Elastic Tensile Recovery of the Power Law Viscoelastic Model

DOI Web Site

Bibliographic Information

Other Title
  • べき法則粘弾性固体の伸長回復挙動に関する研究
  • ベキ ホウソク ネンダンセイ コタイ ノ シンチョウ カイフク キョドウ ニカ

Search this article

Abstract

The elastic recovery behavior of a solid obeying the power law has bee predicted by the linear and nonlinear models. The relaxation modulus of the solid is assumed to be proportional to some power of time, if the solid is extended at a constant rate to a given strain ε1 and then held constant for a fixed time tr. The Boltzmann and Schapery equations of a time-strain reduced type are used for the linear and nonlinear models respectively. The predicted results from both models have experimentally been discussed by two kinds of polyethylene films at a room temperature.<BR>The fractional elastic recovery (U.E.R.) of the linear model, which is recovered during the unloading to the zero level of a stress, is constant regardless of the initial strain ε1 when tr=0, and increases with the initial strain when tr>0. The U.E.R. of the nonlinear model is smaller than that of the linear model and the difference between both values of the U.E.R. is larger at higher strain ε1. The U.E.R. of the model decreases exponentially with the time of stress relaxation tr. If the solid shows the more stress relaxation and the stronger nonlinearity, the U.E.R. of the solid is smaller. The experimental results of the U.E.R. are qualitatively similar to the U.E.R. predicted by using the nonlinear model.<BR>The fractional delayed elastic recovery (D.E.R.), which is recovered after ceasing of unloading, can only be calculated from the linear model. The D.E.R. of the model is constant regardless of ε1 when tr=0, and decreases with ε1 when tr>0. The solid exhibiting a remarkable stress relaxation has higher rate of delayed recovery and then larger D.E.R. Contrary to the above predictions from the linear model, the experimental results of the D.E.R. give the considerable nonlinear effects and are inconsistent with the linear theory.

Journal

Keywords

Details 詳細情報について

Report a problem

Back to top