tensjon

Tensjon is a term used to describe the pulling force transmitted along a flexible element, such as a rope, cable, or belt, when it is loaded along its length. The force acts in the direction of the element and tends to stretch it. In many Norwegian texts the more common term is spenning, but tensjon appears in some technical writings or loanword contexts.

In static situations, a massless rope under a single load transmits a uniform tension along its length. If the rope has mass or experiences changing loads, the tension can vary with position and time. In dynamic systems, accelerations and distributed loads cause the tension to change, which can affect the safety and function of the system.

Tension is closely related to material response. The tensile force T in a member with cross-sectional area A produces a normal stress sigma = T/A. The corresponding axial strain in a linear elastic material follows Hooke’s law, ε = sigma / E = T/(A E), where E is Young’s modulus. These relationships underpin many design calculations: they determine how much a cable, rod, or belt will stretch under a given load and how close the material is to yielding or failure.

Applications of tensjon span lifting and towing systems, cranes, elevator ropes, cable-stayed bridges, and belt drives, where maintaining appropriate tension prevents slack, excessive slip, or slack-induced damage. Note that in electrical contexts, the Norwegian term for voltage is spenning; tensjon is less commonly used in that field.