movement – Game physics of tearing apart

For a game I’m programming I’m looking for a kind of realistic mechanic for simulating the tearing apart of objects. Let me explain:

I have a given point p in a 2-dimensional space (possible later also more dimensions so a solution should be scalable, which i assume is not the problem) and I have a number of forces f1, f2, …, fn acting on this point p. So normally this point moves over time according to the combination of this forces. But now I’m looking for a kind of realistic mechanic that if forces vary strongly the point/objects gets split up in two points/objects that move in different directions.

Here a simple visual example:

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three “similar” forces resulting in one single force (the point will move according to this single vector)

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three forces that “tear” the point apart and result in two vectors (point will be split up in two new points that move according two the respective vector)

I amuse we need two give the point some kind of inner force, that defines how easy it is to tear the point apart?

By kind of realistic I mean something that doesn’t need to be extremely realistic according to the real world physics but something that would fell kind of real in a video game. So an additional benefit would be that it can be easily computed.