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Issue 1, Volume 3,
January 2008
Title of the Paper: Consideration on
Stainless Steel Plate Plastic Deformed by Fluid Impact Substances and
Pressured Nitrogen Blasting
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Authors: Adrian Rosca,
Daniel Rosca and Vasile Nastasescu
Abstract: The paper presents a plastic deformation method for thin plates
made of stainless steel, plastic deformed by pressured nitrogen blasting
combined with impact fluid substances. There are presented experimental
results for comparative values of deformation velocities obtained by
different initial pressured nitrogen blasting, respectively by pressured
nitrogen blasting combined with several quantities of impact fluid
substances.
Keywords: Pressured
nitrogen blasting, Plastic deformation, Stainless steel thin plates
Title of the Paper: Homogenisation
procedure to evaluate the effectiveness of masonry strengthening by CFRP repointing technique
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Authors: A. Cecchi
and A. Barbieri
Abstract: In this work masonry walls, made of clay bricks and mortar joints,
have been investigated and in particular the effectiveness of CFRP repointing technique is analysed
by homogenisation procedure. Masonry walls -
typical of historical buildings and churches – are subject to in plane or/and
out of plane loading and, due to the low tensile strength of mortar joint
(assumed zero in terms of safety), need strengthening procedure to bearing
seismic loads or new service loads related to restoration design. The homogenisation procedure has been carried out taking into
account several geometrical and mechanical parameters of masonry and CFRP
strengthening. The difficulty in modelling masonry
lies in its heterogeneous character, since it is composed by blocks between
which mortar joints are laid. Here a linear elastic analysis is performed
that is significant under service loads, and may be a starting point for non
linear and collapse analysis. The masonry has been identified with a standard
elastic continuum by means of homogenisation
method. Two homogenisation approaches are proposed:
an analytical approach and a numerical approach. Both of them allow to
determine values of homogenised in plane moduli, for running bond texture, strengthened by CFRP,
taking into account the effective micro-structure of masonry and FRP An
extensive numerical analysis has been carried out to investigate the
reliability of homogenisation methods to take into
account the geometrical and mechanical parameters in the analysis of masonry
walls considering different FRP Young moduli. The
sensitivity of strain field to strengthening material is investigated on a
meaningful case such as a masonry wall loaded by horizontal and vertical
displacement respectively along horizontal joints or vertical ones. This case
is of practical interest for the partition masonry walls: infill walls.
Keywords: Masonry, CFRP repointing, Homogenisation, in
plane moduli.
Title of the Paper: Calculation of
Dynamic Stresses using Finite Element Method and Prediction of Fatigue
Failure for Wind Turbine Rotor
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Authors: Z.I. Mahri
and M.S. Rouabah
Abstract: The aim of this work is the calculation of the dynamic loads and
stresses acting on wind turbine blades in order to predict fatigue. The
prediction of the dynamic behaviour of the rotor
constitutes one of the most important processes in the design of wind turbine, this analysis is useful in estimating the
energetic performance of this machine, as well as in predicting the
structural problems such as fatigue failure, which is the major cause of wind
turbine breakdown. In the first part of this work the blade element theory is
used to calculate aerodynamic loads for small wind turbine blades. This
method can also estimate the power coefficient and the total power extracted
by the turbine. In the next part of the work, modal analysis of the blades is
carried out in order to compute frequencies and mode shapes. These parameters
are useful for dynamic load estimation. At last, dynamic stresses are
computed for the root region of the blades, using finite element modelling. The resulting curves of stress vs. time,
obtained for different wind speeds, are used for fatigue analysis in order to
make an optimal choice of blades resistant to fatigue and being energetically
efficient. In both modal and stress analysis two different approaches are
utilized and their results are compared.
Keywords: Wind Energy,
structural dynamics, Aerodynamics, fluid mechanics and Numerical Analysis.
