Mechanical characteristics of groundnut shell particle reinforced polylactide nano fibre

ABSTRACT The PLA-groundnut shell solution is electrospun to produce nanocomposite fibre. The spinneret containing the composite solution was placed 24.7 cm away from the aluminium collector, tilted at an angle of 30 °, and the solution flow rate kept at 1 mL/min. Groundnut Shell particle (GSP) weight fraction used was varied from 3 - 8 wt. %. Particle reinforced nanofibres were formed on the collector from the composite solution at 26 kV. These nanofibres were subjected to tensile test and the result indicates that at 6 wt. % untreated GSP reinforced fibre possessed the best tensile stiffness of 24.62 MPa. This corresponds to 2.201 % increase in Modulus of Elasticity over the unreinforced PLA (1.07 MPa). The 7 wt. % treated GSP fibre showed the least stiffness (0.33 MPa), which is 69 % reduction over that of unreinforced fibre. PLA fibre reinforced with 5 wt. % untreated GSP displayed best blend of properties over the unreinforced with increase of 286 % (4.43 x 10-4 HB), 1,502 % (1.07 MPa), 286 % (0.22 MPa), 6.8 % (0.05 J) and 1,081 % (~ 0.15 MPa) in hardness, stiffness, UTS, energy at break and stress at break respectively. However, ductility decreased by ~33.3 % when compared to the unreinforced (18.27). The 5 wt. % untreated GSP PLA reinforced fibre showed the highest UTS (0.855 MPa). The micrographs showed beads on reinforced fibres, while the virgin PLA showed no beads

Residual strength and damage characterization of repaired glass/epoxy composite laminates using A.E. and D.I.C

In this paper, the effect of introducing different phases of fibre reinforcement in epoxy matrix at the dressed site in adhesively bonded external patch repair for damaged glass/epoxy composites under in-plane compressive loads was investigated. Three repair materials consisting of an epoxy matrix reinforced with either micro sized particulate fibres, chopped short fibres or continuous fibres were used in this study. Since this investigation extensively focuses on the effect of different types of fibre reinforcements on residual compression properties of repaired glass/epoxy composite laminates, the external patches were avoided. Acoustic emission (AE) and digital image correlation (DIC) were utilized to form qualitative and quantitative assessments of the damage progression profile. The compression results illustrate that reinforcing the epoxy adhesive material with glass fibres significantly increased the residual compression strength of repaired glass/epoxy composite specimens. In particular, the use of chopped fibre reinforced adhesive repair material improved the average residual compressive strength by 18.91% in comparison to the specimens conventionally repaired using neat epoxy resin

Effect of water absorption on the mechanical properties of cotton fabric-reinforced geopolymer composites

Cotton fabric (CF) reinforced geopolymer composites are fabricated with fibre loadings of 4.5, 6.2 and 8.3 wt%. Results show that flexural strength, flexural modulus, impact strength, hardness and fracture toughness are increased as the fibre content increased. The ultimate mechanical properties were achieved with a fibre content of 8.3 wt%. The effect of water absorption on mechanical and physical properties of CF reinforced geopolymer composites is also investigated. The magnitude of maximum water uptake and diffusion coefficient is increased with an increase in fibre content. Flexural strength, modulus, impact strength, hardness and fracture toughness values are decreased as a result of water absorption. Scanning electron microscopy (SEM) is used to characterise the microstructure and failure mechanisms of dry and wet cotton fibre reinforced geopolymer composites