2026
GABORONE INSTITUTE OF PROFESSIONAL STUDIES
AUTOMOTIVE ENGINEERING DEPARTMENT
TUTORIAL SHEET 1
MODULE
CODE
: STRENGTH OF MATERIALS
: SM
LECTRURER
: ENG. SEDANGE
Question 1
a) Distinguish the difference between Material Science and Material Engineering. Outline their
importance to the automotive industry.
[ 8 marks]
b) Define the following terms:
i.
Material.
[2marks]
ii.
Strength.
[2marks]
iii.
Load.
[2marks]
c) Sketch diagrams to show the three (3) main types of loading common in the study of strength of
materials.
[6marks]
d) Illustrate the difference between bending and torsion forces when applied on a circular bar.
[6marks]
e) Demonstrated the following type of loading :
i.
Transverse loading.
[2marks]
ii.
Radial loading.
[2marks]
f) Define the following terms :
i.
Stiffness.
[2mark]
ii.
Ductility.
[2mark]
iii.
Malleability.
[2mark]
iv.
Hardness.
[2mark]
v.
Plastic deformation.
[2mark]
vi.
Toughness.
[2marks]
vii.
Brittleness.
[2marks]
g) Briefly explain the following properties of materials, where applicable give automotive
examples:
i. Mechanical properties.
[5marks]
ii. Thermal properties.
[5marks]
iii. Optical properties.
[5marks]
iv. Chemical properties.
[5marks]
v. Magnetic properties.
[5marks]
vi. Electric properties.
[5marks]
h) Consider material selection and the material classification of ten (10) typical automotive parts/
components. Briefly describe and explain their application based on the properties physical,
mechanical and thermal of materials etc.
[12marks]
i) Discuss briefly how each of the following influences material application:
i.
Material Structure.
[5marks]
ii.
Material properties.
[5marks]
iii.
Material Processing.
[5marks]
Question 2
a) Define and write an equation expression the following terms:
i. Stress.
ii. Strain.
b) State hook’s law.
c) Differentiate between Elasticity and Plasticity .
[3marks]
[3marks]
[2marks]
[4 marks]
d) Use a clear graph diagram to express and explain the relationship between stress and strain of a
material undergoing a tensile force as shown by the figure below .
[10marks]
e) A rectangular bar having a cross-sectional area of 75 mm2 has a tensile force of 15 kN applied
to it. Calculate the stress in the bar.
f) A circular wire has a tensile force of 60.0 N applied to it and this force produces a stress of 3.06
MPa in the wire. Calculate the diameter of the wire.
[4marks]
g) A rectangular bar having a cross-sectional area of 75 mm2 has a tensile force of 15 kN applied
to it. Calculate the stress in the bar.
h) A pipe has an outside diameter of 25 mm, an inside diameter of 15 mm and length 0.40 m and it
supports a compressive load of 40 kN. The pipe shortens by 0.5 mm when the load is applied.
Determine;
i.
The compressive stress.
[4marks]
ii.
The compressive strain in the pipe when supporting this load.
[4marks]
i)
Determine the stress in each section of the bar shown in Figure below when subjected to an axial
tensile load of 20 kN. The central section is 30 mm square cross-section; the other portions are
of circular section; their diameters being indicated. What will be the total extension of the bar?
For the bar material E = 210GN/𝑚2 . NB all dimension is given in milli-meters.
j)
A concrete pillar, which is reinforced with steel rods, supports a compressive axial load of 2
MN. Determine stresses σ1 and σ2 given the following:
[5marks]
For the steel, A1 = 4 × 10−3 m2 and E1 = 2 × 1011 N/m2
For the concrete, A2 = 0.2 m2 and E2 = 2 × 1010 N/m2
Question 3
a) Define the coefficient of linear expansion of materials.
[2marks]
b) Give two (2) examples and discuss the application of the thermal expansion principle in the
automotive industry.
[10marks]
c) The length of an iron steam pipe is 20.0 m at a temperature of 18°C. Determine the length of the
pipe under working conditions when the temperature is 300°C. Assume the coefficient of linear
expansion of iron is 12 × 10–6 K–1.
[5marks]
d) Illustrate the difference between thermal stress and thermal strain.
[6marks]
e) What is a compound bar and state two (2) Advantage and two (2) Applications of
Compound bars.
[5marks]
0
f) A rod is 2m long at a temperature of 10 𝐶. Find the expansion of the rod when the
temperature is raised to 800 𝐶 . if this expansion is prevented. Find the stress induced in the
material of the rod. Take E= 1.0x105 𝑀𝑁/𝑚2 and 𝛼= 0.000012 per degree centigrade.
[5marks]
g) A steel rod of 3m diameter and 5m long connected to two grips and the rod is maintained
at a temperature of 950 𝐶. Determine the stress and pull extension when the temperature falls to
300 𝐶.
[5marks]
h) A rod consists of two parts that are made of steel and copper as shown in figure below.
The elastic modulus and coefficient of thermal expansion for steel are 200 GPa and 11.7 x10−66
per 𝑂 𝐶respectively and for copper 70 GPa and 21.6 x 10−6 per 0C respectively. If the
temperature of the rod is raised by 500C, determine the:
i.
ii.
Type of Forces the rod will experience.
Stresses acting on the rod.
Bonus Solved examples SECTION A
Use the following table for qns 1-4 SA
Bonus Solved examples SECTION B
Bonus Solved examples SECTION C