Instability  

From The Art and Popular Culture Encyclopedia

Jump to: navigation, search

Related e

Google
Wikipedia
Wiktionary
Wiki Commons
Wikiquote
Wikisource
YouTube
Shop


Featured:
Train wreck at Montparnasse (October 22, 1895) by Studio Lévy and Sons.
Enlarge
Train wreck at Montparnasse (October 22, 1895) by Studio Lévy and Sons.

In numerous fields of study, the component of instability within a system is generally characterized by some of the outputs or internal states growing without bounds. Not all systems that are not stable are unstable; systems can also be marginally stable or exhibit limit cycle behavior.

In control theory, a system is unstable if any of the roots of its characteristic equation has real part greater than zero (or if zero is a repeated root). This is equivalent to any of the eigenvalues of the state matrix having either real part greater than zero, or, for the eigenvalues on the imaginary axis, the algebraic multiplicity being larger than the geometric multiplicity.

In structural engineering, a structure can become unstable when excessive load is applied. Beyond a certain threshold, structural deflections magnify stresses, which in turn increases deflections. This can take the form of buckling or crippling. The general field of study is called structural stability.

Atmospheric instability is a major component of all weather systems on Earth.

See also

See also

Plasma stability





Unless indicated otherwise, the text in this article is either based on Wikipedia article "Instability" or another language Wikipedia page thereof used under the terms of the GNU Free Documentation License; or on original research by Jahsonic and friends. See Art and Popular Culture's copyright notice.

Personal tools