|
|
|
Slide presentation general
|
|
Braids in history
|
|
|
|
New trends
|
|
|
|
Kumihimo groups
|
|
|
Engineering application
|
|
| Each presentation comprises 15-minute talk and 5-minute discussion using PowerPoint
or equivalent slide-show software. |
|
|
Equipment
|
A PC with a Windows XP/Vista and a Macintosh OS X are available.
Number of pixel of the projector in the Center Hall is 1024 x 768 (XGA) |
|
|
Media of your PowerPoint file
|
･USB flash memory (recommended)
･CD-R
･Transfer via Internet using e-mail (less than 2MB), free
file transfer service (less than 100 MB) (recommended).
No other media is acceptable. |
|
| Engineering Applications |
Chairperson: Asami Nakai
|
|
| Muratec Braiders for Produce of Carbon Fiber Reinforced Plastics |
Tadashi Uozumi
|
9:45-10:05
|
|
Carbon fiber reinforced plastics (CFRP) are used in the advanced industrial field
like aircraft, aerospace, racing car as formula 1 due to its character of ultra lightness
and high strength. However, in the most production process of CFRP there remains
manual procedure that relayed on the personal experience in quality. Therefore it
is required to develop new production process to supply CFRP as the industrial products.
Braiding is one of the textile techniques for fabricating performs of CFRP. The braided
CFRP indicates superior mechanical properties, as reinforcing fibers in a braid are
oriented continuously without cutting them. It was reported that the braided composites
indicated the high joint strength and high impact absorption. The other advantage
of the braiding is the flexibility of the design of the rigidity distribution. However,
to produce the braided CFRP as the industrial products, the production by the conventional
batch method is not practical and it is required to develop the new commercial production
method. My presentation describes our automatic production system based on braiding
technology. |
| Development of Braided Pultrusion Process |
Yoshihiro Takai et al.
|
10:05-10:25
|
|
Pultrusion process is one of the composite production methods to be suitable for
mass production. A continuous production with uniform cross sections is maintained
by using this process. However, there is little research for pultrusion of continuous
fiber reinforced thermoplastic composites (CFRTP). Thermoplastic resin has so high
melt viscosity that it is difficult to impregnate into the reinforcing fiber bundles.
In these surroundings, we have developed Micro-braided yarn, in which the matrix
resin fiber bundles are braided by tubular braiding machine on a reinforcement fiber
bundle. Since the resin fiber bundles are directly in contact with a reinforcing
fiber bundle, the melted thermoplastic resin could easily impregnate into the reinforcing
fiber bundles.
In this study, braided pultrusion products of continuous carbon fiber reinforced
polyamide6,6 composites (CF/PA66) were fabricated by connecting the braiding machine
to pultrusion machine. We called this process Braiding Pultrusion Process for Thermoplastics
ﾒBPP-TPﾓ. We made braided thermoplastic rod by this process, and the impregnation
state and mechanical properties were investigated. |
| Fabrication and Mechanical Properties of Braided Composite Tube |
Akio Ohtani et al.
|
10:25-10:45
|
|
Braided fabric proves useful as the reinforcements of fiber reinforced composite
materials because of the following features; one of the important features is continuity
of the fiber bundle in the braided fabric and this results in higher mechanical properties.
Other characteristic is capability of changing the braiding angle according to the
requirements. There are many parameters which decide the internal structure and mechanical
properties of braided composite such as braiding angle, the distance between braiding
yarns, and the cross-sectional shape of braiding yarn. The difficulty arises in that
these parameters are not independent value and have the interrelationship with each
other.
The purpose of this study is to clarify the relationship between the internal structure
and mechanical properties for carbon fiber braided composite circular and rectangular
tube. Carbon fiber reinforced braided composite tubes, with different fiber bundle
orientation angle (called ﾒBraiding angleﾓ), were fabricated. The cross-section along
the braided fiber bundle of the composite was observed and the parameters of the
internal structure, that is braiding angle, distance between fiber bundles, and shape
of the fiber bundle cross-section (aspect ratio and area of the fiber bundle), were
quantified. The bending test was performed for each specimen, and the relationship
between the internal structure and the bending properties was clarified. And more,
the theoretical analysis were performed by considering the internal structural parameters. |
| Crushing Performance of 3D Braided Composite Tubes |
Y. Yang et al.
|
10:45-11:05
|
|
| The energy absorbing performance of braided composite tube with rectangular cross-section
is studied in this paper. The tubes, which fabricated by 3D rotary braiding machine
were quasi-statically compressed and the crush zones were examined microscopically.
Their crushing performance and energy absorption capabilities were compared with
that which fabricated by traditional 2D braiding machine in order to evaluated the
effect of the 3D braided texture. It was found that the differences of crushing behavior
are concentrated on the differences of the length of propagated longitudinal central
cracks. Therefore, here, crack area is proposed as a new parameter for square FRP
to evaluate the effect on the energy absorption capability. For the braided tubes
fabricated by 2D braiding machine, the crack area was getting smaller and smaller
with the increasing of braiding angle from 25 to 60. On the other hand, the tubes
fabricated by 3D rotary braiding machine obtained higher Es values compared with
that fabricated by 2D braiding machine, specially, for those tubes with a small braiding
angle. Because the braiding yarns go across through the thickness direction to restrain
the crack propagation effectively, as a result, high bending stresses are generated
which lead to many fiber fractures and contribute to the total absorbed energy greatly. |
|
