Abstract: The mechanical properties of rock under high temperature, high geostress and high pore
pressure are the basic and important information to assess the safety of underground engineering in
west China. Based on the environmental conditions of the west route of south-to-north water
transfer project in west China, a series of triaxial tests at confining pressures (0 to 60MPa) and
temperatures (25°C to 70°C) as well as pore pressure (0 to 10MPa) have been conducted for a
sandstone. It is reported that under the temperatures varying from 25°C to 70°C, the strength of the
rock increases with the increment of confining pressure, while the deformation modulus of the rock
doesn’t change distinctly with the increment of confining pressures. It is also indicated under the
temperatures condition in the experiments, when the confining pressure is lower than 40MPa, the
strength of the rock increases with the increment of temperature, whereas when the confining
pressure is higher than 40MPa, the strength of rock tend to decrease with increment of temperature.
It is further shown that the strength decreases with increasing pore pressure, and the decreasing
rates tend to decrease with the increment of confining pressures.
Abstract: It is very important to choose a similar material which simulates rock mass correctly in
geo-mechanics model test. In this paper, we introduce similar material research status and analyze
the principle of selecting and compounding. According to the experiences of similar material
research, we develop a new similar material (we call it iron barites sand cementation material,
abbreviate IBSCM) through hundreds of compounding experiment. This similar material is made
up of iron ore powder, barites powder, sand, rosin, alcohol and gypsum powder. Iron ore powder,
barites powder and sand are main materials, the solution of rosin and alcohol is glue, and gypsum
powder is regulator. Specimen mechanics tests show that different rock mass can be simulated by
the model materials with different materials compounding. The new similar material is easy to
buy and its price is cheap, and it has some advantages, such as high density, stable performance,
easy dryness, and easy cutting. The new similar material can simulate a lot of rock mass, so it is
an ideal similar material. At last, we apply this new type similar material to tunnel
geo-mechanical model test and gain the ideal result.
Abstract: This paper presents the results of an investigation on the force transfer mechanism in an
embedded column base of a composite structure. In the experimental program, eighteen push-out
specimens were tested. The factors influencing the mechanism of force transfer were the amount of
confining reinforcement, compressive strength of concrete, and diameter of stud connectors. The
results of experiment indicated that force transfer could be characterized into two stages, and the
factors governing each stage were identified. The first stage was governed by the bond strength
between the steel column base and the concrete. The second stage begun after chemical debonding
and was governed by the shear strength of stud connectors as well as the frictional strength between
the steel and the concrete. Based on the experimental results, the equations to estimate the bond
strength, the friction strength, and the shear strength of stud connectors were proposed. The load
carrying capacity of an embedded steel column base could be predicted by taking the sum of the
shear strength of stud connectors and the friction strength. The predicted load carrying capacity was
found to agree well with the experimental results over various range of concrete stress.
Abstract: In the construction of composite bridge structures, various types of shear connectors are
usually used to provide an efficient load transfer and the composite action of two or more different
materials. In the previous work conducted by authors, a new type of the shear connector was
introduced, which is the perforated shear connector with flange heads (T-shaped perforated shear
connector), and the structural behavior of the shear connector was discussed based on the results of
push-out tests. For the practical design of new shear connector, it is necessary to develop the
equation for the prediction of the load carrying capacity of the shear connector. In this study, the
existing design equations for the Perfobond shear connector were briefly analyzed and the equation
for the prediction of the shear capacity of T-shaped perforated shear connector was suggested
empirically. By comparing the results obtained by the suggested equation, the existing equations for
the Perfobond shear connector, and the experiment, the applicability and effectiveness of the
suggested equation was estimated.
Abstract: Measurement of fiber orientation distribution state is very important constituent to find out
decision of processing condition of product or mechanical special quality of moldings in fiber
reinforced polymer composite material. Therefore, reliable measurement method of fiber orientation
angle distribution is established, and need researcher about simplicity measuring method urgently the
nondestructiveness. In this research, to investigate about accuracy of fiber orientation angle
distribution measurement of fiber reinforced composite material by intensity method, find fiber
orientation function value that is measure of fiber orientation distribution state constructing fiber
orientation simulation picture by plotter changing diameter and length and orientation state of fiber.
