Studies on effect of pre-crack length variation on Inter-laminar fracture toughness of a Glass Epoxy laminated composite

Abstract

Abstract. Laminates of fiber reinforced polymer composites are good in in-plane properties and inherently weak in through thickness direction. To address this through thickness properties, the inter-laminar fracture toughness (G Ic and G IIc ) of a unidirectional (UD) Glass epoxy composite laminates were subjected to Mode-I and Mode-II loadings. Experiments were conducted using Double cantilever beam (DCB) and End notch flexure (ENF) specimens with varying pre-crack lengths. Mode I energy release rate (G Ic ) were also evaluated with modified beam and modified compliance theories. The experimental results reveal that, G Ic fracture toughness increases with increasing in pre-crack length, where as in G IIc the effect of increase in pre-crack length exhibits reduced fracture toughness.

Mode I fracture toughness of Carbon/glass hybrid comopsite

“…Damage deformation mechanisms are instrumental in redistributing the overstresses around the notch; therefore, improving their fracture behavior [5][6][7]. In addition, various specimen types such as compact *Corresponding Author Institutional Email: eng_mahmoudsamir@yahoo.com (M. S. EL-Wazery) tension specimens (CTS), end notch flexure (ENF) specimens and single edge notch bending (SENB) were used to evaluate the mode-I fracture toughness [8][9][10]. Jung and Kim [11] investigated the fracture toughness of carbon-glass/epoxy hybrid composites after fabricate by using vacuum assisted resin transfer molding and found that the fracture toughness reduced with increasing in glass fiber content.…”

Evolution of the strain energy release rate during ductile or brittle failure in woven‐ply reinforced thermoplastic laminates under high temperature conditions

“…There are a few studies in the literature dealing with the effect of precrack length variation on fracture toughness of fibers‐reinforced laminated composites . By means of experiments conducted on Double cantilever beam and End notch flexure specimens with varying precrack lengths, the mode I and mode II energy release rates ( G Ic and G IIc ) can be evaluated in polymer‐based composites laminates . The experimental results reveal that, G Ic fracture toughness increases with increasing precrack length, whereas the effect of increase in precrack length exhibits reduced fracture toughness G IIc of UD glass‐fibers reinforced composites .…”

“…By means of experiments conducted on Double cantilever beam and End notch flexure specimens with varying precrack lengths, the mode I and mode II energy release rates ( G Ic and G IIc ) can be evaluated in polymer‐based composites laminates . The experimental results reveal that, G Ic fracture toughness increases with increasing precrack length, whereas the effect of increase in precrack length exhibits reduced fracture toughness G IIc of UD glass‐fibers reinforced composites . The influence of crack length and delamination width on the mode‐III energy release rate of laminated composites has also been investigated in the case of UD glass fibers reinforced polyester laminates .…”

Mode I Interlaminar Fracture Toughness and Fractographic Observation of Multidirectional Carbon Fiber/Epoxy Composites

“…Regarding interlaminar fracture behavior, a number of studies in which various specimens were tested have been reported recently. Huddar et al [8] reported the effect of initial crack length on mode I interlaminar fracture toughness of glass fiber/epoxy laminated composites. They observed that the interlaminar fracture toughness at crack initiation increased with increasing initial crack length.…”