Creep behavior modeling of polymeric composites using Schapery model based on micro-macromechanical approaches

Abstract

Composites are finding increased usage in the design of specific structures in various industries. Polymer matrix composites suffer from creep phenomenon, even at low temperatures, due to the viscoelastic behavior of the matrix. Consequently, accounting for these phenomena in the design of composite structures is of utmost importance. In the present article, the creep behavior of materials has been examined using Schapery's integral. This constitutive model has been employed as a recursive-iteration algorithm in the form of a UMAT subroutine and then applied in the analysis procedure of ABAQUS. This procedure has first been used for isotropic polymers. The micromechanical approach has then been utilized to assess the creep behavior of unidirectional composites, assuming elastic fibers and a viscoelastic matrix, with the help of the concept of the representative volume element. Finally, the creep response of unidirectional and multidirectional composites has been studied at different stress and temperature levels according to the macromechanical viewpoint of Sawant. Considering the fact the Prony series and nonlinear parameters have been calculated in a particular span of stress and temperature, they are only useable in a specific range of temperature and stress level, and will result in greater error outside this range. A good correlation between the results of theoretical modeling and existing experimental data, confirmed the optimal performance of the developed model.