Entangled structures as high cycle compression springs

•High cycle tests of low stiffness, low cost, thin section compression spring for large areas.•Stress–strain curves of steel wool samples over high cycle compression.•Linear behavior observed in samples for strains less than 10%.•Ability to conform to irregular surface while changing mechanical properties.•Spring applications for elevated temperatures or aggressive environments.

Entangled structures, such as steel wool, can be used as inexpensive, high cycle, low stiffness, thin profile compressive springs where uniform pressure on a surface is required particularly in elevated temperature and/or harsh environments. Mechanical compression tests were performed on a variety of steel wool samples to determine the stress–strain curve behavior over high cycles. After initial conditioning cycles, good repeatability can be obtained with hysteresis dependent on strain. The results show a nonlinear behavior over large strains (>10%) and reasonable linear behavior for strains less than 10%. The properties of an entangled structure spring can be selected to achieve the desired stiffness for a particular application.