FEA on Welding Bead

Hi,

I need to do the FEA on a water tank.

My supervisor said he is interested to know whether the welding is strong enough or not. But when I run the Mesh, the welding bead gives a lot of problem.

Because it is a water tank, actually I am thinking to use shell mesh.

But is that the correct way since my supervisor will ask me why don't I check the Welding in FEA?

Also, what is the best method to represent the water weight in this kind of FEA? I know the weight will be 2000Kg.

Any idea?

Thanks.

SolidworksSimulation