Recognize this fiber orientation simulation picture by image scanner, and measure fiber orientation
angle distribution state by this realized intensity information. This time, I wish to measure reliable
fiber orientation angle distribution comparing fiber orientation function calculation value saving in
the advance with fiber orientation function value that is measured by intensity method. The results
show that measurement accuracy of the fiber orientation angle distribution by intensity method is
affected by the fiber aspect ratio when the total length of oriented fiber is same. The average gradient
of fiber orientation function is 0.94 for 1000mm of the total fiber length and is 0.93 for 2000mm when
the fiber aspect ratio is over 50. Measurement accuracy by intensity method is about 94% and the
reliable data can be obtained by intensity method.
Abstract: The study for cyclic load-displacement relationship and seismic characteristics of square
Concrete-Filled Steel Tubular (CFT) columns is experimentally and analytically conducted. Nine
CFT column specimens are tested under constant axial loading and monotonically increasing lateral
loading. For predicting the strength and ductility of CFT columns, fiber analysis technique is used.
The analytical results show reasonable agreement with experiment results and the moment capacity
of CFT columns is predicted with reasonable accuracy using the fiber model. The influence of the
steel tube on the lateral response of CFT columns is studied for the evaluation of seismic
Abstract: Bending collapse behaviors and energy absorption characteristics of aluminum-GFRP
hybrid tube beams were evaluated by using experimental tests combined with theoretical analysis.
Hybrid tube beams composed of glass fiber-epoxy layer wrapped around on aluminum tube were
made in autoclave with the recommend curing cycle. The hybrid tube beams showed a considerable
improvement in their bending performance. The maximum bending moment and specific energy
absorption of the hybrid tubes were higher than those of the aluminum tubes. They were also
evaluated as a function of ply orientation and thickness of GFRP layer. A modified theoretical
model was developed to predict the resistance to the collapse of hybrid tube beams subjected to a
bending load. Theoretical ultimate bending moments and moment-rotation angle curves of hybrid
tube beams were in good agreement with experimental ones. Hybrid tube beams strengthened by
GFPR layer with 90°/0° and 45°/-45° ply orientation showed an excellent bending strength and
energy absorption capability, respectively. Therefore, on the basis of above results, it was
concluded that aluminum-GFRP hybrid tube beams might be employed as reinforcing and/or energy
absorbable light weight space frame.
Abstract: Polycarbonate/multiwalled carbon nanotubes (PC/MWNT) nanocomposites with
different contents of MWNT were successfully prepared by melt compounding. The mechanical
properties of the PC/MWNT nanocomposites were effectively increased due to the incorporation of
MWNTs. The composites were characterized using scanning electron microscopy in order to obtain
the information on the dispersion of MWNT in the polymeric matrix. In case of 0.3 wt% of MWNT
in the matrix, strength and modulus of the composite increased by 30% and 20%, respectively. In
addition, the dispersion of MWNTs in the PC matrix resulted in substantial decrease in the electrical
resistivity of the composites as the MWNTs loading was increased from 1.0 wt% to 1.5 wt%.
Abstract: The development characteristics of impact-induced damage in carbon-fiber-reinforcedplastics
(CFRP) laminates were experimentally studied using a drop-weight impact tester. Five
types of CFRP laminates were used to investigate the effect of stacking sequences and thicknesses.
The efficiency of absorbed energy to impact energy was different for CFRP laminates with different
stacking sequences or thicknesses. The DA/AE ratio of delamination area (DA) to absorbed energy
(AE) was almost the same for CFRP laminates with the same stacking sequence regardless of the
thickness. We found that the DA/AE ratio could be used as a parameter to characterize the impact
damage resistance in CFRP laminates with different stacking sequences.
Abstract: The strain distribution around the unstiffened and stiffened circular cutout of the isotropic
stainless steel (ANSI type 304) and the GFRP laminated composite cylindrical shells subjected to
axial compression are studied. The experimental results are obtained and compared with numerical
analysis. In experiment, the strain is measured around the circular cutout by strain measuring
system under the axial uniform compression loading. The numerical analysis is performed by the
commercial finite element code ANSYS. The strain concentration factor (SCF) is defined to
investigate the strain concentration around the circular cutout. The SCF of the stainless steel
cylindrical shell with a stiffened cutout is decreased 39% in experiment and 50 % in numerical
analysis. The SCF of GFRP laminated composite cylindrical shell is decreased 22% in experiment
and 31 % in numerical analysis.