PSI - Issue 60

N. Khandelwal et al. / Procedia Structural Integrity 60 (2024) 582–590 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

586

5

Distribution beam

Curved block

Pipe specimen

Hinge support

Roller support

Fig. 3. Typical loading arrangement for fracture test of pipe specimen.

Table 2. Geometrical details of pipe specimen.

Diameter of pipe ( )

Notch angle ( ) 60 0

Inner span ( ) 760

Outer span ( ) 1780

Length of pipe ( ) 1996 4960

Thickness of pipe ( )

Specimen No.

171 325

14.6 25.7

SSPW 6-25

60 0

1200 4000

SSPW 12-27

All linear dimensions are in mm and angles in degrees.

4. Results and discussion Two pipe specimens (1) SSPW 6-25, (2) SSPW 12-27 made up of 304LN stainless steel pipes have been numerical investigated with the proposed phase field formulation in three dimensional finite element frame work in ABAQUS using user-defined (UEL) subroutines. These subroutines are solved in staggered approach with three layer mechanism where first layer consists of an element having single degree of freedom (DOF) representing phase field variable at each node. The second layer contains finite element with displacement DOF at each node. Third layer work as feedback loop comprising of first layer elements with dummy DOF to check a convergence criterion. Geometric properties and material properties are already defined as given in Tables 1 and 2, respectively. Furthermore, we choose 0 = 2.75 mm as length scale parameter for both the specimens. Load vs. displacement curve and crack propagation path obtained for both the pipe specimens by imposing the monotonic increasing vertical displacements ( ) at two locations on the top circular portion of pipe to replicate the experimental loading,