Lap shear bolted plates
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This document summarizes a study on bolt failures in a heavy steel lap shear joint. The goals were to evaluate grade 5 bolts currently in use, demonstrate sequential bolt failure, determine maximum load capacity, and calculate a safety factor for a heavy lift rigging fixture. Testing of an assembly with 8 bolts found failures at 2 bolts and 6000 lbs of load. Testing of an assembly with 6 bolts found failures at 4 bolts and 6000 lbs of load, indicating complete failure would occur at 3 tons of load. The document recommends stamping the plates with a maximum 1.5 ton load and changing to higher strength Grade 8 bolts to increase the bolt safety factor of 1.2 to an acceptable 1.5.
Lap shear bolted plates
- 1. Bolt failure study in a heavy steel plate lap shear joint 10/12/17 rev A Don Blanchet 3B Associates dwb3298@verizon.net 15 x 10 x 1 plates lap shear 他 UNC-10 8 placesPrepared for CBL construction Vitoria , Brazil
- 3. Goals Evaluate the grade 5 他 inch bolts that are in use. Demonstrate sequential bolt failure. Set the maximum load capacity. Heavy lift rigging fixture application factor of safety.
- 4. Bolt Torque
- 5. Results 8 bolts 2 failures
- 6. Results: 8 bolts 2 failures Fixed end welded Load applied 6000 lbs
- 7. Results 6 bolts 4 failures
- 8. Results: 6 bolts 4 failures Fixed end welded Load applied 6000 lbs With a 3 ton load , the assembly will fail completely In sequence 2-bolts, 4-bolts, 2-bolts
- 9. Bolt Safe loading 1.5 Tons
- 10. Bolts factor of safety 1.2 or 20% margin of safety
- 11. Max stress in plates factor of safety = 2.6
- 12. Recommendations Stamp plates with max load 1.5 tons Change from grade 5 to Grade 8 bolts