What is the approximate ductility (%EL) of a brass that has yield strength of 275 MPa?(b) What is the approximate Brinellhardness of 1040 steel having yield strength of 690 MPa?Discuss

1.It is known that the yield strength of an iron is related to grain diameter as shown in the table. Determine the grain diameter that would have yieldstrength of 205 MPa.Grain Diameter (mm)Yield Strength (MPa)5 x 1021358 x 103260

2.(a) What is the approximate ductility (%EL) of a brass that has yield strength of 275 MPa?(b) What is the approximate Brinell hardness of 1040 steel having yield strength of 690 MPa?Hint: refer to Figure 7.19 in the textbook.

3. (a) What is the maximum tensile load Pthat canbe applied without causing yielding of the material?(b)Indicate in the drawing where you expect cracks to initiate and the direction of crack propagation if an excessive load is applied. Yield strength of the material is 475 MPa.

4.While inspecting a machineusingx-ray, you found an internal crack of length 4 mmperpendicular to a stress in service. If the material has a plane-strain fracture toughness of 28mMPa, what is the limiting stress for a factor of safety of 1.5? The geometric correctionfactor for this crack is 1.12.

5.A 12.5-mm-diameter cylindrical rod of 2014-T6 aluminum alloy is subjected to a repeated tension-compression load cycling along its axis. Computer the maximum and minimum loads (force) that can be applied to have a fatigue life of at least 1.0 x 107cycles. Assume a mean stress of 50 MPa. Hint: reference page 32 of lecture file 140305.

6.A flat plate is subjected to constant-amplitude uniaxial cyclic tensile and compressive stresses of 120 and 35 MPa, respectively. If the largest initial surface crack is 1.00 mm and the material has a plain-strain fracture toughness of 35 mMPa, estimate the fatigue life. The Paris equation, in MPa and m units, for the material is da/dN = (5.0 x 1012)(K)3.2.The geometriccorrection factor is 1.4.

7.A flat plate is subjected to constant-amplitude uniaxial cyclic tensile and compressive stresses of 120 and 35 MPa, respectively. Compute the critical internal crack length if the fatigue life must be a minimum of 0.7 x 106cycles. The maximum initial internal crack length is 0.8 mm. The Paris equation for the material is da/dN = (7.5 x 1013)(K)1.8in MPa and m units. The geometric correction factor is 1.12.