Abstract: The plastic forming process of sheet plate takes an
important place in forming metals. The traditional techniques of tool
design for sheet forming operations used in industry are experimental
and expensive methods. Prediction of the forming results,
determination of the punching force, blank holder forces and the
thickness distribution of the sheet metal will decrease the production
cost and time of the material to be formed. In this paper, multi-stage
deep drawing simulation of an Industrial Part has been presented
with finite element method. The entire production steps with
additional operations such as intermediate annealing and springback
has been simulated by ABAQUS software under axisymmetric
conditions. The simulation results such as sheet thickness
distribution, Punch force and residual stresses have been extracted in
any stages and sheet thickness distribution was compared with
experimental results. It was found through comparison of results, the
FE model have proven to be in close agreement with those of
experiment.
Abstract: In the package design industry, there are a lot of tacit knowledge resided within each designer. The objectives are to capture them and compile it to be used as a teaching resource and to create a video clip of package design process as well as to evaluate its quality and learning effectiveness. Interview were used as a technique for capturing knowledge in brand design concept, differentiation, recognition, rank of recognition factor, consumer survey, knowledge about marketing, research, graphic design, the effect of color, and law and regulation. Video clip about package design were created. The clip consisted of both the speech and clip of actual process. The quality of the video in term of media was ranked as good while the content was ranked as excellent. The students- score on post-test was significantly greater than that of pretest (p>0.001).
Abstract: The present work deals with the structural analysis of
turbine blades and modeling of turbine blades. A common failure
mode for turbine machines is high cycle of fatigue of compressor and
turbine blades due to high dynamic stresses caused by blade vibration
and resonance within the operation range of the machinery. In this
work, proper damping system will be analyzed to reduce the
vibrating blade. The main focus of the work is the modeling of under
platform damper to evaluate the dynamic analysis of turbine-blade
vibrations. The system is analyzed using Bond graph technique. Bond
graph is one of the most convenient ways to represent a system from
the physical aspect in foreground. It has advantage of putting together
multi-energy domains of a system in a single representation in a
unified manner. The bond graph model of dry friction damper is
simulated on SYMBOLS-shakti® software. In this work, the blades
are modeled as Timoshenko beam. Blade Vibrations under different
working conditions are being analyzed numerically.
Abstract: Quality control is the crucial step for ISO 9001
Quality System Management Standard for companies. While
measuring the quality level of both raw material and semi
product/product, the calibration of the measuring device is an
essential requirement. Calibration suppliers are in the service sector
and therefore the calibration supplier selection is becoming a worthy
topic for improving service quality.
This study presents the results of a questionnaire about the
selection criteria of a calibration supplier. The questionnaire was
applied to 103 companies and the results are discussed in this paper.
The analysis was made with MINITAB 14.0 statistical programs.
“Competence of documentations" and “technical capability" are
defined as the prerequisites because of the ISO/IEC17025:2005
standard. Also “warranties and complaint policy", “communication",
“service features", “quality" and “performance history" are defined as
very important criteria for calibration supplier selection.
Abstract: Energy consumption rate during the cooling process
of industrial glass tempering process is considerably high. In this
experimental study the effect of dimensionless jet to jet distance
(S/D) and jet to plate distance (H/D) on the cooling time have been
investigated. In the experiments 4 mm thick glass samples have been
used. Cooling unit consists of 16 mutually placed seamless aluminum
nozzles of 8 mm in diameter and 80 mm in length. Nozzles were in
staggered arrangement. Experiments were conducted with circular
jets for H/D values between 1 and 10, and for S/D values between 2
and 10. During the experiments Reynolds number has been kept
constant at 30000. Experimental results showed that the longest
cooling time with 87 seconds has been observed in the experiments
for S/D=10 and H/D=10 values, while the shortest cooling time with
42.5 seconds has been measured in the experiments for S/D=2 and
H/D=4 values.
Abstract: In this paper, a new cooling system using a nacelle duct
is proposed for the mechanical room in the household refrigerator. The
conventional mechanical room consists of a condenser, a compressor
and an axial fan. The axial fan is mainly responsible for cooling the
condenser and the compressor. The new cooling system is developed
by replacing the axial fan with the nacelle duct including the small
centrifugal fan. The parametric study is carried out to find the optimum
designs of the nacelle duct in terms of performance and efficiency.
Through this study, it is revealed that the new system can reduce the
space, electrical power and noise compared with the conventional
system
Abstract: this paper aims to provide an approach to predict the
performance of the product produced after multi-stages of
manufacturing processes, as well as the assembly. Such approach
aims to control and subsequently identify the relationship between
the process inputs and outputs so that a process engineer can more
accurately predict how the process output shall perform based on the
system inputs. The approach is guided by a six-sigma methodology to
obtain improved performance.
