I've become obsessive again
While doing a model of a largish freighter, I decided that I wanted to put the same effort into 'designing' it for a game. I'll end up using a weird hodge-podge on FFS1 and other bits and pieces taken from where-ever.
Wouldn't you know? I'm stuck on the hull already. I want more than just "hull= x dtons and heavy armor". I started thinking about structure and how it could be used in a realistic fashion as a limit to available thrust and the affects on performance when carrying different massed loads and how damage to structure can alter things.
I decided that structure covers any part of a ship that is responsible for carrying the mass of the ship/vehicle. Armor can be placed over the structure or else the armor can BE the structure ( monocoque construction ). I am just unsure as yet how to determine load carrying capacities for eiher the armor or the structure.
I've been studying materials and such things as stress, strain, young's modulus, buckling and toughness. I have a couple of ideas and I'll work through this all eventually.
Stress will relate to the strength of a material per unit area before failing in compression. strain relates to how brittle or flexible a material is. The ratio is Young's modulus, if I understand it correctly and can be graphed with stress and strain as the axis. Toughness is the area under the graphed curve and is the toughness described in the Striker, MT and FFS charts for armor.
So, given a structure's volume, we can determine the area of support in m^2 by dividing the volume by length along the axis of thrust. Using that and the material's compressive strength, we can find out the maximum force the structure can support without failing.
However, there is another factor to consider... buckling.
Given a material's compressive strength and the material's toughness, we should be able to guestimate at the material's modulus to be used in a simplified form of an equation giving the limit of stress before a structure buckles ( based on a simplified method from Euler).
F/A = E*(pi)^2/(l/r)^2
F/A is the same relationship for compressive strength
So the structure can support the lesser of the two amounts
For armor, I might use the thickness and approximate the x-sectional area of the armor using w*h*.7854 minus (w-2*thickness)*(h-2*thickness)*.7854 for use with the methods mentioned above.
Structure support and hull armor support add to each other.
The difference between the two is that structure takes damage only when called for by the hit tables once the armor is penetrated (MgT hit tables); the support from the hull armor takes damage every time the hull armor is penetrated regardless.
In order to make tracking damage easier, perhaps sructure can be given a number of 'points' based on load capacity ( 1 point per 50,000 Newtons, for example )
As damage is taken, the max thrust available before crumpling the ship goes down. You want more G's? Dump mass!
If aero drag exceeds the given amount of safe newtons, ship crumples in atmosphere.
As far as finding the young's modulus or compressive strength of materials, there is lots of info on the webs for common materials and alloys. Given that and the usual material lists' given values for toughness, I might be able to figure many of them out. Toughness is the area under the stress/strain curve and the slope of that curve is young's modulus. My calculus is very shaky, but I think I can work it out.
unless I've totally misunderstood things I've been reading that is
Just kicking an idea around.