A Study of Tensile Behavior on Drilling Induced Damage of Hybrid Composite

This report basically discusses the research on a study of tensile behavior on driUing
induced damage of hybrid composite. The drilled holes may cause problems such as
delamination, fiber pull out and interlaminar cracks of the holes. With loading condition,
these problems may affect the performance of the final composite structure hence affect the
mechanical properties of the mechanical parts. This study involves the fabrication 4mm with
55% FVF glass fiber and carbon fiber reinforced polyester. The test alongside with other
mechanical test which includes the drilling operation is performed by using a 5mm HSS drill
bit with 650 rpm, 1300 rpm, 1800 rpm, 2500 rpm spindle speed and 0.05 mm/rev, 0.10
mm/rev and 0.15 mm/rev feed rate. The damages within the hole region are assessed in terms
of damage factor and the surface roughness. Tensile test is executed on the fabricated samples
to determine the tensile properties of drilled and non-drilled samples. The tensile tests are
performed using a Universal Testing Machine Amsler HAIOO. Delamination extension due to
the tensile load, damage factor and surface roughness are gathered and compared for every
sample. Furthermore, microstructure of the samples are analyzed after the tensile test and
reported in this report. The fmdings of this project show that the maximum ultimate tensile
strength of drilled sample is 296.975 MPa meanwhile for the non-drilled the ultimate tensile
strength obtained is 3 72.200 MPa. The results show that the ultimate tensile strength for both
drilled and non-drilled samples have 37.6% difference. The lowest feed rate which is 0.05
mmlrev and 1300 rpm which are the best option in drilling parameter which result in least
damage of the samples and those parameters offer better surface around drilling region.