Abstract: The stabilized soil is a reinforcement material being applied extensively to civil
engineering and hydraulic engineering. At present, chemical methods are used to improve density and
strength of soil by increasing the state of inter-particles’ contacts and forces among particles or
particle groups. Liquid stabilizer is the chemical reinforcing agent of stabilized soil. The physical and
chemical interaction of reinforcing agent - clay - water affects the reinforcement of soil. The
mechanism of strengthening soil using the Liquid stabilizer had not been clear. In laboratory, many
experiments were carried out in order to study strengthening mechanism of the stabilized soil. From
the result of the test and analysis of its characteristics, we recognized that the reinforcement effect of
the liquid stabilizer is controlled by the mini-structure of the stabilized soil, and strength of the
stabilized soil comes mainly from its mini-structure.
Abstract: We developed a device that makes possible the normal production of low-temperature
plasma under atmospheric pressure. For plasma generation, a radio frequency of rf (13.56MHz) was
used. From the Fourier transform infrared (FT-IR) analysis, the absorption peak of C=O (the carbonyl
group) was observed around 1715 cm-1, and the absorption peak of CH was observed around 2950
cm-1. Of those, from the conclusion that the absorption peak of C=O was proportional to the amount
of CO2 added, we discovered that the C=O carbonyl group originated from the CO2 molecules.
Abstract: Recently, the influence of heat conduction has been considered to be a big problem. Then,
the influence of heat conduction was investigated by the experiment which changed the material,
thickness of the specimen and frequency of a cyclic load. Then, the infrared hybrid method was
developed to separate individual stress components. However, it has the influence by heat
conduction in the infrared stress measuring method. Therefore, an error will arise in the infrared
hybrid analysis. Then, the system which corrects the error by the inverse analysis was developed.
Thereby, the accuracy of the stress intensity factor was able to be raised. Furthermore, the accuracy
of hybrid method considering to heat conduction was discussed in comparison with the 3-D
finite-element analysis and 2-D hybrid method.
Abstract: The displacement obtained from the experiment is including large error and it is
impossible to evaluate the stress and the strain with high accuracy using raw displacement data. The
2-D intelligent hybrid method was applied in order to evaluate the 2-D stress field. In the
infinitesimal deformation within elastic region of steel or an aluminum alloy, the quantity of
displacement is less than 1 pixel, and analysis accuracy deteriorates. We need the system which can
analyze the displacement more exactly in sub-pixel field. Hence, the Newton-Raphson method was
applied after obtaining the displacement at any point of the image. On uniform deformation field,
the infinitesimal strain was estimated with less than 0.01pixels of an error by DIC by taking into
consideration only the 1st deformation gradient in the Newton Raphson method. On nonuniform
deformation near the crack tip, it was estimated with about 0.018pixels error by taking the 2nd
deformation gradient into consideration.
Abstract: In this study, singular stress fields at the ends of fibers are discussed by the use of models of
rectangular and cylindrical inclusions in a semi-infinite body under pull-out force．The body force
method is used to formulate those problems as a system of singular integral equations where the
unknown functions are densities of the body forces distributed in a semi-infinite body having the same
elastic constants as those of the matrix and inclusions.Then generalized stress intensity factors at the
corner of rectangular and cylindrical inclusions are systematically calculated with varying the elastic
ratio, length, and spacing of the location from edge to inner of the body. The effects of elastic modulus
ratio and aspect ratio of inclusion upon the stress intensity factors are discussed.
Abstract: Free-edge stress singularity usually prevails at the edge of the interface of the bonded
dissimilar materials. When two materials are bonded by using an adhesive, an interlayer develops
between two materials. An interlayer may inserted between two materials to defuse the residual
stress due to the difference in the coefficients of thermal expansion.
In this study, to investigate the effect of the interlayer on the free-edge stress singularity of the
bonded dissimilar materials with an interlayer, the stress distributions on the interface were
examined numerically and theoretically. Relation between the free-edge stress singularity of the
bonded dissimilar materials with and without an interlayer was investigated by using the boundary
element method. It was found that the effect of the interlayer on the stress distribution was limited
within a small area of the order of the interlayer thickness. Stress distributions near the edge of the
interface were controlled by the free-edge stress singularity of the bonded dissimilar materials
without an interlayer.
Abstract: On the human-rifle system, the human body is affected by the firing impact. The firing
impact will reduce the firing accuracy and change the initial shooting posture. Therefore the study of
biomechanical characteristics using human-rifle modeling and numerical investigation is needed. The
muscle-skeleton model was developed by the finite element method using beam and spar elements. In
this study, a structural analysis has been performed in order to investigate the human body impact by
firing a 5.56mm small caliber machine gun. The firing experiments with a standing shooting posture
were performed to verify analytical results. The result of this study shows analytical displacements of
the human-rifle system and experimental displacements of real firing. In the results, the analytical
displacement on the human body is presented.
Abstract: The Jominy end-quench curves of non-alloyed and alloyed steels can be predicted by
nonlinear equation method. Without considering the interaction effects of alloying elements on the
curves, however, the prediction for multi-alloyed steels may be different markedly from that
experimentally determined. Hence, an improved mathematic model for predicting the Jominy
end-quench curves of multi-alloyed steels was proposed by introducing a parameter named
“alloying element interactions equivalent” to the nonlinear equations. With the improved model, the
predicted Jominy curves agree very well with the experimental ones for more than 300 steel grades
found in the literature. A computer-aided design system for hardenability of structural steels was
then developed. The system not only can quantitatively evaluate the hardenability of structural
steels, but also is very helpful to design steels and hardenability-aimed components. The optimal
composition range of a new steel was so successfully designed as an example. Further research
results show that the computer-aided design system so developed can also be used for monitoring of
hardenability variation in steel industrial production.
Abstract: Flow-induced localized corrosion is regarded as one of the main degradation mechanisms
of materials. As an initial step of the simulation of a pipe, a plate is chosen to simplify the problem. In
this paper, finite element method is used to simulate the corrosion process in the plate by employing
nonlinear geometry and physics equations of the material to describe the quasi-static process. An
elastic modulus iterative procedure was performed to obtain the material parameters in consideration
of the nonlinear physical properties of corrosion. The effect of corrosion is then considered by
introducing a criterion between depth and time, calculating corrosion depth at progressive given time.
Dead and live finite elements are employed to consider the invalidation of the material. Thus the
movable boundary conditions can be taken into account and the dynamic status of corrosion can be
simulated. Stress corrosion process under flowing fluid condition is analyzed and then the results of
representative examples are compared with published results.
Abstract: The high-speed fracture mechanics of glass bottles by using underwater
shockwaves technique and its application for recycling system of glass bottles were discussed.
The proposed small fragments, also called “Cullet”, generation technique can decrease the
recycling cost by carrying out of crashing and cleaning process simultaneously. In this study,
the effects of the explosive conditions and multi-specimen’s arrangements on the “Cullet”
sizes were investigated and basic data for commercialization of this method were obtained.
An FEM simulation and framing photograph were used to observe underwater shock wave
and fracture propagation.