Question-4 (20) a) Explain modes of failure associated with bolted connections. b) Compute the allowable tensile load for the double-shear butt joint shown. The plates are equivalent to A36 carbon steel. The bolts are 0.75-in.-diameter A325-N high-strength bolts in standard holes. The holes diameter is 0.875 inch. P TABLE 19.1 Structural Steels A36 carbon A992 high-strength low-alloy Splice plates-7 Bolts not shown F 35 TABLE 19.2 Allowable stresses in ksi (MPa) Allowable Bearing Stress 58 (400) 65/448) 4" F=(15)F 87 (600) 97.5 (672) NIF + Allowable shear stress on steel fasteners (Bearing-type connection) 36 (250) 50 (345) LO Description of Fastener A307 low-carbon bolts A325 bolts threads in shear plane 27.0 (186) A325 bolts threads excluded from shear plane 3140 (228.5) A490 bolts threads in shear plane 34.0 (228.5) A490 bolts threads excluded from shear plane 42.0 (289.5) Note: U.S. Customary System values are based on the AISC Specification. Si values are converted from U.S. Customary System values. 2 Platc-7" x Allowable Shear Stress (F) (ksi (MPa)] Gage lines (Gross) F = (0.60)F Allowable Tensile Stress 21.6 (150) 30 (207) (Net) F. - (0.50) F 29 (200) 32.5 (224) Note: U.S. Customary System values are from the AISC Specification. Sl values are converted from U.S. Customary System values. Minimum vallars P