Abstract:Milling machines are widely used in the machining
industry and use a rotary cutter to remove material from a stock
piece of material in order to create a finished and fully dimensioned
product. This running machine, along with the process of removing
material from a workpiece, causes several types of vibrations in the
system, which can cause error in obtaining the required tolerances
provided by the designer. An efficient solution is to replace the
machining table, but finding the proper material is difficult. Steel is
the current standard but does not sufficiently reduce the vibrations,
so other materials, such as tungsten and carbon-epoxy composites,
were considered. Tungsten is far too expensive and heavy to use
and replace, making it inefficient. Carbon-epoxy and glass-epoxy
composites prove to be excellent dampers due to the friction
between strands, but recycling and manufacturing composites can
be expensive and potentially bad for the environment if not done
properly. The objective of this project is to create a bio-composite
which will both provide damping to the system and be eco-friendly.
Natural flax fibers were chosen alongside an organic epoxy to
create the composite material, due to their availability and
mechanical properties. The flax-epoxy bio-composite was tested
against aluminum, steel, and glass-epoxy. It proved to be a more
effective damper than aluminum and steel due to its higher
damping ratio and low density, but failed to surpass glass-epoxy
due to the thickness of the flax fabric. In terms of damping ratio
per unit density, flax-epoxy comes close to glass-epoxy and may
even surpass it with thinner plies. |