= 10,400 lb (tension) ϕrn Therefore, the bolts are adequate. The connection plates are 1/4 inch thick and 3 inches wide. = 0.0469 in3 The maximum moment in the plate is: = 534 lb (1.5 in.) = 801 in-lb MU The bending stress is: = = 801/0.0469 = 17,088 psi OK fb MU /Z Prying action can have the effect of increasing the tensile forces in the bolts. AISC 360 permits prying action to be neglected if the plate meets minimum thickness requirements, given by: where = 3 inches is the tributary length per pair of bolts p = (b-db/2) = (1.5-0.625/2) = 1.1875 in. b' = 0.13 in. This is less than the 0.25inch thickness provided, so prying need not be considered further. The welds of the vessel leg to the vessel body and of the leg to the upper connection plate are proportioned in a similar manner. The calculation can be simplified by assuming the weld is of unit thickness. This yields a demand per inch of weld and an appropriate weld thickness can then be selected. The vessel leg has an outer diameter, of 2.38 inches. The weld properties for a weld of unit thickness d, are: = 2.25 in3 = = 7.45 in. A =3.14(2.38) πd The shear in the weld is: = 532 lb/7.45 in. = 714 lb/in. v
ϕrn = 10,400 lb (tension) Therefore, the bolts are adequate. The connection plates are 1/4 inch thick and 3 inches wide. = 0.0469 in3 The maximum moment in the plate is: MU = 534 lb (1.5 in.) = 801 in-lb The bending stress is: fb = MU /Z = 801/0.0469 = 17,088 psi OK Prying action can have the effect of increasing the tensile forces in the bolts. AISC 360 permits prying action to be neglected if the plate meets minimum thickness requirements, given by: where p = 3 inches is the tributary length per pair of bolts b' = (b-db/2) = (1.5-0.625/2) = 1.1875 in. = 0.13 in. This is less than the 0.25inch thickness provided, so prying need not be considered further. The welds of the vessel leg to the vessel body and of the leg to the upper connection plate are proportioned in a similar manner. The calculation can be simplified by assuming the weld is of unit thickness. This yields a demand per inch of weld and an appropriate weld thickness can then be selected. The vessel leg has an outer diameter, d, of 2.38 inches. The weld properties for a weld of unit thickness are: = 2.25 in3 A = πd =3.14(2.38) = 7.45 in. The shear in the weld is: v = 532 lb/7.45 in. = 714 lb/in.
121715_DesignExamples_15-18.docx