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Corresponing author: Rakshith T E-mail address: rakshith7655@gmail.com

Doi: http://dx.doi.org/10.11127/ijammc.2016.04.15 Copyright@GRIET Publications. All rights reserved.

Advanced Materials Manufacturing & Characterization Vol 6 Issue 1 (2016)

Advanced Materials Manufacturing & Characterization

journal home page: www.ijammc-griet.com

Optimization Of Parameters For Elbow Component Using Manufacturing Simulation

Rakshith T.1 M. S. Srinath2 Y. Arunkumar3 Hemanth S Thulasi4

PG student, Dept. of IAR, Malnad College of Engineering, Hassan, India Professor, Dept. of Mechanical Engineering, Malnad College of Engineering, Hassan, India

Professor, Dept. of I&P, Malnad College of Engineering, Hassan, India Research Scholar, Dept. of Mechanical Engineering, Malnad College of Engineering, Hassan

A B S T R A C T

Pre forming state of a segment assumes a vital part in mass shaping

procedure. Pre forming operation in manufacturing of billet and

planning of die assumes an extensive part in forging procedure. The

parameters that are considered in designing and analysis of forging

dies are under fill, cracks flash allowance and uniform stress and strain.

In the present examination it was found that the impact of these

parameters would influence on the nature of forgings. To take

advantages of models and materials method, and to bring down the

expenses, computer simulation has been utilized, however, it copies the

real process and gives a watched worth for producing load, flash

allowance, unfilled zones and die cavity filling. Through computer

simulation it is conceivable to get powerful stress and strain

distribution in axis symmetric die forging. In the present work

compelling plan of lower and upper die on for a automotive module,

elbow and its proportionate billet outline has been made by utilizing

UNIGRAPHICS NX 8 CAD tool. These models are imported to general

purpose metal forming simulator software AFDEX-2014. Simulation of

closed die forging has been carried out by conveying all the vital

parameters like temperature, materials, lubricants, density and so on.

Several iterations have been done by changing the dimensions of initial

billet to reduce unfilled area, flash, even distribution of stress and

strain and also optimization of billet size has been achieved.

Keywords: Closed die forging; Elbow; AFDEX; Flash; Uniform stress distribution

1. INTRODUCTION

1.1 Forging is the working of metal into a valuable shape by

pounding or squeezing. It is considered as one of the most

established metal working arts [1]. Hot and warm producing

innovation has picked up parcel of potential as of late in

automobile and aviation industries [2]. In present day

scenario on account of immense necessities in the produced

part and centered towards the benefit, it has turn out to be

essential to advance the quality, expenses and lead time.

Normally forging procedure includes numerous pre-shaping

procedures which are then trailed by completing procedure.

1.2 Simulation has turn out to be essential instrument for the

improvement of new or enhancing procedures. Simulation is

being utilized to simulate number of shaping procedures

underway of segments like interfacing bars, razor sharp edge

and different parts utilizing different simulation software [3].

The simulation procedure will cut down the time and expense

of advancement of new products [4].

1.3 In producing procedure, obliged last shape is exceptionally

hard to acquire when the introductory conditions are not

changed in light of the fact that the beginning state of the

work piece impacts on the last shape. Inquires about were

done to diminish unfilled zone and flash for even dispersion

of stress and strain utilizing the ESL system.

1.4 Producing segments assumes an essential part in automotive

and aerospace industry. Upgrading the parameters is

imperative to enhance the nature of forged segments. A few

079

works has been done in this respects. A portion of the

overwhelming obligation segments which are utilized as a

part of car industry and other mechanical applications are

streamlined for expanded proficiency to convey high load

limit and high weakness resistance by refining the grain

structure [6].One such parameter is preformed shape, which

is improved by utilizing FE Simulation [5].Computer supported

simulation is utilized as a part of examining the material

stream in a few manufacturing operations [3]. Numerical

simulation methods are utilized for checking of voids

advancement while forging operations [6]. Shape

optimization of work piece is done by utilizing the

comparable static burden for manufacturing process [3].

Impact of the mold plan on the cementing of substantial

forging is done utilizing numerical simulation [4].

1.5 There are diverse programming or numerical systems

accessible for optimizing the procedures including DEFORM

3D, AFDEX, FORGE, STATISTICA, ANSYS, FEM, Monte Carlo

technique and numerous other methods[5],[6].

