Objective of the experiment:
1 - Study the relationship between the force (P) and
elongation (ΔL).
2 - Stability and study the relationship between strain (ε)
and stress (σ).
3 - Study the concept of the mechanical properties of solids.
4 - Establish a modulus of elasticity (E)
This is a ppt which will give u a better understanding of fracture toughness of a material in short time. It also has great exposure to testing method that we do in our laboratory class in undergraduate courses. So good luck with slide.
In these slides, an important mechanical property of Materials, that is HARDNESS, is discussed along with the different procedures which are used for determination of Hardness value of a certain material.
I hope, you'll find it helpful...!
Tensile, Impact and Hardness Testing of Mild SteelGulfam Hussain
The main purpose of this report is to study the mechanical properties and
failure mode of mild steel. Three types of standard tests i.e. tensile test, impact
test, and hardness test were conducted on the standard specimens of mild steel.
From the tests, results were obtained; Tensile strength, Impact strength, and
hardness were calculated. It was observed that Tensile Strength, Impact Strength
and Hardness of MS specimen were 1450.833 N/mm², 29.5 J & 59.25 HRB.
In the material testing laboratory, a Charpy impact test was performed on three different types (hot,cold,and steel alloy)of steels testing each variety at four different temperatures (32°C(RT), 100°C,0°C and -22°C ). From results (shown below), we determined that the a transition is from ductile failures to brittle failures
This presentation is for mechanical engineering/ civil engineering students to help them understand the different type of destructive mechanical testing of materials. The tensile testing, hardness, impact test procedures are explained in detail.
Experiment 4 - Testing of Materials in Tension Object .docxSANSKAR20
Experiment 4 - Testing of Materials in Tension
Object: The object of this experiment is to measure the tensile properties of two polymeric
materials, steel and aluminum at a constant strain rate on the Tension testing machine.
Background: For structural applications of materials such as bridges, pressure vessels, ships,
and automobiles, the tensile properties of the metal material set the criteria for a safe design.
Polymeric materials are being used more and more in structural applications, particularly in
automobiles and pressure vessels. New applications emerge as designers become aware of
the differences in the properties of metals and polymers and take full advantage of them. The
analyses of structures using metals or plastics require that the data be available.
Stress-Strain: The tensile properties of a material are obtained by pulling a specimen of
known geometry apart at a fixed rate of straining until it breaks or stretches to the machines
limit. It is useful to define the load per unit area (stress) as a parameter rather than load to
avoid the confusion that would arise from the fact that the load and the change in length are
dependent on the cross-sectional area and original length of the specimen. The stress,
however, changes during the test for two reasons: the load increases and the cross-sectional
area decreases as the specimen gets longer.
Therefore, the stress can be calculated by two formulae which are distinguished as
engineering stress and true stress, respectively.
(1) = P/Ao= Engineering Stress (lbs/in
2 or psi)
P = load (lbs)
Ao= original cross-sectional area (in
2)
(2) T= P/Ai = True Stress
Ai = instantaneous cross-sectional area (in
2)
Likewise, the elongation is normalized per unit length of specimen and is called strain. The
strain may be based on the original length or the instantaneous length such that
(3) =(lf - lo)/ lo = l / lo = Engineering Strain, where
lf= final gage length (in)
lo= original gage length (in)
(4) T= ln ( li / lo ) = ln (1 +) = True Strain, where
li = instantaneous gage length (in)
ln = natural logarithm
For a small elongation the engineering strain is very close to the true strain when l=1.2 lo,
then = 0.2 and T= ln 1.2 = 0.182. The engineering stress is related to the true stress by
(5) T= (1 + )
The true stress would be 20% higher in the case above where the specimen is 20% longer
than the original length. As the relative elongation increases, the true strain will become
significantly less than the engineering strain while the true stress becomes much greater than
the engineering stress. When l= 4.0 lo then = 3.0 but the true strain =ln 4.0 = 1.39.
Therefore, the true strain is less than 1/2 of the engineering strain. The true stress (T) = (1+
3.0) = 4, or the true stress is 4 times the engineering stress.
Tensile Test Nom ...
