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    The document contains 5 questions regarding mechanical properties of materials including: 1) Definitions of engineering stress, engineering strain, Young's modulus, and yield strength. 2) Calculation of maximum load without plastic deformation for a bronze alloy specimen. 3) Calculation of modulus of elasticity from stress-strain data for a titanium alloy. 4) Calculation of strain for an aluminum alloy specimen under tensile loading. 5) Calculation of radius for a brass alloy specimen under tensile loading corresponding to a given stress and elongation.

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    Quiz

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    The document contains 5 questions regarding mechanical properties of materials including: 1) Definitions of engineering stress, engineering strain, Young's modulus, and yield strength. 2) Calculation of maximum load without plastic deformation for a bronze alloy specimen. 3) Calculation of modulus of elasticity from stress-strain data for a titanium alloy. 4) Calculation of strain for an aluminum alloy specimen under tensile loading. 5) Calculation of radius for a brass alloy specimen under tensile loading corresponding to a given stress and elongation.

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    The document contains 5 questions regarding mechanical properties of materials including: 1) Definitions of engineering stress, engineering strain, Young's modulus, and yield strength. 2) Calculation of maximum load without plastic deformation for a bronze alloy specimen. 3) Calculation of modulus of elasticity from stress-strain data for a titanium alloy. 4) Calculation of strain for an aluminum alloy specimen under tensile loading. 5) Calculation of radius for a brass alloy specimen under tensile loading corresponding to a given stress and elongation.

    Copyright:

    © All Rights Reserved
    Download as DOCX, PDF, TXT or read online from Scribd
    Download as docx, pdf, or txt
    17 views4 pages

    Quiz

    Uploaded by

    api-253978194
    The document contains 5 questions regarding mechanical properties of materials including: 1) Definitions of engineering stress, engineering strain, Young's modulus, and yield strength. 2) Calculation of maximum load without plastic deformation for a bronze alloy specimen. 3) Calculation of modulus of elasticity from stress-strain data for a titanium alloy. 4) Calculation of strain for an aluminum alloy specimen under tensile loading. 5) Calculation of radius for a brass alloy specimen under tensile loading corresponding to a given stress and elongation.

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    © All Rights Reserved
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    of 4

    Question 1

    Using the text Materials Science for Engineers, 8e, by Shackelford


    , define the following the mechanical properties of a material:
    (a) Engineering stress.- Load on a sample divided by the original (Stress-free) area.
    (b) Engineering strain.- Increase in sample length at a given load divided by the original (Stressfree) length.
    (c) Youngs Modulus.- Slope of the stress-strain curve in the elastic region.
    (d) Yield strength The strength of a material associated with the approximate upper limit of
    Hookes law behavior.

    Question 2
    For a bronze alloy, the stress at which plastic deformation begins is 250 MPa (36,360 psi), and
    the modulus of elasticity is 120 GPa (17.4 x 106 psi).
    What is the maximum load that may be applied to a specimen with a cross-sectional area of 325
    mm2 (0.5 in.2) without plastic deformation?
    Sigma y = 2.50 x 10^8
    E = 1.20 x 10^11 (Not needed)
    A = 3.25 x 10^-4 m^2
    F=?
    F = Sigma x A
    = 2.50 x 10^8 x 3.25 x 10^-4
    = 81,250 N
    Or
    = 8.9 x 10^4

    Question 3
    Stress Strain Curve and Calculation

    The following three stress () strain () data points are provided for a titanium alloy for
    aerospace applications:

    Stress ()

    Strain ()

    300 MPa

    0.002778

    600 MPa

    0.005556

    (a) Sketch a stress strain curve for the alloy.

    (b) Calculate the Modulus of Elasticity, E.


    By simple using Hookes Law, we can determine the Modulus by
    E = Stress/Strain
    Or

    E = sigma/e
    Checking the first #:
    3.0 x 10^6/2.778 x 10^-3
    = 1079913607
    Or
    107 MPa
    Doing the second #:
    6.0 x 10^6/5.556 x 10^-3
    Again we get:
    = 1079913607
    Or 107 MPa

    Question 4
    A specimen of an aluminum alloy 3003-H14 having a rectangular cross section 10 mm x 12.7
    mm is pulled in tension with 25,000 N force, producing only elastic deformation. Using the data
    in Table 6.1 on Page 158, calculate the resulting strain.
    A = 10 mm x 12.7 mm or 1.27 x 10^-2
    F = 2.5 x 10^4 N
    E = 7.0 x 10^10 N/m^2
    e= ?
    e= Sigma/E
    = Sigma = F/A)
    =2.5 x 10^4 N/1.27 x 10^-2 x 7.0 x 10^10 N/m^2
    = 25,000/889,000,000
    So

    = 2.8 x 10^-5 N/m^2

    Question 5
    First, review Example Problem 6.3 on Pages 162 163.
    A cylindrical specimen of a brass alloy having a length of 60 mm must elongate only 10.8 mm
    when a tensile load of 50,000 N is applied, corresponding to a stress of 420 MPa.
    Under these circumstances, what must be the radius of the specimen? Consider this brass alloy
    to have the stress-strain behavior shown in Figure 6.6 on Page 155.
    First we have to determine our Strain:
    Which is simply:
    Engineering Strain = L L0/L0
    = 10.8 60 mm/60 mm
    =-0.82 mm^2
    Now we know our stress is listed as 420 x 10^6
    Now we have enough info to calculate our Area:
    Stress = P/A0
    Which translates to:
    A0 = P/Stress
    = 50,000 N/420 x 10^6
    = 1.19 x 10^-4
    The last piece to determine is our Radius:
    Which is simply the same engineering stress formula:
    Stress = P/A0
    Although it is converted after punching in for Pi and other parameters to make:
    Radius = 50,000/Pi(420 x 10^6)^2
    After calculation it turns out to be:
    2.87191537 x 10^-14

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