The objective of this course is to provide a basic overview of failure analysis. It will include discussion of failure mechanisms, analytical techniques and case histories
• To provide you with a clear understanding of terms used so that you can ask the right questions and interpret common observations with ease
Types of failures
Failure modes
How to conduct failure analysis
Analyze data
Failure mechanism
Prevention of Failures
Failures examples
One of the welding processes that used in Engineering field is the brazing. Soldering is similar to the brazing but there are several differences.
Thanks for the colleagues who give this slides to publish.
The objective of this course is to provide a basic overview of failure analysis. It will include discussion of failure mechanisms, analytical techniques and case histories
• To provide you with a clear understanding of terms used so that you can ask the right questions and interpret common observations with ease
Types of failures
Failure modes
How to conduct failure analysis
Analyze data
Failure mechanism
Prevention of Failures
Failures examples
One of the welding processes that used in Engineering field is the brazing. Soldering is similar to the brazing but there are several differences.
Thanks for the colleagues who give this slides to publish.
You’ve worked hard to define, develop and execute a performance test on a new application to determine its behavior under load. You have barrels full of numbers. What’s next? The answer is definitely not to generate and send a canned report from your testing tool. Results interpretation and reporting is where a performance tester earns their stripes.
In the first half of this workshop we’ll start by looking at some results from actual projects and together puzzle out the essential message in each. This will be a highly interactive session where we will display a graph, provide a little context, and ask “what do you see here?” We will form hypotheses, draw tentative conclusions, determine what further information we need to confirm them, and identify key target graphs that give us the best insight on system performance and bottlenecks.
In the second half of this session, we’ll try to codify the analytic steps we went through in the first session, and consider a CAVIAR approach for collecting and evaluating test results: Collecting, Aggregating, Visualizing, Interpreting, Analyzing, And Reporting.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
The installation of Helical Confinement in the Compression Zone of reinforced High Strength Concrete beams is also investigated in this study. Helical Confinement is more effective than the rectangular ties, Compression Longitudinal reinforcement and steel fibers in increasing the strength and ductility of Confined Concrete. A total number of 3 Specimens were casted. The Pitch distance for helical confinement of two specimens is 50mm, 60mm and the Pitch distance for normal confinement is 50mm. The Specimen is of a size of 600mm X 300mm X 300mm. It contains of 8 mm dia bar as longitudinal reinforcement and 6mm dia bar as transverse reinforcement. M 40 and Fe 500 Grade steels were used. After 28 Days of Curing. The Specimens were taken out and allowed to dry and tested under universal testing machine of capacity 1000 KN. The Effect of Yield strength ductility, were studied from Stress – Strain and Load – Displacement Curves. This Study Concluded the Helical Reinforcement is an effective method for increasing the Strength and Ductility of Reinforcement High Strength Concrete Beam.
surface characteristics and electrochemical impedance investigation of spark-...mohammad fazel
In this study, the surface characteristic of oxide films on Ti-6Al-4V alloy formed by an anodic oxidation treatment at potentials higher than the breakdown voltage was evaluated.
Comparison of Fatigue Characteristic for AISI 1039 Steel with Surface Treatmentijceronline
Wear and fatigue resistance in steel components used in various industries can be improved by surface treatments. Coatings systems which are used for improving the mechanical properties, generally, decreased the components fatigue life due to micro cracks, that propagate through the substrate , it is possible to improve the fatigue resistance of a component by the application of shot peening treatment, whose compressive residual stresses delay or eliminate the initiation and propagation of fatigue cracks. The aim of this study is to obtain the fatigue limit of untreated, shot peened, and hard chromium coating of medium carbon steel AISI 1039 and comparison between them. Fatigue tests were carried out using small samples with 4 mm diameter, with hard chromium layer of (47.1) µm thick. Rotating-bending fatigue test was carried out on samples after shot peening with steel balls of about 20 minutes peening time. Experimental results showed that hard chromium electroplating decreased the fatigue life and fatigue limit in comparison with the uncoated steel. As the highest thickness for coating was 23µm. On the other hand, Shot peening Results indicated that the fatigue strengths of samples are increased and the highest fatigue limit was (298.566Mpa) after treated the samples by shot peening for 20 minutes.
Comparative Study on Anchorage in Reinforced Concrete Using Codes of Practice...IJERA Editor
The evaluations of anchorage strength of bars in reinforced concrete are varied in codes of practice and
equations by researchers on the base of their approaches and philosophies.
This paper (Part I) aims to have a comparative study between the predictions by codes of practice of BS8110
and EC2 and those equations by Darwin et al, Morita and Fuji, Batayneh and Nielsen and results of 164 tests
from literature.
