I've made a custom set of constraints for a set of blocks that are connected together. Is it possible to break these constraints via a sheer force, so that constraints that are parallel to the direction of force will break a lot easier than ones that are perpendicular.
Here's a quick example that shows how you can achieve that. In this example, I weaken the constraints strength attribute at every timestep, until they reach a very small strength where I delete them - since these are glue constraints, they will only break with impacts which is why I delete them so the pieces will gradually break off.