A husband has not been given the right to compel
his wife to wear the Hijāb (garment that covers the head and chest). If your
wife is intellectually convinced that the Hijāb is not required by Islam, the
only thing you can and should do is to have a good exchange of views with her
regarding her arguments. You should try to state the stance of Islam in a very
polite and humble manner and leave her to ponder over it. Also, keep thinking
about your own arguments. At times, one tends to be more dogmatic than rational.
Keep thinking on how you can improve your presentation.
In principle, you must try to convince and educate your
wife in following any directive of Islam. You have not been authorized to use
force in such matters. Also, you will not be held responsible for any deed of
your wife if you tried your best to stop her from something that was wrong
according to your own perception.