Issue 2, Volume 3,
February 2008
Title of the Paper: Optimum
determination of partial transmission ratios of three-step helical gearboxes
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Authors: Vu Ngoc Pi
Abstract: In this paper, a new study on the applications of the optimization
and regression techniques for optimum determination of partial ratios of
three-step helical gearboxes in order to get different objectives including
the minimum gearbox length, the minimum gearbox cross section dimension and
the minimum mass of gears is presented. From the moment equilibrium condition
of a mechanic system which includes three gear units and their regular
resistance condition, three optimization problems for getting the minimum
gearbox length, the minimum gearbox cross section dimension and the minimum
mass of gears were conducted. In addition, explicit models for the prediction
of the partial ratios of the gearbox were given by using regression analysis
technique. With these models, the calculation of the partial ratios becomes
accurate and simple.
Keywords: Gearbox design;
Optimum design; Helical gearbox; Transmission ratio.
Title of the Paper: An Original
Approach of Tensile Behaviour and Elastic
Properties of Multiphase Pre-Impregnated Composite Materials
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Authors: Horatiu
Teodorescu, sorin Vlase, Luminita Scutaru and Florin Teodorescu
Abstract: An original approach to compute the longitudinal tensile break
stress of multiphase composite materials with short fibers reinforcement is
presented. The most obvious mechanical model which reflects a multiphase
composite material is a pre-impregnated material, known as prepreg. In the class of prepregs
the most known are Sheet- and Bulk Molding Compounds (SMCs
and BMCs). The model is seen as consisting of three
phase compounds: resin, filler and fibers, model that is reduced to two phase
compounds: substitute matrix and fibers. The Sheet Moulding
Compounds reinforced with discontinuous and almost parallel fibers, subjected
to longitudinal tensile loads, presents a specific note by the existence of a
shear mechanism between fibers and matrix. This shear mechanism transfers the
tensile load through the fibers. The Young’s moduli
for the substitute matrix and for the entire composite are computed and a
comparison between the theoretical approach and the experimental data is
accomplished. The paper presents also an original homogenization method to
predict the elastic properties of these materials. The upper and lower limits
of the homogenized coefficients for a 27% fibers volume fraction SMC are
computed. It is presented a comparison between the upper and lower limits of
the homogenized elastic coefficients of a SMC material and the experimental
data. The estimation model used as a homogenization method of these
heterogeneous composite materials, gave emphasis to a good agreement between
this theoretical approach and experimental data.
Keywords: Prepregs, Sheet Molding Compounds, Substitute matrix,
Homogenization, Heterogeneity, Estimation method, Elliptic equations, Elastic
coefficients.
Title of the Paper: Consideration
concerning the static and dynamic stability of metallic bunker on
environmental engineering
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Authors: Adrian Rosca
and Daniela Rosca
Abstract: The paper presents considerations concerning static and dynamic
stability of metallic bunker on environmental engineering. There are
presented theoretical considerations and experimental results concerning the
shock wave velocity / dynamic pressure, the shock wave influence on the
bunker’s walls deformation and long term stability.
Keywords: metallic bunker,
static/dynamic stability, air shock waves, environment engineering
Issue 3, Volume 3,
March 2008
Title of the Paper: Finite element
analysis of tunnel-soil-building interaction using displacement controlled
model
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Authors: Ma Keshuan
and Ding Lieyun
Abstract: Using some building affected by the river-crossing highway tunnels
of Wuhan
as engineering background, this paper investigates the interaction between
the tunneling in soft soils and adjacent structures. A full three-dimensional
finite element model, which takes into account the presence of the building
during the excavation of the tunnel, is well analyzed. The soil behavior
discussed in this paper is assumed to be governed by an elastic
perfectly-plastic constitutive relation based on the widely adopted
Mohr-Coulomb criterion with a non-associative flow rule. The paper consists
of three parts. The first part presents the 3-D finite element numerical
model, and the second part provides a full analysis of the construction of a
shallow tunnel close to a five level building. Comparison between the full
couple model analysis and the full 3D free-field analysis is given in the
final part. The corresponding comparison results provide a fundamental
guidance for the shield tunnel design and construction.
