kontinuummechanika

Kontinuummechanika is a branch of physics and engineering that treats matter as a continuous medium rather than as discrete particles. This approximation is valid when the characteristic length scale of the phenomenon being studied is much larger than the average distance between atoms or molecules. In continuum mechanics, properties like density, velocity, and stress are considered to be continuous functions of position and time. This allows for the use of differential equations to describe the behavior of the material.

The fundamental principles of continuum mechanics are conservation of mass, conservation of momentum (Newton's second law), and conservation of energy. These principles are applied to a "continuum element," which is a small, infinitesimal volume of the material. The behavior of the entire material is then derived by integrating these principles over the entire body.

Key concepts within continuum mechanics include:

Deformation: The change in shape or size of a material under the influence of external forces. This is described by strain tensors.

Stress: The internal forces that particles within a continuous material exert on each other, measured per unit area. This is described by stress tensors.

Flow: The motion of fluids, which are a type of continuum. This is governed by fluid dynamics equations like the Navier-Stokes equations.

Solid mechanics, a subfield of continuum mechanics, deals with the behavior of solid materials under stress and strain. Fluid mechanics, another subfield, deals with the behavior of liquids and gases. Continuum mechanics is essential for understanding and predicting the behavior of a vast range of physical systems, from the flow of air around an airplane wing to the deformation of bridge structures under load.