I have to analyze the valency pattern of this clause "These glorious full colour prints that resulted were known as brocade pictures". Can I consider "were known" as a copular verb followed by the subject predicative "as brocade pictures"?
The copular verb/linking verb is "were" (to be), the linking verb number 1. It is followed by "known", the predicative complement. Here "known" is used as an adjective. "known" is followed by "as brocade pictures". Here I think the terms for this part will diverge. I would say this word group is a complement to the adjective "known".
I don't think that "were known" can be seen as linking verb. But today there are so many grammar systems with different views that everything is possible.
May I add that I don't use the term valency, though I know it. But I think verbs are not comparable to elements of chemistry. Verb constructions can be changed, one construction can be transformed into another one, and new constructions can be developed. So I don't like the mechanical view that verbs have valency.