SUPPORT WITH gap only in -Z

[aruser]

Hello,

Could you help me defining a support which works only in -Z (compression) after 5mm gap.

That is in +Z (tension) is absolutely free.

Also free in shear and moments.

Thanks

[aruser · Accepted solution]

The point is that I can perform that kind of support but it only works in one direction.

In the attached example, the support is defined and works correctly for the load case 1, this is that the support starts after 5mm of deformation in -Z.

But in load case 2, the support should be absolutely free to uplift and it works as fixed.

[Rafal.Gaweda]

GAP works in two directions.
You have to create nonlinear function to get this effect.

[aruser]

Hello,
Could yo please show me how to do that nonlinear function? I've tried with some functions but I don't get the expected way of working.

Thansk

[Rafal.Gaweda · Accepted solution]

The easiest way:

[aruser]

Hi,

I've tried as you described but the model is not convergent. If I erase that support I get a convergetn model so I deduce something is wrong with that non-linear support definition.

Fin attached my robot model with my attempt of definig as yours.

Thanks

[Rafal.Gaweda · Accepted solution]

Set Newton-Raphson algorithm

Corrected file attached.

[aruser]

Thanks Rafal,
It's working correctly.

Could you please explain briefly (or refer to other document) what means "Máximum number of BFGS corrections" and "Matrix update after each iteration" ?

What is the relasionship between both? Becasue first I tried with 0 BFGS and Matrix update unselected and dind't work. After also selected matrix update and worked correctly.

Regards