Which ones in particular do you want?..all of them? I think you can get the user defined models on the ITASCA website...unless you want the inbuilt constitutive models...found in the directory...?
Thanks for your answer. Unfortunately the models uploaded on the ITASCA website right now are for FLAC v8.0 and are not compatible with my version (v 7.0). This is why I am asking if anyone had downloaded them in the past.