Well, what's "strange?"
In other words, being sexually and/or violently violated is not, however common, anything normal or in any way small. So, expecting someone to bounce right back, or to be the same person they were is generally expecting much too much. We never get to be the same person again: we are all indelibly changed.
There are not "common behaviours," because not only is every survivor and individual, every assault is different. For some survivors, they may become withdrawn in some ways, but for others they may be more gragarious than they were. Some may have less interest in consensual sex or dating, others more. Some may be very upset, weepy, volatile, others may appear in no way shaken. It truly is ALL over the map.
But honestly, there's no one normal way to react to a violation or an attack.
There are a LOT of rape support forums and boards on the net if you're interested in first-person stories, and to see how much this stuff varies. Here's one to start with: http://www.survivingtothriving.org/mainpage
But you can dig up more yourself easily with a Google search, or read some more polished studies in books you can find via your local library.
[This message has been edited by Miz Scarlet (edited 02-24-2006).]