1.6 In this paper the parameters like billet shape, under fill,

strain, stress, die contact and hydrostatic pressure is

considered to simulate and analyze the closed die process.

Pre-structure shape and improvement of the outline assumes

a huge part in mass framing procedure for choosing the

measure of material devoured and energy alongside the

material stream analysis [5]. The main focus of the present

work is to diminish flash utilizing the assembling simulation

for the material AISI 1015 carbon steel (800 C - 1200 C) of the

elbow plan. 2. DESIGN METHODOLOGY

2.1 SIMULATION PROCEDURE In this investigation, the detailed steps involved to carry out

simulations highlighted in Fig.1. Preparatory stage part geometry

is considered for the investigation and after that CAD model is

created utilizing UG NX tool. Taking into account the model

suitable dies on are outlined in the same bundle. Contingent upon

the model chose and its capacity, material is chosen in such a

route to the point that the part can work. Regarding the material

organization and the property for the given item, dies material is

chosen.

Fig.1. Step by step procedure

involved in simulation of forging process.

Once the CAD model is prepared, the next step is to simulate the

process and AFDEX tool is used for simulation.

If there are any errors or deformities found, relating changes are

made in die configuration and/or in billet shape and size. Changes

has been done without much of a stretch be actualized in outline

stages to enhance the nature of finished product. This simulation

procedure is preceded till the minimum deformities are

accomplished.

If the minimum defects observed through the simulation, the item

goes into the CNC machine for production. The part drawing of the

elbow is considered for the present examination is indicated in Fig.

2.

All dimensions are in mm

Fig.2. Detail drawing of Elbow with different views

080

Table.1. Composition of Element Weight %

AISI Number AISI 1015

C 0.08

Mn 2.00

Si 1.00

Cr 16.0-18.0

Ni 10.0- 14.0

P 0.045

S 0.03

Mo 2.0-3.0

Table.2. Property of AISI 1015 Carbon steel

AISI Number AISI 1015

Young's Modulus 159250 MPA

Poisson's Ratio 0.3

Density 7850 Kgm/m^3

Coefficient of Thermal Expansion 1.8007E-5 /o C

Forging Temperature 800°-1200°C

Chemical composition of elbow component and property of AISI

1015 carbon steel is described in Table 1 and 2.

Carbon steels are steels that contain only carbon as their chief

alloying element. Traces of 0.4% silicon and 1.2% manganese are

present in these steels. Small quantities of copper, nickel,

molybdenum, aluminum and chromium can also be found in the

carbon steels.

AISI 1015 carbon steel is characterized with good mach inability

and formability and can be hardened by cyaniding.

2.2 MODELING IN UNIGRAPHICS NX8.0 One of the preparatory tasks in forging configuration method is

the transformation of the accessible machined part into produced

part. The important part parameters for forging envelope, corner

and filet radii and fitting draft edges are added to each machined

part cross segment. The ordinary transformation of the machined

part information into manufacturing information obliges a lot of

time. In the present CAD strategy, the procedure of

transformation is to a great extent improved by utilization of the

intelligence with the realistic screen. This methodology can be

connected to an extensive number of forging segments and the

information needed to do this change have been spared inside of

the computer, so that is accessible for less experienced clients.

The cross segment is acquired by a three dimensional machined

part geometry. This cross area should be altered to adjust to

process constraints. This procedure includes choice of the

separating lines, expansion of machining and draft allowance and

filet and corner radii. The determination of these parameters is

basic for getting desert free forgings.

The determination of this point relies upon the producing

material, the kind of forging gear and the unpredictability of the

manufacturing. The following adjustment to the cross area is the

disposal of every single sharp comer by including corner and filet

radii. These radii diminish stress fixations, influence die fill and

enhance die on life. The estimation of the comer radii has been

picked as 1.5 mm and for filet radii as 2 mm. The procedure for

applying these radii is done in the UG NX tool, where it should be

possible by selecting two lines.

Machine recompense of 2 mm is included while simulating for all

sides of the segment. In any case, for assembling reason the

allowance is included depending on physical structure of the part.

STL records the introduction ought to be in Y-heading as the load

connected would be in this course. It is even conceivable to situate

the parts inside of the AFDEX yet to keep away from the

unpredictability and to make it less demanding as arranged in NX 8

product such that the lower die starts out, trailed by the billet and

on top upper die on all arranged in Y-course. When the dies and

billets are planned in NX 8 the parts are spared exclusively as

".STL" document expansion. The spared .STL documents are

stacked to the AFDEX programming library.

