Are there any research databases that accept submission of published articles?
From Wikipedia:


  The Social Science Research Network (SSRN) is a website devoted to the rapid dissemination of scholarly research in the social sciences and humanities.


SSRN allows you to submit full text papers (for example preprints) and abstracts (for example of published and paywalled articles). Setting up an account is free and requires only an email address and password. I am not aware of any API for mass uploads.

In my experience, papers on SSRN are quickly indexed by Google Scholar.