Forging simulation of Rocker arm using AFDEX software

Transcription

1 Forging simulation of Rocker arm using AFDEX software Basavasagar 1, Prof. Bharat S Kodli 2 1M.TECH Scholar, Production Engineering, Department of Mechanical Engineering, PDA College of Engineering Gulbarga , Karnataka-INDIA 2Professor, PG Coordinator, Production Engineering, Department of Mechanical Engineering, PDA College of Engineering Gulbarga , Karnataka-INDIA Abstract-.The purpose of this paper is to simulate the closed die forging process, prediction of defect and eliminating it to increase the product life. The task is to simulate the Rocker arm using AFDEX software. To achieve this objective CAD technology is combined with this process simulation tools to enable modeling of rocker arm.the structure of the rocker arm model was performed using catia. Then forging simulation was performed using AFDEX. Keywords : (AFDEX, CATIA, Rockerarm, stress) I. INTRODUCTION Forging is defined as a metal working process in which the useful shape of work piece is obtained in solid state by compressive forces applied through the use of dies and tools. Forging process is accomplished by hammering or pressing the metal. It is one of the oldest known metalworking processes with its origin about some thousands of years back. Traditionally, forging was performed by a smith using hammer and anvil. Forging process produces parts of superior mechanical properties with minimum waste of material. In this process, the starting material has a relatively simple geometry; this material is plastically deformed in one or more operations into a product of relatively complex configuration. Forging usually requires relatively expensive tooling. Thus, the process is economically attractive when a large number of parts must be produced and/or when the mechanical properties required in the finished product can be obtained only by a forging process [1]. A forging die and a rectangular billet are modeled. Die/billet interface contact friction, and die geometry are varied to determine the effects of these variables on material flow, stress, strain, and die force. An attempt has been made to compute the load requirement in the closed die forging process by using MSC Super Forge during different stages of the process [2]. In the previous days in research works a three dimensional model using MSC/ DYNA is used to closed die forging process. There are so many forging simulation software like ansys, MSc,super forge etc,are used to stimulate a forging simulation of closed die forging process but in these simulation of rocker arm it can besimulated using AFDEX (Advisor as friend for forging design expert ) software. The main objective of these paper is to stimulate and analyzing of closed die forging process [3].Forging is affected by so many parameters such as work piece,temperature, Friction between die andwork piece and preformed billet. The 3D modeling of rocker arm and die sets are performed by CATIA software, after simulation and analysis of rocker arm performed by AFDEX Software.These software has a capability of identifying die filling, die contact and defect formation etc. These software is also used to displays a variety of parameters like strain rate, effective stress and temperature, shear stress and final shape of component. II.SIMULATION Metal forming software (AFDEX-2012) will be used in this project to design and simulate the metal forging process. AFDEX is a general purpose metal forming simulator, which can be applied not only to conventional bulk metal forming processes including forging, rolling, extrusion, and drawing, but also to new creative bulk metal forming processes. AFDEX is theoretically based on the rigid-thermoviscoplastic finite element method. AFDEX can solve the metal flow and heat transfer problems present in metal forming and die structural analysis[4]. III. METHODOLOGY In the present simulation of rocker arm using AFDEX Software the below shown figure (1) represents a flow chart of steps involved in simulation according to flow chart simulation was performed.as from flow chart initially we design a cad model of rocker arm by given 2d drafting of rocker arm as shown in figure. From the modeled rocker arm we extract a suitable dies.according to the process, materialcomposition, and properties given for the product selecting a suitable die material. Finally simulation is carried on AFDEX (Advisor as friend for Forging Design Experts). If any defects are present, changes are made in the dies. This leads to improved results in the final product. The forging simulation process will continue till we get product with least defects.after successful simulation of rocker arm it gives the least defects the rocker arm proceeds to the mass production.figures shows 2d drafting of rocker arm considered for the analysis.. The work piece material considered for the present analysis is AISI 1015 low-carbon steel. The chemical composition, Mechanical properties of AISI 1015 low-carbon steel are presented in Table 1 and Table 2. ISSN: Page 169

2 Iron 99.13% Carbon Mn Sulfur Phosphorus Table: 2 Mechanical Properties OF AISI 1015 low carbon steel Tensile strength Yield strength 385 Mpa 325 Mpa Hardness rockwell 111 Density 7.87g/cc Fig: 1 Methodology. Possions ratio 0.30 Forging temperature Modeling in CATIA software 3D modeling software CATIA is used to model the part, billet, and dies. Modeled components are shown in below Figures. Fig: 2 Part drawing of rocker arm. Table :1 chemical properties of AISI 1015 STEEL. Fig: 3 3D Model of Rocker Arm ISSN: Page 170

