ESA Analysis Calculation

[seal78]

Let me preface this by saying that I am very green when it comes to this area.

I have a component that is required to withstand 20G equivalent static acceleration in the lateral direction. The component is mounted near the base.

Best I have been able to tell is, when the equivalent acceleration is given, then the equivalent force is a simple F=ma calculation. Please correct me if I'm off on this.

That being said, what sort of stress analysis would be appropriate to verify that the component meets this requirement?

Thanks in advance for any help.

 

[desertfox]

Hi seal78

How can we tell you the best stress analysis when we don't know the size, shape or how the component is supported, can you post a picture or sketch of your situation.


desertfox

 

[Twoballcane]

Hmmmm...sounds like homework...

Tobalcane
"If you avoid failure, you also avoid success."

 

[seal78]

Unfortunately I can't post any pictures or describe the component in detail. I realize that makes any useful interchange more difficult.

What I was really looking for is a basic understanding of the significance of an "equivalent static acceleration" value. I have dealt a little bit with shock tests where the G level, duration, and pulse shape are specified. However in the scenario that I was describing, none of this information is provided.

Conceptually, how would you use a static value to determine whether or not a design is sufficient. I have assumed that the static value relates the effects of a shock event to an equivalent static force.

I was hoping that someone might be able to confirm / correct / re-direct my understanding.

 

[desertfox]

Hi seal78

Well your static equivalent force is simply 20*g*(mass of object) see this link:-

http://www.ptc1.com/public/PDF/Shock Application Notes.pdf

But your original post "what sort of stress analysis" well is the component in bending, compression,tension, shear?
If you can't tell us ask yourself how can we answer.

desertfox

 

[GregLocock]

That's how we rough out the loads in a suspension and chassis. So, fix the base realistically and apply a 20*g*m force to the CG.

Yes it is crude. If you have a good value for the equivalent load it is amazing how close to the final design you can get. For the sake of argument typical numbers on a non-aero circuit car are 3g vertically, 2g in the other two directions. Those are low for a production car.



Cheers

Greg Locock


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