Abstract: To investigate the behavior of sheet metals during
forming tailor welded blanks (TWB) of various thickness made via
Co2 Laser welding are under consideration. These blanks are formed
used two different forming methods of rubber as well as the
conventional punch and die methods. The main research objective is
the effects of using a rubber die instead of a solid one the
displacement of the weld line and the press force needed for forming.
Specimens with thicknesses of 0.5, 0.6, 0.8 and 1mm are subjected to
Erichsen two dimensional tests and the resulted force for each case
are compared. This is followed by a theoretical and numerical study
of press force and weld line displacement. It is concluded that using
rubber pad forming (RPF) causes a reduction in weld line
displacement and an increase in the press force.
Abstract: A numerical analysis of a reinforced concrete (RC) wall under missile impact loading is presented in this study. The model created by Technical Research Center of Finland was used. The commercial finite element code, LS-DYNA was used to analyze. The structural components of the reinforced concrete wall, missile and their contacts are fully modeled. The material nonlinearity with strain rate effects considering damage and failure is included in the analysis. The results of analysis were verified with other research results. The case-studies with different reinforcement ratios were conducted to investigate the influence of reinforcement on the punching behavior of walls under missile impact.
Abstract: In industry, on of the most important subjects is die
and it's characteristics in which for cutting and forming different
mechanical pieces, various punch and matrix metal die are used.
whereas the common parts which form the main frame die are not
often proportion with pieces and dies therefore using a part as socalled
common part for frames in specified dimension ranges can
decrease the time of designing, occupied space of warehouse and
manufacturing costs. Parts in dies with getting uniform in their shape
and dimension make common parts of dies. Common parts of punch
and matrix metal die are as bolster, guide bush, guide pillar and
shank. In this paper the common parts and effective parameters in
selecting each of them as the primary information are studied,
afterward for selection and design of mechanical parts an
introduction and investigation based on the Mech. Desk. software is
done hence with developing this software can standardize the metal
common parts of punch and matrix. These studies will be so useful
for designer in their designing and also using it has with very much
advantage for manufactures of products in decreasing occupied
spaces by dies.
Abstract: In order to apply partially filled steel grid composite deck as the horizontal supporting structure of various kinds of infrastructures, the variation of its flexural strength according to design parameters such as cross and longitudinal bars constituting the steel grid and the type of shear connection is evaluated and compared experimentally. The result shows that the design sensitivity of the deck to the spacing of the cross bars is insignificant in the case of structure with low risk of punching failure or without load distribution problem. By means of shear connection composed by transverse rebar and longitudinal bar without additional shear stud bolts, the complete interaction between steel grid and concrete slab is able to be achieved and the composite deck can develop its bending resistance capacity.
Abstract: In this paper back-propagation artificial neural
network (BPANN) is employed to predict the limiting drawing ratio
(LDR) of the deep drawing process. To prepare a training set for
BPANN, some finite element simulations were carried out. die and
punch radius, die arc radius, friction coefficient, thickness, yield
strength of sheet and strain hardening exponent were used as the
input data and the LDR as the specified output used in the training of
neural network. As a result of the specified parameters, the program
will be able to estimate the LDR for any new given condition.
Comparing FEM and BPANN results, an acceptable correlation was
found.
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: This paper aims to study the methodology of building the knowledge of planning adequate punches in order to complete the task of strip layout for shearing processes, using progressive dies. The proposed methodology uses die design rules and characteristics of different types of punches to classify them into five groups: prior use (the punches must be used first), posterior use (must be used last), compatible use (may be used together), sequential use (certain punches must precede some others) and simultaneous use (must be used together). With these five groups of punches, the searching space of feasible designs will be greatly reduced, and superimposition becomes a more effective method of punch layout. The superimposition scheme will generate many feasible solutions, an evaluation function based on number of stages, moment balancing and strip stability is developed for helping designers to find better solutions.
Abstract: In a metal forming process, the friction between the
material and the tools influences the process by modifying the stress
distribution of the workpiece. This frictional behaviour is often taken
into account by using a constant coefficient of friction in the finite
element simulations of sheet metal forming processes. However,
friction coefficient varies in time and space with many parameters.
