Instrumented ball joints/ vertical loads

[Wall67Fbird]

I have a project where I will need to measure lon, lat, and vert loads at all four corners of a off-road vehicle. I have modified and installed strain gages on ball joints to measure lon and lat loads but I was curious if anyone has instrumented ball joints to measure vertical loads? My first thought would be to turn down a portion of the taper to the base diameter and mill flats for the gages. I would think this is not ideal since axial load cells tend to have low output and this doesn't seem like the best application to measure axial compression load but I may be wrong. Has anyone had experience with this or have any ideas?

Here are a few pics of ball joints I have modified in the past to measure lon/lat (shear) loads.


Thanks

 

[BrianE22]

I've only done them for lateral and longitudinal bending. I looked at it years ago and decided the axial strain from vertical loads was way smaller than the bending strains from the horizontal loads. If, in your case, the strains from vertical loading were high enough I don't see why it wouldn't work.

 

[Wall67Fbird]

Thanks for the reply Brian. I guess if I have the room I may try to add an axial bridge to measure the vertical with the lon and lat. I will be surprised if I get decent sensitivity out of it but it's worth a try.

I will probably go ahead and do bending bridges on the spindles as a backup for vertical.The rear of the vehicle doesn't have ball joints so I will have to look at bridges on the rear spindles for all 3 axis.

Have you instrumented other suspension components?

 

[BrianE22]

I have done other components. I did it for simulation purposes and not so much for absolute load measurement. For vertical I used strain gauged springs and an accelerometer on the unsprung mass.

 

[Wall67Fbird]

Brian, do you have any photos or examples you could share? I have done a few components but it would be nice to get some ideas from other that have had more experience.