Vetokokeen

Vetokokeen is the Estonian term for the tensile test, a standard method used in materials science to determine how a material behaves under uniaxial tension. The test provides quantitative data on mechanical properties such as strength, ductility, and stiffness, and it yields a stress–strain relationship that characterizes the material’s performance.

In a typical vetokokeen, a specimen with a defined cross-sectional area and gauge length is gripped at both ends of a universal testing machine. A controlled tensile load is applied at a constant rate or at a specified strain rate until failure. During the test, the force and the elongation of the specimen are recorded, often with an extensometer or other displacement-measuring devices. The resulting data are used to construct a stress–strain curve from which key properties are derived.

Common outputs include the yield strength (the stress at which plastic deformation begins), the ultimate tensile strength (the maximum stress the material can withstand), the elongation at break (ductility), and the reduction of area. Depending on the material, the test may also provide information on toughness and behavior in the elastic and plastic ranges. For polymers, composites, and metals, adjustments in grip design, heating, or testing speed may be required to obtain reliable results.

Vetokokeen standards are defined by international and regional organizations, such as ISO, EN, and ASTM, and specify specimen geometry, testing speeds, and data reporting. The method is widely used for quality control, material development, and structural design.