6) For a Screw Dislocation, identify: Strains around dislocation O All of the Choices Listed Tensile Compressive Shear

Answer the ques a

A copper rod is deformed using a uniaxial tensile force of 16000 N. Deformation continues until sufficient strain hardening has occurred such that the applied force is too small to allow further deformation. After deformation, the rod has a diameter of 0.01 m and a length of 1.5 m. Assume that copper follows the strain hardening lawwith K of 310 MPa and n=0.54   Please calculate the true strain after the deformation ?

Briefly explain the (a) how and (b) why the size of elastic deformation changes as the thickness of the specimen increases when a rod-shaped specimen made of the same material is bent.

The stress-strain curve for a metal is plotted as shown in Figure Q1 (a). On the graph,show the yield point, fracture point, proportional limit and ultimate point

Fatigue strength for non- ferrous materials in defined at stress cycles 10^3 10^5 10^7 10^9

In an engineering application, the material is a strip of iron with a fixed crystallographic structure subject to a tensile load during operation. The part failed (yielded) during operation and needs to be replaced with a component with better properties. You are told that two other iron strips had failed at yield stresses of 110 and 120 MPa, with grain sizes of 30 microns and 25 microns respectively. The current strip has a grain size of 20 microns. The diameter of the rod is 1 mm and the load applied is 100 N. What is the yield stress of the new part C and would you recommend it for operation? Select one: Oa. 133.5 MPa, yes O b. OC. Od Oe. 120.5 MPa, no 129.5, yes 140.5, no 123.5 MPa, yes

Strain = 600 Stress = Strain = 500 Stress = 400 500 300 400 300 200 200 100 100 0.000 0.002 0.004 0.006 Strain 0.00 0.04 0.08 0.12 0.16 0.20 Strain Stress (MPa)

An iron specimen is plastically deformed in shear by 1%, and it has u dislocation density of 1 10 14 m/ m 3 Assume that the dislocation density did not change in the 1% strain of thisspecimen, the Burger's vector (b) is a 2 [1 1 1] the slip plane is (110). the shear stress isapplied to the (110) plane, and the lattice parameter of the BCC iron is 0.286 nm. Calculate the magnitude of the Burger's vector for these dislocations in iron. Calculate the average distance moved by the mobile dislocations as a result of the 1% shear strain.

Considering a finite cylinder of single crystal aluminum with a diameter (D) that has an axial unit screw dislocation at the center, what is the stress field around this dislocation in terms of D (diameter of cylinder) and r (radius which is the distance from dislocation center)