Name of a class of mechanical systems similar to the $n$-body problem I am wondering if there is a particular name for the class of mechanical systems defined by "$n$ copies of the same system linked together". I know this is not completely clear, however, my reference example is the pendulum, which can be connected to other pendulums generating the double pendulum, the triple pendulum and so on, where the equations of motion can be written for the generic $n$-chain of pendulums.
Similarly, I can think of the $n$-body problem which falls in the same category.
I tried looking for "scalable systems" but I don't find what I need. I hope that there is some commonly used name to reference this class of systems.
I hope to receive some hint, I don't need specific examples (well they could help of course), but I would prefer some keyword to go on with my research.
 A: A few examples of models of physical systems involving a large number of identical systems are:

*

*Crystals : Crystalline lattices, when the objects in question are in a solid ordered state, see also crystallography or solid state physics. Behavior of atoms in a lattice, behavior of electrons in a lattice, conductivity, semiconductors, magnets.


*Gases: One example is the ideal gas model which aims at linking the individual characteristics of the gas molecules to the thermodynamic variables of said gas.


*Fluid dynamics.


*Another example is the attempts to model the mutual interactions of the protons an neutrons in a nucleus (see shell model).


*Beyond the realm of physics, there is also all the theories about graphs and networks related to computer science.
A: A term that is close but perhaps not identical to what you want to use is "ensemble". This has a somewhat specific meaning in statistical mechanics (a lot of imagined copies of the system evolving independently), but I have seen it used for systems where there are copies of a subsystem that have some (weak) links.
A: Certainly. In mechanical engineering this is called a distributed system and its behavior is described by continuum dynamics.
