Question

CRBEMENo 6 (16 points) Answer the following questions about rolled steel W-beams (use the sable provided as necessary): Which one of the following characteristics makes a W-beam "optimal" (as i. assumed for this class)? a narrowest flange width largest section modulus lightest weight shallowest depth d. Ir the beam is bent about horizontal x-x avis and requires a minimum section modulus of 43.4 in', which of the following beams would make the "short list"? (For this question only, mark all that apply, you may have multiple answers!) ii. W16x31 3. b W12x26 W10x45 d. W8x48 important consideration in If you had to pick between a W12x50 or a W16x50, which is th your selection as the structural engineer? iii. select the W12x50 because the web is thinner select the W12x50 because it weighs less select the W16x50 because the flanges are narrower d. a. h. select the W16x50 because it has a larger section modulus For a W8x15 beam, the area shown in the table is 4.44in2, however if the area of the flanges and webs are determined from the dimensions provided, the area is A-2(4.015"(.315" ) + [8.11"-2(.315") ](.245")= 4.36in What best explains this difference between 4.44in2 and 4.36in2? V. table value is intentionally reported larger to be conservative table value accounts for extra area in the rounded fillets at the flange-to-web corners table value has a calculation roundoff error a. b C. as shown, the resulting horizontal centroidal If two W10x54 beams were welded together moment of inertia would be most nearly: can't be determined b. a. 1410 in 606 in 303 in c. d. + LNe -24 -2A Designation (in xiby) Area (in) b. I.. Ser S t- tin) 17.99 (in) 7495 ) 0570 (n) W18 x 50 14.7 10 7 7.3 155 0.355 s00 w18x 46 13.5 18.06 6,060 225 743 12 1 35 0.605 9.350 788 225 712 W18 x 40 11.8 17.90 6.015 0.315 127 0.525 612 84 721 WIB3 10.3 ST 74153 512 122 672 4 2 17.70 6.000 0425 0.300 530 w16 57 16.8 26.43 10 7.120 0.715 0430 758 92.2 81 6. 727 6 w16x 50 14.7 659 16.25 7.070 0630 0.380 W16 45 32 34 57 28 25 15 13.3 16.13 7.035 0.565 0.345 W16x 40 11 16.0 6995 0.505 0.205 518 547 63 W1636 245 7.00 52 10.6 15 86 0430 0-295 6.51 6.985 448 565 1 17 W16 x 31 9.12 15.68 5.525 0.440 0275 373 641 12 4 4 472 57 14 3192 SL4 12 w14 x53 15.6 13.92 s 060 o 660 0370 541 778 5.89 W14 x 4 191 14 1 0.595 0.530 0 340 485 5a5 13.79 s.03 203 199 0.305 S82 452 13 587 2677. 48 5.83 233 91 W14 x 43 12.6 13.66 7.995 428 62.7 365 L55 6.770 11.2 24.10 051 0.310 54. W14x 38 1.53 5745 0.455 0.285 340 10.0 13.9 W14 x 34 s82 149 6.730 0.385 0.270 291 420 5.73 13.6 W14 30 8.85 13.8 7.00 2.0 1.04 39.3 5.000 12.125 0335 0.230 199 290 5.54 6.49 13.74 W14 x 22 3.07 0.515 740 138 0.810 5.3 241 12 52 W12 x 87 25.6 139 .96 12.19 8.080 0.640 0.370 394 647 5.18 56 3 s0.0 17.3 5.34 14.7 W12 x 50 350 12.4 194 0335 5.15 12.06 8.045 0.575 13.2 w12 x 45 0.300 0230 151 0.547 12.22 204 334 517 6.490 7.65 W12x 26 W12 x 22 0.260 156 103 2.31 4.030 0 425 254 491 4.66 12.35 6.48 0.220 17.1 2.82 141 0.773 3.990 0.265 0.225 4.47 11.99 11.91 4.71 W12x 16 0.753 0.200 14.9 462 1-19 2.36 3.970 4.16 W12 x 14 103 20.6 0.615 0.370 303 4.37 2.56 10.030 60.0 10.09 15.8 w10x 54 0.350 248 49.1 432 2.01 8.020 0.620 0.530 53.4 13.3 10.10 13.3 W10x 45 42.1 0.315 4.27 196 209 450 11.3 7.985 9.92 11 5 WID39 1.37 5.75 0.300 170 324 4.38 167 5.810 0.510 8.84 10.47 WI0x 30 18.8 2.14 0.874 O810 0.250 963 4.14 4.29 4.020 4.000 0.395 10.24 5.62 W10x19 3.95 289 1.45 68.9 13.8 0.270 0.210 0.935 0.810 0.230 9.99 441 W10 x 15 0.785 10.9 390 60.4 3.72 2.18 110 0.190 53.8 3.960 3.54 9.87 W10x 12 2.12 21.4 8.6 0.570 272 8.280 8.220 9.00 19.7 w8x67 wsx58 2.10 18.3 228 75.1 52.0 365 0.510 0.400 8.75 17.1 15.0 2.08 3.61 60.9 43.3 184 8.50 8.110 0.685 14.1 ws48 2.04 12.2 35.5 27.5 49.1 353 0.560 0.360 146 8.070 11.7 8.25 w8 40 2.02 37.1 9.27 3.47 110 0.285 7.995 a.435 9.13 8.00 wsx 31 5.63 1.61 3.42 3.29 3.41 183 20.9 82.8 0.400 0.245 7.93 6.495 7.08 ws 24 0.876 1.70 118 48.0 0.245 0.315 4.015 4.44 8.11 WB15 10 Last Name Exam No. 2 Formula Sheet dV -Mc Section Properties: dr max S Rectangle: dM S - dx bh 12 VQ AV=- w(x)dx bh2 S= 6 VQ AM = V(x)dx Solid Circle: It -y td 3V r Tmax 2A 64 4 V = Ee d3 tr3 Tmar= Aweb S= 4 32 M E, d EI rt 32 2 -My Allowable Stresses: Taltow= 10 ksi = 69 MPa Gatlow=21 ksi = 145 MPa Steel: 483 KPa Tallow 70 psi =650 psi =4482 KPa Timber: allow Material Properties: Material Properties Aluminum: Steel 260 MPa u38 ksi 400 MPa =58 ksi: 240 MPa ay 35 ksi 250 MPa ay=36 ksi E = 10,100 ksi = 70 GPa E = 29,000 ksi = 200 GPa 26 GPa G= 3,700 ksi 77 GPa G= 11,200 ksi 1

Answer 1

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SOf W 50 647 S 8lin3 The Selected stuctural Section should be Euch that it should Yesist moment Fcm more Simpla banding Theo - Ma S is option d nect answO Leauec it has sdect WIGxSO section madulcs lagon a blb

A 2 t.05 x35) (8.1-20.35o.5 4.36in2 The above Cakalated aea ' fa the follang Section D filete sectanO Suetan Table Value of 4ele in 2s fa sectian The main diffevene s that n section Tables thaY onsidoned the reas of fllets Hanges web oect ansu is oftion

W lo S4 has follong Pertie d (O.09in A IS.8 in 303 in (0,01 5.04" 2 Resultant oment of It AY a(303)t 2[Is.8x S.ous sction 410.28 in Covect answo oton