Effect of Hybridization on Open-Hole Tension Properties of Woven Kevlar/Glass Fiber Hybrid Composite Laminates

Abstract

Hybrid laminates consisting of woven Kevlar/glass fiber composite plies were studied in terms of their residual tensile strength, stiffness and fracture surface. Residual tensile strength and stiffness were determined from the open hole tension test according to ASTM D5766. The laminates of Kevlar fiber reinforced polymer (KFRP), glass fiber reinforced polymer (GFRP) and hybrid of Kevlar-glass fiber reinforced polymer (KGFRP) were fabricated using a vacuum bagging process. Three different ratios of Kevlar to glass fiber plies were prepared in this study which were 20:80, 50:50, and 80:20. Results showed that hybrid laminate consisting of 80:20 Kevlar to glass fiber plies, produced higher residual tensile strength and stiffness when compared to the other hybrid system. Furthermore, strength and stiffness of hole specimens were reduced within 50-63% when compared to unhole specimens due to existence of the hole. In addition, the effect of adding nanosilica to the hybrid system was also studied. 5 wt% of nanosilica was added to the hybrid composite laminates and results showed that higher tensile strength and stiffness was observed in GFRP and 20:80 KGFRP specimens, while the tensile strength was decreased with an increased number of Kevlar fiber. This research was conducted as there are limited number of studies that have been done on the tensile strength of woven hybrid composite laminates so far, especially on hybridization of Kevlar and glass fiber with consideration on the effect of hole and addition of nanofillers.

Enhanced Open-Hole Strength and Toughness of Sandwich Carbon-Kevlar Woven Composite Laminates

“…The scenario with the open hole is the topic of this research. Research into the open hole of hybrid composite laminates has been one of the recent focuses [ 19 , 20 , 21 , 22 , 23 ].…”

“…A study by Guled and Chittappa [ 30 ] into hybrid CF/Kevlar/Epoxy laminates concluded that using CF laminate on the outer skin enhances the interlaminar shear strength of the overall laminate. Shaari et al [ 20 , 21 , 23 ] studied the open-hole tension (OHT) test for Kevlar/glass fiber (GF)/epoxy fiber hybrid laminate composites for different hybridization ratios, hole sizes, and stacking sequences. The OHT of GF laminates improved due to the existence of Kevlar fiber.…”

The influence of the inter-ply hybridisation on the mechanical performance of composite laminates: Experimental and numerical analysis

“…Despite the popularity of the glass fibre reinforced polymer composites (GFRP ) use in aircraft and aerospace engineering industries, for a long time due to their high specific strength-to weight ratio, non-corrosive properties and have a very low strain-to-failure. 1 – 4 Accordingly, this is considered as a disadvantage for using these laminates under a tensile or/flexural loading conditions. 5 Additionally, in civil infrastructures, structural stability is a key factor that maintains a structure to be safe in usage under static or dynamic loading conditions.…”

“… 6 Kevlar has excellent mechanical properties such as high strength with lightweight, thermal stability and good resistances to abrasion resulting in wide use in aerospace, military applications, protective apparel and marine industry. 3 , 7 , 8 However, the major limitation for using them in the different sectors are their weaknesses in tensile, compression and bending loading. 9 One possible way to achieve better performance is by adopting a hybrid composite that is made up of two or more different fibres or resins.…”

Notch-sensitivity of hybrid carbon-fibre/self-reinforced polypropylene composites

“…Hybrids comprising of continuous aramid/glass [25], and glass/carbon [26] fibre weaves can be optimised to achieve higher net strength retention than the nominal non-hybrid composites. Czél et al [27] investigated notch sensitivity of carbon/carbon pseudoductile hybrids.…”