In this paper a case study of the manufacture of a hermetic
reciprocating compressor is presented. The application of artificial
neural networks (ANNs) technique is introduced to improve
performance prediction within this manufacturing environment. The
results demonstrate that the approach predicts accurately and
effectively.
Abstract: Impact is one of very important subjects which always have been considered in mechanical science. Nature of impact is such that which makes its control a hard task. Therefore it is required to present the transfer of impact to other vulnerable part of a structure, when it is necessary, one of the best method of absorbing energy of impact, is by using Thin-walled tubes these tubes collapses under impact and with absorption of energy, it prevents the damage to other parts.Purpose of recent study is to survey the deformation and energy absorption of tubes with different type of cross section (rectangular or square) and with similar volumes, height, mean cross section thickness, and material under loading with different speeds. Lateral loading of tubes are quasi-static type and beside as numerical analysis, also experimental experiences has been performed to evaluate the accuracy of the results. Results from the surveys is indicates that in a same conditions which mentioned above, samples with square cross section ,absorb more energy compare to rectangular cross section, and also by increscent in speed of loading, energy absorption would be more.
Abstract: We consider a single-echelon, single-item inventory
system where both demand and lead-time are stochastic. Continuous
review policy is used to control the inventory system. The objective
is to calculate the reorder point level under stochastic parameters. A
case study is presented in Neonatal Intensive Care Unit.
Abstract: Inconel 718, a nickel based super-alloy is an
extensively used alloy, accounting for about 50% by weight of
materials used in an aerospace engine, mainly in the gas turbine
compartment. This is owing to their outstanding strength and
oxidation resistance at elevated temperatures in excess of 5500 C.
Machining is a requisite operation in the aircraft industries for the
manufacture of the components especially for gas turbines. This
paper is concerned with optimization of the surface roughness when
turning Inconel 718 with cermet inserts. Optimization of turning
operation is very useful to reduce cost and time for machining. The
approach is based on Response Surface Method (RSM). In this work,
second-order quadratic models are developed for surface roughness,
considering the cutting speed, feed rate and depth of cut as the cutting
parameters, using central composite design. The developed models
are used to determine the optimum machining parameters. These
optimized machining parameters are validated experimentally, and it
is observed that the response values are in reasonable agreement with
the predicted values.
Abstract: The objective of this research was to study influence
parameters affecting to mechanical property of austenitic stainless
steel grade 304 (AISI 304) with Gas Metal Arc Welding (GMAW).
The research was applying factorial design experiment, which have
following interested parameters: welding current at 80, 90, and 100
Amps, welding speeds at 250, 300, and 350 mm/min, and shield gas
of 75% Ar + 25% CO2, 70% Ar + 25% CO2 + 5% O2 and 69.5% Ar +
25% CO2 + 5% O2 + 0.5% He gas. The study was done in following
aspects: ultimate tensile strength and elongation. A research study of
ultimate tensile strength found that main factor effect, which had the
highest strength to AISI 304 welding was shield gas of 70% Ar +
25% CO2 + 5% O2 at average of 954.81 N/mm2. Result of the highest
elongation was showed significantly different at interaction effect
between shield gas of 69.5%Ar+25%CO2+5%O2+.5%He and
welding speed at 250 mm/min at 47.94%.
Abstract: Dynamics of a vapour bubble generated due to a high local energy input near a circular thin bronze plate in the absence of the buoyancy forces is numerically investigated in this paper. The bubble is generated near a thin bronze plate and during the growth and collapse of the bubble, it deforms the nearby plate. The Boundary Integral Equation Method is employed for numerical simulation of the problem. The fluid is assumed to be incompressible, irrotational and inviscid and the surface tension on the bubble boundary is neglected. Therefore the fluid flow around the vapour bubble can be assumed as a potential flow. Furthermore, the thin bronze plate is assumed to have perfectly plastic behaviour. Results show that the displacement of the circular thin bronze plate has considerable effect on the dynamics of its nearby vapour bubble. It is found that by decreasing the thickness of the thin bronze plate, the growth and collapse rate of the bubble becomes higher and consequently the lifetime of the bubble becomes shorter.
Abstract: Perceptions of quality from both designers and users
perspective have now stretched beyond the traditional usability,
incorporating abstract and subjective concepts. This has led to a shift
in human computer interaction research communities- focus; a shift
that focuses on achieving user experience (UX) by not only fulfilling
conventional usability needs but also those that go beyond them. The
term UX, although widely spread and given significant importance,
lacks consensus in its unified definition. In this paper, we survey
various UX definitions and modeling frameworks and examine them
as the foundation for proposing a UX evolution lifecycle framework
for understanding UX in detail. In the proposed framework we identify
the building blocks of UX and discuss how UX evolves in various
phases. The framework can be used as a tool to understand experience
requirements and evaluate them, resulting in better UX design and
hence improved user satisfaction.