In the material testing laboratory, Tensile test was done on a mild steel specimen as figure 4 to identify the young’s modulus, ultimate tensile strength, yield strength and percentage elongation. The results were as table 1
Objective of the experiment:
1 - Study the relationship between the force (P) and
elongation (ΔL).
2 - Stability and study the relationship between strain (ε)
and stress (σ).
3 - Study the concept of the mechanical properties of solids.
4 - Establish a modulus of elasticity (E)
This is a ppt which will give u a better understanding of fracture toughness of a material in short time. It also has great exposure to testing method that we do in our laboratory class in undergraduate courses. So good luck with slide.
In these slides, an important mechanical property of Materials, that is HARDNESS, is discussed along with the different procedures which are used for determination of Hardness value of a certain material.
I hope, you'll find it helpful...!
Tensile, Impact and Hardness Testing of Mild SteelGulfam Hussain
The main purpose of this report is to study the mechanical properties and
failure mode of mild steel. Three types of standard tests i.e. tensile test, impact
test, and hardness test were conducted on the standard specimens of mild steel.
From the tests, results were obtained; Tensile strength, Impact strength, and
hardness were calculated. It was observed that Tensile Strength, Impact Strength
and Hardness of MS specimen were 1450.833 N/mm², 29.5 J & 59.25 HRB.
In the material testing laboratory, a Charpy impact test was performed on three different types (hot,cold,and steel alloy)of steels testing each variety at four different temperatures (32°C(RT), 100°C,0°C and -22°C ). From results (shown below), we determined that the a transition is from ductile failures to brittle failures
This presentation is for mechanical engineering/ civil engineering students to help them understand the different type of destructive mechanical testing of materials. The tensile testing, hardness, impact test procedures are explained in detail.
Experiment 4 - Testing of Materials in Tension Object .docxSANSKAR20
Experiment 4 - Testing of Materials in Tension
Object: The object of this experiment is to measure the tensile properties of two polymeric
materials, steel and aluminum at a constant strain rate on the Tension testing machine.
Background: For structural applications of materials such as bridges, pressure vessels, ships,
and automobiles, the tensile properties of the metal material set the criteria for a safe design.
Polymeric materials are being used more and more in structural applications, particularly in
automobiles and pressure vessels. New applications emerge as designers become aware of
the differences in the properties of metals and polymers and take full advantage of them. The
analyses of structures using metals or plastics require that the data be available.
Stress-Strain: The tensile properties of a material are obtained by pulling a specimen of
known geometry apart at a fixed rate of straining until it breaks or stretches to the machines
limit. It is useful to define the load per unit area (stress) as a parameter rather than load to
avoid the confusion that would arise from the fact that the load and the change in length are
dependent on the cross-sectional area and original length of the specimen. The stress,
however, changes during the test for two reasons: the load increases and the cross-sectional
area decreases as the specimen gets longer.
Therefore, the stress can be calculated by two formulae which are distinguished as
engineering stress and true stress, respectively.
(1) = P/Ao= Engineering Stress (lbs/in
2 or psi)
P = load (lbs)
Ao= original cross-sectional area (in
2)
(2) T= P/Ai = True Stress
Ai = instantaneous cross-sectional area (in
2)
Likewise, the elongation is normalized per unit length of specimen and is called strain. The
strain may be based on the original length or the instantaneous length such that
(3) =(lf - lo)/ lo = l / lo = Engineering Strain, where
lf= final gage length (in)
lo= original gage length (in)
(4) T= ln ( li / lo ) = ln (1 +) = True Strain, where
li = instantaneous gage length (in)
ln = natural logarithm
For a small elongation the engineering strain is very close to the true strain when l=1.2 lo,
then = 0.2 and T= ln 1.2 = 0.182. The engineering stress is related to the true stress by
(5) T= (1 + )
The true stress would be 20% higher in the case above where the specimen is 20% longer
than the original length. As the relative elongation increases, the true strain will become
significantly less than the engineering strain while the true stress becomes much greater than
the engineering stress. When l= 4.0 lo then = 3.0 but the true strain =ln 4.0 = 1.39.