3 they are aligned manually. So care must be taken while modeling dies and billet in CATIA. Fig:.4 : 3D Model of billet. As the given part has along Y axis, a rectangular billet is used. Dies and billets are drawn in such a manner that they are all aligned in the same axis. As AFDEX accepts only.stl files, upper die, lower die and billet are saved with.stl extension. All the files of dies and billets with.stl extension are imported to AFDEX database [4]. Table: 4 Forging Parameters. Type of Forging Hot Close-Die- Forging (HCDF) Work Piece Material AISI 1015 (T= C) Die Material Tool steel H 13 Press Type Friction Type Crank press Graphite water hot Steel Fig:5 3D Model of Die sets. For the simulation of rocker arm in the catia software some changes has to be made because the rocker arm contains hole and some intricate portions these cannot be forged because it has considered as machining allowances and the forged part in the figure shown. The forged part has to be added extra material in the rocker arm and fillet and giving radius to the Rocker arm as shown in figure. Fig :6 Forging component involved all allowances. Coefficient of Friction 0.7 Draft angle for die for ease of ejection IV.RESULT AND DISCUSSION 5-7 degree Temperature Stroke(-Y) 1.26 mm A. EFFECTIVE STRESS Figure (7) shows effective stress of the rocker arm that ensures the stress on the rocker arm while forging. In figure 5 shows the billet is forged and the effective stress is E+2 in 4.29 seconds with complete flash around the billet that ensures the better strength of Rocker arm. The different color highlights effective stress at each intersection point of die contact with billet and the global coordinates shows the values of effective stress at different orientation of rocker arm.in the analysis of rocker arm stress is always less than the effective stress of material. Even though AFDEX allows dies and billets to move in X, Y and Z directions and rotate about X, Y and Z directions it causes lot of problems in positioning, if ISSN: Page 171

4 C. UNDER FILL. Figure 9 shows the completely filled state of material without any cavity on surface of billet, by this it results better strength of the rocker arm.the below figure shows9(a) billet is goimg to forged between between upper and lower dies and figure 9(b) shows forged rocker arm with completely cavity filled9(a)and white colour indicates unfilled and green colour indicates filled. Fig: 7 Effective stress of forged rocker arm. B. TEMPERATURE The temperature gradient is a physical quantity that describes in which direction and at what rate temperature changes most rapidly around the particular location. Temperature is an objective comparative measure of hot or cold. In Fig 8 it shows the accurate temperature at each node of billet the temperature changes on the rate of stroke and the die contact on the work material. The different color indicates the temperature changes on billet with according to the change in stroke rate. The maximum temperature changes are found at the die contact with maximum stress on the billet at initial stages the flash is less and the temperature is comparatively low. In fig the rate of volume of billet is increased and the time of stroke is also increased for this temperature gradient on billet is also increased. Fig :9(a) Billet is going to forged between upper and lower dies. Fig : 9(b) complete filled rocker arm. D. HYDROSTATIC PRESUURE. The figure(10) shows hydrostatic pressure of completely filled forged rocker arm it forged between upper and lower dies and it takes to complete a forging is in 4.28 seconds and it shows mpa as shown in figure and hydrostatic presuure is varying in its values according to stage wise.rocker arm requires mpa of hydrostatic pressure is require to forged between between upper and lower dies and takes 4.28 seconds..fig :8 temperature of rocker arm ISSN: Page 172

5 Fig : 10Hydrostatic pressure of Rocker arm. E.NODAL VELACITY. The below figure shows nodal velacity of rocker arm as shown in below figure (11) and it was forged brtween upper and lower dies and it takes time 4.28 seconds and nodal velacity is showing at the end of forging of third stage at the rate of 2.56 mm/ s the above nodal velacity shows the thesemuch of velacoty is required to forge a rocker arm. V.CONCLUSION Fig: 12 Load v/s Stroke diagram. In the present work 3D model of rocker arm component is simulated with AFDEX software to study on forging simulation and overall functionality of rocker arm.. Notable conclusions from this study are By adopting the AFDEX simulation software, it is possible to evaluate the flow analysis of material at each stage. Therefore distribution was good and no defect is observed. From the above results it can be concluded that the die cavity is completely filled because stress is less than the ultimate stress of material. The results reducing defects by complete filling of material is achieved and has good strength of workability. REFERENCES Fig : 11Nodal velacity of rocker am. F. GRAPHS The below figure (12) shows load v/s stroke its very important in the simulation of rocker arm because the rocker arm is forged between upper and lower dies. It takes to forge a rocker arm is 4.28 seconds and it takes load of 2.10 tons / s to forge a rocker arm. [1]. forging process withtheir defects mahendra g rathi. [2]. simulation of stud bolt and nut using afdex software uday.m and m..r doddamani. [3]. simulation of connecting rod using afdex Mahesh.m.p Profbharat.s.kodli. [4]. `. [5] Valuvetronic engine technology A.M.N Venkatasiva sandeep 1, Ramesh. [6] Design and data hand book by k.balaveerreddy. [7] data given from dhio research and engineering pvt ltd Bangalore. [08] Hot Closed die forging process b.tomov ISSN: Page 173