impact attenuator

[russel]

I am using honeycomb Aluminium 3003 1/4 density 5.2 pcf...
i found some formula regarding the calculation for the dimensions of the attenuator
Scr*(crush stroke)*(area of crush) =kinetic energy of the body collapsing{where Scr= crush strenght}
Scr=16.56*(t/d)^1.67 {t= foil thickness, d=cell size}
Does anyone have any idea whether these calculations are correct or not???

Russel

[russel]

I am using honeycomb Aluminium 3003 1/4 density 5.2 pcf...
i found some formula regarding the calculation for the dimensions of the attenuator
Scr*(crush stroke)*(area of crush) =kinetic energy of the body collapsing{where Scr= crush strenght}
Scr=16.56*(t/d)^1.67 {t= foil thickness, d=cell size}
Does anyone have any idea whether these calculations are correct or not???

Russel

[Ben K]

I'd crush some small samples and find out.

Ben

[moose]

For SCR - I wouldn't trust a random formula, you are going to need data from a supplier or going to have to do some testing. There are also factors with relation to crush speed, etc that come into play.

For the KE - Yes, that formula makes sense - just think about the units (but if it holds up linearly is TBD):

SCR = PSI (Lb / in ^2)
Area = in ^ 2
Crush stroke = in

so if you multiply through, you get lb*in, which a unit of energy.

[russel]

hey m talking about static crush strength. dynammic crush strength will be 1.08 times static for 7 m/s velocity.