Keywords: Finite Element;
Three-dimensional; Slurry shield tunneling; Structure; Excavation; Settlement
Title of the Paper: Development of a
Spiral Trajectory for High Speed Roughing of Light Alloy Aerospace Components
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Authors: Jean-Francois Chatelain, Rejean Roy and Rene
Mayer
Abstract: A new spiral cutting method and its implementation within a CAD/CAM
application software is proposed to save more than 16% in the roughing
process of pockets for light alloy aerospace parts. The application prototype
developed automatically generates the tool paths related to specific pocket
profile geometry. It is shown, through experimentation using the prototype,
that the parameters which define the spiral tool path geometry have a direct
and important impact on cutting times. During the roughing operation, the
proposed tool path takes into consideration the slant of the walls but also
allows maximizing the quantity of material to be removed. The approach
developed indicates great potential for roughing optimization of parts having
multiple pockets.
Keywords: CAD, CAM, roughing, spiral trajectories, tool path,
machining.
Title of the Paper: Die Attach Film
Performance in 3D QFN Stacked Die.
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Authors: A. Jalar,
M. F. Rosle and M. A. A. Hamid
Abstract: Consumer demand for smaller and lighter products in wiresless application with maximum functionality had drive the semiconductor industries toward the developement of 3-dimensional stacked die. One of the key
technology is relies on die stacking process. A suitable bonding condition
and material set are essential to achieve required reliability performance.
This study is to relate the effects of variables bonding parameter on the
mechanical adhesion and delamination of the die
attach film in QFN stacked die. Samples are deliberately built with nine
combination sets of die attach parameters including bonding temperature,
force and time to achieve a minimum reliability performance under IPC/JEDEC
Moisture Sensitivity Level 3 at reflow 260°C. Characterisation
of die attach film was carried out using differential scanning calorimetry whereas it performance was carried out using
shear testing machine and scanning acoustic test (SAT) is used to detect the
interfacial delamination between DAF and die. The best
die attach process is characterized by stable values of die attach film
thermal resistance properties and optimum touch area between die/die attach
film and die attach film/die.
Keywords: Die attach
film, QFN, delamination
Issue 4, Volume 3,
April 2008
Title of the Paper: Finite Element
Analysis of Micro – Electro – Mechanical
Systems: Towards the integration of MEMS in design
and robust optimal control schemes of smart
microstructures.
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Authors: John K. Sakellaris
Abstract: Microelectromechanical Systems (MEMS) is
the technology of the very small, and merges at the nano-scale
into "Nanoelectromechanical" Systems
(NEMS) and Nanotechnology. MEMS are also referred to as micro machines, or
Micro Systems Technology (MST). MEMS are separate and distinct from the
hypothetical vision of Molecular nanotechnology or Molecular Electronics.
MEMS generally range in size from a micrometer (a millionth of a meter) to a
millimeter (thousandth of a meter). At these size scales, the standard
constructs of classical physics do not always hold true. Due to MEMS' large
surface area to volume ratio, surface effects such as electrostatics and
wetting dominate volume effects such as inertia or thermal mass. Finite
element analysis is an important part of MEMS design. The paper presents the
design of a vibration control mechanism for a beam with bonded piezoelectric
sensors and actuators and an application of the arising smart structure for
vibrations suppression too. The mechanical modelling
of the structure and the subsequent finite element approximation are based on
Hamilton’s
principle and classical engineering theory for bending of beams in connection
with simplified modelling of piezoelectric sensors
and actuators. Two control schemes LQR and H2 are considered. The latter
robust controller takes into account uncertainties of the dynamical system
and moreover incompleteness of the measured information, it therefore leads
to applicable design of smart structures. The numerical simulation shows that
sufficient vibration suppression can be achieved by means of the proposed
general methods. It is given as a perspective to the MEMS technology towards
the direction of integrating MEMS in design and robust optimal control
schemes.
Keywords: Finite Element
Analysis, Micro – Electro – Mechanical Systems, ANSYS software, Coupled
problems, Micro - actuator, Bi - stable electromagnetic actuation, UV-LIGA
technology, Simulation, Active structural control, Smart beam, Composite
structure, Piezoelectric layer.
Title of the Paper: Spectral
distribution of a star-shaped coupled network
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Authors: Xu
Gen Qi, Nikos E. Mastorakis
Abstract: In this paper we study a star-shaped coupled network of strings and
Euler-Bernoulli beams with damping. Suppose that the exterior vertices of the
coupled network are clamped and at common node there is a damping. In the
present note, our attention concentrate on the
spectral distribution of an operator determined by the system. Under certain
condition we show that the spectrum of the operator distributes in a strip
parallel the imaginary axis.
