Investigation of bending and mod II failures in thick plates using peridynamic theory

Peridynamic theory is a nonlocal Continuum Mechanics theory for predicting the deformation and damage behavior of structures subjected to various loads. Within the scope of this PhD thesis, two different problems are investigated using the bond-based Peridynamic theory. First, a Peridynamic plate model is developed to solve the deflection and rotation distribution on thick orthotropic plates subjected to bending. The proposed Peridynamic plate model considers the deformation of the surface normals which are disregarded in existing thin plate models in the literature. Deformation behaviour of an isotropic plate subjected to bending is solved using proposed PD plate model. The obtained results are validated with the literature and the results of Finite Element Analysis. Afterwards, bending problems for various orthotropic plates are considered. The PD results for orthotropic plates are validated with Finite Element Analysis results. Finally, propagation of pre-existing cracks on orthotropic plates are analyzed. The PD results are in good agreement with Finite Element Analysis and literature which indicates that the proposed Peridynamic Mindlin Plate model is appropriate to investigate the deformation and damage in thick orthotropic plates under bending. Dynamic crack propagation along the bonding interface of bonded Homalite plates are also investigated using bond-based Peridynamic theory within the scope of this PhD thesis. The specimen and the boundary conditions for the bonded plates are the same as experimental study of Rosakis et al. (1999). The edge impact is introduced to specimen as time dependent pulse velocity boundary condition.The effects of the impact speed and interface toughness on the crack propagation speed are investigated parametrically. Both sub-Rayleigh and intersonic crack propagation are observed in parametric studies. For the intersonic crack propagation, shock waves are identified in the particle velocity contours. The lowest intersonic crack tip speed is obtained as 1.57 times the shear wave speed. It is observed that for certain combinations of impact velocity and fracture toughness, the crack tip velocity changes from the sub-Rayleigh region to the intersonic region. Obtained PD results for dynamic mode II crack propagation are in good agreement with the experimental and numerical studies in the literature.