Peridynamic Model of Nonlinear Viscoelastic Creep and Rupture

The purpose of this paper is to establish a peridynamic method in predicting nonlinear viscoelastic creep behaviour which consists of primary creep, secondary creep, tertiary creep and rupture. A nonlinear viscoelastic creep constitutive equation based on internal state variable (ISV) theory which covers four creep stages and peridynamic equation are examined. The viscoelastic equationis substituted into the peridynamic equation to derivea new peridynamic method with two time parameters i.e. numerical time and viscoelastic real time is designed. The parameters of the viscoelastic equationis analyzed and optimized. In validating this peridynamic method, a comparison is made between numerical and experimental data. The new peridynamic method for nonlinear viscoelastic creep behaviour is approved by the adequate matching of numerical and experimental data in creep strain graph with difference of 10.67%. The overall nonlinearity of experimental and numerical data is acceptably similaras the error between experimental and numerical curves of secondary stage strain rate against load is 8.022%.The variation of constants in the nonlinear viscoelastic model is also studied. The shapes of fractured numerical specimen also show good resemblance with the experimental one.