The Stribeck friction model is investigated in this study to predict
springback behaviour of AA6061-T4 sheets during V-bending
process. The coefficient of friction in Stribeck curve depends on
sliding velocity and contact pressure. The plane-strain bending
process is simulated in ABAQUS/Standard. We compared the
computed punch load-stroke curves and springback related to the
constant coefficient of friction with the defined friction model. The
results clearly showed that the new friction model provides better
agreement between experiments and results of numerical simulations.
The influence of friction models on stress distribution in the
workpiece is also studied numerically
Abstract: In automatic manufacturing and assembling of mechanical, electrical and electronic parts one needs to reliably identify the position of components and to extract the information of these components. Data Matrix Codes (DMC) are established by these days in many areas of industrial manufacturing thanks to their concentration of information on small spaces. In today’s usually order-related industry, where increased tracing requirements prevail, they offer further advantages over other identification systems. This underlines in an impressive way the necessity of a robust code reading system for detecting DMC on the components in factories. This paper compares two methods for estimating the angle of orientation of Data Matrix Codes: one method based on the Hough Transform and the other based on the Mean Shift Algorithm. We concentrate on Data Matrix Codes in industrial environment, punched, milled, lasered or etched on different materials in arbitrary orientation.
Abstract: The manufacturing transmission line tower parts has
being generated hazardous waste which is required proper disposal
of waste for protection of land pollution. Manufacturing Process in
the manufacturing of steel angle, plates, pipes, channels are passes
through conventional, semi automatic and CNC machines for
cutting, marking, punching, drilling, notching, bending operations.
All fabricated material Coated with thin layer of Zinc in Galvanizing
plant where molten zinc is used for coating. Prior to Galvanizing,
chemical like 33% concentrated HCl Acid, ammonium chloride and
d-oil being used for pretreatment of iron. The bath of water with
sodium dichromate is used for cooling and protection of the
galvanized steel. For the heating purpose the furnace oil burners are
used. These above process the Zinc dross, Zinc ash, ETP sludge and
waste pickled acid generated as hazardous waste. The RPG has
made captive secured land fill site, since 1997 since then it was
using for disposal of hazardous waste after completion of SLF
(Secured land fill) site. The RPG has raised height from ground
level then now it is being used for disposal of waste as he designed
the SLF after in creasing height of from GL it is functional without
leach ate or adverse impacts in the environment.
Abstract: Injection forging is a Nett-shape manufacturing
process in which one or two punches move axially causing a radial
flow into a die cavity in a form which is prescribed by the exitgeometry,
such as pulley, flanges, gears and splines on a shaft. This
paper presents an experimental and numerical study of the injection
forging of splines in terms of load requirement and material flow.
Three dimensional finite element analyses are used to investigate the
effect of some important parameters in this process. The experiment
has been carried out using solid commercial lead billets with two
different billet diameters and four different dies.
Abstract: The importance for manipulating an incorporated
scaffold and directing cell behaviors is well appreciated for tissue
engineering. Here, we developed newly nano-topographic oxidized
silicon nanosponges capable of being various chemical modifications
to provide much insight into the fundamental biology of how cells
interact with their surrounding environment in vitro. A wet etching
technique is exerted to allow us fabricated the silicon nanosponges in a
high-throughput manner. Furthermore, various organo-silane
chemicals enabled self-assembled on the surfaces by vapor deposition.
We have found that Chinese hamster ovary (CHO) cells displayed
certain distinguishable morphogenesis, adherent responses, and
biochemical properties while cultured on these chemical modified
nano-topographic structures in compared with the planar oxidized
silicon counterparts, indicating that cell behaviors can be influenced
by certain physical characteristic derived from nano-topography in
addition to the hydrophobicity of contact surfaces crucial for cell
adhesion and spreading. Of particular, there were predominant
nano-actin punches and slender protrusions formed while cells were
cultured on the nano-topographic structures. This study shed potential
applications of these nano-topographic biomaterials for controlling
cell development in tissue engineering or basic cell biology research.
Abstract: In this paper we study the resource allocation problem
for an OFDMA based cooperative two-way relaying (TWR) network.
We focus on amplify and forward (AF) analog network coding
(ANC) protocol. An optimization problem for two basic resources
namely, sub-carrier and power is formulated for multi-user TWR
networks. A joint optimal optimization problem is investigated and
two-step low complexity sub-optimal resource allocation algorithm is
proposed for multi-user TWR networks with ANC protocol. The
proposed algorithm has been evaluated in term of total achievable
system sum-rate and achievable individual sum-rate for each userpair.
