Colawate the adequeny the o aneng strale al temson a lcu ade

Colawate the adequeny the o aneng strale al temson a lcu adequecy follou) ollow 13 kps and daod Jod kips (/ension.members A36 Steel C4x4x2\") ;s connected to a gusset late (A%) with a Li diameter A307 bolt spaing beteende hafts are amd de staneUse both LRFD ared AsD methods

Solution

LRFD DESIGN

The Gross sectional area is Ag=2.86 in² (from Table 1-7 pg36 of AISC)

For net sectional area,

An= Ag-diameter of hole

An=2.86-3/8(3/8+1/8)

An=2.86-3/8(0.5)

An=2.67in²

assume the 85% of the net effective area

Ae=0.85*2.67=2.26 in²

Gross design yeild strength=xAgxFy=0.9x2.86x36=92.664 Kips

Net section fracture=AeFu=0.75x2.26x58=98.31 Kips

The design strength will be the minimum of the yield strength and fracture

That is 92.664 Kips

The design loads are calculated on the basis of the two equations

1.4D and 1.2D+1.6L

1.4D=1.4x19=26.6 Kips

1.2D+1.6L=1.2(19)+1.6(13)=43.6 Kips

the ultimate load is 43.6 kips which is less than the design strength 92.2 kips, so it is adequate.

ASDThe total load=13+19=32 Kips

ultimate design strength based on yiled and fracture

based on yield=92.664/1.67 (1.67 is the factor of safety)=55.48 kips

based on fracture=98/2=49 kips

so the design strength is more than the allowable load

49 kips>26.6 kips

so it is adequate as per ASD method