Therefore, the true strain is less than 1/2 of the engineering strain. The true stress (T) = (1+
3.0) = 4, or the true stress is 4 times the engineering stress.
Tensile Test Nom ...
In the material testing laboratory, Tensile test was done on a mild steel specimen as figure 4 to identify the young’s modulus, ultimate tensile strength, yield strength and percentage elongation. The results were as table 1
Page 6 of 8Engineering Materials ScienceMetals LabLEEDS .docxbunyansaturnina
Page 6 of 8Engineering Materials Science
Metals Lab
LEEDS BECKETT UNIVERSITY
SCHOOL OF THE BUILT ENVIRONMENT & ENGINEERING
Course: BSc (Hons) Civil Engineering BEng (Hons) Civil Engineering
HND Civil Engineering
Laboratory Experiment:
Stress-Strain Behaviour of Mild Steel and High Yield Steel bars.
Associated Module(s)
Level 4 Engineering Materials Science
Object of Experiment
To investigate the stress-strain behaviour of the above materials.
Theory/Analysis
A knowledge of the behaviour of structural steel under load is essential to ensure structural collapse does not occur and that serviceability requirements are achieved. In these respects the following mechanical properties of a material are required:-
1. The yield stress, σy (or 0.2% proof stress)
2. The Elastic (or Young’s) Modulus, E
3. The maximum tensile strength, σmax
4. The stress at failure, ie the fracture stress, σf
5. The % elongation at failure
Apparatus
1. 500kN Denison Testing Machine
2. Extensometer and Denison extension gauge (measures cross head movement)
3. Grade 250 plain round mild steel bar, 20mm diameter
Characteristic strength = 250 N/mm²
Conforms to BS 4449.
4. Grade 460 deformed high yield steel.
Reinforcing bar, T16, 16mm diameter.
Characteristic strength = 460 N/mm²
Conforms to BS 4449.
Method
Each of the bars in turn is placed in the jaws of the testing machine.
The 50mm extensometer is attached to the bar and zeroed.
Load is applied and recorded in increments up to failure. For each load increment, extension readings from the extensometer and the Denison extension gauge are noted.
At the yield point, the extensometer is removed to prevent damage to it and readings continue on the Denison extension gauge.
The load at failure and the manner of failure are noted.
See the Figure below showing the Test Setup.
(
L
G
values; L
G
= 100 mm for the plain
round
bar, and L
G
= 80 mm for the deformed
high yield
bar
) (
L
G
,
gauge length of the samples
) (
P = the tensile force applied to bars from Dennison testing machine
) (
P
) (
Extension of the sample bars is measured by:
the
Dennison (on-board) extension gauge which monitors cross-head
movement
. This effectively gives sample extension readings from the start of the test (P = 0) through to failure.
An extensometer gauge. This is accurate only over the initial linear-elastic phase of the test.
) (
P
)
Each student should prepare and submit a laboratory report, the results and discussion sections are outlined below:a) Results and Calculations
Readings of load (P), against extension (e), have been recorded for each specimen tested and provided to you (appended at the end of this laboratory briefing document).
Knowing the original bar diameters (d), load data can converted to stress (σ) by dividing each load reading by the appropriate cross sectional area.
Strain values are determined by dividing the extension (e) data by the appropriate gauge length for each bar (LG); the g.
Tensile testing is one method routinely used to determine the mechanical properties of plastics. This piece presents an example of measuring the mechanical properties of acrylonitrile butadiene styrene (ABS), Polyoxymethylene (POM), Polyethylene terephthalate (PET) and polystyrene (PS)
Explore the innovative world of trenchless pipe repair with our comprehensive guide, "The Benefits and Techniques of Trenchless Pipe Repair." This document delves into the modern methods of repairing underground pipes without the need for extensive excavation, highlighting the numerous advantages and the latest techniques used in the industry.
Learn about the cost savings, reduced environmental impact, and minimal disruption associated with trenchless technology. Discover detailed explanations of popular techniques such as pipe bursting, cured-in-place pipe (CIPP) lining, and directional drilling. Understand how these methods can be applied to various types of infrastructure, from residential plumbing to large-scale municipal systems.