3. OPTIMIZATION OF FORGING PROCESS

3.1 Analysis of the forging process

Forging procedure is for the most part partitioned away from any

confining influence open die forging and closed die forging. Figure

3 shows the schematic representation of the open die and closed

die forging. Billet is squeezed to obliged shape by the utilization of

power. Preformed billet put a critical part as it help in decrease of

the strengths furthermore help saving the material. Typically

preformed billet are created utilizing the open die forging or

rolling operations. In least complex structure closed die forging is

normally considered as impression die producing. The parts

delivered by closed die forging have high quality and great weight

proportion when contrasted with other machined parts. Closed die

forging is more favored than open die forging. Be that as it may,

closed die forging is not temperate, introductory and support

expense is high relatively. The preformed billet is acquired as

demonstrated in the Fig. 4.

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Fig.3. Schematic representation of the forging

Fig.4. Preformed billet using the rolling operation

3.2 Optimization process of forging using the equivalent static loads for the displacements

In the present work the improvement of production procedure is

considered by utilizing the Equivalent Static Loads (ESL). ESL is for

the removal of static burden direct examination which produces

the equivalent nodal relocation under a dynamic load at a

discretionary time of nonlinear element investigation. The

representing mathematical statement nonlinear element

examination is as shown in equation 1.

M(b)Z"N(t)+C(b)Z'N(t)+K(b,ZN(t))ZN(t)=f(t) --------(1)

(t=t0,t1,. . . . tl)

Where, M is the mass grid, C is the damping grid, K is the stiffness

grid, Z" nodal accelerating vector, Z' nodal speed vector and the

consistent L is the aggregate number of time ventures for the

obliged focuses. Steps that are to be received for various loading

conditions utilized as a part of linear response optimization

process [6].

This innovation is proposed to fulfill the process in upgrading the

successful strain conditions. Proportionate static loads cannot

create the same impact strain both on direct and nonlinear

examination. Displacement vector for direct solidness grids are

distinctive, though for nonlinear stiffness grids are same.

Nodal removal vector can be ascertained from linear static

analysis. Stress and strains are computed from examining the two

productive mathematical statements.

In this paper elbow is considered for the configuration, the billet is

preformed to the obliged shape utilizing the rolling operation.

Figure 6 & 7 demonstrates the 3D model of the upper and lower

die of the present work.

Fig. 6. Isometric view of Elbow upper die profile

Fig.7. Isometric view of Elbow lower die profile

4. SIMULATION The upper die on development prompts metal stream of pattern

into the die cavity and flash is contemplated through the

simulation procedure by utilizing the AFDEX metal shaping

simulation environment. The Table 3 displays the parameter

chose for the simulation. The models are expressed as a part,

which includes loading the part from the NX and changing over

the document to .STL arrangement to the AFDEX tool.

Introductory phase of recreation prompts the component 3D

tetrahedral meshing as shown in the Fig. 8.

082

Fig.8. simulation process Mesh Generation during

Table.3. Simulation settings and Input parameters.

Type of forming Hot Forging

Type of Simulation 3D with flash

Type of analysis Flow analysis

Deformation Rigid Plastic

Billet material Material AISI 1015 carbon

steel

(T=800°-1200°C)

Translational

velocity

300 mm/sec in y direction

Lubrication used Soap cold(Steel)

Fig.9. (1) Detailed view of 3D tetrahedral mesh

generation

(2) Zoomed view of meshed elbow part

5. RESULTS AND DISCUSSIONS 5.1 Results of under fill and Flash

Under fill is a deformity, which is similar to misrun in tossing and

happens when metal does not absolutely fill of die cavity. Three

iterations have been carried out to find out the effective utilization

of die and elbow. It is finished with the billet estimation of Ø 26

mm and 58 mm with total weight 417gms in which flash weight of

28gms were seen with the perfect filling of hole is reduced to 6%

of flash. Figure 10 shows the simulation result for filled and under

filled zone. In this cycle streamlining of total weight 417gms is

refined where the section weight is 395 gms.

