Solution to Problem 261 Thermal Stress Jhun Vert Tue, 04/21/2020 - 09:22 am

Problem 261
A steel rod with a cross-sectional area of 0.25 in2 is stretched between two fixed points. The tensile load at 70°F is 1200 lb. What will be the stress at 0°F? At what temperature will the stress be zero? Assume α = 6.5 × 10-6 in/(in·°F) and E = 29 × 106 psi.
 

Solution to Problem 257 Statically Indeterminate

Problem 257
Three bars AB, AC, and AD are pinned together as shown in Fig. P-257. Initially, the assembly is stress free. Horizontal movement of the joint at A is prevented by a short horizontal strut AE. Calculate the stress in each bar and the force in the strut AE when the assembly is used to support the load W = 10 kips. For each steel bar, A = 0.3 in.2 and E = 29 × 106 psi. For the aluminum bar, A = 0.6 in.2 and E = 10 × 106 psi.
 

Figure 257

 

Solution to Problem 256 Statically Indeterminate Jhun Vert Mon, 04/20/2020 - 11:37 pm

Problem 256
Three rods, each of area 250 mm2, jointly support a 7.5 kN load, as shown in Fig. P-256. Assuming that there was no slack or stress in the rods before the load was applied, find the stress in each rod. Use Est = 200 GPa and Ebr = 83 GPa.
 

Figure P-256

 

Solution to Problem 254 Statically Indeterminate Jhun Vert Mon, 04/20/2020 - 11:30 pm

Problem 254
As shown in Fig. P-254, a rigid bar with negligible mass is pinned at O and attached to two vertical rods. Assuming that the rods were initially stress-free, what maximum load P can be applied without exceeding stresses of 150 MPa in the steel rod and 70 MPa in the bronze rod.
 

Solution to Problem 248 Statically Indeterminate Jhun Vert Mon, 04/20/2020 - 11:06 pm

Problem 248
Solve Problem 247 if the right wall yields 0.80 mm.
 

Solution to Problem 247 Statically Indeterminate Jhun Vert Mon, 04/20/2020 - 11:03 pm

Problem 247
The composite bar in Fig. P-247 is stress-free before the axial loads P1 and P2 are applied. Assuming that the walls are rigid, calculate the stress in each material if P1 = 150 kN and P2 = 90 kN.
 

Figure 247

 

Solution to Problem 246 Statically Indeterminate Jhun Vert Mon, 04/20/2020 - 10:59 pm

Problem 246
Referring to the composite bar in Problem 245, what maximum axial load P can be applied if the allowable stresses are 10 ksi for aluminum and 18 ksi for steel.