Rupture of an extended object: a many-body Kramers calculation.
We show how an extended object's strain field is redistributed when the material ruptures under by thermal activation. Through analytical calculations and molecular dynamics simulations, we show that in a polymer chain the distribution is exponentially localized around the point of rupture. The length scale of localization is determined by the strain and microscopic parameters of the interaction potential. We also derive an analytic expression for the rate of bond rupture by consistently treating the collective modes of the chain and the effect of dissipation on those modes. Our theoretical estimates are of the same order of magnitude as those obtained by simulations, as compared to earlier theories which had overestimated the rate of rupture by approximately two orders of magnitude. It is also noteworthy that the correction comes about through the effective attempt frequency rather than the effective barrier height.
Sain
Anirban
A
Physics Department, Indian Institute of Technology-Bombay, Powai 400076, India. asain@phy.iitb.ac.in
Dias
Cristiano L
CL
Grant
Martin
M