lap shear bolted plates
TRANSCRIPT
Bolt failure study in a heavy steel plate lap shear joint
10/12/17 rev A
Don Blanchet
3B Associates
15” x 10” x 1” plates lap shear
¾ UNC-10 – 8 placesPrepared forCBL constructionVitoria , Brazil
Lift Rigging Safety
Goals
Evaluate the grade 5 ¾ inch bolts that are in use.
Demonstrate sequential bolt failure.
Set the maximum load capacity.
Heavy lift rigging fixture application factor of safety.
Bolt Torque
Results 8 bolts 2 failures
Results: 8 bolts 2 failures
Fixed endwelded
Load applied6000 lbs
Results 6 bolts 4 failures
Results: 6 bolts 4 failures
Fixed endwelded
Load applied6000 lbs
With a 3 ton load , the assembly will fail completely In sequence 2-bolts, 4-bolts, 2-bolts
Bolt Safe loading – 1.5 Tons
Bolts factor of safety 1.2or 20% margin of safety
Max stress in platesfactor of safety = 2.6
Recommendations
Stamp plates with “max load 1.5 tons”
Change from grade 5 to Grade 8 bolts