The good tradeoff between system sum-rate and fairness is
observed in the two-step proportional resource allocation scheme.
Abstract: In this paper back-propagation artificial neural
network (BPANN) with Levenberg–Marquardt algorithm is
employed to predict the limiting drawing ratio (LDR) of the deep
drawing process. To prepare a training set for BPANN, some finite
element simulations were carried out. die and punch radius, die arc
radius, friction coefficient, thickness, yield strength of sheet and
strain hardening exponent were used as the input data and the LDR
as the specified output used in the training of neural network. As a
result of the specified parameters, the program will be able to
estimate the LDR for any new given condition. Comparing FEM and
BPANN results, an acceptable correlation was found.
Abstract: This paper deals with behavior and capacity of
punching shear force for flat slabs produced from steel fiber
reinforced self compacting concrete (SFRSCC) by application
nonlinear finite element method. Nonlinear finite element analysis on
nine slab specimens was achieved by using ANSYS software. A
general description of the finite element method, theoretical modeling
of concrete and reinforcement are presented. The nonlinear finite
element analysis program ANSYS is utilized owing to its capabilities
to predict either the response of reinforced concrete slabs in the post
elastic range or the ultimate strength of a flat slabs produced from
steel fiber reinforced self compacting concrete (SFRSCC). In order to
verify the analytical model used in this research using test results of
the experimental data, the finite element analysis were performed
then a parametric study of the effect ratio of flexural reinforcement,
ratio of the upper reinforcement, and volume fraction of steel fibers
were investigated. A comparison between the experimental results
and those predicted by the existing models are presented. Results and
conclusions may be useful for designers, have been raised, and
represented.
Abstract: The Programmable Logic Controller (PLC) plays a
vital role in automation and process control. Grafcet is used for
representing the control logic, and traditional programming
languages are used for describing the pure algorithms. Grafcet is used
for dividing the process to be automated in elementary sequences that
can be easily implemented. Each sequence represent a step that has
associated actions programmed using textual or graphical languages
after case. The programming task is simplified by using a set of
subroutines that are used in several steps. The paper presents an
example of implementation for a punching machine for sheets and
plates. The use the graphical languages the programming of a
complex sequential process is a necessary solution. The state of
Grafcet can be used for debugging and malfunction determination.
The use of the method combined with a set of knowledge acquisition
for process application reduces the downtime of the machine and
improve the productivity.
Abstract: Intelligent deep-drawing is an instrumental research field in sheet metal forming. A set of 28 different experimental data have been employed in this paper, investigating the roles of die radius, punch radius, friction coefficients and drawing ratios for axisymmetric workpieces deep drawing. This paper focuses an evolutionary neural network, specifically, error back propagation in collaboration with genetic algorithm. The neural network encompasses a number of different functional nodes defined through the established principles. The input parameters, i.e., punch radii, die radii, friction coefficients and drawing ratios are set to the network; thereafter, the material outputs at two critical points are accurately calculated. The output of the network is used to establish the best parameters leading to the most uniform thickness in the product via the genetic algorithm. This research achieved satisfactory results based on demonstration of neural networks.
Abstract: The purpose of this research study is to investigate the manner in which various loads affect the mechanical properties of the formed mild steel plates. The investigation focuses on examining the cross-sectional area of the metal plate at the centre of the formed mild steel plate. Six mild steel plates were deformed with different loads. The loads applied on the plates had a magnitude of 5 kg, 10 kg, 15 kg, 20 kg, 25 kg and 30 kg. The radius of the punching die was 120 mm and the loads were applied at room temperature. The investigations established that the applied load causes the Vickers microhardness at the cross-sectional area of the plate to increase due to strain hardening. Hence, the percentage increase of the hardness due to the load was found to be directly proportional to the increase in the load. Furthermore, the tensile test results for the parent material showed that the average Ultimate Tensile Strength (UTS) for the three samples was 308 MPa while the average Yield Strength and Percentage Elongation were 227 MPa and 38 % respectively. Similarly, the UTS of the formed components increased after the deformation of the plate, as such it can be concluded that the forming loads alter the mechanical properties of the materials by improving and strengthening the material properties.