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Paper Title Page
Abstract: Fatigue fracture behavior of a hybrid composite joint with riveting was evaluated in
comparison to the case of static fracture. Hybrid composite joint specimens for shear test were made
with layers of carbon fiber/epoxy composite and stainless steel. Characteristic fracture behaviors of
those specimens were obviously different under static and cyclic loads. Static shear loading showed
the fracture of a pure shear mode, whereas cyclic fatigue-shear loading caused the local stress
concentration of a tensile mode and thus brought about the tensile fracture at that site. Experimental
results obtained by static and fatigue tests were considered in modifications of design parameters of
the hybrid joint.
1757
Abstract: The concept of light weight design will be very helpful for the tilting train to travel
around a curve at a faster speed because the light weight car body makes the center of gravity
lower. The impact characteristics of composite materials should be investigated because the impact
property of composites is very important. This paper investigates the low-velocity impact
characteristics and residual strength conducted on honeycomb sandwich panels. Low-velocity
impact tests were carried out at different energy levels on honeycomb sandwich panels using a
drop-weight apparatus. The impact-induced damages such as fiber breakage, matrix crack and
delamination are examined with an optical microscope apparatus. Residual strength was evaluated
by applying three point bending load to honeycomb sandwich panels. Experimental results show
that the residual strength is greatly reduced as the impact energy increases. From the microscopic
observation data, matrix crack, fiber breakage and delamination are the main impact damages of
honeycomb sandwich panels.
1761
Abstract: The dynamic instability behavior of delaminated composite plates under transverse
excitations was investigated experimentally and analytically. An electromagnetic device, acting like
a spring with alternating stiffness, was used to parametrically excite the delaminated composite
plates transversely. An analytical method, combined with the finite element method, was used to
determine the instability regions of the delaminated composite plates based on the modal
parameters of the composite plate and the position, the stiffness of the electromagnetic device. The
delamination size and position of composite plates were varied to assess their effects on the
excitation frequencies of simple and combination resonances in instability regions. The
experimental results were found to agree with the analytical ones.
1765
Abstract: A micro mechanical study of Carbon/Epoxy composites with internally dropped plies has
been made using micro-moiré interferometry. The experimental results show that there is a stress
concentration region before the dropped ply. Micro cracks were initiated and propagated in this
region. Two failure mechanisms in the dropped ply region were observed.
1769
Abstract: Progressive failure analysis based on the complete unloading method was conducted to
investigate the crippling failure of carbon/epoxy composite stiffeners under axial compression. A
modified arc-length algorithm was incorporated into a nonlinear finite element method to trace the
equilibrium path after local buckling. For the validation of the finite element method, several
carbon/epoxy Z-section stiffeners were tested in compression. The finite element results on the
buckling and crippling stresses showed good agreement with the experimental results.
1773
Abstract: As these composites have become more popular, composite joint design has become a
very important research area, as these joints are often the weakest parts of composite structures. In
this paper, the strength of a composite laminated bolted joint being subjected to a clamping force
was tested and predicted using the FAI (Failure Area Index) method. The strengths of composite
joints subjected to clamping forces on different geometric shapes and dimensions were predicted
using the FAI method, and the results were compared with experimental results. From the tests and
analyses, the strength of a given composite laminated bolted joint subjected to a clamping force
could be predicted within 22.5% via the FAI method.
1777
Abstract: Geomechanics model test can simulate the real excavation process of geotechnical
engineering and the mechanics deformation properties of the rockmass prototype on the condition
of meeting the similar principles. In order to conducting geomechanics model test, similar
material which can meet similar mechanical properties must be used. It is only after conducting a
massive mechanics experiments that a new-type similar materials called iron crystal sand is
developed in this paper. This material consists of iron ore powder, blanc fix, quartz sand, gypsum
powder and rosin alcohol solution which are evenly mixed in certain proportion and pressed
together. The iron ore powder, blanc fix and quartz sand among them are main materials. The
rosin alcohol solution is the cementing agent and gypsum powder the regulator. The material
mechanics experiments show that this material has following outstanding characteristics: high
volume-weight, wide variable mechanical parameters, stable performance, low price, quick
drying, simple processing and innocuity. It can simulate most rockmass material from soft to hard
ones and can be widely used in geomechanics model tests in fields of energy sources,
transportation, water conservancy and mining.
1781
Abstract: Polymeric carbon nanotube composites constitute one of the most promising alternatives
to conventional filled polymers. The dispersion of nanometer-sized carbon nanotubes in a polymer
matrix markedly improves its physical properties. This approach can also be applied to
biodegradable synthetic aliphatic polyesters such as poly(L-lactic acid) (PLLA), which has been
receiving an increasing amount of attention due to environmental concerns. In this study, the
mechanical properties of PLLA were enhanced by the incorporation of a small amount of carbon
nanotubes (0.8 wt%) in the solution state, which could make this material a good competitor for
commodity materials such as general purpose plastics, while allowing it to retain its
biodegradability. In order to obtain a homogeneous dispersion of the carbon nanotubes in the
matrix, oxygen-containing groups were introduced on the surface of the MWNTs. The good
dispersion of the nanotubes in the PLLA matrix observed by scanning electron microscopy was
attributed to the fact that the PLLA was compatible with the functionalized MWNTs during the
compounding process. The electrical conductivity of the composites was also investigated.
1785
Abstract: Carbon/phenolic composite (CPC) materials have obvious advantages over conventional
materials, which are consisting of carbon fibers embedded in a carbon matrix. The CPCs have
become to be utilized as parts of aerospace applications and its low density, high thermal
conductivity and excellent mechanical properties at elevated temperatures make it an ideal material
for aircraft brake disks. Because of permeation of coupling medium such as water, it is desirable to
perform contact-less nondestructive evaluation to assess material properties and part homogeneity.
In this work, a C/P(Carbon/phenolic) composite material was characterized with non-contact and
contact ultrasonic methods using automated acquisition scanner. Also through transmission mode
was performed because of the main limitation for air-coupled transducers, which is the acoustic
impedance mismatch between most materials and air. Especially ultrasonic images and velocities
for C/C(Carbon/Carbon) composite disk brake was measured and found to be consistent to some
degree with the non-contact and contact ultrasonic measurement methods. Low frequency throughtransmission
scans based on both amplitude and time-of-flight of the ultrasonic pulse were used for
mapping out the material property inhomogeneity. Measured results were compared with those
obtained by the motorized system with using dry-coupling ultrasonics and through transmission
method in immersion. Finally, results using a proposed peak-delay measurement method well
corresponded to ultrasonic velocities of the pulse overlap method.
1789
Abstract: This paper deals with the damage behavior of glass/epoxy composite laminates subjected
to low-velocity impact at various temperatures. For this goal, the impact tests were performed by
using an instrumented impact-testing machine at three temperatures: +20°C, -10°C and -40°C. And
the resultant damages were inspected through the scanning acoustic microscope (SAM). Also, based
on the impact force history and the damage configuration of the laminates, the impact resistance
parameters were employed to evaluate damage resistance of glass/epoxy laminates. As results, it
was found that the temperature changes affect the damage resistance capacity of glass/epoxy
laminates.
1793