This paper investigates the role of material properties on crack path selection in adhesively bonded joints. First, a parametric study of directionally unstable crack propagation in adhesively bonded double cantilever beam specimens (DCB) is presented. The alternating crack trajectories in specimens of various material systems are simulated using the finite element method and the results indica...

The propagation of cracks in layered glass from low-velocity impact of sharp or spherical tip projectiles is observed using high-speed photography. Tests are also carried out to determine the threshold impact energy for chipping in glass blocks and subsurface crack instability in an edge-supported glass plates. The results identify the median and subsurface radial crack systems as the prime dam...

In this master thesis, work done in the TURBO POWER project High temperature fatigue crack propagation in nickel-based superalloys during spring 2012 will be presented. The overall objective of this project is to develop and evaluate tools for designing against fatigue in gas turbine applications, with special focus on the crack propagation in the nickel-based superalloy Inconel 718. Experiment...

Recent observations on the dynamics of crack and fault rupture are described, together with related theory and simulations in the framework of continuum elastodynamics. Topics include con gurational instabilities of tensile crack fronts (crack front waves, disordering, sidebranching), the connection between frictional slip laws and modes of rupture propagation in earth faulting, especially cond...

This paper presents a single-domain boundary element method SDBEM for linear elastic fracture mechanics analysis in the 2D anisotropic bimaterial. In this formulation, the displacement integral equation is collocated on the uncracked boundary only, and the traction integral equation is collocated on one side of the crack surface only. The complete fundamental solution Green’s function for aniso...

The main aim of this paper is to present more accurate stochastic fatigue models for solving the fatigue reliability problems, which are attractively simple and easy to apply in practice for situations where it is difficult to quantify the costs associated with inspections and undetected cracks. From an engineering standpoint the fatigue life of a structure consists of two periods: (i) crack in...

In the present note, the effects of two typical organic solvents, ethanol (95~) and carbon tetrachloride (99~) , on the fatigue crack propagation rates in PMMA are discussed. Fracture mechanics which has been applied successfully to fatigue crack propagat ion in bo th metallic and polymeric sheet materials [1-4] in air is adopted in the present environmental fatigue analyses. The generalized fa...

This note discusses the peridynamic horizon (the nonlocal region around a material point), its role, and practical use in modeling. The objective is to eliminate some misunderstandings and misconceptions regarding the peridynamic horizon. An example of crack branching in a nominally brittle material (homalite) is addressed and we show that crack branching takes place without wave interaction. W...

In this study, the damage fields near the crack tip in edge-cracked sheet specimens subjected to a constant strain rate of 0.05 min were investigated using real-time radiographic techniques. During the tests, Lockheed-Martin Advanced Technology Center’s high-energy real-time x-ray system (HERTIS) was used to monitor damage initiation and evolution processes near the crack tip. The experimental ...