Abstract: Within this work High Temperature Single Impact
Studies were performed to evaluate deformation mechanisms at
different energy and momentum levels. To show the influence of
different microstructures and hardness levels and their response to
single impacts four different materials were tested at various
temperatures up to 700°C. One carbide reinforced NiCrBSi based
Metal Matrix Composite and three different steels were tested. The
aim of this work is to determine critical energies for fracture
appearance and the materials response at different energy and
momenta levels. Critical impact loadings were examined at elevated
temperatures to limit operating conditions in impact dominated
regimes at elevated temperatures. The investigations on the
mechanisms were performed using different means of microscopy at
the surface and in metallographic cross sections. Results indicate
temperature dependence of the occurrence of cracks in hardphase
rich materials, such as Metal Matrix Composites High Speed Steels
and the influence of different impact momenta at constant energies
on the deformation of different steels.
Abstract: Present study focuses on studying the oscillatory
behavior of jet diffusion flames. At a particular jet exit velocity, the
flames are seen to exhibit natural flickering. Initially the flickering
process is not continuous. In this transition region as well as in the
continuous flickering regime, the flickering displays multiple
frequency oscillations. The response of the flame to the exit velocity
profile of the burner is also studied using three types of burners. The
entire range of natural flickering is investigated by capturing high
speed digital images and processing them using a MATLAB code.
Abstract: This paper suggests a fast and stable Target Tracking
system in collaborative control of UAV and UGV. Wi-Fi communication range is limited in collaborative control of UAV and UGV. Thus, to secure a stable communications, UAV and UGV have
to be kept within a certain distance from each other. But existing
method which uses UAV Vertical Camera to follow the motion of
UGV is likely to lose a target with a sudden movement change.
Eventually, UGV has disadvantages that it could only move at a low
speed and not make any sudden change of direction in order to keep
track of the target. Therefore, we suggest utilizing AR Drone UAV front camera to track fast-moving and Omnidirectional Mecanum
Wheel UGV.
Abstract: Presents a concept for a multidisciplinary process
supporting effective task transitions between different technical
domains during the architectural design stage.
A system configuration challenge is the multifunctional driven
increased solution space. As a consequence, more iteration is needed
to find a global optimum, i.e. a compromise between involved
disciplines without negative impact on development time. Since state
of the art standards like ISO 15288 and VDI 2206 do not provide a
detailed methodology on multidisciplinary design process, higher
uncertainties regarding final specifications arise. This leads to the
need of more detailed and standardized concepts or processes which
could mitigate risks.
The performed work is based on analysis of multidisciplinary
interaction, of modeling and simulation techniques. To demonstrate
and prove the applicability of the presented concept, it is applied to
the design of aircraft high lift systems, in the context of the
engineering disciplines kinematics, actuation, monitoring, installation
and structure design.
Abstract: In this paper, quantitative evaluation of ultrasonic Cscan
images through estimation of their Fractal Dimension (FD) is
discussed. Necessary algorithm for evaluation of FD of any 2-D
digitized image is implemented by developing a computer code. For
the evaluation purpose several C-scan images of the Kevlar
composite impacted by high speed bullet and glass fibre composite
having flaw in the form of inclusion is used. This analysis
automatically differentiates a C-scan image showing distinct damage
zone, from an image that contains no such damage.
Abstract: This paper presents a new adaptive impedance control
strategy, based on Function Approximation Technique (FAT) to
compensate for unknown non-flat environment shape or time-varying
environment location. The target impedance in the force controllable
direction is modified by incorporating adaptive compensators and the
uncertainties are represented by FAT, allowing the update law to be
derived easily. The force error feedback is utilized in the estimation
and the accurate knowledge of the environment parameters are not
required by the algorithm. It is shown mathematically that the
stability of the controller is guaranteed based on Lyapunov theory.
Simulation results presented to demonstrate the validity of the
proposed controller.
Abstract: Thin linear-elastic cylindrical circular shells having a
micro-periodic structure along two directions tangent to the shell
midsurface (biperiodic shells) are object of considerations. The aim
of this paper is twofold. First, we formulate an averaged nonasymptotic
model for the analysis of parametric vibrations or dynamical
stability of periodic shells under consideration, which has constant
coefficients and takes into account the effect of a cell size on the
overall shell behavior (a length-scale effect). This model is derived
employing the tolerance modeling procedure. Second we apply the
obtained model to derivation of frequency equation being a starting
point in the analysis of parametric vibrations. The effect of the microstructure
length oh this frequency equation is discussed.
