Henri Édouard Tresca was a
FrenchFrance , officially the French Republic , is a country located in Western Europe, with several overseas islands and territories located on other continents. Metropolitan France extends from the Mediterranean Sea to the English Channel and the North Sea, and from the Rhine to the Atlantic Ocean...
mechanical engineer, and a professor at the
Conservatoire National des Arts et MétiersThe Conservatoire National des Arts et Métiers , or National Conservatory of Arts and Crafts, is a doctoral degree-granting higher education establishment operated by the French government, dedicated to providing education and conducting research for the promotion of science and industry...
in
ParisParis is the capital of France and the country's most populous city. It is situated on the river Seine, in northern France, at the heart of the Île-de-France region...
.
He is the father of the field of plasticity, or non-recoverable deformations, which he explored in an extensive series of brilliant experiments begun in 1864. He is the discoverer of the Tresca (or maximal
shear stressA shear stress, denoted , is defined as a stress which is applied parallel or tangential to a face of a material, as opposed to a normal stress which is applied perpendicularly.-General shear stress:...
) criterion of
materialMaterial is synonymous with substance, and is anything made of matter hydrogen, air and water are all examples of materials. Sometimes the term "material" is used more narrowly to refer to substances or components with certain physical properties that are used as inputs to production or manufacturing...
failureFailure refers to the state or condition of not meeting a desirable or intended objective, and may be viewed as the opposite of success. Product failure ranges from failure to sell the product to fracture of the product, in the worst cases leading to personal injury, the province of forensic...
. The criterion specifies that a material would flow plastically if
Tresca's criterion is one of two main failure criteria used today. The second important criterion is due to von Mises. See comparison on the image left:
Tresca's stature as an engineer was such that
Gustave EiffelAlexandre Gustave Eiffel , was a French structural engineer and entrepreneur and a specialist of metallic structures...
put his name on number 3 in
his list of 72 peopleOn the Eiffel Tower, seventy-two names of French scientists, engineers and some other notable people are engraved in recognition of their contributions by Gustave Eiffel. The engravings are found on the sides of the tower under the first balcony...
making the Eiffel tower in Paris possible.
Tresca was also among the designers of the
standardStandardization or standardisation is the process of developing and agreeing upon technical standards. A standard is a document that establishes uniform engineering or technical specifications, criteria, methods, processes, or practices. Some standards are mandatory while others are voluntary. ...
metre etalon. After the Treaty of the Meter 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 modified X cross section named for the French scientist, Tresca who designed them. The Tresca section was designed to provide maximum stiffness. Small elliptical areas on the upper surface of the central rib at each end of the bars were highly polished, and three lines, nominally 0.5 mm apart, were ruled on these surfaces, the distance between the middle lines of each group defining the standard length. 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 OrderThe 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 Mendenhall, superintendent of the U.S...
in 1893 declared the meter to be the fundamental length standard, No. 27 became the primary national standard for all length measurements. It remained so until 1960.
Tresca was made an honorary member of the
American Society of Mechanical EngineersThe American Society of Mechanical Engineers is a professional body, specifically an engineering society, focused on mechanical engineering....
in 1882.
See also
- Yield surface
A yield surface is a five-dimensional surface in the six-dimensional space of stresses. The state of stress of inside the yield surface is elastic. When the stress state lies on the surface the material is said to have reached its yield point and the material is said to have become plastic...
- von Mises stress
The von Mises yield criterion suggests that the yielding of materials begins when the second deviatoric stress invariant reaches a critical value . For this reason, it is sometimes called the -plasticity or flow theory. It is part of a plasticity theory that applies best to ductile materials,...
- Mohr-Coulomb theory
Mohr-Coulomb theory is a mathematical model describing the response of brittle materials such as concrete, or rubble piles, to shear stress as well as normal stress. Most of the classical engineering materials somehow follow this rule in at least a portion of their shear failure envelope...
- Yield (engineering)
The yield strength or yield point of a material is defined in engineering and materials science as the stress at which a material begins to deform plastically. Prior to the yield point the material will deform elastically and will return to its original shape when the applied stress is removed...
- Stress
In continuum mechanics, the concept of stress, introduced by Cauchy around 1822, is a measure of the average amount of force exerted per unit area of a surface within a deformable body on which internal forces act...
- Strain
In continuum mechanics, the infinitesimal strain theory, sometimes called small deformation theory, small displacement theory, or small displacement-gradient theory, deals with infinitesimal deformations of a continuum body...
- 3-D elasticity
External links
- http://mechanima.upb.de/Geschichte/1814%20-%20Tresca/