Clarification on what exactly the G force is here?

[theStruggler]

Hello,

I am trying to carry out FEM analysis on a steering knuckle. I have found some articles with typical braking and cornering loads to apply and they are all expressed in G-Force (here are two the articles I found:

http://iosrjournals.org/iosr-jmce/papers/ICAET-2014/me/volume-4/8.pdf?id=7622

and

http://www.altairatc.com/india/prev...optimization_and_finite_element_vitpune.pdf).

The braking force for instance in both is 1.5G. I would like to know what exaclty that means this case?

Is it 1.5 x the whole car's weight or is it 1.5 x the weight of the car supported by that wheel (1/4 of the total car weight)?

Thank you for your help.

 

[theStruggler]

Hey Bob, question for you. Are you familiar with Aluminum 2024? As I was searching for what material might be suitable for the knuckle, I came across this website

http://www.emachineshop.com/machine-shop/Custom-Aluminum-Parts-Machining/page486.html

from which it seems as though aluminum 2024 6061 and 7075 might do the job.

Any thoughts?

Thanks!

 

[BUGGAR]

My experience has been with 6061. Primarily for building and bridge structures but a lot of mechanical structures, too.

I've built some car chassis pieces, brackets and such, from 6061 T6 and find it wont fail nice and soft and hold pieces together like mild steel does. It is more prone to fracture when overstressed so I go big on my 6061 parts. Hell, aluminum is light so I can go big.

Your stresses will likely be below the endurance limit of the material so fatigue shouldn't matter (but check anyway).

There is just no better experience than getting some pieces of the material you are thinking of using and breaking them in your shop.

Bob