Zhigang Suo

Zhigang Suo

Allen E. and Marilyn M. Puckett Professor of Mechanics and Materials, Harvard University
Talk Title: Fatigue-resistant materials
suo
In developing a material for a load-bearing application, attention inevitably falls on the resistance of the material to the growth of a crack, characterized by toughness under monotonic load, and by threshold under cyclic load.  Many methods have been discovered to enhance toughness, but they do not enhance threshold. Here we describe a principle of stretchable and fatigue-resistant materials. To illustrate the principle, we embed unidirectional fibers of a soft and stretchable material in a matrix of a much softer and much more stretchable material, and adhere the fibers and the matrix by sparse and covalent interlinks. When the composite is cut with a crack and subject to a load, the soft matrix shears readily and delocalizes the high stretch of a fiber over a long segment. The material achieves a fatigue threshold more than one order of magnitude higher than natural rubber. The principle of stretchable and fatigue-resistant materials is applicable to various materials, layouts, and methods of fabrication, opening an enormous design space for general applications.

Contact Information

Pierce 309
Harvard University
suo@seas.harvard.edu