Mechanical and vibrational study of raw and surface‐treated ramie fiber hybridized carbon fiber epoxy composites

Abstract

AbstractHybrid polymer composites' lightweight, biodegradability, damping, and cost‐effectiveness have made them popular in recent decades. This study evaluated the raw and alkali‐treated hybrid composite's free vibration studies and mechanical properties by changing the ramie fiber layers (core) from two to four and keeping the carbon fiber layers (top and bottom) constant. Thus, to enhance the mechanical properties, the ramie fiber was treated prior with 2, 3, and 4 wt% of sodium hydroxide (NaOH). These composites were characterized chemically, mechanically, morphologically, and vibrationally via Fourier transform infrared spectroscopy, flexural and tensile tests, field emission scanning electron microscope, and free vibration setup, respectively. The tensile and flexural samples were loaded under quasistatic conditions and tested at 1 and 2 mm/min to evaluate tensile and flexural properties, respectively, and a free vibration test built the natural frequencies and reliable damping factor using clamped‐clamped and clamped‐free boundary conditions. Two layers of carbon fiber (exterior layer) and two layers of ramie fiber (core layer) at 3 wt% NaOH produced maximum tensile strength (523 MPa) and flexural modulus (68,869 MPa) among natural and hybrid composite combinations. This study shows that hybridization and alkaline treatment improve composite material mechanical properties in a specific ratio.Highlights Mechanical and vibration analysis of carbon/ramie hybrid composites was studied. Ramie fiber's surface treatment was carried out in NaOH at 2, 3, and 4 wt%. Surface treatment uplifts mechanical and vibration properties than untreated. Ramie fiber's chemical consequences were analyzed through Fourier transform infrared spectroscopy and field emission scanning electron microscope tests. Surface treatment at 3 wt% builds higher mechanical and vibrational properties.