Abstract: Al2O3-TiC composites were fabricated by hot-pressing Cobalt coated powders at low
temperature through liquid phase sintering. Cobalt coating layers effectively hinder the growth of
grain and harmful reaction between Al2O3 and TiC particles, which would improve the mechanical
properties of Al2O3-TiC composites. The hardness decreases with the increase of Co content and the
bending strength was enhanced to 782MPa owing to the grain refinement effect of Co phase. The
fracture toughness, about 9.23 MPa.m1/2, was measured for the composites containing 3wt% Co
sintered at 1550°C. SEM images of fracture surface show that the toughening effect should be
attributed to the conversion of fracture mode caused by the Co phase.
Abstract: Elasticity solution is presented for simply-supported, orthotropic, piezoelectric
cylindrical shell with finite length under local ring load in the middle of shell and electrostatic
excitation. The highly coupled partial differential equations (p.d.e.) are reduced to ordinary
differential equations(o.d.e.) with variable coefficients by means of trigonometric function
expansion in longitudinal direction for displacement and external forces. The resulting ordinary
differential equations are solved by Galerkin finite element method. Numerical examples are
presented for [0/90/P] lamination with sensor and actuator for different thicknesses.
Abstract: In this article, the densely SrCo0.8Fe0.1Sn0.1O3-δ (SSCF) tubular membranes were prepared
by the traditional extrusion method. The prototype oxygen separator was constructed by the
resulting SSCF tubular membrane. The resulting oxygen product had purity over 99%. At 920oC, a
tubular membrane with a wall thickness of 1.4mm, had the permeation rate of 2.4ml/min.cm2,
which kept unchanged during 1000hrs operation.
Abstract: The properties of photoluminescence (PL) and electroluminescence (EL) of 5,10,15,20-
tetra-p-tolyl-21H, 23H-porphine (TTP) doped poly[2-methoxy-5-(2’-ethylhexyloxy)-1,4-
phenylenevinylene] (MEH-PPV) was studied in this paper. A multi-color emission from the
corresponding light-emitting device was observed.
Abstract: The paper presents an effective damage detection method of complex composite structures.
It can be carried out through the experimental modal analysis of the damaged structure. The method
using the improved Cross Modal Strain Energy (CMSE) technique and Niche GA has many
advantages compared with other damage detection methods. The CMSE method can use any modes
of the structure and the modes don’t need to be normalized or consistent in scale. The Niche GA
improves the efficiency of the calculation and enhances the capacity of identifying structural damage
localization. The model is the composite material airfoil case. The numerical results show that the
method proposed in this paper is successful for damage detection of complex structures.
Abstract: Thermal vibration characteristics of the composite thin-cylindrical shell embedded with
shape memory alloy (SMA) fibers are investigated. The shape memory alloy material behavior is
programmed in the form of an ABAQUS user subroutine code (UMAT), and this program is
successfully verified by using the response of pseudoelasticity and the shape memory effect (SME) at
various temperatures and stress levels. Based on the ABAQUS UMAT code, the natural frequency of
the composite thin-cylindrical shell embedded with SMA wires under thermal load and mechanical
load is calculated respectively. Then the effects of the SMA wire temperature and the content on the
thermal vibration characteristics of the structure are discussed. Numerical simulation results show
that the temperature and the volume content of the SMA wires increase the stiffness and buckling
critical load of the structure.
Abstract: Sintered NdFeB permanent magnet is widely used in many applications because of its
excellent magnet property. However the report of EDM research on NdFeB magnet is not available.
This paper presents a detailed investigation of the material removal mechanisms of sintered NdFeB
magnet through analysis of the machining debris and the surface SEM quality. It is included three
types of machining mechanisms: melting and evaporating, thermal cracking, spalling or whole grain
Abstract: The thin polymer composite bipolar plates (the thickness < 1.5 mm) for use in polymer
electrolyte membrane fuel cells (PEMFCs) containing vinyl ester resin, graphite powder,
organoclay have been fabricated by bulk molding compound (BMC) process. Organoclay prepared
by ionic exchange of montmorillonite (MMT) with three different Mw of diamine intercalating
agents was used to reinforce the mechanical properties of the composite bipolar plates. Results
indicate that the basal spacing and content of MMT varied with Mw of POP-diamines are critical in
determining the resultant mechanical properties for bipolar plates. The flexural strength and the
unnotched impact strength of the plate were ca. 38 % (from 30.21 MPa to 45.66 MPa) and ca. 30 %
(from 58.11 J/m to 80.21 J/m) higher than the pristine graphite plate, respectively, as the basal
spacing of MMT (2 phr) was increased from 1.71 to 5.43 nm. The limiting oxygen index (L.O.I.)
and the UL-94 test revealed that the bipolar plate possesses excellent flame retardant with L.O.I.
higher than 50 and UL-94-V0. In addition, the electrical conductivity of the bipolar plates with
different MMT contents and basal spacing of MMT is higher than 100 S/cm.
Abstract: A novel organic–inorganic mesoporous silica functionalized with perfluoroalkylsulfonic
acid groups analogous to that of Nafion® has been prepared. A condensation reaction between surface
silanol groups of the mesoporous silicas and 1,2,2-trifluoro-2-hydroxy-1-trifluoromethylethane
sulfonic acid Beta-sultone was conducted. High proton conducting sulfonated poly(ether ether
ketone) (sPEEK)/ functionalized mesoporous silica composite membranes were prepared through
homogeneous dispersive mixing and solvent casting method. In the study, proton conductivity (σ) of
composite membrane is increased from 0.01 to 0.038 (S/cm) as the modified mesoporous silica
content is increased from 0 to 5 wt. %. It is found that the ion exchange capacity (IEC) is increased
from 1.54 to 1.70 (meq/g) as the modified mesoporous silica content is increased from 0 to 5 wt. %.
From morphology investigation, it is found that incorporation of modified mesoporous silica by rotary
vacuum evaporation enables the preparation of homogeneous membranes. The membranes present a
good adhesion between inorganic domains which could be used for fuel cell applications.
Abstract: In this paper, fiber Bragg grating (FBG) sensor and piezoelectric (PZT) actuator are used to
develop a hybrid system for the evaluation of delamination in glass fiber-reinforced epoxy (GF/EP)
composite laminates. The surface-bonded PZT actuator generates ultrasonic Lamb wave in the
composite laminates, while the FBG sensor, which is embedded in the composite laminates, captures
the Lamb wave signal. Wavelet analysis is introduced to extract signal spectrographic characteristics
in the time-scale domain appropriately. Since the propagation characteristics of Lamb wave is altered
by the existence of damage in the composite laminates, delamination information can be obtained
from the received signal. With the assistance of a signal generation and an acquisition system, this
methodology enables active sensing and non-destructive evaluation of delamination in the composite
laminates. Experiments have been carried out with GF/EP composite beams to examine the feasibility
of the proposed detection technique. The acquired and processed Lamb wave signals corresponding to
different delamination sizes are compared.