I was not aware of an open access dissertation database from Duke, but through the link to Carlson’s dissertation I poked around and found this landing page. It’s not as user-friendly as Durham’s, which has a page for all the dissertations from the Department of Theology and Religion. When you browse by subject on Duke’s page relevant dissertations are spread throughout multiple subjects. Nevertheless, if you know of dissertations from Duke you can just search for them directly. It’s just browsing that’s a bit hard to do.
In case anyone’s not aware, I have a “Free Resources” tab at the top that compiles free resources for biblical studies (courses, dissertations, journals, etc.). For nerds outside the academy without access to a university library, some of these are a real boon (especially dissertations, which are usually upwards of $100 a copy in published form). If anyone’s aware of other resources do let me know, and I will add them to the page.