(Solved): 2. Someone brings you the femoral stem of a hip joint prosthesis that has fractured in its midsect ...

2. Someone brings you the femoral stem of a hip joint prosthesis that has fractured in its midsection after 15 years in a patient. (a) Using your knowledge to date, what is the most likely cause for this failure? Would you expect this fracture to be more brittle or ductile in character? (b) After determining that the above material is no longer suitable for a femoral stem, you decide to examine a new material. Tensile testing results are shown below. A cylindrical dog-bone specimen with a diameter of \( 12.8 \mathrm{~mm} \) and a length of \( 60 \mathrm{~mm} \) in the testing region was used. What is the elastic modulus for this material? What is the maximum stress you would want to apply to this material before it would fail for this application? What is the ultimate tensile strength?