Details

Autor(en) / Beteiligte

• van der Kooij, Hanne M
• Dussi, Simone
• van de Kerkhof, Gea T
• Frijns, Raoul A M
• van der Gucht, Jasper
• Sprakel, Joris

Titel

Laser Speckle Strain Imaging reveals the origin of delayed fracture in a soft solid

Ist Teil von

• Science advances, 2018-05, Vol.4 (5), p.eaar1926-eaar1926

Ort / Verlag

United States: American Association for the Advancement of Science

Erscheinungsjahr

2018

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Stresses well below the critical fracture stress can lead to highly unpredictable delayed fracture after a long period of seemingly quiescent stability. Delayed fracture is a major threat to the lifetime of materials, and its unpredictability makes it difficult to prevent. This is exacerbated by the lack of consensus on the microscopic mechanisms at its origin because unambiguous experimental proof of these mechanisms remains absent. We present an experimental approach to measure, with high spatial and temporal resolution, the local deformations that precipitate crack nucleation. We apply this method to study delayed fracture in an elastomer and find that a delocalized zone of very small strains emerges as a consequence of strongly localized damage processes. This prefracture deformation zone grows exponentially in space and time, ultimately culminating in the nucleation of a crack and failure of the material as a whole. Our results paint a microscopic picture of the elusive origins of delayed fracture and open the way to detect damage well before it manifests macroscopically.