Geometrical non-linear analysis of fiber reinforced elastic solids considering debounding

The study proposes a way to introduce fibers (short or long) inside elastic solids modeled by finite elements without increasing the number of degrees of freedom when debounding is not present. When there is debounding, new degrees of freedom are incorporated only at the slipping contact between fibers and matrix following an elastoplastic non-linear constitutive relation. The matrix is considered elastic while fibers follow a multi-linear elastoplastic constitutive relation. Large deformations and moderate strains are considered. In order to model the debounding between fibers and matrix it is necessary to accurately calculate the contact stresses. Therefore, the development of straight and curved fiber elements of any order and the accuracy analysis of the proposed contact stress calculations are investigated. After defining the best strategy to be followed general examples are solved to validate the contact stress calculation, debounding and plastic fiber behavior.