How can you model a "Y" support at center of a 56" gate valve weighs 17,000Kg?

Model the valve as two rigid bodies adjacent to one another with half the mass each, then place a Y restraint at the centre node.

So, you make a pivot at support node and you'll find unwanted relative rotations and displacements at the both ends. Then you'll end up inaccurate results.

Farhad,

Try to understand the :

1) Physics of the problem.

2) Representation of the problem in a beam element based FEM model,including the modelling of a 3D support as a knife edgesupport.

If you have understood the above two points, you will understand MoverZ's response.

Best Regards

A 17,000 Kg valve, supported by a +Y at the center will not pivot. The only pivoting would be due to adjacent pipe elements where the weight distribution on either side of the valve is not symmetrical. You can always put an additional node in your valve so you have 3 consecutive rigids, with one short rigid equal to the finite length of your real-world Y support in the middle. Then place your 2 Y supports on those two center nodes, each representing one end of the Y support. I think this is over-kill, but it can be done quite easily.