Jännysvenymäkäyrä

Jännysvenymäkäyrä, also known as a stress-strain curve, is a graphical representation of a material's mechanical behavior under tensile load. It plots the stress, which is the force applied per unit area, against the strain, which is the resulting deformation or elongation. This curve provides crucial information about a material's properties, including its elasticity, plasticity, strength, and ductility.

The initial portion of the jännysvenymäkäyrä typically exhibits a linear elastic region. In this phase, the material deforms elastically, meaning it will return to its original shape once the load is removed. The slope of this linear region is known as the Young's modulus or modulus of elasticity, indicating the material's stiffness.

Beyond the elastic limit, the material enters the plastic deformation region. Here, the deformation is permanent. The stress continues to increase, but the rate of strain may increase as well. A significant point in this region is the yield strength, the stress at which the material begins to deform plastically.

Further along the curve, the material reaches its ultimate tensile strength, which is the maximum stress it can withstand before necking begins. Necking is a localized reduction in the cross-sectional area of the specimen. Finally, the curve ends at the fracture point, where the material breaks. The area under the jännysvenymäkäyrä represents the toughness of the material, its ability to absorb energy before fracturing. Different materials exhibit distinct jännysvenymäkäyrät, allowing engineers to select appropriate materials for specific applications.