Mercury Systems Proprietary
Solidworks Simulation Bolted vs. Dip Brazed aluminum side panel
stiffness study
03/15/2014 Rev B Don Blanchet Consulting Engineer, © 3B Associates
Force Fabrication Oxnard , CA
Client request
n I don’t want to invest in extra cost to outsource assemblies to aluminum dip or vacuum brazing houses.
n Having low labor grade people screw them together is less expensive and just as strong.
n Can you show this with FEA ?
Model
# 6-32 screws
Fixed bottom edge
End pressure load
Model – overall 6 x 9 inches
frame
Thin .062 cover
Back view
End Loading should Cause diagonal
Racking and twisting
Loading of bolted cover
Max displacement .00125 inches
un-deformed
Detailed displacement
un-deformed
Cover separation Between screws
Dip Brazed cover (screws removed)
same loading
Max displacement .000158 inches
Braze joint
Conclusion n The brazed cover adds significant stiffness to this
assembly over the design with very closely spaced #6-32 hardware. It is a better structural fabrication method.
n The flexibility ratios are:
– No cover = 9.0 – Screw mounted cover = 7.0 – Brazed cover = 1.0