Ideal for homeowners, contractors, engineers, and anyone interested in modern plumbing solutions, this guide provides valuable insights into why trenchless pipe repair is becoming the preferred choice for pipe rehabilitation. Stay informed about the latest advancements and best practices in the field.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
About
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Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
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Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
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1. 1
TENSILE TEST M.MANOGO
AIM
The aim of a tensile test is to determine some certain material properties like yield
strength, modulus of elasticity, ultimate tensile strength, elongation till fracture and
reduction in area of the specimen after it has been deformed.
Tension tests provide information on the ductility and strength of materials under
uniaxial tensile stress. The test is performed at room temperature (10°C - 38°C). The
measurement of the ductility of a material is simply the reduction of area and we
acquire that after the specimen has been deformed.
The test is going to produce the stress-strain relationship and explain how the
material properties make up the curve, like the yield point as the point where strain
increases and the material experiences some amount of permanent deformation and
the point where the curve begins to fall, the material’s ultimate tensile strength has
been reached. This point is the maximum stress that can be applied to a material
under tension before failure (reference). See figure 1.
TEST SAMPLE
The sample must be the ASTM E8/E8M flat metal alloy specimen with a width of
12.5mm and gauge length of 50mm.
2. 2
APPARATUS
TENSILE TESTING MACHINE
The tensile is performed using an 8801 Instron testing machine. The machine has
proper capabilities to test the flat specimen. The machine has four main parameters:
force capacity, speed, precision and accuracy. Force capacity refers to the fact that
the machine must generate enough force to fracture the specimen.
The machine has the capabilities to properly align the specimen before the test
begins. Alignment for the specimen is critical, if the specimen is misalignment, the
machine will apply a bending force, this is bad for brittle materials because the results
will be skewed. (reference).
EXTENSOMETER
An extensometer measures the test specimen elongation to characterize strain. Using
the strain and the effective stress you can calculate the modulus of elasticity. The
extensometer has a specific software that enables it to record data.
VERNIER CALIPER
An instrument that can be used to measure internal and external distances extremely
accurately. Its scale has an accuracy of 0.01mm. It is used to measure dimeters and
length of the specimen.
SPECIMEN
An ASTM E8/E8M flat type specimen with a 50mm gauge length.
TEST PROCEDURE
Measure each specimen with Vernier callipers to determine the initial cross-sectional
area and average diameter. Then mark the specimens gauge length so that the
distance between the two marks could be measured after. (reference).
Make sure the extensometer and the computer are on the same required method
for the procedure, put it in settings then zero the load cell.
Install the specimen into the grip and make sure the crosshead is in a suitable
position so that the specimen can fit between the jaws. Attach the extensometer,
manually zero the force and extension on the keypad. Set the test settings so that the
extensometer stops at 5mm extension then test the specimen. Do not make any
adjustments when the test is running.
When the specimen fractures the machine will automatically stop, take the
specimen and measure the final gauge length, width and thickness. Take readings
from screen then save your results.
3. 3
SAFETY MEASURES
The ASTM E8/E5M standard have a lot of safety precautions. Here are some
precautions:
The grips of the testing machine must be serrated so that there is no slippage
of the specimen.
If the specimen breaks due to any reason other than the tensile stress, the
results should be discarded, and a new test should be performed on a new
specimen.
The misalignment of the specimen should not be allowed.
Thickness of the specimen should be according to the related standard.
Safety boots should always be worn.
RESULTS
MATERIAL IDENTFICATION: Steel
Sample Identification
ASTM E8M
Flat
specimen
Data
Specimen details before testing
Width mm 12.51 +- 0.01
Thickness mm 2.95 +- 0.01
Cross sectional Area mm2 36.90
Gauge length to be marked on specimen mm 50 +- 0.01
Specimen details after testing
Final Gauge Length mm 54.97
Width (final) mm 10.77
Thickness (final) mm 2.01
Final Area mm2 21.61
Comments: The width and thickness of the specimen
decreases as the test proceeds, this causes the
cross
sectional area to also decrease. The gauge length
increases.
5. 5
(The Engineering Stress versus Strain relationship for
determining the 0.2% proof stress.)
