# Hysteresis 

[ref](https://en.wikipedia.org/wiki/Hysteresis)

the dependence of the state of a system on its history.

# Hertz law

[ref](https://www.sciencedirect.com/topics/engineering/hertz-theory)

contact between two elastic solids

# Newmark time integration

[ref](https://www.sciencedirect.com/topics/engineering/newmark-method)

a method of numerical integration used to solve certain differential equations.