Abstract:
Fiber Reinforced Composite Materials (FRCPs) are extensively used in aerospace, automotive,
structural and multifunctional applications for its outstanding mechanical properties. However,
adoption of environment friendly FRCPs that are strong and stiff for multifaced applications
are impeded by scarcity of strong natural fibers and compatible biodegradable matrices. Strong
and stiff basalt fibers incorporated with ductile yet strong silk fibers can bring out best of both
fibers when incorporated with biodegradable Polylactic Acid (PLA) matrix. Incorporation of
nanofillers can also augment its energy absorption capacity as well as mechanical properties.
Recent literature shows incorporating high temperatures on fabrication process can degrade
natural fibers such as silk, which can impede full exploitation of its properties. In this work,
composite specimens of 5 different stacking sequences are fabricated via hand layup and
vacuum bagging method, where specimens having alternate layers were further incorporated
with Graphene Nanoplatelets (GNPs) with 3%, 6% and 9% by weight of PLA matrix. Tensile,
flexural, impact, interlaminar shear strength, damping, electrical conductivity and moisture
absorption properties were studied as well as its morphological characteristics. This study
shows that, alternate layers of basalt-silk-PLA composites report highest values of tensile
strength, modulus, interlaminar shear strength, impact energy and flexural strength of 136.54
MPa, 3.42 GPa, 0.484 MPa, 36.842 kJ/m2
and 18.06 MPa respectively. Delamination type
failure dominated in all the tested specimens indicating fiber-matrix as the weakest link in
failure. Incorporation of GNPs at 6%wt. of matrix significantly improved the damping ratio of
tested specimens where ALT-6 has 1.54 times the damping ratio of ALT-0. Specimens were
electrically non-conductive at all loadings of GNPs, because of the inability to form conductive
networks due to agglomeration. The resulting mechanical properties also explains the effect of
fabrication process and effect nanofillers on the interfacial properties of the FRCP. High
strength and energy absorbing materials obtained from this study can be applied in multifaceted
application with minimal environmental impact.
Description:
Supervised by
Dr. Mohammad Ahsan Habib,
Professor,
Department of Production and Mechanical Engineering(MPE),
Islamic University of Technology (IUT)
Board Bazar, Gazipur-1704, Bangladesh
This thesis is submitted in partial fulfillment of the requirement for the degree of Bachelor of Science in Mechanical Engineering, 2024
