db = 23.7 in B C D 96 k bf = 8.97 in tf = in k = 1.09 in 13 Fy = 50 ksi Fu = 65 ksi Member A-B, Interior column: A E

Transcription

1 le B1, second floor. t = thickness of connected part Pu = factored load to be resisted d = diameter of the bolt eb = one-half the depth of the beam, ec = one-half the depth of the column, Hub = factored shear force for gusset-to-beam connection. Vub = factored axial force for gusset-to-beam connection. Huc = factored shear force for gusset-to-column connection. Vuc = factored axial force for gusset-to-column connection. N = horizontal distance of gusset plate, V = vertical distance of gusset plate, α = distance from the face of the column flange to the centroid of the gusset-to-beam connection, β = distance from the face of the beam flange to the centroid of the gusset-to-column connection, g = workable gage. rut = tensile force per bolt ruv = shear force per bolt Ft = nomal tensile strength of bolt. D = number of sixteenths-of-an-ch the fillet weld size. ex = horizontal component of eccentricity of Pu with respect to centroid of weld group. C = coefficient for eccentrically loaded weld groupd C1 = electrode strength coefficient Member A-E, Interior floor girder: Pu = k W24x68 ASTM 992 db = 23.7 B C D 96 k bf = 8.97 tf = k = Fy = 50 Fu = 65 Member A-B, Interior column: A E W10x49 ASTM dc = 9.98 tw = 0.34 bf = 10 tf = L6x4x1/2 W10x49 Fy = 50 Fu = Member A-C, : 15 2L6x4x1/2LLBB A36 Ag = Fy = 36 Fu = 58 Gusset plate: α = 16.5 β = 6.7 t = 1/2 N = 20 1/8 V = 13 3/4 W.P. W24x68 SHEET 125 of 131

2 SHEET 126 of 131 eb = ec = Calculate gusset terface forces: r = ( (α+ec) 2 + (β+eb) 2 ) = On the gusset-to-column connection: Huc = ec * Pu/r = Vuc = β * Pu/r = On the gusset-to-beam connection: Hub = α * Pu/r = Vub = eb * Pu/r = Vu Pu Hu Huc Vuc Hub Vub

3 SHEET 127 of 131 Design of gusset-to-column connection: Try : welded to the gusset and bolted with rows of diameter A325-N bolts standard holes to the column flange. Use spacg between bolts and lev = t = Fy = 36 Ab = 2 Fu = 58 n = rut = Huc / n = ruv = Vuc / n = Ft = (fv) < 90 ; fv = ruv / Ab = Ft = > 90 Ft = φ Rn = φ * Ft *Ab = kips/bolt > rut Bearg strength per bolt is: φ Rn = φ (2.4*d*t*Fu) = > φ Rn (table 7-10) = Check pryg action : (Illustration of variables pryg action calculations LRFD fig. 9-4) g = b = g - t/2 = (LRFD Fig. 10-6) a = (angle leg) - g = < 1.25 b= a =

4 SHEET 128 of 131 b' = b - d/2 = a' = a + d/2 = ρ = b' / a' = β = 1/ρ (φrn / rut -1)= if β > 1, α' = 1.0; if β < 1, α' = 1/δ (β/(1-β)) δ = 1 d'/p = α' = p = t req. = ( (4.44 * rut * b ) / ( p * Fy * (1+ δ * α ))) t req. = < 3.5" 1.25" 3" λ 3"

5 SHEET 129 of 131 Design of column-to-gusset connection : Try : welded to the gusset and bolted with rows of diameter A325-N bolts standard holes to the column flange. Use spacg between bolts and lev = W10x49 V β λ Angles 2L6x4x1/ eb ec α N t = Fy = Ab = 2 Fu = n = rut = Huc / n = ruv = Vuc / n = Ft = (fv) < 90 ; fv = ruv / Ab = Ft = > 90 Ft = φ Rn = φ * Ft *Ab = kips/bolt > rut Bearg strength per bolt is: φ (2.4*d*t*Fu) = > φ Rn (table 7-10) =

6 SHEET 130 of 131 Check areas: (sce their strengths are the same this will check which section governs block shear design) Angles Shear areas: Both Angles: (double the area) Agv = 2 Agv = 2 Anv = 2 Anv = 2 Tension areas: Agt = 2 Agt = 2 Ant = 2 Ant = 2 Shear areas: Agv = 2 Anv = 2 Tension areas: Agt = 2 Ant = 2 The gusset plate will govern the design because it has less area than the angles. Check Block shear gusset plate: Shear rupture design strength φvn: LRFD J4-1 φ(.6*fu)*anv = kips Tension rupture design strength φtn: LRFD J4-2 φfu*ant = kips The larger fracture term controls: Pu = Vuc = k Block shear strength: φ Rn = kips < φ Rn = kips > Pu = kips

7 SHEET 131 of 131 Design of gusset-to-beam connection: Pub = (Hub 2 + Vub 2 ) = D req = 1.4 Pub / (1.392 *N) = say sixteenths from LRFD table J2.4 the mimum weld size required is : gusset plate thickness = 1/2 sixteenths Use : sixteenths fillet welds Check local web yieldg of the beam: φ Rn = φ (N k) Fyw * tw = kips > Vub = kips (φ = 1) W10x49 t = 1/2" 2L6x4x1/2 Gusset to to beam beam connection 1/4" Fillet welds Gusset to to column connection 4 rows of 3/4" bolts W24x68