|Born||12 October 1814|
|Died||21 June 1885 (aged 70)|
|Institutions||American Society of Mechanical Engineers, French Academy of Sciences|
He is the father of the field of plasticity, or non-recoverable deformations, which he explored in an extensive series of experiments begun in 1864. He is the discoverer of the Tresca (or maximal shear stress) criterion of material failure. The criterion specifies that a material would flow plastically if
Tresca was also among the designers of the prototype meter bar that served as the first standard of length for the metric system. After the Convention of the Metre had been signed in 1875, the International Bureau of Weights and Measures (BIPM) in Sèvres, France made 28 prototype line standards of platinum-iridium. The bars had a cross section shaped like a modified letter X, designed by Tresca, called the "Tresca section". The Tresca section was designed to provide maximum stiffness. In addition, one surface of the central rib that joined the arms was designed to coincide with the bar's neutral plane, the mathematical plane inside the bar that didn't change length when the bar bent. The two marks near each end of the bar which defined the meter were ruled on this surface. Thus, to first order, the distance between the marks wouldn't change due to the slight sagging of the bar under its own weight between support points. One of the bars was selected as the International Meter. The United States received National Prototype Meters No. 27 and No. 21 in 1890. When the Mendenhall Order in 1893 declared the meter to be the fundamental length standard, No. 27 became the US primary national standard for all length measurements. It remained so until 1960.
- Henri Tresca in Technische Mechanik für Ingenieure
- [Henri] Tresca, Appendix C: Note on the form which it is advisable to adopt for the metres to be constructed by the International Commission, pp 77-93, in Second Report of the Commissioner of Inland Revenue of the Inspection of Weights, Measures and Gas, in Sessional Papers, Volume 2, Second Session of the Third Parliament of the Dominion of Canada, Session 1875, Volume VIII (English translation of Tresca's French paper on Tresca section)