Chapter 8.4, Problem 48P

In the structure shown, an 8-mm diameter pin is used at A, and 12-mm diameter pins are used at B and D. Knowing that the ultimate shearing stress is 100 MPa at all connections and that the ultimate normal stress is 250 MPa in each of the two links joining B and D, determine the allowable load P if an overall factor ofsafety of 3.0 is desired.

In the steel structure shown, a 6-mm-diameter pin is used at C and10-mm-diameter pins are used at B and D. The ultimate shearing stress is 150 MPa at all connections, and the ultimate normal stress is 400 MPa in link BD. Knowing that a factor of safety of 3.0 is desired,determine the largest load P that can be applied at A. Note that link BD is not reinforced around the pin holes.

Each of the three aluminum bars shown is to be twisted through an angle of 2.1°. Knowing that b = 30 mm, τall = 50 MPa, and G = 27 GPa, determine the shortest allowable length of each bar. Refer to Table 3.1. The shortest allowable length of bar (a) is  mm.   The shortest allowable length of bar (b) is  mm.   The shortest allowable length of bar (c) is  mm.

A steel pipe of 12-in. outer diameter is fabricated from 14-in.-thick plate by welding along a helix that forms an angle of 45° with a plane parallel to the axis of the pipe. Knowing that the maximum allowable tensile stress in the weld is 12 ksi, determine the largest torque that can be applied to the pipe.

Two rigid bars AC and BC are connected by a pin at C as shown. Knowing that the torsional spring at B is of constant K, determine the critical load Pcr for the system.

Knowing that σall=16 ksi, determine the maximum allowable value of the centric axial load P.

The ABC element is supported by a pin at C and a BD cable. Knowing that the limit load for the BD cable is 150 kN, and the coefficient Safety with respect to cable failure for BD of 3.5 determine the maximum value of the load P that can be supported. Determine the diameter of pin C, knowing that it is made of steel with an admissible stress of σadm = 270 Mpa, and that it is subjected to shear double.

A steel loop ABCD of length 5 ft and of 3838 -in. diameter is placed as shown around a 1-in.-diameter aluminum rod AC. Cables BE and DF, each of 1212 -in. diameter, are used to apply the load Q. Knowing that the ultimate strength of the steel used for the loop and the cables is 75 ksi, and that the ultimate strength of the aluminum used for the rod is 45 ksi, determine the largest load Q that can be applied if an overall factor of safety of 3 is desired.    The largest load Q that can be applied is  kips.

In the structure shown, an 8 mm diameter pin is used at A, and 12 mm diameter pins are used at B and D. Knowing that the allowable shearing stress is 120 MPa at all connections and that the allowable normal stress and bearing stress is 240 MPa in each of the two links joining B and D, determine the allowable load P