A numerical technique for modeling fatigue crack propagation of multiple coplanar cracks is presented. The proposed method couples the extended finite element method (X-FEM) [Int. J. Numer. Meth. Engng. 48 (11) (2000) 1549] to the fast marching method (FMM) [Level Set Methods & Fast Marching Methods: Evolving Interfaces in Computational Geometry, Fluid Mechanics, Computer Vision, and Materials ...

As cyclic fatigue is considered to be a major cause of clinical tooth fractures, achieving a comprehensive understanding of the fatigue behavior of dentin is of importance. In this note, the fatigue behavior of human dentin is examined in the context of the Kitagawa-Takahashi diagram to define the limiting conditions for fatigue failure. Specifically, this approach incorporates two limiting thr...

A model has been developed to predict crack opening and closing behavior for propagating fatigue cracks which undergo significant sliding displacements at crack flanks. Crack surfaces were described statistically by assuming a random distribution of asperity heights and a mean density of asperities and asperity radii. The propagating crack was subdivided into strips, and each strip was treated ...

Fatigue of materials, like alloys, is basically fatigue-crack growth in small cracks nucleating and growing from micro-structural features, such as inclusions voids, or at micro-machining marks, large to failure. Thus, the traditional nucleation stage (Ni) microcracks (initial flaw sizes 1 30 μm about 250 μm) metal alloys. crack-growth tests were conducted on a 9310 steel under laboratory air r...

Recent studies have shown that nanotwinned copper (NT Cu) exhibits a combination of high strength and moderate ductility. However, most engineering and structural applications would also require materials to have superior fracture toughness and prolonged subcritical fatigue crack growth life. The current study investigates the effect of twin density on the crack initiation toughness and stable ...

In this paper, we propose an approach for diagnostics and prognostics of damaged aircraft structures, by combing high-performance fatigue mechanics with filtering theories. Fast & accurate deterministic analyses of fatigue crack propagations are carried out, by using the Finite Element Alternating Method (FEAM) for computing SIFs, and by using the newly developed Moving Least Squares (MLS) law ...

The role of foreign-object damage (FOD) and its effect on high-cycle fatigue (HGF) failures in a turbine engine Ti– 6Al–4V alloy is examined in the context of the use of the Kitagawa–Takahashi diagram to describe the limiting conditions for such failures. Experimentally, FOD is simulated by firing 1 and 3.2 mm diameter steel spheres onto the flat specimen surface of tensile fatigue specimens at...

The fracture and fatigue properties of a newly developed bulk metallic glass alloy, Zr41.2Ti13.8Cu12.5 Ni10Be22.5 (at. pct), have been examined. Experimental measurements using conventional fatigue precracked compact-tension C(T) specimens (,7-mm thick) indicated that the fully amorphous alloy has a plane-strain fracture toughness comparable to polycrystalline aluminum alloys. However, signific...

Modelling Crack Propagation in Aluminium-Alloys 2524-T3 and 7050-T7452 Subjected to Fatigue Loading at Low Temperature M. D. Liu and J. J. Xiong * School of Transportation Science and Engineering, Beihang University, Beijing 100191, China; [email protected] * Correspondence: [email protected] Abstract: This paper seeks to model the crack propagation in of AAs (aluminum-alloys) 2524-T3 and 705...

This paper presents an overview of our recent enhanced 3D extended finite element toolkit for Abaqus (XFA3D) for fatigue damage assessment of welded aluminum structures under block loading. To alleviate the computational burden associated with the insertion and propagation of arbitrary cracks in the presence of a welding induced residual stress field, a nodal enriched displacement field coupled...