Keywords: Star shape
network stabilization string beam
Title of the Paper: Nonlinear effects
in seismic base isolations
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Authors: Dinu
Bratosin
Abstract: By interposing a layer with low horizontal stiffness but with high
damping characteristics between the structure and his foundation, an aseismic isolation system partly decouples the building
structure from the horizontal components of the earthquake ground motion and
thus diminishes the structural demand. As a result of the lateral flexibilization, the natural period of the former
fixed-base structure undergoes a jump and the new base-isolation structure
has a new and larger natural period. This “period-shift” can extract a
structure away from the dominant period of the earthquake ground motion and
thus can avoid the destructive effects given by the system resonance. The
dynamic behavior of the materials and devices of the isolating layer governs
the performance of base-isolation system. The dynamic properties, such as
horizontal stiffness and damping capacity determine the filtering role of the
isolating layer and, finally, the structural dynamic response. But all of
materials and devices used in an isolating layer systems exhibit, more or
less, a nonlinear behavior. In addition, all site soils materials have the
well-known nonlinear mechanical characteristics, which affect the dynamic
structural response. Thus, in the dynamic response evaluation of a
base-isolated system the nonlinear behavior of both isolator and site layers
must taken into account. This paper presents a
method for the necessary period-shift determination by using the dynamic
linear or/and nonlinear magnification functions. For the nonlinear
magnification functions determination we shall use a nonlinear Kelvin-Voigt
model (NKV model) for base-isolated structure, which is able to model the
effects of the soils and isolating layer nonlinearity on the shape and
resonant magnitude of the magnification functions. Thus, we shall obtain a
proper tool for modeling the resonant peak dispersion, which is a very
important condition for a correct period-shift evaluation and therefore for a
correct isolation design.
Keywords: Earthquake
engineering, Nonlinear dynamics, Seismic base-isolation
Title of the Paper: Dynamical Behavior
of Foundations in Linear and Nonlinear Elastic Characteristic Hypothesis
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Authors: Adrian Leopa
and Silviu Nastac
Abstract: This study presents a viewpoint regarding dynamic behavior of the technological
equipment foundation who works in the production process with shocks and
vibration. In this way was analyzed the variations of three cinematically
parameters acceleration, velocity and movement, as well as a frequency
response of the vertical movement of the foundation. These analyses were made
by comparison for the two considerate hypotheses: linear and non-linear
elastic characteristic of the viscous-elastic system.
Keywords: vibration,
non-linear, linear, detect, damage, frequency
Issue 5, Volume 3,
May 2008
Title of the Paper: New Structural
Configurations for Vibroisolation Devices with High
Isolation Performances
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Authors: Silviu
Nastac and Adrian Leopa
Abstract: This paper is a summary of the large study regarding the isolation
performances improvement of the vibration isolation devices. The main area of
this study was framed by the passive isolation, using different structural
configurations, based on the compressing and torsion rubber elements. First,
it is present the few theoretical aspects regarding the dynamic analysis of
the passive elastic anti-vibrational devices and
their isolation degree evaluation. It have to be mentioned that in this paper
there are presented only the final structural configurations of passive
isolation devices, obtained by a selection procedure based on the numerical
simulation and instrumental tests of dynamic behaviour
for each type. Taking into account the structure of the basic compressing and
torsion elastic elements, their working principle, and their functional
restraints, there was tested a lot of possible configurations, both from the
structural, and from the functional points of view. Through the comparative
analysis of the acquired results, it was fixed two final and operational
structural configuration. All the theoretical
suppositions, completed by the computer simulation on the numerical models, was entirety validated through the experimental tests on
realistic models. Concluding the ensemble of numerical and instrumental
tests, it could be mentioned that the major advantages of these special
structural and functional configuration, with a view to the increasing of the
isolation degree and to the passive anti-vibrational
elastic devices performances incrementation, point
at the high isolation performance, relative to a simple and robust structure.
Using of these innovative anti-vibrational devices
leads to high values of the isolation degree for a large area of technical
and industrial applications, and also for vibration sensitive embedded
equipments. As it could be see on the paper, the basic structural
configuration could be easy modified, on call, as a function of a practical application service requirements, by
changing a spatial distribution of the elastics components.
