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A Very Brief History of Fatigue Research- Part 2 – August Wöhler and the Late 19th Century

This is the second of a three-part series on the history of fatigue analysis.  It has been adapted from the upcoming Ph.D. dissertation of VEXTEC’s Robert McDaniels. You can read Part 1 here.

While early and important work was being done by Wilhelm Albert, Jean-Victor Poncelet, William Rankine, and other researchers in the growing field of fatigue in the 1800’s, by far the most influential person at the beginning of the systematic study of fatigue was August Wöhler.  His influence on early fatigue research is so great that an entire section of Walter Schutz’s paper on the history of fatigue [6] and an entire section of Stepan Timoshenko’s book “History of Strength of Materials” are dedicated to Wöhler’s work [9].  Wöhler was a railroad engineer who worked his way from the machine shop manager to the head of all rolling stock and machine shops of the railroad in Frankfurt, Germany [9, 13].   During his long and influential career he established materials specifications for the metals that were used in railroad applications, fostered the creation of a network of material testing laboratories in Germany, and standardized those labs’ testing and reporting procedures [9].  He also designed and built many different types of fatigue testing machines, and performed many different types of tests [6].  He was the first to understand the importance of both stress amplitude and mean stress on the fatigue life of components [6].  He differentiated between safety factors for components that had finite-design lives and components that were designed for infinite life [6].  Wöhler was also the first researcher to seriously consider the effect of residual stresses on fatigue [9].  He also published the results of his rotating bend fatigue test results in tabular form, and he is generally credited as the originator of the concept of the “endurance limit” [3].  His influence was so great that many years later, this rotating bend fatigue data (and other fatigue data) were presented as curves that his successors called Wöhler curves in his honor [6].

The next significant contributor to our understanding of fatigue was Johann Bauschinger [6].  His main contribution was the discovery and description in 1886 of the effect which bears his name.  The Bauschinger effect is the effect whereby induced strains beyond the elastic limit in one loading direction decreases the elastic limit in the opposite direction [3, 14].  This was an important discovery because it led the way to the theories of L.F. Coffin Jr. and S.S. Manson in the 1950’s, and for understanding both the low cycle fatigue phenomena and damage accumulation theories that are still used today [6].

REFERENCES

  1. Turnbull, H.W. ed., The Correspondence of Isaac Newton: 1661-1675, Volume 1, London, UK: Published for the Royal Society at the University Press. p. 416 (1959).
  2. “Wilhelm Albert”, Wilhelm Albert. Wikipedia. created 06 February 2016, accessed 31 Dec 2016.
  3. Suresh, S. Fatigue of Materials. pp. 1-11 (1998).
  4. Hansson, T.J. “Fatigue Failure Mechanisms and Fatigue Testing” NATO Science and Technology Organization Educational Notes. EN-AVT-207-14 (2012).
  5. Albert, W. A. J. “Über Treibseile am Harz” Archive für Mineralogie Geognosie Bergbau und Hüttenkunde, vol. 10, pp. 215-34 (1838).
  6. Schutz, W. “A History of Fatigue,” Engineering Fracture Mechanics, vol. 54. No. 2, pp. 263-300 (1996).
  7. Bhat, S. and Patibandla, R. “Metal Fatigue and Basic Theoretical Models: A Review,” Alloy Steel -Properties and Use. Dr. Eduardo Valencia Morales, ed. (2011).
  8. Mitchell, M.R. Fatigue, ASM Handbook, Vol. 19, 554-555. Materials Park, Ohio (1996).
  9. Timoshenko, S.P. History of the Strength of Materials. pp. 162-173 (1983).
  10. Bathias, C., and Pineau, A. Fatigue of Materials (2010).
  11. “The Versailles Rail Accident,” Versailles Rail Accident. Wikipedia. Created 22 November 2016, accessed 31 Dec 2016.
  12. ASM HANDBOOK. Vol 19, Fatigue and Fracture.  ASM International. pp.76-86 (1996).
  13. “August Wohler,” August Wohler. Wikipedia. Created 21 October 2016, accessed 02 January 2017.
  14. ASM dictionary, ASM International. p. 454 (1992).
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A Very Brief History of Fatigue Research- Part 1- The Beginning

This is the first of a three-part series on the history of fatigue analysis.  It has been adapted from the upcoming Ph.D. dissertation of VEXTEC’s Robert McDaniels.  You can read Part 2 here.

