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

engineer Engineers, as practitioners of engineering, are professionals who Invention, invent, design, build, maintain and test machines, complex systems, structures, gadgets and materials. They aim to fulfill functional objectives and requirements while ...

, 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 striation (fatigue), striati ...

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 ( ; ; ) is the capital and largest city of the States of Germany, German state of Lower Saxony. Its population of 535,932 (2021) makes it the List of cities in Germany by population, 13th-largest city in Germany as well as the fourth-l ...

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

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

to study at the Higher Vocational College of Hannover from 1835, under the direction of Karl Karmarsch. 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 (1869–1933) ...

works in

Berlin Berlin ( ; ) is the Capital of Germany, capital and largest city of Germany, by both area and List of cities in Germany by population, population. With 3.7 million inhabitants, it has the List of cities in the European Union by population withi ...

where he worked on the manufacture of

rail tracks Railway track ( and UIC terminology) or railroad track (), also known as permanent way () or "P way" ( and Indian English), is the structure on a railway or railroad consisting of the rails, fasteners, sleepers ( railroad ties in American ...

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

Belgium Belgium, officially the Kingdom of Belgium, is a country in Northwestern Europe. Situated in a coastal lowland region known as the Low Countries, it is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeas ...

, 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 (, ; Central Marchian: ''Frankfort an de Oder,'' ) is the fourth-largest city in the German state of Brandenburg after Potsdam, Cottbus and Brandenburg an der Havel. With around 58,000 inh ...

. 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 contrasts with ...

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: ''Prūsija'') was a German state centred on the North European Plain that originated from the 1525 secularization of the Prussian part of the State of the Teutonic Order. For centuries, the House of Hohenzoll ...

Ministry of Commerce to investigate the causes of

fracture Fracture is the appearance of a crack or complete separation of an object or material into two or more pieces under the action of stress (mechanics), stress. The fracture of a solid usually occurs due to the development of certain displacemen ...

in railroad

axle An axle or axletree is a central shaft for a rotation, rotating wheel and axle, 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 ...

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 Imperial is that which relates to an empire, emperor/empress, or imperialism. Imperial or The Imperial may also refer to: Places United States * Imperial, California * Imperial, Missouri * Imperial, Nebraska * Imperial, Pennsylvania * I ...

in 1874, based at the board's headquarters in

Straßburg Strasbourg ( , ; ; ) is the prefecture and largest city of the Grand Est region of eastern France, in the historic region of Alsace. It is the prefecture of the Bas-Rhin department and the official seat of the European Parliament. The cit ...

, a post he held until his retirement in 1889.

Fatigue studies

Wöhler started his axle investigations by research into the theory of elasticity and was led, in 1855, to a method for predicting the deflection of lattice beams that anticipated the work of

Émile Clapeyron Benoît Paul Émile Clapeyron (; 26 January 1799 – 28 January 1864) was a French engineer and physicist, one of the founders of thermodynamics. Life Born in Paris, Clapeyron studied at the École polytechnique, graduating in 1818. He also studi ...

. 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,ISO 15 is a bearing which carries a load by placing rolling elements (such as balls, cylinders, or cones) between two concentric, grooved rings called race ...

s to allow for

thermal expansion Thermal expansion is the tendency of matter to increase in length, area, or volume, changing its size and density, in response to an increase in temperature (usually excluding phase transitions). Substances usually contract with decreasing temp ...

His work on

fatigue Fatigue is a state of tiredness (which is not sleepiness), exhaustion or loss of energy. It is a signs and symptoms, symptom of any of various diseases; it is not a disease in itself. Fatigue (in the medical sense) is sometimes associated wit ...

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 (American English) or standardisation (British English) is the process of implementing and developing technical standards based on the consensus of different parties that include firms, users, interest groups, standards organiza ...

, testing and certification of

iron Iron is a chemical element; it has symbol Fe () 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, forming much of Earth's o ...

and

steel Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...

. He died in Hannover in 1914.

References

External links

* {{DEFAULTSORT:Wohler, August 1819 births 1914 deaths German railway mechanical engineers People from the Kingdom of Hanover

Life

Fatigue studies

References

Further reading

External links