So I've read up (NASA has good stuff) that nuclear weapons detonated in space are primarily a radiation hazard. Thermal and concussive effects are negligible, other than I suppose hot fragmentation from the missile/warhead itself if close enough.
Now the radiation can be significant, according to NASA, even a 20 kT detonation can expose humans to lethal radiation doses from a detonation 30 km away, maybe more.
But for this question, assume that "shielding" basically negates the radiation hazard.
The other mechanism for a nuclear warhead kill is if you can detonate the nuclear warhead inside the ship. This will most certainly be lethal, if not outright vaporizing a portion of the ship.
In reality, nuclear weapons are not designed to penetrate, most are air detonations to maximize the concussive destructiveness.
So here's my question: is it realistic to expect a nuclear warhead to survive the impact of penetrating a ships armor so that it can detonate inside the ship as intended? Or would the action of penetrating the armor be so violent as to basically destroy the nuclear bomb components before they can detonate?
Let's assume the target ship is heavily armored, likely multi layer, with some sort of outer energized or explosive reactive armor, followed by layers of special composites and ceramics, and finally a thick metal alloy hull.
EDIT: @Nosajimiki - great response, thanks. In regards to the effects of 1 MT space detonation, I did some reasearch.
A 1 MT blast yields 4180 TJ of energy. For air blasts, I've read that approximately 50% of this energy goes into the blast, 35% to thermal, 5% to immediate radiation effects, and 10% to "lingering" radiation effects.
Here's my thought: I took 40% of the 4180 TJ (thermal + immediate radiation). Assuming a spherical blast, the target will only receive a portion of that 40%. I assumed 25%. That means the target is subjected to approximately 400 TJ. In my WB exercise, ships are "large". I assumed an average warship, 1200 m x 80 x 125 m with 30 cm of armor. I assumed, for this purpose, regular iron. It would take nearly 1100 TJ to melt the hull. If you choose better (real) material, you can get this up to 3300 TJ to melt the hull. With a little "future handwavium", this can be increased to nearly 6000 TJ "reasonably". Adding "futuristic" heat tiling further improves the odds of the target.
Any further input would be invaluable to me. Thanks.