Keywords: isolation
efficacy, passive elastic devices, rubber elements
Title of the Paper: Enhancement of
Panel zone (PZ) contribution to the ductility of post-Northridge welded
connections
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Authors: Amir
A. Hedayat and Murude Celikag
Abstract: In welded connections, beam-end and panel zone (PZ) are the only
sources to dissipate the seismic energy released during an earthquake. Energy
dissipation at the PZ is accompanied by the inelastic shear deformation at
PZ. In seismic codes, in order to reach to the maximum plastic rotation
capacity of connection, the inelastic shear deformation is controlled by a
balance condition with respect to the initiation of flexural yielding of beam
flanges. Hence, connections are classified as weak, balance and strong panel
zone connections. In the case of weak PZ, balance condition can be obtained
by increasing the thickness of the column’s PZ or using doubler
plates. This study was aimed to obtain balance condition for connections with
strong panel zones. Therefore, a circular hole was opened at the column web
in the PZ region. A pre-tested post-Northridge connection which has a strong
panel zone was modeled using finite element analysis. Then the effects of
different diameter holes on the behavior of this type of connection were
investigated. Further, a function was proposed to determine the PZ shear
yielding resistance in the presence of a circular hole in PZ. Analytical
results showed that the column with a PZ hole ratio (hole diameter divided by
PZ height) of 18% associated with a PZ hole of 50 mm radius and balance ratio
of 0.81 appears to be the best configuration for increasing the PZ plastic
rotation from 0.05% to 0.2%. This increase in plastic rotation capacity of PZ
would only increase the total plastic rotation capacity of the connection by
10%. This indicates that a connection of this type also require modifications
at the beam-end to increase both the total plastic rotation capacity and
contribution of panel zone to the inelastic behavior of connection.
Keywords: Post-Northridge
connections; Panel zone; Ductility; Inelastic shear deformation
Title of the Paper: The influence of
the lubricant from a rectilinear pair above the work accuracy of the elastic
elements from the high precision mechanisms
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Authors: Madalina
Calbureanu, Raluca Malciu, Mihai Lungu and Dan Calbureanu
Abstract: The paper presents the determination by experiment of the vibration
of a long elastic cinematic element with a mobile rectilinear pair,
lubricated by two kinds of oil with low and high values for lubrication
properties and cinematic viscosity. The lubricant pressures’ field is
analyzed by using the finite element method (COSMOSM program), starting with
the datum obtained by experiment in the analysis of the elastic cinematic
element vibration. The vibration acceleration for the elastic element was
measured and the spectrum analysis was attached for each case separately. The
efficacy acceleration and the power spectral density for different kinds of
oil were comparatively presented. More actions are proposed for the high
accuracy mechanism in order to obtain less vibration on the elastic cinematic
elements.
Keywords: Lubricated
rectilinear pair, elastic element, pressures field, film breaking phenomenon,
spectral analysis
Title of the Paper: Advanced
Computational Concepts about Projecting a Multiple Designs of Self-Supporting
Metallic Structure using Finite Element Method in Determination the Buckling
Factor and Running the Stress Analysis
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Authors: Madalina
Calbureanu, Emil Albota, Raluca Malciu, Romulus Lungu and
Dan Calbureanu
Abstract: The paper presents the fully and correctly computation of a
self-supporting metallic structure by using the capabilities of NISA-program
and Finite Element Method. The stress and buckling analysis using SHELL and
TRUSS Elements are performed for optimizing the design of the structure. The
system of loading forces includes all the types of loads specified by the
international standards for the civil buildings. The values of loads depend
on the structure location zone. Permanent, temporary (quasi-permanent and
variable) loads and the extremity loads are considered. It is been also
realized a designing of the structure based on the obtained results. The
advanced computational concept used in designing multiple shapes for the
metallic structures were introduced by MACRO program. This program can
realize automatically modeling of the structure introducing in a parametrical
way the dimensions of the metallic building.
