Growth of three-dimensional cracks in finite-thickness plates

✍ Scribed by E.E. Gdoutos; N. Hatzitrifon

• Publisher: Elsevier Science
• Year: 1987
• Tongue: English
• Weight: 1020 KB
• Volume: 26
• Category: Article
• ISSN: 0013-7944
• DOI: 10.1016/0013-7944(87)90036-1

✦ Synopsis

The stress field in a finite-thickness plate weakened by a three-dimensional crack and subjected to tension in a direction ~r~ndicular to the crack plane is studied. The cases of an embedded elliptical, semi-elliptica and quarter-elliptical surface crack are considered. The stress analysis takes place by a finite element computer program which uses twenty-node isoparametric and fifteen-node enriched elements. The stress intensity factor variations along the periphery of the elliptical cracks are given for various plate thicknesses. The results of the stress analysis are used in conjunction with the strain energy density theory to study the growth characteristics of the cracks. The history of non-self-similar crack growth from initiation to final instability through the intermediate stage of stable growth is analyzed. The increments of crack growth from each point of its front are determined on the basis that the critical element in the direction of crack growth absorbs a critical amount of strain energy density. Crack growth becomes unstable when the last increment from the critical point of the crack front takes a limiting value. Results for the crack growth characteristics are given for the three types of cracks considered and various plate thicknesses.