Issue 75

V. Thondamon et alii, Fracture and Structural Integrity, 75 (2026) 88-103; DOI: 10.3221/IGF-ESIS.75.08

2 ' K EL E J 

(8)



E

'

(9)

E



 2 1  

Plastic component of the J-integral is expressed as:





* PL t W a J   

 * CMOD p A  0

(10)

  1.040 0.687 a

 



(11)

CMOD

W

where, t is thickness of the pipe specimen, W is width of the pipe specimen, a 0 is initial crack length, η CMOD is dimensionless function of geometry of the pipe, A p is area under plastic part of load-CMOD curve. The above expressions are valid for 0.1 ≤ a/W ≤ 0.7.

F AD APPROACHES

F

ailure assessment line provides demarcation between the acceptable zone and unacceptable zone in a FAD. It provides the limiting interaction between the fracture ratio and the load ratio. From the failure assessment line and the position of the assessment point of the specimen, it can be assessed whether the structural component is safe or unsafe, for a given crack length and corresponding applied load. If the assessment point of the specimen falls between the failure assessment line and the axes of the FAD, the structural component is safe for the crack length and corresponding applied load. SINTAP procedure [1] The SINTAP procedure was developed to assess the integrity of structures with flaws, for use in European industry. It offers different levels of complexity to provide flexibility for industrial applications and user needs. The failure assessment line equation provided in this procedure is the same as the one provided in R6 procedure. This procedure provides different equations for materials which exhibit a lower yield plateau and materials which does not exhibit a lower yield plateau. For materials which exhibit a lower yield plateau,

   



  2 1 2 1 0.5 L  

 

L L

1.0 1.0

  r



K f L 

   

(12)

r

r

r

0

r

For materials which do not exhibit a lower yield plateau,

   







  r L

 

2 1 2

6 L L L  

max

1 0.5 

0.3 0.7exp 0.6 0  

  r







K f L 

   

(13)

r

r

r

r

max

L L 

r

r



 2.5

max

 

L

R

1 150

r

p

where R p is the material’s proof stress in MPa BS 7910:2005 [21]

BS 7910:2005 standard, guide to methods for assessing the acceptability of flaws in metallic structures addresses the integrity assessment of both new and existing constructions using non-destructive testing methods. The acceptance levels for the

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