Question

Yesterday I got my dress ironed sentence pattern

Answer 1

I got my dress ironed yesterday

Answer 2

It is a complex sentence.

There are two clauses in the sentence.

One is the principal clause and the other is the subordinate clause.  

Here the principal clause is I got my dress ironed.

The related clause is yesterday, where the full clause is it was on yesterday.

Apparently, the sentence may seem to be a simple sentence but it is a complex one.