Abstract: Interactive CAD systems have to allocate and
deallocate memory frequently. Frequent memory allocation and
deallocation can play a significant role in degrading application
performance. An application may use memory in a very specific way
and pay a performance penalty for functionality it does not need. We
could counter that by developing specialized memory managers.
Abstract: Nowadays, power systems, energy generation by wind
has been very important. Noting that the production of electrical
energy by wind turbines on site to several factors (such as wind speed
and profile site for the turbines, especially off the wind input speed,
wind rated speed and wind output speed disconnect) is dependent. On
the other hand, several different types of turbines in the market there.
Therefore, selecting a turbine that its capacity could also answer the
need for electric consumers the efficiency is high something is
important and necessary. In this context, calculating the amount of
wind power to help optimize overall network, system operation, in
determining the parameters of wind power is very important.
In this article, to help calculate the amount of wind power plant,
connected to the national network in the region Manjil wind,
selecting the best type of turbine and power delivery profile
appropriate to the network using Monte Carlo method has been.
In this paper, wind speed data from the wind site in Manjil, as minute
and during the year has been. Necessary simulations based on
Random Numbers Simulation method and repeat, using the software
MATLAB and Excel has been done.
Abstract: Lean, which was initially developed by Toyota, is
widely implemented in other companies to improve competitiveness.
This research is an attempt to identify the adoption of lean in the
production system of Malaysian car manufacturer, Proton using case
study approach. To gain the in-depth information regarding lean
implementation, an activity on the assembly line called Set Parts
Supply (SPS) was studied. The result indicates that by using lean
principles, tools and techniques in the implementation of SPS enabled
to achieve the goals on safety, quality, cost, delivery and morale. The
implementation increased the size of the workspace, improved the
quality of assembly and the delivery of parts supply, reduced the
manpower, achieved cost savings on electricity and also increased the
motivation of manpower in respect of attendance at work. A
framework of SPS implementation is suggested as a contribution for
lean practices in production system.
Abstract: Modular fixtures (MFs) are very important tools in
manufacturing processes in terms of reduction the cost and the
production time. This paper introduces an automated approach for
assembling MFs elements by employing SolidWorks as a powerful
3D CAD software. Visual Basic (VB) programming language was
applied integrating with SolidWorks API (Application programming
interface) functions. This integration allowed creating plug-in file and
generating new menus in the SolidWorks environment. The menus
allow the user to select, insert, and assemble MFs elements.
Abstract: Power transformer consists of components which are
under consistent thermal and electrical stresses. The major
component which degrades under these stresses is the paper
insulation of the power transformer. At site, lightning impulses and
cable faults may cause the winding deformation. In addition, the
winding may deform due to impact during transportation. A
deformed winding will excite more stress to its insulating paper thus
will degrade it. Insulation degradation will shorten the life-span of
the transformer. Currently there are two methods of detecting the
winding deformation which are Sweep Frequency Response
Analysis (SFRA) and Low Voltage Impulse Test (LVI). The latter
injects current pulses to the winding and capture the admittance
plot. In this paper, a transformer which experienced overheating and
arcing was identified, and both SFRA and LVI were performed.
Next, the transformer was brought to the factory for untanking. The
untanking results revealed that the LVI is more accurate than the
SFRA method for this case study.
Abstract: This paper presents the study of hardness profile of spur gear heated by induction heating process in function of the machine parameters, such as the power (kW), the heating time (s) and the generator frequency (kHz). The global work is realized by 3D finite-element simulation applied to the process by coupling and resolving the electromagnetic field and the heat transfer problems, and it was performed in three distinguished steps. First, a Comsol 3D model was built using an adequate formulation and taking into account the material properties and the machine parameters. Second, the convergence study was conducted to optimize the mesh. Then, the surface temperatures and the case depths were deeply analyzed in function of the initial current density and the heating time in medium frequency (MF) and high frequency (HF) heating modes and the edge effect were studied. Finally, the simulations results are validated using experimental tests.
Abstract: Aiming at most of the aviation products are facing the problem of fatigue fracture in vibration environment, we makes use of the testing result of a bracket, analysis for the structure with ANSYS-Workbench, predict the life of the bracket by different ways, and compared with the testing result. With the research on analysis methods, make an organic combination of simulation analysis and testing, Not only ensure the accuracy of simulation analysis and life predict, but also make a dynamic supervision of product life process, promote the application of finite element simulation analysis in engineering practice.
