# Looking for formula for lateral and/or eccentric loads

1. Oct 20, 2015

### RWS000

Need formula to calc. lateral and/or eccentric loads on trailer hitch ball when moving down the road hauling a trailer with gross trailer weight (GTW) of 10000 lbs, Tongue weight (TW) of 1200 lbs.

2. Oct 21, 2015

### CWatters

Can such a thing be calculated? Weight acts vertically so where would lateral forces come from? Cornering? Vibration? Cross winds? Impacts from holes in the road? Does resonance/swaying play a role? Not my field but sounds like a lot of unknown factors come into the likely forces on a hitch.

3. Nov 9, 2015

### RWS000

Sorry for late reply...out of pocket.
Anyway, lets see if I can use a non moving situation for testing. Assume a weight sensing load cell is inserted under hitch ball (between hitch ball base and top of drawbar). Then nut at bottom of shank of ball is torqued tight against bottom of draw bar creating a vertical "preload" on load cell sensor of 12,343 lbs. Then a horizontal test load of 30,000 lbs is applied to the center axis of hitch ball. The distance from ball axis to bottom of ball base is 2.125 inches. The thickness of sensor is 20mm. The thickness of drawbar is 19mm. I am confused on how to develope a full force diagram to determine the resultant vertical force load to the top of the load cell sensor (so I can determine what capacity load cell to purchase verses the load that will be applied to it in this situation). Can you help me?

4. Nov 9, 2015

### CWatters

So basically there is a horizontal shear force applied to a sensor that is intended to measure only vertical loads. If the load cell was "ideal" it would only indicate the preload of 12,343lbs because the horizontal test load of 30,000 has no vertical component. However the sensor is unlikely to be ideal. I think this is one the sensor manufacturer will have to help answer.

5. Nov 9, 2015

6. Nov 9, 2015

Tks much....