Simulation Driven Innovation 1

Forming Simulation of Front Hood of a Missile

Abhishek Kumar Scientist ‘C’

DRDO Kanchanbagh

Hyderabad

Ch. Venkateswarlu Scientist ‘D’

DRDO Kanchanbagh, Hyderabad

B. Shiv Dayal Rao Scientist ‘F’

DRDO Kanchanbagh

Hyderabad

Dr. K Ramesh Kumar Scientist ‘G’

DRDO Kanchanbagh,

Hyderabad

Keywords: Forming, Maraging Steel, HyperForm, Simulation The paper deals with forming simulation of front hood. The front hood is one of the critical

components of the missile and houses the bunch of wires which communicates the electric signals from one section of the missile to another. It is made up of maraging steel and having the thickness of 0.8mm. Simulation was carried out using HYPERFORM to predict the tonnage requirement and zones of thinning and wrinkling. The good correlation is found between simulated results and actual formed component.

Introduction

Front hood plays a very important role in proper functioning in the missile. It covers the cables which run along the different sections on the missile. These cables connect the different electronic components housed inside the missile during the flight. Thus, the protection of cables is very essential and should not be neglected at any cost. Front hood safeguards the cables from external aerodynamic loads and protect them against kinetic heating. At the same time, the shape of conduits should be aerodynamically friendly so that they should not cause additional drag to the missile.

Figure 1: Front Hood

Simulation Driven Innovation 2

Fig.1 shows the CAD Model of front hood. It is fastened with the missile section using screws. Front hood is made up of maraging steel material and having the sheet thickness of 0.8mm. Maraging steel is an ultra high strength material and commonly used in defence industry. The limiting factor in design process of sheet metal components is the necessity of producing the desired shape without any cracks or wrinkles. The aerospace industries are growing rapidly and the demand for precise and accurate information concerning parts design and formability of metal sheet becomes essential. Sheet metal forming simulation plays an indispensable role in integrating manufacturing necessities into the product design process at an early stage. The objects of this works will focus on simulating the forming process using HyperForm module of HyperWorks Software in order to come up with a clear and better understanding of metal flow of sheet metal forming process. Process Methodology CAD model of Die, Punch are modeled using Solidworks software. Figure 2 illustrates the assembly forming set up. . It consists of base plate punch (for holding the punch), punch, die and base plate of die (for holding the die). The Solid models of press tools (die and punch) are imported to the HyperForm and outermost skin profiles are extracted. These extracted surfaces act as die and punch for sheet metal forming simulation. The front hood is modeled as a sheet metal component. The Blank size is calculated analytically by using constant volume criterion. The material properties of maraging steel are obtained using tensile test specimens. The planar anisotropy also known as plastic strain ratio is calculated by conducting the separate tensile tests as per prescribed ASTM standards.

Figure 2: Tool Assembly

The process is modeled as close as possible to the actual process. Fig. 3 shows the model set up in HYPERFORM.

Simulation Driven Innovation 3

Figure 3: Model Set Up in HYPERFORM

Results & Discussions The simulated results and actual formed component are shown in the figure 4. The thickness plot indicates the probable zones thinning and wrinkling. The formed component is also having the similar wrinkling and thinning zones. The maximum thinning is 10 percent and wrinkling of 8 percent.

Figure 4: Percentage thinning plot

The forming limit diagram (FLD) as shown in figure 5, clearly indicates that the process is completely safe and does not result into any tearing. The maximum load acting on the punch is approximately 20 Tons. Figure 6 shows the tonnage requirement with respect to time.

PUNCH

DIE

BLANK

Wrinkling Zones

Simulation Driven Innovation 4

Figure 5: FLD Plot

Force vs Time Plot Formed Front Hood

Figure 6: Force vs Time Plot and Formed Front Hood

Simulation Driven Innovation

Benefits Summary: The software helped in gaining confidence on the forming process and its various parameters. Challenges : HYPERFORM should have database of aerospace materials such as maraging steel etc. and must incorporate tonnage requirement in the incremental analysis. Future Plans: The similar procedure can be extended material. Conclusions: The use of HyperForm simulation gave the better understanding of forming operations and it has provided efficient way to determine important process parameters and helped in minimizing the tool tryouts. paper presented a simulation study concerning the sheet metal forming process and its evaluation using FLD.

The authors would like to thank Karthikhis active technical support. The authors would also like to thank support and encouragement to carry out this activity.

The software helped in gaining confidence on the forming process and its various parameters.

should have database of aerospace materials such as maraging steel etc. and must incorporate tonnage requirement in the incremental analysis.

can be extended for similar type of the component made up of ultra high str

orm simulation gave the better understanding of forming operations and it has provided efficient way to determine important process parameters and helped in minimizing the tool tryouts.

simulation study concerning the sheet metal forming process and its evaluation using

ACKNOWLEDGEMENTS

Karthik Guda, DesignTech, Hyderabad, and Yogeshhis active technical support. The authors would also like to thank Dr. D R Yadav Sc'G for their continuous support and encouragement to carry out this activity.

5

The software helped in gaining confidence on the forming process and its various parameters.

should have database of aerospace materials such as maraging steel etc. and must

for similar type of the component made up of ultra high strength

orm simulation gave the better understanding of forming operations and it has provided efficient way to determine important process parameters and helped in minimizing the tool tryouts. This

simulation study concerning the sheet metal forming process and its evaluation using

Yogesh, Altair Engineering for Sc'G for their continuous