Keywords: Self-supporting
metallic structure, design, buckling factor, stress analysis
Issue 6, Volume 3,
June 2008
Title of the Paper: A Strain-based
Non-linear Elastic Model for Geomaterials
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Authors: Andrew Heath
Abstract: The non-linear elastic behaviour of geomaterials has traditionally been modeled using stressdependent elastic models. The approach used by many
researchers is not rigorous where the “elastic” models can create energy and
can predict permanent deformation under certain circumstances. Other
researchers have used rigorous hyperelastic models
where energy is conserved by the elastic portion of the model, but these
models have stress-dependent stiffness which can slow computation and lead to
iterative solutions in finiteelement or other
strain-based computation techniques. To overcome these problems a rigorous
elastic model is investigated which predicts similar behaviour
to hyperelastic models, but has the advantage of
being elastic strain based which allows more direct solution in strain-based
finite-element or other computational codes.
Keywords: Elasticity, Geomaterials, Non-linear, Finite Element, Elastic strain
Title of the Paper: Modelling
Muddy Flash Floods and Debris Flows
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Authors: B. Nsom,
B. Ravelo, W. Ndong, N. Latrache, K. Bouchlaghem and S.
Elouragini
Abstract: After long and intense rains in a mountainous region, large
quantities of water flow in the torrents. For some reason, this flow can be
obstructed by cross-linked branches and debris (natural dam). When the
hydrostatic pressure exerted by the fluid exceeds a given yield value, the
dam collapses and the fluid is released inside and outside the torrent bed,
as well. Such scenario which is known as a dam-break flow can describe the
initiation of certain geological flows, (debris flows, mudflows, etc.). As
for any gravity current, the flow description depends on the time scale.
Immediately after the dam collapse, the inertial forces are the dominant ones
and this configuration can model a flah flood.
Flash floods develop at time and space scales that conventional observation
systems are not able to monitor, so reliable modelling
remains a crucial step. At larger time scale, a viscous regime takes place
where the viscous forces become the dominant ones and this configuration can
model a classical debris flow. Debris floods develop in a long domain, i.e. a
domain of space that is much longer than it is wide. They generally erode
their bed and transport much energy and can move rocks and boulders upon very
long distances. Both, the flash flows and the debris floods constitute
dangerous phenomena for public safety and quality of life. The originality of
the present approach is to consider these two flood waves as special cases of
a single global model of a dam-break flow of a muddy fluid, depending on the
time scale. The study was experimental, analytical and numerical, as well.
The experimental study performed in previous work consisted in designing
model fluids to be used in the laboratory experiments, characterizing these
synthetic muds and monitoring the corresponding
dam-break flows in the laboratory. The corresponding results agreed with the
theoretical study presented here and which consists in stating the equations
of motion governing the different flows studied, and solving them in their
non dimensional form, both analytically and numerically.
Keywords: Dam failure,
Finite difference method, Herschel-Bulkley fluid,
Inertial regime, Numerical models, One dimensional flow, Shallow water
approximation, Similar solution, Viscous regime.
Title of the Paper: On the eigenvalues optimization of beams with damping patches
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Authors: Veturia
Chiroiu
Abstract: The paper discusses the behavior of beams with external nonlocal damping patches made from traditional and auxetic materials. Unlike ordinary local damping models,
the nonlocal damping force is modeled as a weighted
average of the velocity field over the spatial domain, determined by a kernel
function based on distance measures. The performance with respect to eigenvalues is discussed in order to avoid resonance. The
optimization is performed by determining the location of patches from
maximizing eigenvalues or gap between them.
Keywords: eigenvalues, optimization, damping patches,
Euler-Bernoulli beam, nonlocal theory, auxetic material
Issue 7, Volume 3,
July 2008
Title of the Paper: Mechanical Behavior
Analysis with the Finite Elements Method of
Solar Collector’s Tracking Systems
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Authors: Mihai
Tiberiu Lates
Abstract: The paper presents the finite elements analysis of the mechanical
behavior for three main solar collector tracking systems: for plate, for dish
and for trough solar collectors; There are presented the modeling algorithm
by using FEM, the characteristics of the loads and of the restrictions. Finally,
the aim is to find out
the critical position of the tracking systems, when the equivalent stresses
and the displacements have a maximum value and to identify the free
oscillations characteristics (modes, frequencies, accelerations). According
to the conclusions can be compared, as mechanical behavior, the analyzed
structure of the tracking
systems.
