by shifting short-term creep compliance curves using the time–temperature superposition principle. The master curve provided a creep prediction to 961.6 days with the measured data in only 12.5 days.