Isaac Newton wrote to Robert Hooke “If I have seen further, it is because I have stood on the shoulders of giants.”[1]   Since the first research on metal fatigue began in the 18th century, a very large number of researchers from all over the world have contributed to the knowledge base that has been amassed.  Some workers have contributed to the characterization of fatigue failures, the discovery of the mechanisms of fatigue, and the testing of materials. Other researchers have contributed by adding to the theoretical and mathematical models that allow us to make predictions about how components will behave in the future when subjected to periodic loading under different conditions.  Fatigue research is truly a multidisciplinary field that incorporates:

  • Mechanical engineering expertise to understand the stresses and strains to which components are subjected;
  • Materials science expertise to understand how the stresses and strains affect, and are affected by, the microstructure of the components; and
  • Statistical expertise to recognize and mathematically describe the microstructures, loads, and geometries of the components that are all inherently variable, and how these variabilities will affect the fatigue behavior of an individual component, or a fleet of components.

The first person to observe and report what we now know as metal fatigue was a German mining administrator named Wilhelm Albert.[2]  He investigated the failure of mine hoist chains.  He then built a machine which subjected lengths of chain to repeated loads of up to 100,000 cycles.[3]  He authored the first paper on metal fatigue in 1838.[4-6]

The importance of fatigue in transportation was well established by the 1850’s.[6]  The failure of axles of both horse drawn and railroad carriages were investigated by Arthur Morin in France, and William Rankine and J.O. York in Great Britain.[6]  The actual usage of the term “fatigue” has been attributed to most often to Jean-Victor Poncelet [7-9], but also to Morin, Frederick Braithwaite, and his colleague Mr. Field.[3, 6]  Whoever coined the term, the historical record is clear that by the mid-19th century, it was already well-established that fatigue was a significant problem in all modes of transportation, and in many industries as well.

Unfortunately, it is often catastrophic accidents that provide the impulse and direction of fatigue testing and research.  One of the first accidents that spurred the growth and direction of fatigue research was the famous railroad mishap that occurred in 1842, on the railroad from Versailles to Paris, France.[3, 6, 7, 10, 11]  While transporting revelers back to Paris from King Louis Phillipe I’s birthday celebration at Versailles, a locomotive suffered an axle failure, which caused a derailment.  The trailing carriages ran into the engine, and they all caught fire.[11]  The crash killed over 60 people, and was the one of the worst railroad accidents that occurred during the 19th century.[7]  A failure analysis investigation was conducted by Rankine, who found brittle cracking of the shaft.  Railroad mishaps, many caused by fatigue failures, were so commonplace that newspapers in Great Britain were reporting “the most serious railway accidents of the week” even into the late 1880’s.[6, 12]  By the mid 1800’s, several engineers in the British railroad industry had conducted tests of axles and members used in railroad bridges, and had already determined that even a load of half the ultimate strength of iron and steel components was sufficient to cause failure of metal components.  They had also created a predecessor to what engineers now call the endurance limit or “safe life” of components used in the railroad industry.[9]  In addition, they also identified sharp notches and corners as locations where cracks were likely to form, a precursor to the modern concept of stress risers, and had begun to investigate the idea of microstructural changes in the metal, [9] although they were decades too early to be able to explore microstructure the way that we currently can.

References

  1. Turnbull, H.W. ed., The Correspondence of Isaac Newton: 1661-1675, Volume 1, London, UK: Published for the Royal Society at the University Press. p. 416. (1959)
  2. “Wilhelm Albert”, Wilhelm Albert.Wikipedia. created 06 February 2016, accessed 31 Dec 2016.
  3. Suresh, S. Fatigue of Materials. Pp. 1-11. (1998).
  4. Hansson, T.J. “Fatigue Failure Mechanisms and Fatigue Testing” NATO Science and Technology Organization Educational Notes. EN-AVT-207-14. (2012)
  5. Albert, W. A. J. “Über Treibseile am Harz” Archive für Mineralogie Geognosie Bergbau und Hüttenkunde, vol. 10, pp 215-34 (1838)
  6. Schütz, W. “A History of Fatigue,” Engineering Fracture Mechanics, vol. 54. No. 2 pp 263-300 (1996).
  7. S. Bhat and R. Patibandla. “Metal Fatigue and Basic Theoretical Models: A Review”, Alloy Steel -Properties and Use, Dr. Eduardo Valencia Morales (Ed.), (2011).
  8. Mitchell, M.R. Fatigue, ASM Handbook, Vol. 19., 554-555. Materials Park, Ohio. (1996).
  9. Timoshenko, S.P. History of the Strength of Materials. Pp. 162-173. (1983).
  10. Bathias, C., and Pineau, A. Fatigue of Materials.,  (2010)
  11. “The Versailles Rail Accident”, Versailles Rail Accident. Wikipedia. Created 22 November 2016, accessed 31 Dec 2016.
  12. ASM HANDBOOK Vol 19 Fatigue and Fracture.  ASM International. pp.76-86. (1996).