Keywords: Solar
collector, Tracking system, FEM, Stresses, Displacements, Vibrations.
Title of the Paper: Bending beams, a
computer-aided approach
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Authors: Carmen E. Eisinger-Borcia
Abstract: This paper presents a new general computer-aided (CA) way for optimization
of bending beams that is an example of using the CA capabilities to obtain a
large quantity of data to receive new qualitative information. Our method is
obtained combining two new results based on the CA approach: (1) the
computer-aided method of obtaining the influence coefficients for bending a
beam and (2) the State Matrix Strategy- a quasi-optimization tool. The CA
method of obtaining the influence coefficients stands for any statically
determined or undetermined straight beam of a constant cross section under
all the combinations of loading and boundary conditions. The extension to a
non-constant cross section is easy to obtain. The adopted model for the
bending beam is an n-lumped beam unrelated to how big is
n. The flexibility of this mathematical model synergistically completed by
the Mathematica® software symbolic calculus
capabilities, allows us to determine the values of the design parameters that
optimize the elasto-dynamic behavior of bending
beams, according to predefined criteria, static and dynamic as well.
Keywords: bending, lumped beam, influence coefficients,
computer-aided optimization, Mathematica®.
Title of the Paper: The Effect of
Frequency and Amplitude of Vibration on the Coefficient of Friction for
Metals
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Authors: Jamil
Abdo And Mahmoud Tahat
Abstract: Experiments were conducted to determine the effects of frequency
and amplitude of vibration on friction. The experimental analysis also seeks
to take into account a variety of factors influencing the coefficient of
friction such as normal load and surface roughness. An in-house pin-on-disc
apparatus was constructed with a spindle speed control and applied
forced-feedback to perform the tests. The response surface methodology is
utilized to investigate the effects of the factors and their cross influence
on the coefficient of friction for the Steel C1020 and Aluminum 7079. The
analysis of variance is done on the experimental data to evaluate the
statistical significance of the model. The response equation for the
coefficient of friction of Steel C1020 and Aluminum 7079 were determined. The
ranges of frequency and amplitude of vibration were 120 – 600 Hz and 15 – 225
μm, respectively. Studies have shown that the
coefficient of friction decreases with the increase of frequency and
amplitude of vibration within the observed ranges for both metals whereas the
in case of Aluminum 7079 the coefficient of friction is about 13 % when it
compares with the coefficient of friction of Steel C1020.
Keywords: Frequency and
amplitude of vibration, Coefficient of friction, Pin on disc.
Title of the Paper: Creep Analysis of
Thin Rotating Disc under Plane Stress with no Edge load
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Authors: SANJEEV SHARMA, MANOJ SAHNI
Abstract: - Creep stresses and strain rates for a
transversely isotropic and isotropic materials have been obtained for
a thin rotating disc using Seth’s transition theory. Results obtained have
been discussed numerically and depicted graphically. It is seen that a disc
made of transversely isotropic material rotating with higher angular speed
increases the possibility of fracture at the bore as compared to a disc made
of isotropic material and possibility of fracture further decreases with the
increase in measure N. The deformation is significant for transversely
isotropic disc for the measure N =7.
Key words: Creep, Transition, Stresses,
Strain Rates, Transversely Isotropic and Rotating Disc
Title of the Paper: Intelligent Modular
Design of Automatic Dimensional Inspection Systems.
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Authors: LUCIANA CRISTEA MIHAI MANESCU
Abstract: The new production has
to undertake a continuous quality improvement due to its major economic
involvement; the consequence consists in high performances in the quality
assurance. Therefore the author of this work wants to present some concerns
in the automatic dimensional inspection systems field. The new production has
to undertake a continuous quality improvement due to its major economic
involvement; the consequence consists in high performances in the quality
assurance. Therefore the author of this work wants to present some concerns
in the automatic control system field. This paper presents aspects of the
design for an intelligent modular inspection system. The performed researches
aimed at an original method of grouping the parts based on the relation
between dimensional inspection process characteristics and modular design of
all inspection equipments with a high universality and flexibility degree.
Keywords: Inspection, mechatronics, modular design, automation, dimension.
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