hi all, i'm creating a physics based game. My design works by pre-fracturing objects into distinctive chunks at authortime, to prevent extensive processing later (some realtime fracturing will also occur, but that's unrelated). So i have lots of walls that are made up of lots of little chunks, and my intention is to simulate things as such that the wall doesn't behjave like it's made of discrete chunks, just as one large piece of material (that conveniently fractures along those lines) Anyways that's just context. I want to ask for a 101 explanation of three different physical behaviours, and i also want to know how the property of Brittleness relates to them, and what other properties i might need to model these behaviours convincingly: 1. Cumulative damage. If you hit a steel beam hard (but not hard enough to bend it) with a sledgehammer, then you'll have no real appreciable effect. The impact is dissipated away, probably through vibration or minor deformation or somesuch, and the piece of steel is more or less unchanged. But if you smack a lump of concrete with a sledgehammer (not hard enough to shatter it), it will typically lose little chunks, gain cracks, and generally decrease in structural integrity./ Making it easier to destroy with more hits of the same force. Briefly explain this to me? 2. Localisation of impacts As far as i'm aware, when you hit an object ( say, a brick wall) the impact is dissipated across the surface/volume of the object, and thusly may cause lots of cracks along that wall until it eventually crumbles. But when you hit that same object really really hard in a small area (for example, by firing an AP tank shell at it) you'll tend to punch a small hole right through, and leave most of the rest of the wall relatively undamaged. How does this work, that harder impacts seem to do less overall damage to an object than ones it can successfully resist? And also why does this happen. Why for example, does the brick wall not implode inwards in an attempt to dissipate the incoming force evenly, and crumble into little shards of rubble. 3. Reverberation. Probably not a correct term, and probably strongly related to #2. Is there any way to meaningfully determine how likely/how far a material will spread out incoming forces? If i'm going to hit the middle of a wall with a million pascal, is there any way to meaningfully determine in then physical makeup of that wall, whether i want a hole punched through the middle, or i want the whole thing to resist and implode towards the impact point? In terms of the context of my simulation, how can i meaningfully determine how much of the force applied to a chunk, should be transferred to the chunks it touches, and how should this force curve falloff with distance? how large muist a wall be for one part of it to feel nothing from an impact at the other end? The concept of brittleness fits in here somewhere, i'm sure. But i'm not entirely clear on where. Would an especially brittle material Be more, or less capable of resisting cumulative damage? Would it be more likely to have holes punched through it, or to collapse under massive stress on a small area? Are there other material properties besides brittleness that govern these behaviours ? What are they?