August Wöhler (22 June 1819 – 21 March 1914) was a German railway

engineer Engineers, as practitioners of engineering, are professionals who invent, design, analyze, build and test machines, complex systems, structures, gadgets and materials to fulfill functional objectives and requirements while considering the l ...

, best remembered for his systematic investigations of

metal fatigue In materials science, fatigue is the initiation and propagation of cracks in a material due to cyclic loading. Once a fatigue crack has initiated, it grows a small amount with each loading cycle, typically producing striations on some parts o ...

Life

Born in the town of

Soltau Soltau () is a mid-sized town in the Lüneburg Heath in the district of Heidekreis, in Lower Saxony, Germany. It has around 22,000 inhabitants. The city is centrally located in the Lüneburg Heath and is known nationwide especially for its touri ...

Hanover Hanover (; german: Hannover ; nds, Hannober) is the capital and largest city of the German state of Lower Saxony. Its 535,932 (2021) inhabitants make it the 13th-largest city in Germany as well as the fourth-largest city in Northern Germany ...

, the son of local teacher Georg Heinrich Wöhler, he showed early mathematical ability and won a

scholarship A scholarship is a form of financial aid awarded to students for further education. Generally, scholarships are awarded based on a set of criteria such as academic merit, diversity and inclusion, athletic skill, and financial need. Scholarsh ...

to study at the Higher Vocational College of Hannover from 1835, under the direction of

Karl Karmarsch Karl Karmarsch (17 October 1803 – 24 March 1879) was an Austrian-born (since 1830) German educator, founding director of the Polytechnic School in Hanover, later to become the University of Hannover. From 1817 to 1823, he was associated with t ...

. In 1840, he was recruited to the

Borsig Borsig is a surname. Notable people with the surname include: * (1867–1897), German entrepreneur * August Borsig (1804–1854), German businessman * Conrad von Borsig (1873–1945), German mechanical engineer * Ernst Borsig Ernst August Pau ...

works in

Berlin Berlin ( , ) is the capital and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constitue ...

where he worked on the manufacture of

rail tracks A railway track (British English and UIC terminology) or railroad track (American English), also known as permanent way or simply track, is the structure on a railway or railroad consisting of the rails, fasteners, railroad ties (sleepers, ...

. In 1843, after a brief stay in Hannover, he started to receive instruction in locomotive driving in

Belgium Belgium, ; french: Belgique ; german: Belgien officially the Kingdom of Belgium, is a country in Northwestern Europe. The country is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeast, France to th ...

, returning as an engineer on the Hanover-Brunswick line of the Royal Hanoverian State Railways. By 1847, Wöhler was chief superintendent of rolling stock on the Lower Silesian-Marcher railway in

Frankfurt (Oder) Frankfurt (Oder), also known as Frankfurt an der Oder (), is a city in the German state of Brandenburg. It has around 57,000 inhabitants, is one of the easternmost cities in Germany, the fourth-largest city in Brandenburg, and the largest German ...

. The railroad was

nationalised Nationalization (nationalisation in British English) is the process of transforming privately-owned assets into public assets by bringing them under the public ownership of a national government or state. Nationalization usually refers to pri ...

by the

Prussian state railways The term Prussian state railways (German: ''Preußische Staatseisenbahnen'') encompasses those railway organisations that were owned or managed by the State of Prussia. The words "state railways" are not capitalized because Prussia did not have a ...

in 1852 and Wöhler's growing reputation led to his appointment by the

Prussian Prussia, , Old Prussian: ''Prūsa'' or ''Prūsija'' was a German state on the southeast coast of the Baltic Sea. It formed the German Empire under Prussian rule when it united the German states in 1871. It was ''de facto'' dissolved by an e ...

Ministry of Commerce to investigate the causes of

fracture Fracture is the separation of an object or material into two or more pieces under the action of stress. The fracture of a solid usually occurs due to the development of certain displacement discontinuity surfaces within the solid. If a displa ...

in railroad

axle An axle or axletree is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In the former case, bearing ...

s, work that was to occupy Wöhler over the next two decades. The recognition of his keen administration and technical leadership resulted in his appointment as director of the newly formed

Imperial Railways in Alsace-Lorraine The Kaiserliche Generaldirektion der Eisenbahnen in Elsaß-Lothringen or EL (English: General Directorate of the Imperial Railways in Alsace-Lorraine) were the first railways owned by the German Empire. They emerged in 1871, after France had ced ...

in 1874, based at the board's headquarters in

Straßburg Strasbourg (, , ; german: Straßburg ; gsw, label=Bas Rhin Alsatian, Strossburi , gsw, label=Haut Rhin Alsatian, Strossburig ) is the prefecture and largest city of the Grand Est region of eastern France and the official seat of the Eu ...

, a post he held until his retirement in 1889.

Fatigue studies

Wöhler started his axle investigations by research into the theory of

elasticity Elasticity often refers to: *Elasticity (physics), continuum mechanics of bodies that deform reversibly under stress Elasticity may also refer to: Information technology * Elasticity (data store), the flexibility of the data model and the cl ...

and was led, in 1855, to a method for predicting the deflection of lattice beams that anticipated the work of Émile Clapeyron. He also introduced the practice of supporting one end of a bridge on

roller bearing In mechanical engineering, a rolling-element bearing, also known as a rolling bearing, is a bearing which carries a load by placing rolling elements (such as balls or rollers) between two concentric, grooved rings called races. The relative m ...

s to allow for

thermal expansion Thermal expansion is the tendency of matter to change its shape, area, volume, and density in response to a change in temperature, usually not including phase transitions. Temperature is a monotonic function of the average molecular kinetic ...

His work on

fatigue Fatigue describes a state of tiredness that does not resolve with rest or sleep. In general usage, fatigue is synonymous with extreme tiredness or exhaustion that normally follows prolonged physical or mental activity. When it does not resolve ...

marks the first systematic investigation of ''S-N curves'', also known as '' Wöhler curves'', to characterise the fatigue behaviour of materials. Such curves can be used to minimise the problem of fatigue by lowering the stress at critical points in a component. Wöhler showed clearly that fatigue occurs by crack growth from surface defects until the product can no longer support the applied load. The history of a fracture can be understood from a study of the fracture surface. He developed apparatus for repeated loading of railway axles, mainly because many accidents were caused by sudden fatigue fracture. The presentation of his work at the Paris Exposition in 1867 brought it to a wide international audience. Wöhler was an advocate of state

standardisation Standardization or standardisation is the process of implementing and developing technical standards based on the consensus of different parties that include firms, users, interest groups, standards organizations and governments. Standardization ...

, testing and certification of

iron Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...

and

steel Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant ty ...

. He died in Hannover in 1914.

References

External links

* {{DEFAULTSORT:Wohler, August 1819 births 1914 deaths Engineers from Lower Saxony German railway mechanical engineers

Life

Fatigue studies

References

Further reading

External links