volume 34, issue 17, P1319-1326 1994
DOI: 10.1002/pen.760341704
View full text

Abstract: Abstract Stress‐relaxation behavior is studied in polypropylene samples subjected to different cyclic preloadings and to simple tension. The relaxation tests are performed under different sets of strain amplitude, number of cycles, and strain rate, using a closed‐loop, electrohydraulic, servocontrolled testing machine. The calculated stress‐strain curves are determined from a constitutive equation based on an overstress theory in which an equilibrium stress and a viscosity function are treated. The calculated…

expand abstract