[[wiki-architecture]] · [[Building Materials]] · [[ARCHITECTURE]] · [[000]] # Strain hardening exponent The strain hardening exponent (also called the strain hardening index), usually denoted n {\displaystyle n} , is a measured parameter that quantifies the ability of a material to become stronger due to strain hardening. Strain hardening (work hardening) is the process by which a material's load-bearing capacity increases during plastic (permanent) strain, or deformation. This characteristic is what sets ductile materials apart from brittle materials. The uniaxial tension test is the primary experimental method used to directly measure a material's stress–strain behavior, providing valuable insights into its strain-hardening behavior. The strain hardening exponent is sometimes regarded as a constant and occurs in forging and forming calculations, as well as the formula known as the Hollomon equation (after John Herbert Hollomon Jr.), originally posited as: σ = K ϵ n {\displaystyle \sigma =K\epsilon ^{n}} where σ {\displaystyle \sigma } represents the applied true stress on the material, ϵ {\displaystyle \epsilon } is the true strain, and K {\displaystyle K} is the strength coefficient. The value of the strain hardening exponent lies between 0 and 1, with a value of 0 implying a perfectly plastic solid and a value of 1 representing a perfectly elastic solid. Most metals have an n {\displaystyle n} -value between 0.10 and 0.50. In one study, strain hardening exponent values extracted from tensile data from 58 steel pipes from natural gas pipelines were found to range from 0.08 to 0.25, with the lower end of the range dominated by high-strength low alloy steels and the upper end of the range mostly normalized steels. == Tabulation == == References == - [[Building Construction/Structural Systems]] - [[Wiki-Architecture/Urban Planning and City Architecture]] - [[Building Services/Electrical Systems]] - [[Professional Practice/Construction Management/Cost Estimation]] - [[Professional Practice/Public & Cultural]] - [[Professional Practice/Codes & Standards/National Building Code of India/Part 10 - Landscape and Signs/Section 1 - Landscape Planning]] - [[Urban and Planning/Urban Design Principles]] - [[Building Construction/Estimating & Costing]] - [[Urban and Planning/Smart Buildings]] - [[History and Theory/World History/Medieval Architecture]] == External links == More complete picture about the strain hardening exponent in the stress–strain curve on www.key-to-steel.com