It is shown that if the displacement field and stress intensity factor are known as functions of crack length for any symmetrical load system acting on a linear elastic body in plane strain, then the stress intensity factor for any other symmetrical load system whatsoever on the same body may be directly determined. The result is closely related to Bueckner's [1] "weight function". through whic...

Cement-based composites (for example, concrete) are brittle materials that crack when loaded in tension. Current strategies for crack detection are primarily based upon visual inspection by an inspector; such approaches are labor-intensive and expensive. Direly needed are sensors that can be included within a structural health monitoring (SHM) system for automated quantification of crack damage...

The excellent mechanical properties of carbon nanotubes (CNTS) are driving research into the creation of new strong, tough nanocomposite systems. Here, the first evidence of toughening mechanisms operating in carbon-nanotube-reinforced ceramic composites is presented. A highly ordered array of parallel multiwall CNTs in an alumina matrix was fabricated. Nanoindentation introduced controlled cra...

The effects of particle size, volume fraction and matrix strength on the stress-controlled axial fatigue behavior and the probability of particle fracture were evaluated for 2124 aluminum alloy reinforced with SiC particles. Average particle sizes of 2, 5, 9 and 20/~m and volume fractions of 0.10, 0.20 and 0.35 were examined for four different microstructural conditions. Tensile and yield stren...

The force required to peel a film from a substrate is generally a complex function of geometry, the constitutive properties of the film and substrate, and the interfacial cohesive properties. In most analyses, the effects of the transverse shear force that is an integral aspect of almost any peel test are neglected, although they can be incorporated in an indirect fashion through models that in...

Cantilever nanobeams subjected to the axial pressure are considered under assumption that material behaviour can be modelled with help of nonlocal theory elasticity. The and nanocolumns consideration have rectangular cross section piecewise constant dimensions weakened by crack-like defects at re-entrant corners steps. critical buckling loads stepped calculated sensitivity respect crack paramet...

The feeder pipe in the pressurized heavy water reactor (PHWR) is exposed to a possible leakage during operation. Because of the geometrical complexity of the pipe and its inaccessibility due to a high radiation environment, it is difficult to examine the defect by the conventional ultrasonic method. The guided ultrasonic inspection was chosen for the inspection of the pipe. The torsional mode h...

Atomic Force Microscope images of a crack intersecting the free surface of a glass specimen are taken at different stages of subcritical propagation. From the analysis of image pairs, it is shown that a novel Integrated Digital Image Correlation technique allows to measure stress intensity factors in a quantitative fashion. Image sizes as small as 200 nm can be exploited and the surface displac...

this paper focuses on using the recently developed extended finite element model for buckling analysis of edge cracked columns under concentric axial load. the effect of crack depth and its location on the carrying capacity of columns is studied. the effect of different boundary conditions is also investigated. numerical examples are offered to show the efficiency and effectiveness of the propo...