Study of a Three-Dimensional Crack Terminating at an Interface

1986 ◽  
Vol 53 (2) ◽  
pp. 311-316 ◽  
Author(s):  
J. C. Lee ◽  
L. M. Keer
Keyword(s):  
Body Force ◽  
Crack Opening ◽  
Three Dimensional ◽  
Circular Crack ◽  
The Body ◽  
Solution Technique ◽  
Bimaterial Interface ◽  
Opening Displacement ◽  
Body Force Method ◽  
Method Of Solution

In this study the stress intensity factors for a three-dimensional crack perpendicular to and terminating at a bimaterial interface are calculated. It is assumed that the crack is pressurized by a uniform pressure. The method of solution used here is based upon the body-force method and requires the analytical results from the elasticity point-force solution for a bimaterial interface. The solution technique leads to the reduction of the problem to a two-dimensional singular integral equation, which can be solved numerically for the crack opening displacement. Numerical examples of a semi-circular, semi-elliptical crack and growth of circular crack are given.

Assessment Procedure for Multiple Volumetric Flaws in p-M Diagram

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Shinji Konosu
Keyword(s):  
Body Force ◽  
Pressure Vessels ◽  
The Body ◽  
Assessment Procedure ◽  
Force Method ◽  
Reference Stress ◽  
Body Force Method ◽  
Common Problems ◽  
Shielding Effects

Assessment of multiple volumetric flaws is one of the most common problems relating to pressure vessels and piping components. Under the current fitness for service rules, such as ASME, BS, and so on, multiple volumetric flaws are usually recharacterized as an enveloping volumetric flaw (defined as a single larger volumetric flaw) as well as multiple cracklike flaws, following their assessment rules. However, the rules proposed in their codes will not often agree and their justification is unknown. Furthermore, they can provide unrealistic assessment in some cases. In this paper, the interaction between two differently sized nonaligned volumetric flaws such as local thin areas is clarified by applying the body force method. Unlike multiple cracklike flaws, the effect of biaxial stresses on the interaction is evident. Based on the interaction that indicates the magnification and shielding effects and reference stress solutions, a new procedure for multiple volumetric flaws is proposed for assessing the flaws in the p-M (pressure-moment) diagram, which is a simple assessment procedure for vessels with volumetric flaws.

Simplification of the body force method by using the approximated boundaries composed of triangular surfaces.

1988 ◽  
Vol 54 (508) ◽  
pp. 2093-2098
Author(s):  
Hironobu NISITANI ◽  
Hiroshi NOGUCHI ◽  
Dai-heng CHEN ◽  
Hiroaki MINE
Keyword(s):  
Body Force ◽  
The Body ◽  
Force Method ◽  
Body Force Method
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