Suspension loads

[TMAPV]

Hi,

University student here, look at suspension load paths, I made an excel sheet that calculates the loads on the different suspension members when a load is applied. When I input a load acting on the tyre patch though, I get a really weird result where for example my Pushrod is in tension when in theory it should in in compression (for Fz +ve for example). Not sure if this is due to my unit vectors done the wrong way round. Could someone check and make sure I'm not going crazy, as I am pretty sure after checking it multiple times that I've done it right.

I attached the excels sheet. Matrix A contains the x y z unit vectors for the force and moments respectively. Vector B contains the Force/Moments applied at tyre contact patch.

Any help/explanation would be appreciated

-tmapv

 

[GregLocock]

I suggest you start with a simple orthogonal symmetrical set of hardpoints. Putting the spring/damper vertically above the CP reveals that your sign convention is wrong.

Cheers

Greg Locock


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[TMAPV]

Thanks for looking! Hmm, might be the way I did the first 3 rows of Matrix A, was sure I did it correctly. But like you pointed out, I thought it was meant in compression instead of tension for that load.... :S