Excessive displacements/stresses with model.

I'm attempting to model the max.displacement of a small arrangement seen below, but no matter what the fixtures/connections I cannot find any sensible results.

There are two tappered holding dowels inserted into a block to hold a U-bar in place. I'm making the dowels bonded with the block (there is slight interference there), then having no penetration constraints on the two dowels and the u-bar. Yet the u-bar seems to just deform excessively past the dowels and create huge stresses - even with a relatively small load.

I've attached the simulation setup if anyone fancies taking a look.

Thanks,

Jason