Key Engineering Materials
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Vols. 368-372
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Vol. 367
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Vols. 359-360
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Key Engineering Materials
Vols. 353-358
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Vol. 352
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Vols. 348-349
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Vol. 347
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Key Engineering Materials
Vols. 345-346
Vols. 345-346
Key Engineering Materials Vols. 353-358
Paper Title Page
Abstract: A material mixing method to obtain an optimal topology for a structure in a thermal
environment was suggested. This method is based on Evolutionary Structural Optimization (ESO).
The proposed material mixing method extends the ESO method to a mixing several materials for a
structure in the multicriteria optimization of thermal flux and thermal stress. To do this, the
multiobjective optimization technique was implemented. The overall efficiency of material usage
was measured in terms of the combination of thermal stress levels and heat flux densities by using a
combination strategy with weighting factors. Optimal topologies having multiple thermal criteria
for a printed circuit board (PCB) substrate were presented to illustrate validity of the suggested
material mixing method. It was found that the suggested method works very well for the
multicriteria topology optimization.
2832
Abstract: An active micro-mixer equipped with an oscillating stirrer is considered by analyzing the
mixing behaviors, i.e. the effect of the Karman vortex, the flow structure after the stirrer, etc. The
mixing was calculated by the D2Q9 model of Lattice Boltzmann methods. In this study, the time–
averaged mixing index formula, I D , is newly proposed for time dependent flow. Three models are
tested and the mixing indices are compared. From the results, it was found that the mixing of Model
III is enhanced and stabilized much more than the other models. Therefore, an optimum design for a
dynamic micro-mixer with an oscillating stirrer was performed. The design variables were
established as the length, the angle and frequency of the stirrer. It is found that the optimal design
variables are determined by 0.66, 107.9 o and 0.49 Hz.
2836
Abstract: Sufficient workspace and high natural frequency of a micromanipulator are the
fundamental requirements in its design. In this study, a previous design was analyzed from the
viewpoint of the axiomatic design. Then, a new design parameter as displacement amplifier which
transforms a coupled design into a decoupled design, was suggested. And a design procedure based
on axiomatic design was developed. A planar 3-DOF parallel-type micromanipulator was chosen as
an exemplary device. According to the suggested design procedure, the micromanipulator having
the required natural frequency was designed in the first step, and then the displacement amplifier
satisfying the required work space was designed sequentially. To check the effectiveness of the
manipulator and displacement amplifier, simulations and experiments were performed. Those are
verified that the displacement amplifiers implemened work very well for satisfying the required task
workspace.
2839
Abstract: The micromanipulator is basically required sufficient workspace and high natural
frequency. However, previous designs are hard to satisfy the required workspace and natural
frequency simultaneously. In this study, a previous design was analyzed from the viewpoint of the
axiomatic design. Then, a new design parameter as displacement amplifier which transforms a
coupled design into a decoupled design, was suggested. And a design procedure based on axiomatic
design was developed. A spatial 3-DOF parallel-type micromanipulator was chosen as an exemplary
device. According to the suggested design procedure, the micromanipulator having the required
natural frequency was designed in the first step, and then the displacement amplifier satisfying the
required work space was designed sequentially. To check the effectiveness of the manipulator and
displacement amplifier, simulations and experiments were performed. Those are verified that the
displacement amplifiers implemened work very well for satisfying the required task workspace.
2843
Abstract: Topology optimization of the inner reinforcement for a vehicle’s hood has been
performed by evolutionary structural optimization (ESO) using a smoothing scheme. The purpose of
this study is to obtain optimal topology of the inner reinforcement for a vehicle’s hood considering
the static stiffness of bending and torsion, and natural frequency simultaneously. To do this, the
multiobjective optimization technique was implemented. Optimal topologies were obtained by the
ESO method. From several combinations of weighting factors, a Pareto-optimal solution was
obtained. Also, a smoothing scheme was implemented to suppress the checkerboard pattern in the
procedure of topology optimization. As the weighting factor of the elastic strain efficiency goes
from 1 to zero, it is found that the optimal topologies transmits from the optimal topology of static
stiffness problem to that of natural frequency problem. Therefore, it is concluded that ESO method
with a smoothing scheme is effectively applied to topology optimization of the inner reinforcement
of a vehicle’s hood considering the static stiffness and natural frequency.
2847
Abstract: The FEM was used to analyze the stress distribution of a motorcycle frame on the condition
of normal running, starting up, turning and braking, respectively. Having been carrying on the
2000km of running test, the initial design motorcycle frame was found several cracks or fractures in
the bending points of the square tube and in the welding seam, whose reasons were analyzed then. The
metallographical structures of materials and crack parts of the frame were observed and analyzed and
Q235. Based on the results mentioned above, the Q345 steel(Chinese steel mark) was used to replace
the Q195 steel in the bending square tube and the prop of the steering column. And the welding and
manufacture processes were optimized and improved. Finally, the motorcycle frame whose materials
had been optimized could keep running in good condition and satisfy the demands after 16000km of
running test.
2851
Abstract: Since most marine engines are generally very huge and heavy, it is required to keep
safety from accidents in dealing them. Several types of lifting lugs have been used to assemble
hundred ton–large steel structures and carry the assembled engines. Recently a few crashes have
been occurred in carrying engines due to breaking down the lugs. Although the stability evaluation
of the lifting lug has therefore been very important for safety, systematic design procedure of the
lugs, which includes the structural analysis considering stability, has few reported. This paper
describes the three dimensional finite element structural modeling for a lifting lug, the studies for
determining the reasonable loading and boundary conditions, and the stability evaluation with the
results of structural analyses. It should be very helpful for designing the other types of lifting lugs
with safety.
2855
Abstract: Fatigue fracture behavior of a hybrid joint part for the tilting car body was evaluated in
comparison to the case of static fracture. The specimens of hybrid joint part applied in the real
tilting car body were fabricated for the bending test. Characteristic fracture behaviors of hybrid joint
part specimens under cyclic loads were obviously different from the case under static loads. Static
bending load caused the shear deformation and fracture in the honeycomb core region, while cyclic
bending load did the delamination along the interface between composite skin and honeycomb core
layers as well as the fracture of welded joint part. Experimental results obtained by static and
fatigue tests were reflected in modifications of design parameters of the hybrid joint structure in the
real tilting car body.
2860
Abstract: Coolant rubber hoses for automobile radiators under thermal and mechanical loadings can
be degraded and thus failed due to the influences of contacting stresses of air, coolant liquid and to the
locally formed electricity. In this study, degradation behavior of the radiator hose made of EPDM
rubber was evaluated. The thermo-oxidative aging test showed that the surface hardness IRHD of the
rubber increased together with a reduction of failure strain. By the electro-chemical test it was shown
that the penetration of coolant liquid into the skin of the rubber hose arose inducing an increase in
weight of specimens as well as a decrease in failure strain and IRHD hardness. The penetration of
coolant liquid altered considerably the micro-structure and the micro-hardness distribution along the
depth in the rubber hose. On the basis of the above results failure mechanisms of degraded EPDM
rubbers were suggested according to the kinds of contacting stresses.
2864
Abstract: In this paper, a speckle microinterferometric system was employed to study the thermal
deformation of the Cu microbridges with different dimensions. The deflections of the microbridges
caused by the thermal loading were measured with real-time by the speckle microinterferometric
system and the surface temperatures of the bridges were recorded using a digital thermometer. The
deformation evaluation after microbridges buckling was also recorded with our testing system. Then,
the experimental results were compared with the finite element analysis (FEA).
2871