hysteresikierroksi

Hysteresikierroksi is a term used in some theoretical discussions to describe a hysteretic rotational response, where the angular position of a rotor or rotor-like element exhibits memory of past loading. In this sense, the relationship between applied torque or drive input and the resulting angular displacement forms a loop, rather than a single-valued curve, when the input is cycled.

The concept is typically modeled with memory-based frameworks adapted for rotation. A minimal phenomenological description uses internal state variables that capture prior loading and material or interface states, yielding equations where the angular position φ(t) depends on the current input M(t) and an internal state s(t), while s evolves with the history of M(t). Popular modeling approaches borrowed from hysteresis theory—such as Preisach or Prandtl–Ishlinskii operators—are extended to angular coordinates. The area of the φ–M loop relates to energy dissipated per rotation cycle.

Several mechanisms can give rise to hysteresikierroksi-like behavior. Mechanical sources include friction and stick–slip in joints or gears, and viscoelastic or viscoplastic deformation in rotor components. Magnetic, ferroelastic, or magnetostrictive effects in rotor materials can also produce history-dependent reorientation of internal domains that affects the macroscopic rotation.

Experimental detection involves torque–angle or drive–angle measurements that reveal hysteresis loops. Quantities such as coercive angular moment (the torque needed to reduce rotation to a reference) and remanent angle (remaining rotation at zero drive) may be defined to characterize the phenomenon.

Applications are primarily in theoretical analysis and specialized actuator technology, where memory effects may be exploited for damping, repeatable motion under varying load, or energy dissipation control. The term itself is a coined descriptor and is not universally standardized, with related discussions often using more general language such as rotational hysteresis or memory-dependent actuation.