- #1
abrooski
- 3
- 0
Hey folks,
I created and verified a model with hand calculations, and decided to re-use my same logic.. Which now is giving me false numbers. Was wondering if you guys could help me out.
Setup/Verification (See attached Reaction_Forces picture):
Any help would be appreciated!
I created and verified a model with hand calculations, and decided to re-use my same logic.. Which now is giving me false numbers. Was wondering if you guys could help me out.
Setup/Verification (See attached Reaction_Forces picture):
- Body in motion being held down by straps.
- Uniform Center of Gravity (CG) in model.
- Reaction forces (in red) are found in top 4 corners, x,y,z for each.
- Moment Force is verified by summing cross product of each force reaction (x,y,z) and its relative locations from body CG. Resulting moment is 0.5% off my program approximation. Great!
- [reaction 1 cross product] + [R2 crossP] + [R3 crossP] + [R4 crossP] = One axis moment reaction. Perfect.
- Same body in motion. CG is now offset from exact middle of body. New CG.
- Reaction forces adjust accordingly as expected. Nice.
- Moment is predicted by program with a sizeable addition in one of the 3 axis.. Roughly equivalent total though.
- Hand calculated Moment, using same method as above with cross product of reaction forces and relative locations from NEW CG, is completely wrong. 55% wrong.
- Are there more than 4 reaction cross products now?
Any help would be appreciated!