LAB REPORT
Course Name:
MCLE 270 – Materials Laboratory
Lab Title:
Tensile Strength Test
Prepared by:
MOHAMMAD KHALID AHMED IBRAHIM – 22316890
Department: Mechanical Engineering
Faculty: Faculty of Engineering
University: Cyprus International University
Instructor/Lab Assistant: BERKE EYYAMOGLU
Semester: Spring 2025–2026
1. Introduction
Tensile testing is one of the most important mechanical tests used to determine the mechanical
behavior of materials under axial tensile loading. The experiment provides information about the
strength and deformation characteristics of a material when subjected to increasing tensile force until
fracture occurs. The engineering stress–strain curve obtained from the test helps identify important
mechanical properties such as Young’s modulus, yield strength, ultimate tensile strength (UTS), ductility,
and fracture strength.
In this experiment, a steel specimen was tested using a Universal Testing Machine (UTM). Since no
extensometer was used, the strain values were calculated from the crosshead displacement recorded by
the testing machine. The aim of the experiment was to analyze the engineering stress–strain behavior
of the steel specimen and determine its important mechanical properties.
2. Materials / Apparatus
The following equipment was used during the experiment:
• Universal Testing Machine (UTM)
• Load cell for force measurement
• Crosshead displacement measurement system
• Computer with data acquisition software
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• Vernier caliper for specimen dimensions
• Steel tensile specimen
Specimen dimensions:
• Diameter = 10 mm
• Initial gauge length (L₀) = 300 mm
3. Procedure
1. The diameter and initial gauge length of the steel specimen were measured before the
experiment.
2. The specimen was fixed securely between the grips of the Universal Testing Machine.
3. The testing parameters and loading rate were adjusted using the machine software.
4. A tensile load was gradually applied to the specimen.
5. During the test, force and displacement data were continuously recorded by the computer
system.
6. The specimen elongated as the tensile force increased.
7. The test continued until necking and final fracture occurred.
8. The recorded data were exported to Excel.
9. Engineering stress and engineering strain values were calculated using:
10. Engineering Stress:
σ = F / A₀
• Engineering Strain:
ε = ΔL / L₀
where:
• F = Applied force (N)
• A₀ = Original cross-sectional area (mm²)
• ΔL = Change in length (mm)
• L₀ = Initial gauge length (mm)
• The engineering stress–strain graph was plotted in Excel.
• Important regions and mechanical properties were identified from the graph.
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4. Results and Discussion
4.1 Data Analysis
The original diameter of the specimen was 10 mm.
Cross-sectional area:
A₀ = πd² / 4
A₀ = π(10²) / 4
A₀ = 78.54 mm²
Engineering stress was calculated using:
σ = F / 78.54
Engineering strain was calculated using:
ε = Distance / 300
The experimental data were processed in Excel to generate the engineering stress–strain curve.
4.2 Engineering Stress–Strain Curve
The engineering stress–strain curve was generated using the experimental data from Excel.
The graph contains the following regions and points:
• Elastic region
• Yield point
• Plastic region
• Ultimate Tensile Strength (UTS)
• Fracture point
Observations from the Graph
• In the elastic region, stress and strain increased linearly according to Hooke’s Law.
• After the yield point, the material entered the plastic region where permanent deformation
occurred.
• The stress continued increasing until the Ultimate Tensile Strength (UTS) was reached.
• After the UTS point, necking started and the stress decreased until fracture occurred.
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4.3 Mechanical Properties
Property
Value
Unit
Young’s Modulus (E)
≈ 44 GPa
GPa
Yield Strength
≈ 420 MPa
MPa
Ultimate Tensile Strength (UTS)
≈ 565 MPa
MPa
Fracture Strength
≈ 565 MPa
MPa
4.4 Discussion
The material behaved as expected for a ductile steel specimen. At the beginning of the test, the
specimen showed elastic behavior where deformation was reversible and stress was proportional to
strain. After reaching the yield point, the material entered the plastic region and permanent
deformation occurred.
The stress continued increasing until the Ultimate Tensile Strength (UTS) was reached at approximately
565 MPa. Beyond this point, necking began, causing a reduction in the cross-sectional area of the
specimen. Finally, fracture occurred after significant plastic deformation.
The obtained results are generally consistent with the expected behavior of structural steel materials.
Small differences between experimental and theoretical values may be caused by several factors,
including:
• Crosshead displacement measurement instead of extensometer measurement
• Machine compliance
• Slight slipping at the grips
• Human errors during setup and measurement
• Calibration limitations of the testing machine
Because no extensometer was used, the strain values may be slightly higher than the actual material
strain, especially in the elastic region. This also affects the calculated Young’s modulus.
Tensile testing is very important in engineering because it helps engineers understand material
behavior under loading conditions. The obtained properties are used in material selection, structural
design, and safety analysis in mechanical and civil engineering applications.
5. Conclusion
In this experiment, a tensile test was performed on a steel specimen using a Universal Testing Machine.
The engineering stress–strain curve was successfully obtained using experimental force and
displacement data.
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Important mechanical properties such as Young’s modulus, yield strength, Ultimate Tensile Strength
(UTS), and fracture strength were determined from the graph. The material showed typical ductile
behavior with clear elastic and plastic deformation regions.
The experiment also demonstrated the importance of tensile testing in evaluating material
performance and understanding how materials behave under tensile loading conditions.
6. References
1. MCLE 270 Laboratory Manual – Tensile Strength Test.
2. Callister, W. D., Materials Science and Engineering: An Introduction.
3. ASTM E8 Standard Test Methods for Tension Testing of Metallic Materials.
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