TY - JOUR
T1 - Fracture mechanics and fatigue life assessment of box-shaped welded structures
T2 - FEM analysis and parametric design
AU - Delkhosh, E.
AU - Khurshid, M.
AU - Barsoum, I.
AU - Barsoum, Z.
N1 - Funding Information:
Sweden’s Innovation Agency VINNOVA is gratefully acknowledged for financial support of project VariLight through Grant Number 2016-03363. Acknowledgments
Funding Information:
Open access funding provided by Royal Institute of Technology. Dr. Bruce J Carter from Fracture Analysis Consultants is also acknowledged for his technical support with the software FRANC3D.
Publisher Copyright:
© 2020, The Author(s).
PY - 2020/9/1
Y1 - 2020/9/1
N2 - In this study, Linear Elastic Fracture Mechanics (LEFM) approach is used to evaluate the fatigue strength of a box-shaped welded structure. A parametric study is also undertaken to study the effect of various weld parameters on the fatigue strength, such as lack of weld metal penetration, load position, and plate thicknesses. FRANC3D software was adopted to obtain the stress intensity factor values for two types of full-length and intermediate crack sizes, located at the critical region of the weld of the box-shaped structure. It was concluded that the LEFM approach could capture the crack propagation from the weld root reasonably well under the given conditions and estimate residual fatigue life of the welded structures conservatively. Compared to fatigue life estimations by nominal stress method (1,714,564 cycles) or effective notch stress method (63,385 cycles), the LEFM approach can estimate the residual life more accurately. Especially for intermediate (4 mm) lack of penetration (LOP) of weld metal case (589,198 cycles) in comparison to the experiments (1,216,595 cycles). The parametric study showed that the fatigue life increases with increase in the thickness of flanges, lesser LOP in the weld root, and when load is applied more toward the center of the plate.
AB - In this study, Linear Elastic Fracture Mechanics (LEFM) approach is used to evaluate the fatigue strength of a box-shaped welded structure. A parametric study is also undertaken to study the effect of various weld parameters on the fatigue strength, such as lack of weld metal penetration, load position, and plate thicknesses. FRANC3D software was adopted to obtain the stress intensity factor values for two types of full-length and intermediate crack sizes, located at the critical region of the weld of the box-shaped structure. It was concluded that the LEFM approach could capture the crack propagation from the weld root reasonably well under the given conditions and estimate residual fatigue life of the welded structures conservatively. Compared to fatigue life estimations by nominal stress method (1,714,564 cycles) or effective notch stress method (63,385 cycles), the LEFM approach can estimate the residual life more accurately. Especially for intermediate (4 mm) lack of penetration (LOP) of weld metal case (589,198 cycles) in comparison to the experiments (1,216,595 cycles). The parametric study showed that the fatigue life increases with increase in the thickness of flanges, lesser LOP in the weld root, and when load is applied more toward the center of the plate.
KW - Fatigue crack growth
KW - Finite element method
KW - Linear Elastic Fracture Mechanic
KW - Stress intensity factor
KW - Welded structures
UR - http://www.scopus.com/inward/record.url?scp=85086849463&partnerID=8YFLogxK
U2 - 10.1007/s40194-020-00945-9
DO - 10.1007/s40194-020-00945-9
M3 - Article
AN - SCOPUS:85086849463
SN - 0043-2288
VL - 64
SP - 1535
EP - 1551
JO - Welding in the World
JF - Welding in the World
IS - 9
ER -