Hello,
I made a MB model for my aircraft. It's a rigid body at CG which connects rigid nose and main gears with spring-dampers and tire elements. I run a static simulation and it runs smoothly in very few iterations.
The model is as sketched above. I apply at each axle 0.5 the vertical force on each wheel. At the CG I report the sum of all the side forces to have the overall balance in side direction.
The tire model does not work if i set MU to 0.5. I cant get a side force in the output. So I decided to apply the side force at each axle (and the transport moment from ground to axle). I recover the vertical force on each tire using its varsub variable (it provides the forces in W frame) and define a force and the transport moment at tire center point on the axle.
It works. The aircraft rolls and one side is compressed. However, if I check the total sum of the vertical forces I do not get the weight. The tires actually are not normal to the ground and they roll as well. I think this is the source of the problem. I tried to attach the tire to the axle with a ball joint so that they stay normal to the ground. Now the sum of forces is the weight. why? No problem with convergence but in one case I really do not figure out why the normal forces are not equal to the weight