Abstract: Above Elbow Prosthesis is one of the most commonly
amputated or missing limbs. The research is done for modelling
techniques of upper limb prosthesis and design of high torque, light
weight and compact in size elbow actuator. The purposed actuator
consists of a DC motor, planetary gear set and a harmonic drive. The
calculations show that the actuator is good enough to be used in real
life powered prosthetic upper limb or rehabilitation exoskeleton.
Abstract: The objective of this paper is to estimate realistic
principal extrusion process parameters by means of artificial neural
network. Conventionally, finite element analysis is used to derive
process parameters. However, the finite element analysis of the
extrusion model does not consider the manufacturing process
constraints in its modeling. Therefore, the process parameters
obtained through such an analysis remains highly theoretical.
Alternatively, process development in industrial extrusion is to a
great extent based on trial and error and often involves full-size
experiments, which are both expensive and time-consuming. The
artificial neural network-based estimation of the extrusion process
parameters prior to plant execution helps to make the actual extrusion
operation more efficient because more realistic parameters may be
obtained. And so, it bridges the gap between simulation and real
manufacturing execution system. In this work, a suitable neural
network is designed which is trained using an appropriate learning
algorithm. The network so trained is used to predict the
manufacturing process parameters.
Abstract: Sharing the manufacturing facility through remote
operation and monitoring of a machining process is challenge for
effective use the production facility. Several automation tools in term
of hardware and software are necessary for successfully remote
operation of a machine. This paper presents a prototype of workpiece
holding attachment for remote operation of milling process by self
configuration the workpiece setup. The prototype is designed with
mechanism to reorient the work surface into machining spindle
direction with high positioning accuracy. Variety of parts geometry
is hold by attachment to perform single setup machining. Pin type
with array pattern additionally clamps the workpiece surface from
two opposite directions for increasing the machining rigidity.
Optimum pins configuration for conforming the workpiece geometry
with minimum deformation is determined through hybrid algorithms,
Genetic Algorithms (GA) and Particle Swarm Optimization (PSO).
Prototype with intelligent optimization technique enables to hold
several variety of workpiece geometry which is suitable for
machining low of repetitive production in remote operation.
Abstract: An optical fiber Fabry-Perot interferometer (FFPI) is
proposed and demonstrated for dynamic measurements in a
mechanical vibrating target. A polishing metal with a low reflectance
value adhered to a mechanical vibrator was excited via a function
generator at various excitation frequencies. Output interference
fringes were generated by modulating the reference and sensing
signal at the output arm. A fringe-counting technique was used for
interpreting the displacement information on the dedicated computer.
The fiber interferometer has been found the capability of the
displacement measurements of 1.28 μm – 96.01 μm. A commercial
displacement sensor was employed as a reference sensor for
investigating the measurement errors from the fiber sensor. A
maximum percentage measurement error of approximately 1.59 %
was obtained.
Abstract: Conventionally the selection of parameters depends
intensely on the operator-s experience or conservative technological
data provided by the EDM equipment manufacturers that assign
inconsistent machining performance. The parameter settings given by
the manufacturers are only relevant with common steel grades. A
single parameter change influences the process in a complex way.
Hence, the present research proposes artificial neural network (ANN)
models for the prediction of surface roughness on first commenced
Ti-15-3 alloy in electrical discharge machining (EDM) process. The
proposed models use peak current, pulse on time, pulse off time and
servo voltage as input parameters. Multilayer perceptron (MLP) with
three hidden layer feedforward networks are applied. An assessment
is carried out with the models of distinct hidden layer. Training of the
models is performed with data from an extensive series of
experiments utilizing copper electrode as positive polarity. The
predictions based on the above developed models have been verified
with another set of experiments and are found to be in good
agreement with the experimental results. Beside this they can be
exercised as precious tools for the process planning for EDM.
Abstract: Analytical solution of the first-order and third-order
shear deformation theories are developed to study the free vibration
behavior of simply supported functionally graded plates. The
material properties of plate are assumed to be graded in the thickness
direction as a power law distribution of volume fraction of the
constituents. The governing equations of functionally graded plates
are established by applying the Hamilton's principle and are solved
by using the Navier solution method. The influence of side-tothickness
ratio and constituent of volume fraction on the natural
frequencies are studied. The results are validated with the known
data in the literature.