The forces in explosions are not easy to predict as they are 3D expanding wave forms that will react at hyper speeds to unexpected external forces. A blast wave has many different things going on. Wave speed and propagation, the normal propagation speed through the medium, how it handles surface reflections and surface imperfections and weaknesses.
The shock wave of the blast front is always much faster than the normal propagation speed. Think the speed of sound through air, water, dirt and stone are all different, and all much slower than a blast wave through those items. A basic damage effect is compressing whatever is in the way, then releasing the compression redirecting the blast wave front.
Designing personal armor to withstand a blast wave is a very difficult military problem Flaws in connections or overlaps will allow the blast wave to dismember the victim. Titanium armor plates will flex, ballistic cloth will compress, fluids will rupture containers leaving the victim in need of a top quality hospital in a formally safe combat zone.
Be very skeptical before accepting any armor when you have not seen a real test against the unexpected.