No, and it would be ineffective with the plate on the abdominals. Now, if you placed the plate on the thorax right underneath the neck, that would increase the effectiveness of the crunch if you can do the crunch with good form through a full range of motion.
The only way I have seen this done is to rest your head and shoulders on a stability ball, place the weight (plate, medicine ball, etc.) on your abdomen and do pelvic lifts. Should hit the glutes as well, msybe even more so than the abs but you will still need those ab muscles for stabilization!!
As A=Jock said, hold the weight on your chest, then you will be adding resistance to the ab work. You could also hold a mediciine ball between your knees when doing reverse crunches. I often add a light-to-moderate weight med ball to my ab work.
I use weights w/abs all the times. When I use a plate I place it on my head--kind of between the crown & hairline--& do a basic crunch. It's been very effective for me but it is definitely an exercise you need to work up to, especially when it comes to proper form.
When I incorporate using a weight for abs, I'll put a 5lb. plate behind my head, so instead of clasping my hands together, I'll hold the plate.
I've tried Maximus' way, but my neck just isn’t strong enough to hold much weight at all.