Forced sex is a common fantasy for many women, and men. In the fetish domain, it generally falls into what's called Consensual Non-Consent (CNC).
In reality, there is no case, or even remote justification for rape or non-consensual sex of any kind. In the fetish CNC or role-play domain however this fantasy can be interesting to explore.
My wife and I both share the CNC fetish, and have explored it several times. This kind of play requires lots of clear communication, significant trust, and scenarios with discussion of boundaries, safe words, and recruiting of vetted, trusted participants. CNC scenarios vary significantly, from simulated kidnapping, hostage, bondage, and related fantasy play, to scenarios that involve being out of control; drunk, drugged, or otherwise helpless.
Related, breeding, including impregnation play is another relatively common fantasy. This is sometimes coupled to CNC play. I'm a participant and member in a fetish community that does breeding and impregnation, including fantasy, as well as real breeding (this usually implies many random partners for one woman), and impregnation (usually scenarios that involve a sexual surrogate, in the role of "husband/impregnator"). Some of these are coupled to CNC, usually focused on situations where the impotent husband is indirectly involved, "forced to watch," while his wife is either "forced," or an otherwise willing participant, punishing her impotent, weak husband.
These are kinks that kind of push to the extreme. No one should consider doing this "for real," in the context of rape or pure non-consensual events.