Henri Édouard Tresca (12 October 1814 – 21 June 1885) was a French
mechanical engineer
Mechanical may refer to:
Machine
* Machine (mechanical), a system of mechanisms that shape the actuator input to achieve a specific application of output forces and movement
* Mechanical calculator, a device used to perform the basic operations of ...
, and a professor at the
Conservatoire National des Arts et Métiers
A music school is an educational institution specialized in the study, training, and research of music. Such an institution can also be known as a school of music, music academy, music faculty, college of music, music department (of a larger ins ...
in Paris.
Work on plasticity
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 stated one of the first criterion of material
failure
Failure is the state or condition of not meeting a desirable or intended objective, and may be viewed as the opposite of success. The criteria for failure depends on context, and may be relative to a particular observer or belief system. One ...
, that now brings his name. The criterion specifies that a material would
flow plastically if
Tresca's criterion is one of two main failure criteria used today for
ductile
Ductility is a mechanical property commonly described as a material's amenability to drawing (e.g. into wire). In materials science, ductility is defined by the degree to which a material can sustain plastic deformation under tensile stres ...
materials. The second important criterion is due to
Richard von Mises
Richard Edler von Mises (; 19 April 1883 – 14 July 1953) was an Austrian scientist and mathematician who worked on solid mechanics, fluid mechanics, aerodynamics, aeronautics, statistics and probability theory. He held the position of Gordo ...
. See comparison on the image left:
Design of the International Prototype Metre
Tresca was also among the designers of the
prototype metre bar that served as the first standard of length for the
metric system
The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Intern ...
. After the
Convention of the Metre
The Metre Convention (french: link=no, Convention du Mètre), also known as the Treaty of the Metre, is an international treaty that was signed in Paris on 20 May 1875 by representatives of 17 nations (Argentina, Austria-Hungary, Belgium, Braz ...
had been signed in 1875, the
International Bureau of Weights and Measures
The International Bureau of Weights and Measures (french: Bureau international des poids et mesures, BIPM) is an intergovernmental organisation, through which its 59 member-states act together on measurement standards in four areas: chemistry ...
(BIPM) in
Sèvres
Sèvres (, ) is a commune in the southwestern suburbs of Paris, France. It is located from the centre of Paris, in the Hauts-de-Seine department, Île-de-France region. The commune, which had a population of 23,251 as of 2018, is known for ...
, 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
In mechanics, the neutral plane or neutral surface is a conceptual plane within a beam or cantilever. When loaded by a bending force, the beam bends so that the inner surface is in compression and the outer surface is in tension. The neutral pl ...
'', 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 Metre. The United States received National Prototype Metres No. 27 and No. 21 in 1890. When the
Mendenhall Order
The Mendenhall Order marked a decision to change the fundamental standards of length and mass of the United States from the customary standards based on those of England to metric standards. It was issued on April 5, 1893, by Thomas Corwin Mend ...
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.
Recognition
Tresca was made an honorary member of the
American Society of Mechanical Engineers
The American Society of Mechanical Engineers (ASME) is an American professional association that, in its own words, "promotes the art, science, and practice of multidisciplinary engineering and allied sciences around the globe" via " continuing ...
in 1882.
Tresca's stature as an engineer was such that
Gustave Eiffel
Alexandre Gustave Eiffel (born Bonickhausen dit Eiffel; ; ; 15 December 1832 – 27 December 1923) was a French civil engineer. A graduate of École Centrale des Arts et Manufactures, he made his name with various bridges for the French railway ...
put his name on number 3 in
his list of 72 people making the Eiffel tower in Paris possible.
See also
*
Yield surface
A yield surface is a five-dimensional surface in the six-dimensional space of stresses. The yield surface is usually convex and the state of stress of ''inside'' the yield surface is elastic. When the stress state lies on the surface the materi ...
*
von Mises stress
The term ''von'' () is used in German language surnames either as a nobiliary particle indicating a noble patrilineality, or as a simple preposition used by commoners that means ''of'' or ''from''.
Nobility directories like the ''Almanach de G ...
*
Mohr-Coulomb theory
*
Adiabatic shear band
In physics, mechanics and engineering, an adiabatic shear band is one of the many mechanisms of failure that occur in metals and other materials that are deformed at a high rate in processes such as metal forming, machining and ballistic impact. ...
*
Yield (engineering)
In materials science and engineering, the yield point is the point on a stress-strain curve that indicates the limit of elastic behavior and the beginning of plastic behavior. Below the yield point, a material will deform elastically and wi ...
*
Stress
Stress may refer to:
Science and medicine
* Stress (biology), an organism's response to a stressor such as an environmental condition
* Stress (linguistics), relative emphasis or prominence given to a syllable in a word, or to a word in a phrase ...
*
Strain
*
3-D elasticity
Linear elasticity is a mathematical model of how solid objects deform and become internally stressed due to prescribed loading conditions. It is a simplification of the more general nonlinear theory of elasticity and a branch of continuum mech ...
*
Viscoplasticity
Viscoplasticity is a theory in continuum mechanics that describes the rate-dependent inelastic behavior of solids. Rate-dependence in this context means that the deformation of the material depends on the rate at which loads are applied. The i ...
References
External links
Henri Tresca in Technische Mechanik für Ingenieure*
enriTresca, 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)
{{DEFAULTSORT:Tresca, Henri
1814 births
1885 deaths
People from Dunkirk
French engineers
French materials scientists
Members of the French Academy of Sciences