Preloaded Joint


Statically Loaded Tension Joint with Pre-load [see Budynas p. 442-444]:
According to Budynas, the pre-tension is the "muscle" of the joint, and its magnitude is determined by the bolt strength. If the full bolt strength is not used in developing the pre-tension, then money is wasted and the joint is weaker. Thus, as a rule, a bolt will either fracture during tightening, or not at all. Pre-tensioning or pre-loading of non-permanent joints is done by streching bolts to 75% of their proof strength.
(1) Enter bolt information: Table 1, Table 4, Table 5.
Bolt Length (L):	Bolt Threaded Length (L_T):	Bolt Diameter (d):
Inches	Inches	Inches
Gripping Length (l):	Threaded Area (A_t):	Young's Modulus (E):
Inch	Inch²	ksi
(2) Enter flange materials properties:
Hole Diameter (d):	Joint Thickness (l):	Young's Modulus (E):
Inches	Inches	ksi


Bolt Stiffness (Kb):	klbf/inch
Flange Stiffness (Km):	klbf/inch
	Rate of load carried by the bolt (C)
	Rate of load carried by the flange (1-C)

Final Joint Analysis
Is this a non-permanent assembly?Yes No
Bolt Proof Strength (S_p):	Bolt T. Stress Area (A_t):	Load Safety Factor (n_L):
ksi	Inch²	[min. 2]
Joint Operating Load (ksi):	ksi [force trying to separate flanges]
	[Rounded up to the next integer]
	[Factor guarding against bolt yield]
	[Factor guarding against separation]