Hard magnetics in ultra-soft magnetorheological elastomers enhance fracture toughness and delay crack propagation Articles uri icon

authors

  • MORENO MATEOS, MIGUEL ANGEL
  • HOSSAIN, MOKARRAM
  • STEINMANN, PAUL
  • GARCIA GONZALEZ, DANIEL

publication date

  • February 2023

start page

  • 1

end page

  • 19

issue

  • 105232

volume

  • 173

International Standard Serial Number (ISSN)

  • 0022-5096

Electronic International Standard Serial Number (EISSN)

  • 1873-4782

abstract

  • Pre-existing flaws in highly stretchable elastomers trigger fracture under large deformations. For multifunctional materials, fracture mechanics may be influenced by additional physical phenomena. This work studies the implications of hard magnetics on the fracture behaviour of ultra-soft magnetorheological elastomers (MREs). We experimentally demonstrate that MREs with remanent magnetisation have up to a 50% higher fracture toughness than non pre-magnetised samples. Moreover, we report crack closure due to the magnetic field as a mechanism that delays the opening of cracks in pre-magnetised MREs. To overcome experimental limitations and provide further understanding, a phase-field model for the fracture of MREs is conceptualised. The numerical model incorporates magneto-mechanical coupling to demonstrate that the stress concentration at the crack tip is smaller when the MRE is pre-magnetised. Overall, this work unveils intriguing applications for functional actuators, with better fracture behaviour and potential better performance under cyclic loading.

subjects

  • Mechanical Engineering

keywords

  • hard magnetics; ultra-soft magnetorheological elastomers; multifunctional materials; experimental mechanics; phase-field modelling; soft fracture