Effect of Holes and Defects on Flexural Strength and Fracture Toughness of GFRP Composite under Three-Point Bending

Abstract:

The glass fiber reinforced plastic (GFRP) composite materials are widely used in industries; these composites are coupled into large structures by drilled holes. In the present investigation, the characteristics of such drilled holes and defects were studied using GFRP composite samples with open-hole (at different positions), half-through holes and epoxy filled holes under three-point bend loading conditions. The “composite with epoxy filled holes” envisages maximum flexural strength, "composite with holes at a depth of 2.5 mm" showed intermediate and "composite with an open hole" exhibited minimum flexural strength. However, the flexural strength of the "composite" was increased when the relative distance between the holes was increased. The hypothesis of investigating the effect of defects in the form of Teflon exhibited significant results. The flexural strength was minimum in the case of multiple defects, however, it showed maximum fracture toughness. It was also observed that if the defect is present only at one end, it exhibited maximum flexural strength and minimum fracture toughness value.

• Periodical: Materials Science Forum (Volume 1068)
• Pages: 11-18
• DOI: https://doi.org/10.4028/p-4ezn3l
• Online since: August 2022
• Authors: Pawan Kumar*
• Keywords: Composite, Defects, Flexural Strength, Holes

References

[1] Ryu, Chung-Hyeon, et al. Nondestructive evaluation of hidden multi-delamination in a glass-fibre-reinforced plastic composite using terahertz spectroscopy., Composite Structures 156 (2016) 338-347.

DOI: 10.1016/j.compstruct.2015.09.055

[2] Mohan, N. S., S. M. Kulkarni, and A. Ramachandra. Delamination analysis in drilling process of glass fiber reinforced plastic (GFRP) composite materials., Journal of Materials Processing Technology 186.1-3 (2007) 265-271.

DOI: 10.1016/j.jmatprotec.2006.12.043

[3] Patterson, Brendan A., et al. Influence of temperature dependent matrix properties on the high-rate impact performance of thin glass fiber reinforced composites., Composites Part B: Engineering 192 (2020) 108009.

DOI: 10.1016/j.compositesb.2020.108009

[4] Kumar, Pawan, et al. Effect of Rate of Loading on Jute Fibre-Reinforced Polymer Composite., Transactions of the Indian Institute of Metals (2020) 1-5.

[5] Mufti, Aftab, et al. Durability of GFRP reinforced concrete in field structures., Proceedings of the 7th international symposium on fiber-reinforced polymer reinforcement for reinforced concrete structures (FRPRCS-7), Kansas City, Mo. (2005).

DOI: 10.14359/14898

[6] Yang, Xiao, Yu Bai, and Faxing Ding. Structural performance of a large-scale space frame assembled using pultruded GFRP composites., Composite Structures 133 (2015) 986-996.

DOI: 10.1016/j.compstruct.2015.07.120

[7] Ribeiro, M. C. S., et al. Re-use assessment of thermoset composite wastes as aggregate and filler replacement for concrete-polymer composite materials: A case study regarding GFRP pultrusion wastes., Resources, Conservation and Recycling 104 (2015) 417-426.

DOI: 10.1016/j.resconrec.2013.10.001

[8] Sendeckyj, G. P. Effects of defects in composite structures., (1983).

[9] Senthil, K., et al. Defects in composite structures: Its effects and prediction methods–A comprehensive review., Composite Structures 106 (2013) 139-149.

DOI: 10.1016/j.compstruct.2013.06.008

[10] Pereszlai, Csongor, et al. Drilling fibre reinforced polymer composites (CFRP and GFRP): An analysis of the cutting force of the tilted helical milling process., Composite Structures 262 (2021): 113646.

DOI: 10.1016/j.compstruct.2021.113646

[11] Yao, X. F., et al. Tensile strength and fracture behaviours of complex GFRP composites with a central hole., Journal of composite materials 39.14 (2005) 1247-1260.

DOI: 10.1177/0021998305049054

[12] Afaghi-Khatibi, Akbar, Lin Ye, and Yiu-Wing Mat. An effective crack growth model for residual strength evaluation of composite laminates with circular holes., Journal of Composite Materials 30.2 (1996) 142-163.

DOI: 10.1177/002199839603000201

[13] Eriksson, Ingvar, and Carl-Gustaf Aronsson. Strength of tensile loaded graphite/epoxy laminates containing cracks, open and filled holes., Journal of composite materials 24.5 (1990): 456-482.

DOI: 10.1177/002199839002400501

[14] Backlund, Jan, and Carl-Gustaf Aronsson. Tensile fracture of laminates with holes., Journal of Composite Materials 20.3 (1986) 259-286.

DOI: 10.1177/002199838602000304

[15] Khashaba, U. A. Fracture behaviour of woven composites containing various cracks geometry., Journal of composite materials 37.1 (2003) 5-20.

DOI: 10.1177/0021998303037001679

[16] Garrett, R. A. Effect of defects on aircraft composite structures. Mcdonnell Aircraft Co St Louis Mo, (1983).

[17] Woigk, Wilhelm, et al. Experimental investigation of the effect of defects in Automated Fibre Placement produced composite laminates., Composite Structures 201 (2018): 1004-1017.

DOI: 10.1016/j.compstruct.2018.06.078

[18] Wickramasinghe, Sachini, Truong Do, and Phuong Tran. FDM-based 3D printing of polymer and associated composite: A review on mechanical properties, defects and treatments., Polymers 12.7 (2020) 1529.

DOI: 10.3390/polym12071529

[19] Padmanabhan, K., and Kishore. Influence of circular defects on the flexural strength of Kevlar/epoxy composites., Journal of reinforced plastics and composites 11.2 (1992) 211-219.

DOI: 10.1177/073168449201100207