Development of a method to predict strength and failure of isotropic and composite structures under tension and bending loadings using bond-based peridynamic theory

Nowadays, finite element method using classical local theory equations is usually used while determining the material behavior, damage and its level in composite structures. However, finite element method utilizes experimental methods to determine damage level and direction since it is not enough to model crack tips. These type of classical methods on the basis of lineer elastic fracture mechanics have difficulties to predict damage initiation, magnitude, propogation speed and nucleation. Classical continuum mechanics is based on spatial partial derivatives. Peridynamic theory is based on integro-differential equations and therefore inherently more suitable for failure initiation and propagation in materials. One of the advantages of peridynamic theory is its ability to predict crack tip damage behavior in both isotropic and composite materials. Peridynamic theory is implemented in finite element programs ABAQUS in this study. In addition to this, quasi-static solvers are prepared by using MATLAB. In implementation, truss elements represent peridynamic bonds in FEA softwares. A MATLAB code is developed to create peridynamic models suitable to this approach and ABAQUS input files are constituted. With the help of this code, discontinuties like circular cutouts and cracks are modeled in analyzed geometries. Results obtained using peridynamic theory are compared with FEA solutions and results from literature. In general, peridynamic results are in good agreement with results from literature and FEA solutions. Based on the results obtained in this study, it is also concluded that the procedure in this study using peridynamic theory has an important potential to model failure initiation and failure propagation in materials.