TY - JOUR
T1 - Elasto-plastic fatigue life improvement of bolted joints and introducing FBI method
AU - Honarmandi, Peyman
AU - Zu, Jean W.
AU - Behdinan, Kamran
PY - 2005/7/1
Y1 - 2005/7/1
N2 - The failures of bolted joints, which are the basic and popular fasteners in industry, are mostly due to fatigue. This paper presents an effective method to improve the elasto-plastic fatigue life of a bolt. A complete bolted joint is considered and modeled with the finite element approach to calculate stress and strain. The code based on crack initiation theory is developed to calculate the fatigue life of the bolted joint. Local plasticity and mean stress correction are both applied in this analysis. Among the many factors that influence failure and fatigue behavior in bolt-nut fasteners, geometry has the most important effect on fatigue life. The geometry of a bolt is classified to four decisive parameters: Thread Flank Type, Thread Root Radius, Thread Run-out, and Head Fillet Radius. However, sensitivity studies are performed to investigate the effect of each of the four geometrical parameters on fatigue life. Finally, a new bolt design configuration is proposed and the results are compared with the conventional bolt. This new design is named FBI which stands for "Fatigue-Bolt-Improvement method. This modification in design and fabrication of bolts will greatly reduce the stress concentration at the critical area, and will increase the fatigue strength of the bolt as compared to the classic standard bolt.
AB - The failures of bolted joints, which are the basic and popular fasteners in industry, are mostly due to fatigue. This paper presents an effective method to improve the elasto-plastic fatigue life of a bolt. A complete bolted joint is considered and modeled with the finite element approach to calculate stress and strain. The code based on crack initiation theory is developed to calculate the fatigue life of the bolted joint. Local plasticity and mean stress correction are both applied in this analysis. Among the many factors that influence failure and fatigue behavior in bolt-nut fasteners, geometry has the most important effect on fatigue life. The geometry of a bolt is classified to four decisive parameters: Thread Flank Type, Thread Root Radius, Thread Run-out, and Head Fillet Radius. However, sensitivity studies are performed to investigate the effect of each of the four geometrical parameters on fatigue life. Finally, a new bolt design configuration is proposed and the results are compared with the conventional bolt. This new design is named FBI which stands for "Fatigue-Bolt-Improvement method. This modification in design and fabrication of bolts will greatly reduce the stress concentration at the critical area, and will increase the fatigue strength of the bolt as compared to the classic standard bolt.
KW - Bolt failure and fracture
KW - Bolted joint
KW - Crack initiation method
KW - FBI design
KW - Fatigue analysis of bolts
KW - Fatigue life improvement
UR - http://www.scopus.com/inward/record.url?scp=29344471897&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=29344471897&partnerID=8YFLogxK
U2 - 10.1080/15367730500374381
DO - 10.1080/15367730500374381
M3 - Article
AN - SCOPUS:29344471897
SN - 1539-7734
VL - 33
SP - 311
EP - 330
JO - Mechanics Based Design of Structures and Machines
JF - Mechanics Based Design of Structures and Machines
IS - 3-4
ER -