Circle One Materials that undergoes plastic deformation prior to failure is said to be "brittle." 2. T or F T or F 3. Grain structure of metals is not affected by plastic strain such as making wire. T or F . 4. The mechanical behavior of all materials is affected by temperature. T or F 5. Elastic deformation does not change the arrangement of atoms in materials. T or F 6. Materials that show plastic deformation are ductile. T- or F 7. A true elastic behavior reaches an instantaneous yield point. T or E Repeated loadings may create stresses that are less than the strength of the material which leads to "fatigue failure." 8.

Problem 1 An aluminum rod is rigidly attached between a steel rod and a bronze rod as shown. Axial loads are applied at the positions indicated. Aluminum Steel A=800mm2 A=1000mm2 Bronze A=700mm? 4P 2P 500mm 600mm 700mm 1. What is the maximum value of P that will not exceed the axial stress bronze of 105 MPa? 2. What is the maximum value of P that will not exceed the axial stress in aluminum of 90 MPa? 3. If P=10KN, what is the axial force to be carried by the aluminum in KN? 4. If P is 5KN, what is the axial stress of steel?

There is no force on a beam, but the beam is subjected to a very large temperature difference above and below. As shown in the figure below, try to calculate the vertical displacement of the midpoint of the beam, assuming that the temperature coefficient of the entire beam is a = 11.7×10^-6 °F. Tip: See Mechanics of Materials for Beam Deformation Geometry

QUESTION 3 UWE The figure below shows the cross section of unsymmetric Bristol I-beam. The I-beam experiences a maximum M=4 kNm sagging bending moment. And the beam is pulled apart with end-loading forces of 20 kN. Calculate the maximum tensile stress the beam experiences. (State your answer to the nearest whole number Mega-Pascals.) 120 mm 60 mm I 40 mm 30 mm 220 mm 30 mm