Abstract: A composite material with carbon fiber and polymer
matrix has been used as adherent for manufacturing adhesive joints.
In order to evaluate different fiber orientations on joint performance,
the adherents with the 0°, ±15°, ±30°, ±45° fiber orientations were
used in the single lap joint configuration. The joints with an overlap
length of 25 mm were prepared according to the ASTM 1002
specifications and subjected to tensile loadings. The structural
adhesive used was a two-part epoxy to be cured at 70°C for an hour.
First, mechanical behaviors of the adherents were measured using
three point bending test. In the test, considerations were given to
stress to failure and elastic modulus. The results were compared with
theoretical ones using rule of mixture. Then, the joints were
manufactured in a specially prepared jig, after a proper surface
preparation. Experimental results showed that the fiber orientations
of the adherents affected the joint performance considerably; the
joints with ±45° adherents experienced the worst shear strength, half
of those with 0° adherents, and in general, there was a great
relationship between the fiber orientations and failure mechanisms.
Delamination problems were observed for many joints, which were
thought to be due to peel effects at the ends of the overlap. It was
proved that the surface preparation applied to the adherent surface
was adequate. For further explanation of the results, a numerical
work should be carried out using a possible non-linear analysis.
Abstract: This research was to evaluate a technical feasibility of
making single-layer experimental particleboard panels from bamboo
waste (Dendrocalamus asper Backer) by converting bamboo into
strips, which are used to make laminated bamboo furniture. Variable
factors were density (600, 700 and 800 kg/m3) and temperature of
condition (25, 40 and 55 °C). The experimental panels were tested for
their physical and mechanical properties including modulus of
elasticity (MOE), modulus of rupture (MOR), internal bonding
strength (IB), screw holding strength (SH) and thickness swelling
values according to the procedures defined by Japanese Industrial
Standard (JIS). The test result of mechanical properties showed that
the MOR, MOE and IB values were not in the set criteria, except the
MOR values at the density of 700 kg/m3 at 25 °C and at the density
of 800 kg/m3 at 25 and 40 °C, the IB values at the density of 600
kg/m3, at 40 °C, and at the density of 800 kg/m3 at 55 °C. The SH
values had the test result according to the set standard, except with
the density of 600 kg/m3, at 40 and 55 °C. Conclusively, a valuable
renewable biomass, bamboo waste could be used to manufacture
boards.