Question

IF-1250 lb LI The bracket is to be bolted to a vertical face by means 3/8-16UNC-2A SAE Grade 5 bolts. The bolts are preloaded to 90 percent of the proof load. The joint constant, C, is equal to 0.173. Compute the maximum tension stress in the bolts and identify which bolt(s) in which it will occur. Compute the factor of safety for the most severely load fastener taking into account combined tension and shear.

Answer 1

Date: - 125016 1211 Given bolt size 34-16 UNC SAE GR. 5 bolt bolt pne load 907X(proof load) joint const- 00173 on this care bolts are subjected to direct Shearing load which is equally spread by all the bolts, shear load on each bolt = Wsh = 12.50 = 312.5 lbs since the f will try to fill the bracket in clockwise direction about point c therefone the bolts will be subjected to tenalle load due to turching moment.

Date : The maximum loaded bolts are al &2. as they are far from edge c. max tensile load ? let w be the load in bolt penunit distance due to turning effect of bracket & W, fwy be the wad at distance L, & L. from point c. ا د رانيا ت Wer whe total moment of this load about c & = 2WL; 2 + 2W L₂ C for 4 bolts) Total moment about c- W.L. c) WL = 20 L, 2 + 2w L₂ ? => wa WL, 2(4;2+2₂) as bolt 1&2 are heavily loaded Max tensile load - WL x L₂ 244, 422) Wte Wi - 1250 x 8 x 5 - 1250x40 12 ( 12 + 52) Wt = 961 lbs equivalent tensile load - Wte $2 - (Wet VWz² + 4s)2 - 1 (961 + Vast +46 1053 16. www.terex.in

Date : from chant SAE grade 5 bolt proof strength = 85,000 psi (for 3/16 UNC). pretoad - 90%. X 85000 75 stopsi yield strength = 92,000 psi equivalent tensile stress & & Wte Albolt) 1053 I (0375) 9538 psi fos = 92,000 as, 28 = 9.64 (tos: eg Tendy