I finished my Ph.D. in mechanical engineering back in 2018. Recently, I found out that my Ph.D. thesis was not published by the university online. It is just in paper form at the university library.
Can I somehow publish my thesis online and get paid royalties for it? If yes, how? I know I have to ask permission to my university, but first I would like to decide what to do.
About getting paid: A publisher can only pay you if someone else pays them for access to your thesis. That should prompt you to consider who the audience for your thesis is? Who would pay money to read it?
In reality, the market for PhD theses is quite small. Very few of us write about topics of either such importance, or so eloquently, that others are willing to pay for reading our theses.
Most likely no. It is rather the opposite: you might be approached by quite a few publishers that offer to publish your thesis but you will have to pay them and you are most likely not getting anything (at least not financially). Yes, academia is quite an odd field.
First you need to settle the copyright issue. Who holds it and if it isn't you then what license do you hold from the copyright owner? I doubt that even if a university holds the copyright that they would prevent you publishing your own work. It is more complicated, however, if the work can't be considered a "sole" work due to having been done in a research lab. But settle that first. Part of that is any issues of confidentiality that might arise.
In particular, I would consider a university explicitly monetizing the "sole works" of its students to be very wrong.
Assuming that you have the rights to do it you still have some issues. Publishing "online" is unlikely to result in any monetary payback unless you find a way to put it behind a paywall which has upfront as well as continuing costs. Publishing on arXiv, for example, doesn't pay you anything other than possible "reputation points".
You can, with the appropriate rights, turn it into a book. Some publishers might be interested and would pay royalties, but you will find, almost always, that those disappear within a couple of years.
You can also self-publish a book, perhaps through Amazon.com who provide support for such things. The upfront cost to authors is zero, but it is difficult for potential readers to find such things so the payment you get from the effort will likely be small unless most of the potential readers already know how to find it (and you). If you have an extensive online presence or otherwise high visibility in your field then it might be possible. I've self published textbooks successfully, but literally everyone interested already knew me and how to find my university website. But even that ends after a few years as the needs of the curriculum change.
Note that while a work might be important in a scientific field, the actual audience for it might still be small. The hugely profitable books are more likely to be popularizations of academic work such as those by Carl Sagan, who did real science, but was widely known for his more general explanations which were accessible to non-experts.
To sum it up. It is probably more effort than it is (monetarily) worth. There may be other "paybacks", but in visibility and reputation.
It's unlikely that you will be able to get your published thesis be paid. There might be a few people who would be willing to pay to read your thesis because many universities and institutes have switched to an open access policy.
If no one else pays for the privilege of reading or critiquing your work, then you should ask yourself who will be interested in seeing what you have to say.
Many dissertations, at least in the United States, are sent to ProQuest, often a requirement of the institution. You can also submit your thesis, even if your institution does not require submission.
ProQuest archives dissertations, makes them searchable, and sells printed copies, microfilm versions, and online PDFs. They also sell subscriptions to many libraries. A royalty is paid when copies are sold, or somebody accesses your dissertation via a subscription.
Their searchable database is useful for accessibility, particularly if your institution does not have some sort of online repository. If you are interested in getting paid however, I have never heard of anybody receiving any money from them because the minimal audience and readership in most theses.
(In fact, when I submitted mine, they hooked me on fancy bound printed versions of my thesis, so I spent more buying copies for myself and my parents then I ever will get in royalties.)
If you are willing to put in the effort, and your dissertation is on an important-enough topic with a large-enough audience, it's possible a publisher will publish it.
Putting in the effort: see this source. You'll need some serious rewriting of your thesis, since it is now aimed at a different audience. Things like an Abstract or an Introduction need to be removed, and the common "this thesis is structured as follows, in chapter 1 we do X, in chapter 2 we do Y" also needs to be reworked.
Important-enough topic with large-enough audience: is your thesis on something trendy? Does it have major practical consequences? Did your thesis lead to patents or new + superior technologies that would not have existed otherwise? One way to tell if the answer is "yes" is if your thesis is generating a lot of views/citations/denials. If you don't know these statistics, you can ask your librarian.
If you are willing to put in the effort and your topic is important enough, then there's a chance a publisher will be willing to publish it. The next step is to approach a publisher with a publication proposal. Here's an example from Springer. You'll need to show why you are qualified to write a book - a PhD alone is not enough to be considered an authority - and why you expect the book to do well (Springer does not explicitly ask for these, but I can virtually guarantee that they'll be evaluating it internally). You can cite the research you did for "important enough topic" above to answer the latter question. You might also be asked for sample chapters. Your university press might be the best place to start, since they are the ones most likely to be willing to take a financial risk by publishing your book.
If the publisher agrees to your proposal, then they'll handle everything else, from drafting a contract to performing typesetting, etc.
It may depend on the institution, but often in order to defend a PhD one has to sign an agreement which settles exactly what you are asking for. Could it be you have done it, and forgot?
Yes, there are books based on PhD theses. They often benefit from additional editing suggested or required by the publisher. Of course releasing such book, or even posting your thesis online requires to follow the agreement with the institution.
Public access to research findings is important for the scientific community and for society as a whole. Government-enforced restrictions on copying published works originate in repressive and censorial measures by the British monarchy (read about the Statute of Queen Anne) - and we should not condone them. It is immoral to prevent people from being able to copy your thesis; and - it is detrimental even to your personal interest, of it being widely read, having greater influence, and inspiring others in their research and applied work.
Projects like SciHub (wikipedia.org) and Library Genesis (wikipedia.org) exist for the sole purpose of circumventing such nefarious attempts to limit access to publications only to those who pay. If you publish behind a paywall, your thesis will likely end up in one of these archives. Why not publish it freely to begin with, so that search engines and personal websites can more easily link to it?
Fields differ in what they consider to be the primary "unit" of scholarly output. In computer science conference presentations (e.g., at NeurIPS or a SIG Conference) are highly regarded; biomedicine places much more weight on journal articles instead. A few fields, especially in the humanities, expect academics to write books.
In these fields, it's not uncommon for a dissertation to form the backbone of a person's first book. However, it generally isn't published as-is: one writes a book proposal for potential publishers and revises/expands the text. It is a lot of work and the goal is generally (academic) career advancement rather than the commercial success of the book itself.
Unfortunately, I don't think mechanical engineering is a very book-driven field, but your advisor or thesis committee could probably tell you more. If you're interested in the process, this book is often recommended: https://www.worldcat.org/title/from-dissertation-to-book/oclc/56329536
