Question

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A c-shaped weld group is to attach a tension plate to a gusset plate.

Givens:

P_DL= 55 k

P_LL= 65 k

1. Using A992 steel and LRFD, design the thickness of the tension plate.
2. Use E70 electrodes and 5/16” weld to complete3 the c-shaped weld design.

***please provide steps on how to solve....thank you.

Answer 1

GIVEN DATA Member Details A 992 Grade of Steel Loads 55 kips Dead load 65 kips Live load CALCULATIONS For grade of steel, A 992 50 ksi Yield stress Ultimate stress 65 ksi 「 1.2 Po + 1.6 P L Design Load, 170 kips elding in the gross section Design strength of gross section is obtained as: 0.9 x 50 x Ag 45 A 170 45 Therefore 3.78 in 2 Fracture in the net section Shear lag Factor Effective area 1 A Design strength of net section is obtained as 65 x 1 An 0.75 x 48.75 Am Therefore, A170 48.75 3.49 in 3.78 in2 Threfore, required area is Given width of plate 6 in Therefore, thickness of plate 0.63 Choose 4

GIVEN DATA Member Details Grade of Steel A 992 Member designation PL 3/4x 6 0.750 Thickness of member Connection Details Grade of electrode : E 70 Welding Process : SMAW (assumed) Loads Applied Factored design load, Tu = 170.0 kips CALCULATIONS For grade of steel, ,A 992 Yield stress, F,- 50 ksi F65 ksi Ultimate stress, DESIGN OF WELD lection of weld size and computation of strength Min. size fillet weld - 1 in 4. Max. size fillet weld 4 16 11 in 16 Therefore, use 5 in size fillet weld with E 70 electrode 16 Effective throat thickness, te= 0.707 x 5 16 -0.221 in The design strength 0.75 x 0.221 x 0.6 x 70 6.96 kips/in This cannot exceed the shear rupture strength of the base metal 0.75 x 0.750 x 0.6 x 65 - 21.9 kips/in O.K b) Determination of lengths of weld to be used in the connection Total length of weld, Lw of fillet weld required is: L170.o 6.96 24.4 in

Hence, the length of weld on each side ( 244-6)/2 = 9.21 in Use 10 in weld E 70 (Typ.) 16 E70(Typ/5176 16