The fatigue growth of multiple cracks, of arbitrary lengths, emanating from a row of fastener holes in a bonded, riveted, lap joint in a pressurized aircraft fuselage is studied. The effects of residual stresses due to a rivet misfit, and of plastic deformation near the hole, are included. A Schwartz Neumann alternating method which uses the analytical solution for a row of multiple colinear cr...

The work that I'm going to describe was funded by the Air Force Materials Lab from February 1972 to February 1974. It is described in an AFML report, TR74-80, available from the Air Force. This report describes a more practical type of problem than has been discussed so far. Our work was directed towards building an ultrasonic system to be used on aircraft in the field to detect cracks around f...

AbstracbThe results of an experimental investigation of thermally induced parallel edge cracks in a half-plane consisting of brittle material are reported. A free edge of a glass plate heated to a uniform temperature, was brought in contact with a liquid bath cooled by dry ice. The thermal contraction of the boundary layer produced interacting tension cracks. When no initial cracks existed, a l...

In this paper, the analytical solution of an electric and Volterra edge dislocation in a functionally graded piezoelectric (FGP) medium is obtained by means of complex Fourier transform. The system is subjected to in-plane mechanical and electrical loading. The material properties of the medium vary exponentially with coordinating parallel to the crack. In this study, the rate of the gradual ch...

A selection of surface crack problems is presented to provide insights into Stage I and early Stage II fatigue crack growth. Edge cracks at 45o and 90o to the surface are considered for cracks growing in single crystals. Both single crystal slip and conventional plasticity are employed as constitutive models. Edge cracks at 45o to the surface are considered that either (i) kink in the direction...

PURPOSE To compare contraction stresses in direct and indirect composite restorations using crack analysis. MATERIALS AND METHODS Glass disks with a central cylindrical hole were prepared. Initial cracks were made in the glass using a Vickers indenter at various distances from the edge of the hole. The indentation crack lengths were measured parallel to the tangent of the edge of the hole. Si...

In this project, investigation of stress concentration factor is carried out. Some specimens with edge notches, multiple edge notches, and holes are fabricated. While two specimens are hand sawed to produce edge cracks. The stress concentration factor (K) value is compared between the theoretical values found in standard K value chart with our experimental results. Effect of multiple notches is...