(2) Given a ductile wrought steel material, whose yield tensile strength S = 36 ksi. and ultimate tensile strength Sut = 72 ksi. Select its design factor N = 2 to design the machine element. (a) When the machine element of the ductile material is used for uniaxial static normal stresses, what kind of failure prediction method should be used? [1 pt] Maximum Normal Stress Method; [Maximum Shear Stress Method; Goodman Method [ ] Yield Strength Method; [ ] Endurance Strength Method; 1 (b) When it is used for static shear stress on the ductile material, please estimate its maximum shear stress. [2 pt] (c) When the machine element is used for repeated & reversed normal or shear stresses on the ductile material, what kind of failure prediction method should be used? [1 pt] Maximum Normal Stress Method; [ Maximum Shear Stress Method; [Goodman Method [ ] Yield Strength Method; ( ) Endurance Strength Method; (d) When the machine element of the ductile material is used for repeated & reversed normal or shear stresses, and the machine element is a shaft with diameter D 1.5 inches, (i) The typical values of the endurance strength Sn can be estimated as for steels are 1/2 of [pt] [the yield tensile strength; [ ]the ultimate tensile strength (ii) Calculate the typical value of the endurance strength S. [1 pt] (iii) In order to estimate the actual endurance strength S'a The material factor Cm is listed as [1 pt] [10.66; [10.70; [0.76; []1.0; [10.80 The stress-type factor Cis listed as [1 pt] [10.80; [1.0 For reliability 99.9%, the reliability factor Ca is selected from the following table: [1 pt] Approximate Reliability TABLE 5-3 Factors, CR Desired reliability CR 0.50 1.0 0.90 0.90 0.99 0.81 0.999 0.75 [1.00; [ ] 0.90; [ ] 0.81; [ ]0.75 The size factor Cs is calculated from the following table: [1 pt] Table 5-4 Size Factors Size range D= 0.30 0.30 (v) Calculate the design shear stress td when the machine element is used for repeated & reversed shear stress [1 pt]