Collapsed Mode and Specific Energy Absorption of Glass Filled Polypropylene (GPE) and Glass Filled Polyethylene (GPP) Composite Pipes under Quasi-Static Axial Loading

Abstract:

–The behaviour of extruded glass fibre reinforced thermoplastic pipe under axial crushing load was investigated experimentally. It was envisaged that the difference between the axial and hoop moduli and strengths as well as the volume fraction would influence the mode of collapses and energy absorption. The moduli could be varied using a new extrusion technology, which controls the fibre orientation pattern, hence, the mechanical properties. The ability to vary the moduli and the fibre volume fraction provide means of controlling the collapse mode in order to optimise specific energy absorption. Axial compression tests were performed on glass filled Polypropylene and Polyethylene composite pipes. The samples were chosen with a variety of fibre volume fraction, V_f = 5% to 20% and average angle of orientation, θ = 50^o to 80^o to evaluate the effect of anisotropy and V_f on the energy absorption capacity and collapse modes. The observations indicate that, the samples containing of higher V_f and θ, collapsed in brittle failure mode (fragmentation), while those with less V_f and θ angle collapsed in non-axis-symmetric (diamond) mode with local fracture. The galss fillet with polypropylene-60^o (GPP-60) displayed the highest specific energy absorption (E_s) compared to the other GPE, MDPE and LDPE pipe samples. However, the glass fillet polyethylene – 75^o (GPE-75) displayed the highest E_s and the glass fillet polyethylene – 65^o (GPE-65) displayed the lowest E_s compared with in the GPE pipes. The specific energy absorption of GPP-70 pipe (24 kJ/kg) and GPE-75 pipe (12 kJ/kg) is almost 50 % and 25% of the amount of specific energy absorption of aluminium tubes (60 kJ/kg), respectively. Moreover, it is close to the specific energy absorption of glass-epoxy 15^o (GE-15) / which is 30 kJ/kg, and much higher than aramid-epoxy-15^o (AE-15)/ which is 9 kJ/kg.

• Periodical: Key Engineering Materials (Volume 673)
• Pages: 141-149
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.673.141
• Online since: January 2016
• Authors: H.H. Ya*, H. El-Sobky
• Keywords: Collapse Mode, Crushing Performance, Energy Absorption, Fiber Orientation, GPE Composite Pipe, GPP Composite Pipe, Specific Energy Absorption, Volume Fraction

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