Nonlinear Viscoelastic Creep Prediction of HDPE-Agro-fiber Composites

Abstract

Agro-based plastic composites are being used as deck boards and other load-bearing materials. In these composites, both fibers and plastics contribute to creep when they carry loads. However, the existing literature concentrates on creep prediction and characterization of composites as a single-phase material. In our study, an attempt is made to develop a generic creep prediction model that describes the creep behavior of composites with the constituents’ creep behavior. The ‘theory of mixture’ for composites is extended to describe the creep behavior of this material, which is two phase. This model is validated for HDPE-rice husk composites with power-law-Boltzmann’s superposition principles. The model works well not only to describe creep, but also its nonlinearity. The model is generic enough for extending it to incorporate varying environmental conditions, such as time and temperature. This is the first model to describe creep for a two-phase bio-based composite. This study is a vanguard in correlating Schapery’s ‘single-phase’ model with a ‘two-phase’ model, where the same is validated for step-loading situations.