A Plan to Win the War on Fatigue

 

Abstract:

For some time, we and others have advanced a theory that soft materials—elastomers, gels, and living tissues—attain high toughness through inelasticity, just like metals. This theory has led to a worldwide search for mechanisms of inelasticity—sacrificial bonds that dissipate energy. The materials so created increase toughness by orders of magnitude, but suffer from a molecular disease: fatigue. Symptoms include excessive hysteresis and growth of cracks under cyclic stretch. They are unfit for applications such as artificial heart valves and soft robots. Recently, we have developed soft materials called elastic dissipaters. They have high toughness and low hysteresis. They are fatigue-resistant. This talk describes the fundamental mechanics, along with implementations in practical materials, both soft and hard.

 

Biography:

Zhigang Suo is the Allen E. and Marilyn M. Puckett Professor of Mechanics and Materials at Harvard University. He grew up through the Cultural Revolution, on the campus of Xian Jiaotong University, and graduated from its kindergarten, elementary school, middle school, high school, and college. He wrote his undergraduate thesis on coupled boundary and finite elements, under Professor Xing Ji, at Xian Jiaotong University, in 1985. He wrote his PhD thesis on interfacial fracture mechanics, under Professor John W. Hutchinson, at Harvard University, in 1989. Suo joined the faculty of the University of California at Santa Barbara in 1989, Princeton University in 1997, and Harvard University in 2003. He writes papers under students and collaborators, but tweets unsupervised. An ongoing project is a long thread of tweets, titled One Hundred Years of Toughness, celebrating a paper published by Alan Arnold Griffith in 1921.