big naval gun shock response
TRANSCRIPT
Equipment Shock Response to Big Naval Gun firing
3/13/2017 rev ADon Blanchet
3B Associates
Tools & Goals
Linear Dynamic Finite Element Analysis
Solidworks Simulation 2015
Calculate an instrument box displacement response to a single firing of a large shipboard gun.
Determine if the recommended isolators for an instrument package will prevent the assembly from bottoming out.
Measured shock eventbelow gun turret
15 msec
Shock Response Spectrum calculatedfrom enveloped measurements of multiple test firings
Base input excitation to FEA model
Model –instrument boxtotal weight = 20 lbs
Rubber isolator4 places
Direction of gun recoil shock
Y axis
FEA mesh
90,000 nodes275,000
Degrees of freedom
Max allowable displacementto bottom out condition
0.31inches
FEA results: shock –Y axisdisplacement +Z axismax = 0.073 inches
FEA results: shock –Y axisdisplacement +Y axismax = 0.132 inches rebound
USS Iowa
Conclusion
The chosen shock isolators do not bottom out.
The as designed isolation will bemaintained throughout the shockevent.