0
100000000
200000000
300000000
400000000
500000000
600000000
700000000
800000000
0 0,005 0,01 0,015 0,02 0,025 0,03 0,035
Tensilestress
Tensile strain
Engineering stress vs strain graph
6. 6
Description of tests: Tensile data and calculated results
MATERIAL: STEEL
Date: 09:54:16
Sample Identification
Ultimate Tensile Stress MPa
= 24870
36.90
= 673.98
Proportional limit MPa
Yield Stress MPa
= 427.61
0.2% Proof Stress MPa 655.35
Fracture Stress MPa 500.01
%-Elongation %
%Elongation
= 54,97 – 50 x 100
50
= 9.94 %
%-Reduction in area %
%Reduction in area
= 31.90 – 21.61 x 100
31.90
= 32.26 %
7. 7
Modules of Elasticity GPa = 213.80
Modules of Resilience MJ/m3
= (427.61)^2
2(213803.03)
= 0.43
Modules of Toughness MJ/m3
=
= ½ stress x strain
= ½ (673872314.5) x (0.0291)
=9804842.18
=9.80
DISCUSSION
The tensile test determines mechanical properties of a material. The properties
determined in this test are ultimate tensile strength, yield stress, elongation, and
reduction in area. The properties were calculated in the table above.
The results obtained from the test and the ones calculated shows that the
specimen undergoes ductile fracture. The reduction in areas and the modulus of
toughness shows that the steel used is ductile, a material with high ductility and high
strength will have more toughness and a material with low ductility and low strength
will have low toughness. The material elongated between the onset of yield and
eventually fractured at some point while under tensile load.
Two methods are used to measure ductility:
Reduction in area of fractured region
8. 8
Percentage elongation after fracture
Where:
Ao – Initial cross – sectional area of the tensile specimen
Af – Final cross – sectional area of the tensile specimen
Li – Initial gauge length of the tensile specimen
Lf – Final gauge length of the tensile specimen
On the test the reduction in area was 32.26% while the percentage increase in length
was 9.94%. The shape of the tensile specimen plays a major role in the determination
of its ductility.
The trend portrays a linear elastic behaviour up to the proportional limit. The amount
of tensile stress applied before plastic deformation (yield point) produces below 0.005
of tensile strain.
The yield strength must be calculated from 0.2% strain. An intersection between the
0.2% offset line and the stress – strain curve represents the yield strength at 0.2%
offset line. The line intercepting the 0.2% offset line and the stress – strain curve must
be drawn from 0.2% strain parallel the slope of the stress – strain curve intercepting
at the yield point. The yield strength values have to be replaced by the ultimate tensile
strength values for safety in engineering designs.
In engineering safety, we look at a few considerations:
The consequences of failed structures
Estimation of deterioration
The accuracy of the loads used in the components and structure
Comparison of an already existing labelled stress – strain curve and the one obtained
in the experiment.
Tensile tests are used to asses quality of materials manufactured all around the world.
The test is extremely important and essential to perform to measure the quality of
materials under tension forces. The test determines the strength of various metals.
10. 10
REFERENCES
Clausin, D. P., 1966. The Tensile Fracture of Mild Steel, California: Carlifonia
Institute of Technology.
COLLINS, D., 2019. Linear Motiontips. [Online]
Available at: http://www.linearmotiontips.com
[Accessed 19 april 2020].
Commitee, A., 2016. Standard Test Methods for Tension Testing of Metallic
Metarials, West Coshohoken: ASTM International.
Davis, J. R., 2004. Tensile testing. 2nd ed. Ohio: ASM International.
Hibbeler, R. C., 2011. Mechanics of materials. 8th ed. New York: Cloth.
Spiret, M., 2019. How to perfom a tension strength test on metals according to
ASTM
E8/E8M. The definitive guide to ASTM E8/E8M tension testing of metals, iii(11), p.
90.
Spiret, M., 2020. INSTRON. [Online]
Available at: http://www.instron.com
[Accessed 21 APRIL 2020].
Wikipedia, 2019. wikipedia. [Online]
Available at: http://www.wikipedia.com
[Accessed 26 April 2020].
