Characterization of nonlinear response in quasi-unidirectional E-glass fabric reinforced polypropylene composites under off-axis tensile loading. (October 2017)

• Record Type: Journal Article
• Authors: Zhai, Zhanyu; Jiang, Bingyan; Drummer, Dietmar
• Is Part Of: Polymer testing. Volume 63(2017)
• Page Start: 521
• Page End: 529
• Publication Date: 2017-10
• Subjects: Quasi-unidirectional composites -- Nonlinear -- Plasticity -- Damage; Polymers -- Testing -- Periodicals; Polymères -- Tests -- Périodiques; 620.1920287
• DOI: 10.1016/j.polymertesting.2017.09.019
• Languages: English
• ISSNs: 0142-9418

Abstract

Abstract: The present paper addressed the nonlinear stress-strain response in quasi-unidirectional E-glass fabric reinforced polypropylene composites under off-axis tensile loading. A series of monotonic and cyclic loading-unloading tensile tests were carried out. Both irreversible strains and stiffness degradation were observed in cyclic loading-unloading tests, which indicate that the nonlinear response of composites was induced by a combination of damage and plasticity. A coupled damage-plasticity model was employed to describe the nonlinear off-axis tensile stress-strain relation of materials. In this model, a plastic potential function together with associated plastic flow rule were adopted to assess the evolution of plastic strains. The damage variables in forms of stiffness degradation were expressed as a Weibull function of the effective stress. A full suite of model parameters was experimentally determined from cyclic loading-unloading tensile tests. The stress-strain curves predicted by this model agreed well with experimental results.