1. A steel rotating-beam test specimen has an ultimate strength of 230 kpsi. Estimate the fatigue strength corresponding to a life of 150*103 cycles of stress reversal.

Design a beam shown to carry a repeated central load F varies from Fmin = 800 to F,max 1200 lb.so that it has a design factor equal to N = 4,made from (select) steel, it is to be used in the hot-rolled condition, a reliability of (...%). use. Goodman method of failure

3.2-1 A PL 3/8 x 7 tension member is connected with three 1-inch-diameter bolts,as shown in Figure P3.2-1. The steel is A36. Assume that Ae = An and compute a. the design strength for LRFD b. the allowable strength for ASD

a) The shaft shown in the figure is machined from AISI 1040 CD steel. The shaft rotates at 1600rpm and is supported in rolling bearings at A and B. The applied forces are F, = 1200 lbf and F,= 2400 lbf. Determine the minimum fatigue factor of safety based on achieving infinite life. If infinite life is not predicted, estimate the number of cycles to failure. From Fig. A-15-9 with,r/d = 0.0625/1.625 0.04, D/d 1.875/1.625 1.15, K, =1.95 b) Solve the above problem except include a steady torque of 2200 lbf in being transmitted through the shaft between the points of application of the forces. Use the Goodman criterion. From the problem above we find the completely reversed stress at the critical shoulder fillet to be o = 32.8kpsi, producing o, = 32.8 kpsi and on = 0 kpsi

A PL x 6 tension member is welded to a gusset plate as shown in Figure P3.2-2. The steel has a yield stress F, = 50 ksi and an ultimate tensile stress F = 65 ksi. Assume that A, = A̟ and compute a. the design strength for LRFD b. the allowable strength for ASD

4.7-8 The frame shown in Figure P4.7-8 is unbraced, and bending is about the x-axisof the members. All beams are W18 x 35, and all columns are W10 × 54. a. Determine the effective length factor K for column AB. Do not considerthe stiffness reduction factor. b. Determine the effective length factor K for column BC. Do not considerthe stiffness reduction factor. If F, = 50 ksi, is the stiffness reduction factor applicable to these columns?

Given: The HSS5 × 5 × 3/8 member shown is connected to a 3/4-in gusset plate with fillet welds as indicated. The yield stress of the HSS is Fy = 46 ksi and the tensile strength is Fu = 58ksi. Find: The effective net area of the HSS.

Which of the following parameters does shear stress Not depend on? a. Moment of Inertia O b. Shear Force O c. Material Thickness O d. Normal Force O e. First Moment Area

A simply supported W30x116 is subjected to a uniform service dead load of 1.0 kips/ft(does not include the self-weight of the beam), a uniform service live load of 2.5 kips/ft,and a concentrated service dead load of 45 kips. The beam is 40 ft long and has continuous lateral support. 1. If A572 Grade 50 steel is used, will the W30xl16 be adequate by LRFD? 2. Using Table 3-2, select the lightest weight W-section that can safely carry the required strength by LRFD.

Given: The 1/2-in plate shown in is connected to a gusset plate with fillet welds as indicated.The plate material is A36 steel. Find: The effective net area of the plate.