I wrote a scene that takes you through a sexual assault. It's written from the P.O.V. of the victim.
I did it with dialog and with the characters thoughts -- and tried to convey her emotions -- surprise, fear, anger etc.
There's no doubt about what's going on, but the physical aspect isn't at all graphic or explicit.
Just write the scene -- you might surprise yourself. Or you may find that a fade to black is better.
Or you could post it here. There's no way you or anyone can tell if it's going to work or not without reading it and seeing it in context.
P.S. Donnaf -- if you're at all interested in the scene I wrote, it's in this story that I posted here:
There's a final section designated with three asterisks -- it's the last several paragraphs before that. There's actually more physical description than I remembered -- but it's still not very explicit.
Disclaimer -- I've since edited the story, but not a whole lot. The writing's a little precious -- too may commas and italics...