Porosity analysis of carbon fibre-reinforced polymer laminates manufactured using automated fibre placement

Oromiehie, Ebrahim; Garbe, Ulf; Prusty, B. Gangadhara

doi:10.1177/0021998319875491

Cited by 24 publications

(7 citation statements)

References 27 publications

(38 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Other problems facing the industry are mostly related to damages and air gaps appearing also during the curing process. 5 This is why different methods exist for the monitoring of the curing process of the composites. In our previous work, a system that can effectively monitor the composites during curing using ultrasonic waves was implemented successfully.…”

Section: Introductionmentioning

confidence: 99%

Assessment of cure cycle shortening for advanced composites via ultrasonics and dynamic mechanical analysis

Mahfoud

Harb

2022

Journal of Reinforced Plastics and Composites

View full text Add to dashboard Cite

Composite materials are incorporated in various applications and their industry is widely growing. They offer cost savings and are more environmentally friendly than conventional metal structures. Some of the concerns this industry faces are the energy and time spent on long curing cycles to achieve permanent bonding between the matrix and fibers. In our previous work, a reusable sensing polytetrafluoroethylene (PTFE) system that can monitor the degree of cure of the composite while curing was developed and tested through Lamb waves analysis. This thin film is now used to monitor the same cure parameters for a shorter curing cycle than that suggested by the CFRP manufacturer. The results show that the three cure parameters: Minimum viscosity, full gelation, and vitrification are offset by the same time deducted from the cycle, highlighting the feasibility of using such technology. To verify the viability of this approach, tensile testing and dynamic mechanical analysis are performed on these composites. Tensile testing results show that the average tensile modulus for the shortened cycle is of similar values if not slightly higher than that of the normal cycle. Dynamic mechanical analysis (DMA) results verify both previous conclusions: Time shift of cure parameters and enhanced mechanical properties of the shortened cycle.

show abstract

Section: Introductionmentioning

confidence: 99%

Assessment of cure cycle shortening for advanced composites via ultrasonics and dynamic mechanical analysis

Mahfoud

Harb

2022

Journal of Reinforced Plastics and Composites

View full text Add to dashboard Cite

show abstract

“…In a similar imageJ application, the manual thresholding method, which is based on trial and error, was used to characterize voids in carbon‐reinforced plastic laminates. Pixels were assigned for the particular class of divisions as of the threshold values 0–75 for void, 76–139 for resin, and 140–255 for the fiber, 47 which can bring much error.…”

Section: Methodsmentioning

confidence: 99%

Characterization of the void content and laminate quality of fiber‐reinforced plastic composites manufactured using the resin spray and compaction method

Zegeye,

Delele,

Tsegaw

et al. 2023

Polymer Composites

View full text Add to dashboard Cite

Void fraction and fiber volume fraction (FVF) are among the most important parameters determining the quality of fiber‐reinforced plastic products. Most of the voids in liquid composite molding–manufactured composites are directly related to the viscous matrix (resin) flow through the porous medium (fiber) during impregnation. In this investigation, a different method, resin spray rather than injection was used to reduce the resin's flow path, which resulted in low void content and higher FVF. The resin was sprayed on the surface of the preform, and compaction was applied to infiltrate the resin towards the thickness. Sample laminates were manufactured, and computer tomography scanning was applied to diagnose void content and laminae quality. The images collected from the scanner were analyzed using ImageJ software. Effects of compaction pressure and compaction speed were characterized. According to the investigation, compaction speed was the key factor in determining a laminate's void content. Only 1.5% void fraction was integrated with a compaction speed of 1 mm/min and a compaction pressure of 100 KPa. On the other hand, compaction speed has less of an impact on a laminate's FVF.Highlights The void fraction of a composite is reduced via the spray and compaction method. Fiber volume fraction is not much affected by compaction speed. Slow compaction speeds minimize void content. Spray compaction is a low‐cost manufacturing method.

show abstract

“…1 However, the main problems with the composites industry that limit the fabrication are the long curing cycles and post-cure processing and finishing requirements when compared to traditional metal materials. 2 These curing cycles are often provided by the manufacturers with an unwanted large safety factor that if reduced, can lead to faster manufacturing of CFRPs which innately makes them more popular with many industries. 3 Hence, the need for advanced methods to monitor and evaluate the curing process of carbon fiber composites is growing.…”

Section: Introductionmentioning

confidence: 99%

Numerical lamb wave modeling and analysis for cure cycle shortening of carbon fiber composites

Mahfoud

Harb

2023

Journal of Composite Materials

View full text Add to dashboard Cite

Advanced carbon fiber composites are renowned for their great tenacity as, although being thin, they provide great strength, keeping structures light in weight. The composites industry struggles with longer cure times when compared to other traditional material production. In this study, a computational model for a carbon fiber reinforced polymers (CFRP) plate is developed to imitate experimental monitoring of its cure cycle and degree of cure. The CFRP storage modulus is measured during the curing cycle with the aid of dynamic mechanical analysis, and its trend is incorporated into COMSOL combined structural and electrostatics multiphysics to replicate the same mechanical fluctuations during oven curing. Then, Lamb waves are excited and sensed via sandwiched piezoelectric transducers in a reusable Polytetrafluoroethylene sensing film to monitor the structural health of the structure. Minimum viscosity, gelation and vitrification are cure parameters observed from analyzing voltage and velocity curves of the A0 mode of the sensed signal. The cure cycle is trimmed, and the same cure parameters are shown offset by the 1 h deducted, proving that the numerical model is valid. Further analysis of the numerical voltage and velocity curves suggests an additional cure parameter defined as “gelation initiation” when compared directly to the experimental trends. Additionally, the decomposition of different wavefield modes is scrutinized to describe their scattering throughout the layered structure. Results show a new entrapped antisymmetric mode appearing inside the CFRP laminate at the start of the cure, which suggests that the previously studied A0 mode had been initially converted from the CFRP S0 mode.

show abstract

Porosity analysis of carbon fibre-reinforced polymer laminates manufactured using automated fibre placement

Cited by 24 publications

References 27 publications

Assessment of cure cycle shortening for advanced composites via ultrasonics and dynamic mechanical analysis

Assessment of cure cycle shortening for advanced composites via ultrasonics and dynamic mechanical analysis

Characterization of the void content and laminate quality of fiber‐reinforced plastic composites manufactured using the resin spray and compaction method

Numerical lamb wave modeling and analysis for cure cycle shortening of carbon fiber composites

Contact Info

Product

Resources

About