For composite structure, fracture toughness is a dominant parameter when using cohesive laws to predict the nominal strength. In the present study the compact tension test is performed on composites structures and is simulated using FEM. The process of fracture takes places in two sequential stages, crack initiation and crack propagation. The critical energy release rate is determined using the...

A new modeling approach to subcritical crack propagation (i.e. static fatigue) in ceramics is introduced and applied to the case of ceramic fibers. This approach relies on classical fracture mechanics, in which the zone near the crack’s tip is modified by the environment (particularly through oxidation). Chemical reactions and diffusion are introduced naturally, which makes the model highly dep...

The macroscopic pre-cracked line scratch test (MPLST), in which a debonded edge of a film is loaded in in-plane compression, has been modeled as a generic, coupled fracture–buckle problem using simple beam theory. Near cracktip beam rotation (also called root rotation in literature), which always exists due to the eccentric loading in this type of test, has been incorporated into the governing ...

This paper presents a generalized finite element method (GFEM) for crack growth simulations based on a two-scale decomposition of the solution – a smooth coarse-scale component and a singular fine-scale component. The smooth component is approximated by discretizations defined on coarse finite element meshes. The fine-scale component is approximated by the solution of local problems defined in ...

Mineralized biological materials such as bone, sea sponges or diatoms provide load-bearing and armor functions and universally feature structural hierarchies from nano to macro. Here we report a systematic investigation of the effect of hierarchical structures on toughness and defect-tolerance based on a single and mechanically inferior brittle base material, silica, using a bottom-up approach ...

Critical steps toward designing and developing modern materials include observing, simulating, and predicting 3D deformation and cracking mechanisms at various length scales. In this work, advanced characterization and simulation techniques are employed to study the micromechanisms involved in nucleation and propagation of fatigue cracks in an aluminum alloy used in pressure-vessel structures. ...

Abstract—The present study investigates the effect of inclusions on the shape and size of crack tip plastic zones in engineering materials subjected to static loads by employing the element free Galerkin method (EFGM). The modeling of the discontinuities produced by cracks and inclusions becomes independent of the grid chosen for analysis. The standard displacement approximation is modified by ...

Few studies have focused on a description of the fracture toughness properties of dentin in terms of resistance-curve (R-curve) behavior, i.e., fracture resistance increasing with crack extension, particularly in light of the relevant toughening mechanisms involved. Accordingly, in the present study, fracture mechanics based experiments were conducted on elephant dentin in order to determine su...

A systematic study of crack tip interaction with grain boundaries is critical for improvement of multiscale modeling of microstructurally-sensitive fatigue crack propagation and for the computationally-assisted design of more durable materials. In this study, single, biand large-grain multi-crystal specimens of an aluminum-copper alloy are fabricated, characterized using electron backscattered ...