ME 261 Strength of Materials Midterm Exam 2018

ME 261-Strength of Materials
FALL-2018
MIDTERM EXAM-I
November 12, 2018
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QUESTION 1 : Each of vertical links has ana 8*36 mm uniform rectangular cross-section and each of the four
pins has a 16 mm diameter. Determine
a. the avarage shearing stress in the pin at C
b. the avarage bearing stress at C in link CE
c. the avarage bearing stress at C in memberABC, knowing that this member has a 10*50mm uniform
rectangular cross-section.
d. determine max. value of the average normal stress for BD and CE links.
(20p)
FBD=32.5kN
QUESTION 2: The triangular blocks are glued along each side of the joint. A C-clamp placed between two of
the blocks is used to draw the joint tight. If the clamping force is F=900N, determine the average shear stress
developed in the glued shear plane.(Draw the free body diyagram) (10p)
QUESTION 3: :Fill in the blanks (10p)
(a) _BRITTLE__ materials breaks with no plastic deformation.
(b) _POISSIN RATIOS______ is defined as the negative of the ratio of the lateral strain to the axial strain for
a uniaxial stress state.
(c) When a material is compressed in the axial direction, it will _EXPANSE__ in the transverse direction
(d) In the elastic region, the _YOUNG MODULUS___________ relates  to ε
(e) For statically determinate problems, the number of equilibrium equations is EQUAL OR MORE THAN___
the number of unknown loads (forces or torques)
QUESTION 4: The stress–strain diagram for a polyester resin is given in the figure. If the rigid beam is
supported by a strut AB and post CD made from this material, and subjected to a load of P=80kN, determine
the angle of slope of the beam when the load is applied. The diameter of the strut is 40 mm and the diameter
of the post is 80 mm. (20p)
QUESTION 5 : The two pipes are made of the same material and are connected as shown. If the crosssectional area of BC is A and that of CD is 2A, determine the reactions at B and D when a force P is applied
at the junction C. (10p)
QUESTION 6: The AM1004-T61 magnesium alloy tube AB is capped with a rigid plate E.The gap between E
and end C of the 6061-T6 aluminum alloy solid circular rod CD is 0.2 mm when the temperature is at 30° C.
Determine the elongation and normal stress developed in the tube and the rod if the temperature rises to
40° C. Neglect the thickness of the rigid cap. (15p)
Because total  0.2
QUESTION 7 : The block shown is made of a magnesium alloy for which E = 45 GPa and Poison’s ratio
= 0.35. Knowing that x = - 140 MPa, determine
(a) the magnitude of y for which the change in the height of the block will be zero,
(b) the corresponding change in the length of the AB and BC (15p)
Duration: 120 minutes
Good luck .
Prof.Dr.Buket OKUTAN BABA