Comparative study on viscoelastic models based on creep tests of expansive soils

In this study,a detailed linear thermoviscoelastic model was used for the calculation of thermally and pressure induced residual stresses in injection molded amorphous plastic parts.

Based on the correspondence principle in viscoelastic theory, the viscoelastic model of axisymmetric round headings has been analyzed, obtaining theoretical results of displacement field in the viscoelastic model.

The traditional visco-elastic models can not explain some test results.

Through analysis of biomechanics property of soft tissue, this paper applies the visco-elastic model in the study of soft tissue deformation in surgery simulation.

A kind of viscoelastic-viscoplastic model for orthotropic rockmass is established;and the relevant numerical calculation expressions and the finite element analysis procedures are derived and described respectively.

First of all,a representative element is taken theoretically from the orthotropic rock reinforced by systematic rock bolts,then according to the concept of 慹quivalent material?and under some simplified conditions,the relevant constitutive expression and the failure criterion as well as one kind of viscoelastic-viscoplastic model for the bolted rock are set up and a 3D FEM code is introduced.