Modeling the elastoplastic behavior of agave fiber prior and after its incorporation within a thermoplastic matrix: Analysis of the fiber aspect ratio on the mechanical properties

Abstract The demand for natural fiber‐reinforced polymer composites is increasing in the automotive industry, and Mexican blue‐gave fiber (AF) is getting attention from automakers. Quantitative characterization of the tensile behavior of AF allows for a better ascertain of fiber performance. This work developed a model to study the elastoplastic behavior of AF prior and after its incorporation within a thermoplastic matrix. Finite element predictions showed excellent agreement with both theoretical and experimental values from literature. It was revealed that the increase in the fiber aspect ratio hastens the interaction between nearby defects within the fiber with earlier coalescence of voids, and ultimately fosters the loss of both fiber ductility and load carrying capacity. Moreover, the preponderant character of the damage in AF is controlled by nucleation and growth of voids. On the other hand, AF reinforced thermoplastic composites exhibit a microfailure based essentially on the matrix failure, and the composites become more damage tolerant with the increase in fiber aspect ratio. Stiffer AF leads to a more uniform interfacial shear stress distribution, with higher stiffness of the composite. Therefore, the effectiveness of AF to reinforce polymeric matrixes depends strongly on the elastic mismatch of the coupled materials. Highlights Local stress state in AF is correlated to macroscopic stress. AF may be recognized as a von Mises material. Ductile fracture in AF is controlled by nucleation and growth of voids. Increasing the fiber aspect ratio leads to more damage tolerant composites. Stiffer AF led to a more uniform interfacial shear stress distribution.