Self-Organization of Mechanical Structure by Cellular Automata

This paper deals with cellular automata to self-organize mechanical structures. Each cellular automaton consists of identical cells which change the mechanical properties. Two kinds of models are proposed by adding some local rules to the cells. The first model is based on adaptive function of living systems. Each cell changes the Young's modulus according to the stress which is produced in the cell. If the stressed value is small, the cell decreases the Young's modulus. Conversely, if the value is large, it increases the modulus. We simulated the behavior of the model on a computer and showed that the model self-organizes various topological structures. The second model is intended for formation of crack patterns. Each cell shortens its lifetime whenever it receives a large stress under a repetition load. When the cell spends all its lifetime, it vanishes. The computer simulation shows a similar growth pattern of a crack which is observed in a solid material.