Solution to Problem 130 Bearing Stress

Problem 130
Figure P-130 shows a roof truss and the detail of the riveted connection at joint B. Using allowable stresses of τ = 70 MPa and σb= 140 MPa, how many 19-mm-diameter rivets are required to fasten member BC to the gusset plate? Member BE? What is the largest average tensile or compressive stress in BC and BE?





Solution 130



Good day. I would like to ask a clarification max tensile/compressive stress on the members.
Why did we use A=Area-dt for member BC, but for member BE, we just used the given area of 1780?
Maraming salamat po.