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