PSI - Issue 14

Rohit K. Mahalle et al. / Procedia Structural Integrity 14 (2019) 945–951 Rohit Kumar Mahalle / Structural Integrity Procedia 00 (2018) 000–000

951

7

 To confirm the prediction through graphs, segments of ARTICLE 24 and 25 motor were machined as per the change in depth of cuts arrived from the deviations values arrived from the formulae. The results evaluated were approximately near to the graphical representation.  The validation cut on ARTICLE 24 & 25 segments involved only 2 stage inspection, during the propellant machining operation. This reduced propellant machining operation time by 20%. 5. CONCLUSION Enough number of data has been generated through experiment on 3 different types of articles. These articles were machined on propellant grain surface with visco- elastic properties. Literature available for elastomer machining does not relate to propellant machining. The virtual Depth of Cuts during each stage was analyzed as per the deviation from target Depth of Cuts. A wide range of study has been conducted in this paper, so as to arrive at a point, from where behavior of propellant during machining operation could be understood. The variation in depth of cuts could be used for predicting the deviation from the required value during subsequent cuts. Keeping cutting speed and feed in a range, depth of cuts could be varied in a range so that required depth could be achieved on propellant grain. Effort has been made in this paper to qualify virtual Depth of Cuts thereby minimizing error in machining. There has been additional advantage in machining time and accuracy of machining. To prove this some more data collection is in progress. Acknowledgements The author expresses sincere thanks to the General Manager, SF Complex, Jagdalpur for the support of facility extended and equipments for conducting the study.

References

[1]: GP Sutton, O. Bilblarz in “Rocket Propulsion elements” 7 th Edition, Willey- Inter-Science. [2]: Albert J Shih, Mark A Lewis in “End Milling of Elastomers- Fixture design and tool effectiveness for material removal”. [3]: K. Kishore, V.S. Rohit, A.V. Gopal in “HSS Tool wear mechanism in machining of HTPB Based Composite Propellant Grain”. [4]: K. Kishore, A. Venugopal, V. V. Rao in “Development of a Hollow contouring cutter for machining of Solid Rocket motor (SRM) Propellant Grain