Abstract: Electro Chemical Discharge Machining (ECDM) is an
emerging hybrid machining process used in precision machining of hard and brittle non-conducting materials. The present paper gives a
critical review on materials machined by ECDM under the prevailing machining conditions; capability indicators of the process are
reported. Some results obtained while performing experiments in micro-channeling on soda lime glass using ECDM are also presented. In these experiments, Tool Wear (TW) and Material Removal (MR)
were studied using design of experiments and L–4 orthogonal array. Experimental results showed that the applied voltage was the most influencing parameter in both MR and TW studies. Field
emission scanning electron microscopy (FESEM) results obtained on the microchannels confirmed the presence of micro-cracks, primarily responsible for MR. Chemical etching was also seen along the edges.
The Energy dispersive spectroscopy (EDS) results were used to detect the elements present in the debris and specimens.
Abstract: Tensile armour wires provide a flexible pipe's
resistance to longitudinal stresses. Flexible pipe manufacturers need
to know the effect of defects such as scratches and cracks, with
dimensions less than 0.2mm which is the limit of the current nondestructive
detection technology, on the fracture stress and fracture
strain of the wire for quality assurance purposes. Recent research
involving the determination of the fracture strength of cracked wires
employed laboratory testing and classical fracture mechanics
approach using non-standardised fracture mechanics specimens
because standard test specimens could not be manufactured from the
wires owing to their sizes. In this work, the effect of miniature
cracks on the fracture properties of tensile armour wires was
investigated using laboratory and finite element tensile testing
simulations with the phenomenological shear fracture model. The
investigation revealed that the presence of cracks shallower than
0.2mm is worse on the fracture strain of the wire.
Abstract: This paper provides a framework in order to
incorporate reliability issue as a sign of disruption in distribution
systems and partial covering theory as a response to limitation in
coverage radios and economical preferences, simultaneously into the
traditional literatures of capacitated facility location problems. As a
result we develop a bi-objective model based on the discrete
scenarios for expected cost minimization and demands coverage
maximization through a three echelon supply chain network by
facilitating multi-capacity levels for provider side layers and
imposing gradual coverage function for distribution centers (DCs).
Additionally, in spite of objectives aggregation for solving the model
through LINGO software, a branch of LP-Metric method called Min-
Max approach is proposed and different aspects of corresponds
model will be explored.
Abstract: The present paper concerns with the influence of fiber
packing on the transverse plastic properties of metal matrix
composites. A micromechanical modeling procedure is used to
predict the effective mechanical properties of composite materials at
large tensile and compressive deformations. Microstructure is
represented by a repeating unit cell (RUC). Two fiber arrays are
considered including ideal square fiber packing and random fiber
packing defined by random sequential algorithm. The
micromechanical modeling procedure is implemented for
graphite/aluminum metal matrix composite in which the
reinforcement behaves as elastic, isotropic solids and the matrix is
modeled as an isotropic elastic-plastic solid following the von Mises
criterion with isotropic hardening and the Ramberg-Osgood
relationship between equivalent true stress and logarithmic strain.
The deformation is increased to a considerable value to evaluate both
elastic and plastic behaviors of metal matrix composites. The yields
strength and true elastic-plastic stress are determined for
graphite/aluminum composites.
Abstract: The techniques for estimating the adhesive and cohesive strength in high velocity oxy fuel (HVOF) thermal spray coatings have been discussed and compared. The development trend and the last investigation have been studied. We will focus on benefits and limitations of these methods in different process and materials.
Abstract: Three dimensional analysis of thermal model in laser
full penetration welding, Nd:YAG, by transparent mode DP600 alloy
steel 1.25mm of thickness and gap of 0.1mm. Three models studied
the influence of thermal dependent temperature properties, thermal
independent temperature and the effect of peak value of specific heat
at phase transformation temperature, AC1, on the transient
temperature. Another seven models studied the influence of
discretization, meshes on the temperature distribution in weld plate.
It is shown that for the effects of thermal properties, the errors less
4% of maximum temperature in FZ and HAZ have identified. The
minimum value of discretization are at least one third increment per
radius for temporal discretization and the spatial discretization
requires two elements per radius and four elements through thickness
of the assembled plate, which therefore represent the minimum
requirements of modeling for the laser welding in order to get
minimum errors less than 5% compared to the fine mesh.
Abstract: The mechanical and tribological properties in WC-Co
coatings are strongly affected by hardness and elasticity
specifications. The results revealed the effect of spraying distance on
microhardness and elasticity modulus of coatings. The metallurgical
studies have been made on coated samples using optical microscopy,
scanning electron microscopy (SEM).