Fig.10. Representation of filled areas

5.2 Results of Effective Strain and Stress

Shape enhancement is performed utilizing the ESL innovation for

compelling stress and strain as expressed in the procedure. While

performing the simulation, the outcome for the successful strain is

gotten as indicated in Fig.11. The uniform dispersion of strain and

shaping impact on the web is proportional. In every phase of

simulation, optimization of work piece ought to be done, keeping

in mind the end goal to complete equivalent distribution of

compelling strain. In forging process even conveyance of strain

and material property are vital foundation. However improvement

of diverse outline variables can be broke down.

083

Fig.11. Simulation result of effective strain

Initially emphasis simulation results with the most extreme strain

rate of 6.032 and least strain rate of 1×10-4. Second cycle

simulation result with most extreme strain of 4.723 and least

strain rate of 1×10-4. Third emphasis reform results with greatest

strain estimation of 3.902 and least strain estimation of 1×10-4.

Three iterations have been carried out nearly 35% of difference is

obtained from first iteration to last iteration. To get an effective

component billet dimension of Ø 26 mm and 58 mm is preferred.

Essentially Fig.12 demonstrates the compelling stress

appropriation for the elbow segment is uniform, it can be seen

that greatest stress accomplished is 257.9 MPa as the actual

component dimension is very close to simulated dimension.

Fig.12. Simulation result of effective stress

It can be seen that there is uniform appropriation of stress all

through the part with the exception of a few spots of elbow

corner. It can be observed that the flash is very little and it does

not spill out from the flash gutter nor there are any cracks

distinguished in the part. For optimum stress value of component,

it has found that 16% of difference is obtained by taking billet

dimension of Ø 26 mm and 58 mm.

5.3 Results of Effective Die contact and Hydrostatic pressure

Fig.13. Simulation result of effective die contact

Fig.14. Simulation result of Hydrostatic pressure

Like molds and configurations, dies on are generally changed and

phenomenally composed to the things they are used to make.

Powerful contact between the upper and lower die made

conceivable to get entrenched results.

The twisting in closed die is extremely complicated and along

these lines is very intricate and subsequently outlining closed die

forging and moderate steps are exceptionally discriminating and

obliges high ability. Ideal geometry of the die aftereffect of fitting

comprehension of flow stress, friction conditions and flow of the

metal in the die is considered most extreme weight connected to

get to obliged elbow part is 8.01×102 N/mm2 is obtained by taking

billet dimension of

Ø 26 mm and 58 mm.

6. Load and Stroke Curve As indicated in the Fig 15 streak arrangement happens at point P1,

as die forging come in close contact, the load increments pointedly

at P2 where the die fills totally. Point P3 identifies the last load

needed for the culmination of manufacturing procedure.

084

Fig.15. Result of load v/s stroke in Y-direction

It is observed from Fig.15, flash begins at the stroke estimation of

0.08s and pretty almost at the load of 2.5×101 tons identified as

point P1, die fills absolutely at point P2 with the harsh stroke

estimation of 0.10s and at the induced load estimation of 1×102

tons. Most prominent load required for the summit of creating

technique is 2×102 tons.

Table 4.2: Simulation results.

Iteration

No.

Dia

(mm)

Flash

%

Effective

Strain

Effective

Stress

N/mm2

Hydrostatic

pressure

N/mm2

1 30 28 6.032 2.57×102 2.37×102

2 28 18 4.723 1.97×102 7.87×102

3 26 06 3.902 2.09×102 8.01×102

7. CONCLUSION The important parameters for creation of the elbow component

have been effectively analyzed through AFDEX simulation tool. The

discriminating part is totally filled and there are no under fill in the

corner area of elbow. There are few spots underneath the center

area and it is in the admissible locale of the last obliged segment.

From three iterations it has been observed that the flash

percentage has reduced from 28% to 6% and the component is

effectively filled in the section. However the third cycle comprises

of the minimum effective stress value of 2.09×102N/mm2, last

emphasis comprise of slightest compelling strain estimation of

3.902. Hydrostatic pressure finally applied is 8.01×102 N/mm2. The

outcomes can be assessed by leading analyses considering modern

genuine issues. AFDEX simulation software is found to be to a

great degree helpful in simulation process.

In routine system it is exceptionally hard to get exact shape

advancement for production procedure. In spite of the fact that it

takes additional time and expense will be high. Thus proportionate

static load shape optimization procedure ought to be favored, it

diminishes both time and cost of the forging procedure.

Consequently with the help of simulation tool one can explore

advance technique and die parameters in closed die forging and

can enhance the productivity.

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