Reference no: EM132455762
Assignment - Mechanic of Machine Problems
1. The forearm and biceps support the 2-kg load at A. If C can be assumed as a pin support, compute the resultant internal loadings acting on the cross section of the bone of the forearm at E. The biceps pull on the bone along BD.
2. The square plate is deformed into the shape shown by the dashed lines. If DC has a normal strain εx = 0.004. DA has a normal strain εy = 0.005 and at D, γxy = 0.02 rad. Find the average normal strain along the diagonal CA.
3. The following figure is experimental data for uni-axial engineering stress versus strain curve conducted by a undergrad student in a lab course on a metal.
From the graph, approximate the following numerically and briefly describe (one sentence) how do you obtained each value.
a. Youngs modulus E
b. Ultimate tensile stress
c. Fracture strength
d. Figure b are four schematics of how this sample possibly fracture. Choose one which is most likely and explain why.
4. A steel rectangular block, a = 2.4 cm wide and b = 1.2 cm deep, is subjected to an axial tensile load as shown in the figure. Measurements show the block to increase in length by δx = 7.11x10-5 m (initial length L = 10 cm) and to decrease in width by δz = 0.533x10-5 m, when P is 45 kN. Identify the modulus of elasticity and Poisson's ratio for the specimen material.
These are the selected problems for strain analysis topic. Exercise these problems.
5. The wire has a diameter of 5 mm and is made from A-36 steel. If a 80-kg man is sitting on seat C, determine the elongation of wire DE.
6. The acrylic plastic rod is 200 mm long and 15 mm in diameter. If an axial load of 300 N is applied to it, determine the change in its length and the change in its diameter. EP = 2.70 GPa, νP = 0.4.
7. The thin-walled tube is subjected to an axial force of 40 kN. If the tube elongates 3 mm and its circumference decreases 0.09 mm, determine the modulus of elasticity, Poisson's ratio, and the shear modulus of the tube's material. The material behaves elastically.
8. The lap joint is connected together using a 1.25 in. diameter bolt. If the bolt is made from a material having a shear stress-strain diagram that is approximated as shown, determine the permanent shear strain in the shear plane of the bolt when the applied force P = 150 kip is removed.
9. The rigid beam rests in the horizontal position on two 2014-T6 aluminum cylinders having the unloaded lengths shown. If each cylinder has a diameter of 30 mm. Determine the placement x of the applied 80-kN load so that the beam remains horizontal. What is the new diameter of cylinder A after the load is applied? νal = 0.35.
10. The 8-mm-diameter bolt is made of an aluminum alloy. It fits through a magnesium sleeve that has an inner diameter of 12 mm and an outer diameter of 20 mm. If the original lengths of the bolt and sleeve are 80 mm and 50 mm, respectively, determine the strains in the sleeve and the bolt if the nut on the bolt is tightened so that the tension in the bolt is 8 kN. Assume the material at A is rigid. Eal = 70 GPa, Emg = 45 GPa.
11. An acetal polymer block is fixed to the rigid plates at its top and bottom surfaces. If the top plate displaces 2 mm horizontally when it is subjected to a horizontal force P = 2 kN, determine the shear modulus of the polymer. The width of the block is 100 mm. Assume that the polymer is linearly elastic and use small angle analysis.
