strength of materials problems

8/8/2019 Strength of Materials Problems

1/4

STRENGTH OF MATERIALS PROBLEMS

Multiple Choice:

1. The section of a beam at which the bending moment changes from positive to

Negative is called:a} critical point c} point of inflectionb} deflection point d} nota

2. The stress in an elastic material is:

a} inversely proportional to the materials yield strengthb} inversely proportional to the force actingc} proportional to the displacementd} inversely proportional to the strain

3. The linear portion of the stress-strain diagram of steel is known as the:

a} modulus of elongationb} plastic rangec} strain hardeningd) elastic range

4. Modulus of rigidity of a steel member isa) defined as the unit shear stress divided by the unit shear deformation

b) equal to the modulus of elasticity divided by one plus Poissons ratioc) defined as the length divided by the moment of inertiad) equal to approximately 7/10 of the modulus of elasticity

5. The area of the shear diagram between any two points is equal to:a) change in shear between two points b) total shear between the two pointsc) average moment between the two pointsd) change in moment between the two points

6. Two circular shafts , one hollow and one solid , are made of the same material and

Have the diameters shown. If Th is the twisting moment that the hollow shaft canResist and Ts is the twisting moment that the solid shaft can resist , the ratio Th toTs is:

a) b) c) 9/16d) 15/16


2/4

7. A steel cylinder 12 inches outside and a wall thickness of 1 in. is filled withconcrete and used as a pier to support an axial load in compression.. If theallowable stresses are 40000 psi for steel and 3500 psi for concrete and theYoungs modulus for steel is 30 x 10 6 psi and for concrete is 2.8 x 10 6 psi ,

What is the allowable load on the pier ?a) 200 tons b) 1570000 lbsc) 400 kipsd) 500 kN

8. A short structural member of length L , area A and modulus of elasticity E , isSubjected to a compression load of P. The member will:

a) elongate by PL/AE b) shorten by PL/AEc) buckle at 2EI/L 2

d) nota9. A beam with an isosceles triangle cross section with base b and height h has

A moment of inertia of :a) hb 3 /48b) bh 3 /36c) bh 2 /24d) hb 2 /24

9. The maximum moment in a simple beam of span L subjected to a triangular

Load beginning at zero from the left support to a value at the right supportOccurs at a distance from the left support of :

a) 0.5 L b) 0.577 Lc) 0.667 Ld) 0.750 L

10. A mild steel column is hollow and circular in cross section with an external

Diameter of 350mm and internal diameter of 300mm. It carries a compressiveLoad of 2000 kN. The shortening of the column if its initial height is 5m andE = 200,000 MPa , is:

a) 78.4 N/mm 2 b) 0.00039c) 1.95mmd) nota


3/4

1 A simple beam of length L has a concentrated load of P at a distance a fromThe left support and b from the right support. The maximum moment in theBeam is :

a) Pa2

/L b) notac) Pa 2 /L2 d) Pab/L

1 This subject involved analytical methods for determining strength , stiffness(deformation characteristics) , and stability of the various members in astructural system:

i. mechanics of materialsii. strength of materials

iii. mechanics of deformable bodiesa) one of the three

b) two of the threec) none of the threed) all of the three

1 A simple beam has a span of 5m. The maximum moment in the beam is 69

kN-m . The allowable bending stress is 138 MPa. The required sectionmodulus is:

a) 2.0 x 10 3 mm 3 b) 9.522 x 10 6 mm 3 c) 250 x 10 3 mm 3 d) 500 x 10 3 mm 3

1 A simply supported beam with a span of 6m carries a vertical load thatIncreases uniformly from zero at the left end to a maximum value of 9kN/m. at the right end. The larger reaction occurs at the right and has aValue in kN of:

a) 27 b) 18c) 4.5d) 9

1 The shear force Vx at a section x of a cantilever beam of length LWith a uniform load w is Vx = w (L-x) where x is the distanceOf the section from the fixed support . The bending moment at thatSection is:

a) - wL 2/2 c) -0.5 w (L-x) 2 b) -0.25wL 2 d) - wx 2 /4


4/4

c)

strength of materials problems

Documents