Physically Nonlinear Elastic-Viscoplastic Law of Strain of Cotton Yarn under Tension to Breakage
On the basis of experimental stress-strain diagram, σ(ε), the changes in E modules on strain ε are defined and a complex nonlinear dependence E(ε) is obtained. The method of numerical approximation of obtained dependence E(ε) is offered. With the use of nonlinear dependence E(ε), a physically nonlinear law of strain of cotton yarn under tension is offered. The parameters values of proposed law are determined on the basis of experimental results. Calculated stress-strain diagrams are obtained on the basis of proposed nonlinear law of elastic-visco-plastic strain of yarn. Experimental and theoretical diagrams of σ(ε) are compared. A good agreement is obtained.