Pullout testes are used to determine the fiber's critical length, l c , and the interface shear strength, tau , associated with the stress transfer from the matrix to the fiber in a composite material. In this work, the methods of performing and interpreting pullout tests in lignocellulosic fibers were evaluated. Results from pullout tests in piassava, coir and curauá natural fibers were compared to others published on synthetic fibers in terms of procedures to obtain l c and tau. Based on the marked differences that exist between the behavior of natural fibers with respect to that of synthetic fibers, a proper methodology is proposed to evaluate the results from pullout testing in lignocellulosic fibers.
pullout testing; lignocellulosic fibers; critical length; interface strength
