Deformaatio

Deformaatio is the Finnish term for deformation and refers to a change in shape or size of a body caused by external influences such as forces, temperature changes, or phase transitions. It is a central concept in engineering, physics, geology, and biology, and can be observed in solids and fluids.

In solids, deformation is described by strain. Stress-strain relations depend on material properties: elastic deformation is reversible, following Hooke's law in the elastic limit with Young's modulus and Poisson's ratio. If stress exceeds yield strength, plastic deformation remains after unloading. Some materials exhibit viscoelastic or creep behavior, especially polymers and metals at elevated temperature or over long times.

Common modes of deformation include tensile, compressive, shear, bending, and torsion; combinations are typical in real-world loading.

Applications and contexts: In engineering, deformation is predicted and controlled through design, material selection, and forming processes. In geology, rock deformation under tectonic forces forms folds, faults, and metamorphic textures. In biology, deformation of cells and tissues influences mechanical function and development.

Measurement and modeling rely on experiments such as tension, compression, and shear tests, as well as constitutive models that capture elastic, plastic, and viscoelastic behavior. Understanding deformaatio supports assessments of structural integrity and performance.