Presentation Title
Analysis of Preload in Bolted Joints Under Impulse
Document Type
Poster Session
Department
Engineering
Faculty Mentor
Dr. Mehrdaad Ghorashi
Keywords
bolts, stress, deformation, preload, impulse
Abstract
From transportation to storage to construction, bolted joints are utilized everywhere. Bolted joints in closures such as pressure vessels/tanks require a preload, or a specific amount of tightening of the bolts to seal the vessel when pressurized to avoid leaking. Low preload can result in joint loosening whereas high preload can result in yielding. Therefore, finding feasible and even better optimal values of preload is of great practical importance. In an earlier work in 1996, this problem was tackled with an exponentially decaying pressure applied on a pressure vessel closure. In the present analysis, however, the pressure variation is considered to be an impulse forcing function that is equivalent to the original exponential decaying pressure function. The final aim is to find conservative and optimal preload values for bolted joints of the pressure vessel closure under these conditions. Minimizing bolt elongation and stresses can result in a higher safety factor for a machine or vessel since the fasteners are at higher risk of failure. The problem has been tackled both analytically and by using simulation software. The bolt preload results are compared with those from the 1996 paper and with the ones recommended in practice.
Included in
Analysis of Preload in Bolted Joints Under Impulse
From transportation to storage to construction, bolted joints are utilized everywhere. Bolted joints in closures such as pressure vessels/tanks require a preload, or a specific amount of tightening of the bolts to seal the vessel when pressurized to avoid leaking. Low preload can result in joint loosening whereas high preload can result in yielding. Therefore, finding feasible and even better optimal values of preload is of great practical importance. In an earlier work in 1996, this problem was tackled with an exponentially decaying pressure applied on a pressure vessel closure. In the present analysis, however, the pressure variation is considered to be an impulse forcing function that is equivalent to the original exponential decaying pressure function. The final aim is to find conservative and optimal preload values for bolted joints of the pressure vessel closure under these conditions. Minimizing bolt elongation and stresses can result in a higher safety factor for a machine or vessel since the fasteners are at higher risk of failure. The problem has been tackled both analytically and by using simulation software. The bolt preload results are compared with those from the 1996 paper and with the ones recommended in practice.
