PSI - Issue 14

N. Venkateswaran et al. / Procedia Structural Integrity 14 (2019) 627–633 N.Venkateswaran/ Structural Integrity Procedia 00 (2018) 000–000

633

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PSD vs Frequency

0 0,001 0,002 0,003 0,004 0,005 0,006

0,005

0,005

PSD in (g 2 /Hz )

0,0005

0

500

1000

1500

2000

2500

frequency in (Hz)

Fig. 5. Amplitude curve of PSD with frequency

6. Conclusion Initially Structural analysis is carried out considering the dynamic load of 4 g, and estimated the stress, is less than 2 MPa only. To carry out the shock and Response spectrum analysis, it is necessary to carry out the Natural frequency analysis. Subsequently frequency analysis is carried out with different thickness of the pad with different pad`s location. And it is estimated from different iterations of analysis, single pad with 8 mm thick and when the pad is placed inside of the top plate is giving first mode vibration as 130.5 Hz, is better choice for new bracket. Further Shock analysis using Finite Element method is carried out applying shock load of 50g for 18ms in three different directions separately. It is found out from the shock analysis, when the shock load is applied in the Z direction, the maximum stress occurs as 177.6 MPa, which is less than the yield stress (210 MPa) of the mounting bracket material. It appears to be safe and the factor of safety is 1.2. Similarly Response spectrum analysis is also carried out the for the random vibration, with the PSD inputs. This simulation also shows that the design of mounting bracket is safe. Acknowledgements The authors are grateful to V.Balamurugan, Director, CVRDE for his guidance, support and encouragement. The authors are also grateful to the contributions made by divisions of IFCS and CEAD of CVRDE. References

ABAQUS SYS Inc., August 2014, ABAQUS Tutorial guide - Release 6.142,. Singiresu S. Rao, Fourth edition, 2005, ” Mechanical vibrations ”, Pearson Education, Delhi, pp.- 365 Vibration Data measurement –internal report, 2016 (Restricted).