Question

Determine the available strength of the compression member shown in Figure P4.3-4, in each of the following ways: a. Use AISC Equation E3-2 or E3-3. Compute both the design strength for LRFD and the allowable strength for ASD. b. Use Table 4-14 from Part 4 of the Manual. Compute both the design strength for LRFD and the allowable strength for ASD. FIGURE P4.3-4 15 HSS 10 x 6 x ASTM A500, Grade C steel

Answer 1

ANSWER :
ry 2.39 check for slenderness ratio. 19) calculate eftective slenderness ratio : KL 0.65% (15X12) 90 2.39 = 0.65 x 180 - 17 2.39 =48.953 calculate buckling stress: Fe = (3.14 ) 2 x 29000 ksi (48.9953)2 - 119.468 ksi 29000 4.71 Fe = 7² E Fy = 4.71 50 ksi =4.71X 3.4058 since E113.43 48.953 is less than 13.48 there love Cyptical bucking stress as below 0.658 fe for a Eu ) f

=0-658 ( 19.05 )*5 - 41.96 ksi calciddate nominal compressive strength of column). Pn = For Aq = 41.96 X 13.5ksi in 566.46 Kips. calculate design strength by load resistance and factor design (LRFD) Por 0.98 566-46 kfp3 calculate a Howable strength by allowable stress design (ASD): 566.46 Po QC kips 1.67 = 339-19 Kips. (b) for value of effective slenderness ratio of 48.95 and 50 ksi of Fy from manual interpolate the value of critical stress by LRED de for = 31.5 ksi calculate design strength.

3 Pepn = de For Ag. = 37-7X 13.5ksi.in 509.8 Kips By ASD! For и = 25:) kips calculate design strength Pi for Ag. = nc RL 25.13 X 13.5 Ksi.in? = 339.2 kips