Tensioning

Tensioning is the process of applying tensile force to a flexible element such as a cable, rope, belt, membrane, or structural tendon. The goal is to create or increase stiffness, stability, and control of shape, to counteract applied loads, or to introduce pre-stress into a component or structure. Tensioning can also compensate for sag, shrinkage, or deflection and help maintain alignment and performance over time.

Techniques and tools for tensioning rely on devices such as turnbuckles, hydraulic or screw jacks, winches, or automated tensioning systems. The applied tension is measured and controlled with load cells, dynamometers, tension meters, or feedback-control systems to achieve the desired force and to monitor changes during use.

Common applications span several fields. In construction and civil engineering, post-tensioning of concrete slabs and elements uses tendons anchored at ends and strained after curing, while pre-tensioning is done before casting. In mechanical systems, belt, chain, and cable drives require proper tension to prevent slipping and wear. Tensioning is also used in textiles, sails, tents, and printing or fabric finishing to maintain material flatness and dimensional stability. In some musical instruments and sports equipment, string or fabric tension determines pitch or performance characteristics.

Types of tensioning include pre-tensioning, where the element is tensioned before it is put into service, and post-tensioning, where tension is applied after installation. Considerations include material properties (elasticity, creep, relaxation), temperature effects, fatigue, corrosion, and safety and inspection requirements.