Application of the Extended Isogeometric Analysis (X-IGA) to Evaluate a Pipeline Structure Containing an External Crack

Table 2

Comparison of the KI factors between the proposed method of X-IGA and the analytical, FEM, and X-FEM methods for the case of a crack with a = 3 mm.

KI [MPa.mm^0.5]
Analytical	FEM Method	X-FEM Method	X-IGA; 121 elements	X-IGA; 441 elements	X-IGA; 676 elements
123.62	126.40	122.03	123.95	123.89	123.75
Error ()	2.19	1.29	0.270	0.218	0.105