Micromechanical Model for Predicting the Tensile Properties of Guadua angustifolia Fibers Polypropylene-Based Composites

In this paper, the one-dimensional tensile behavior of Guadua angustifolia Kunth fibre/polypropylene (PP+GAK(s)) composites is modeled. The classical model of Kelly-Tyson and its Bowyer-Bader's solution is not able to reproduce the entire stress-strain curve of the composite. An integral (In-Built) micromechanical model proposed by Isitman and Aykol, initially for synthetic fiber-reinforced composites, was applied to predict micromechanical parameters in short natural fiber composites. The proposed method integrates both the information of the experimental stress-strain curves and the morphology of the fiber bundles within the composite to estimate the interfacial shear strength (IFSS), fiber orientation efficiency factor eta(FOD), fiber length efficiency factor eta(FLD) and critical fiber length l(c). It was possible to reproduce the stress-strain curves of the PP+GAKs composite with low residual standard deviation. A methodology was applied using X-ray microtomography and digital image processing techniques for the precise extraction of the micromechanical parameters involved in the model. The results showed good agreement with the experimental data.

Automated summary

In this study, a new integral micromechanical model was applied to simulate the one-dimensional tensile behavior of Guadua angustifolia Kunth fibre/polypropylene composites. By integrating experimental data and information about fiber bundles morphology, the stress-strain curves of the composite were successfully predicted and showed good agreement with experimental results.