In this part the case of straight anchorage bars without transverse pressure is considered. Some major parameters
including compressive strength, and in terms of ratio of concrete cover to bar diameter and ratio of anchorage
length to bar diameter , are addressed in detail.
Although various parameters are involved in anchorage design equations, it is observed that every code has
merit over the other codes in some aspect. The presented discussion highlights the major areas of differences
which need attentions in the future for more investigations.
The main conclusion has been presented in part II to include the study of straight anchorages with transverse
pressure. The conclusions should cover the both cases to obtain the fair assessments for bond strength by those
expressions used in this study.
Experimental Behavior of RC Beams Strengthened by Externally Bonded CFRP with...IJERDJOURNAL
Abstract:- Carbon fiber-reinforced polymers (CFRP) laminates, or plates, offer very high-strength potential; however, handling of long pieces of these flexible plates can present challenges under field conditions. The development of methods for splicing CFRP plates will enhance the versatility and Practicality of using these materials in field applications. This paper studies the efficiency of CFRP lap splice in externally bonded CFRP flexural strengthened reinforced concrete beams. Seven half-scale beams with different conditions were tested in two-point bending until failure. Two groups were tested; the first one includes control specimens: the first without CFRP strengthening, the second strengthened with full length and without splice, and the third with cutoff at middle of the beam. All specimens in the second group having cut-off at the middle and with lap splice lengths equal 300, 450, 600, 900 mm. respectively on each side of the cut-off. The study illustrates the effect of confinement on the first crack load, failure load, mid-span deflection, and strain in both reinforcement and CFRP. The failure load was also predicted analytically by CEB-FIP (1993), adopting the traditional sectional analysis for strain compatibility. Instead of strain measuring, three accurate bond-slip models are used to provide accurate prediction for the contribution of CFRP in the flexural capacity of the strengthened beam since all strengthened beams are failed by interfacial debonding of CFRP.
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
Similar to Fracture Mechanics & Failure Analysis:Lectures Fractrography (20)
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Introduction to AI for Nonprofits with Tapp NetworkTechSoup
Dive into the world of AI! Experts Jon Hill and Tareq Monaur will guide you through AI's role in enhancing nonprofit websites and basic marketing strategies, making it easy to understand and apply.
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
1. Fractrography
The word fractography origin from the Latin word fractus, meaning
fracture, and graphy derives from the Greek term grapho, meaning
descriptive treatment.
“The science of studying the fracture surface is termed as
fractography”.
Thus, depending on the level of examination, one can have
macrofractography and microfractography.
1) Macroscopic examination
Macroscopic examination is carried out with unaided eye or a simple
handheld magnifier, or a stereomicroscope with low magnification (up
to 50X).
In the stereo microscope, reasonably large specimens can be handled,
and the microscope can easily be adopted for examination of
components in the field or accident site.
The features revealed during macroscopic examination are:
i. Type of fracture
ii. Origin of fracture
iii. Presence of secondary cracks
iv. Presence of external debris or corrosion products
v. Discoloration
vi. Presence of wear marks in the vicinity of fracture
vii. Plastic deformation preceding fracture
viii. Dimensional changes in the component
ix. Evidence of any overheating
x. Post-fracture damage such as rub marks
2. Example:
Macrofractography of ductile tensile sample:
A ductile tensile fracture in a component of circular cross section consists of
three distinct zones as shown in the figure.
1. The inner flat/fibrous zone with a fibrous appearance is where the
fracture starts and grows slowly.
2. The fracture propagates fast along the intermediate radial zone. The
radial lines extended backward point to the fracture origin. Sometimes
the radial lines start from the origin itself.
3. The fracture finally terminates at the shear lip zone that is the annular
region near the periphery of the fracture surface. The shear lip zone is
at an angle of 45° to the tensile stress direction.
3. Fig. 166 "Cup and cone" tensile fracture of cylindrical test specimen is
typical for ductile metals; annealed AISI 1035. Fracture originates near the
center of the section with multiple cracks that join and spread outward.
When cracks reaches a region near the surface, the stress state changes
from tension to macro shear, forming a fracture at approximately 45° to the
plane of the major fracture--the familiar "shear lip." (D.J. Wulpi, Consultant)
Example: Macrofractography of Brittle sample:
Figure: Fast, unstable crack propagation may sometimes be manifested as
a series of chevron marks on the fracture surface
4. Example:
Four fatigue-fracture surfaces that were produced in bending in the
laboratory with the use of assorted notches to simulate service conditions;
the material is AISI W1 tool steel. All at 2×
The specimen in Fig. 760, which was tested without a notch and
fractured after 432,000 cycles at 365 MPa (53 ksi), shows two cracks
origins at opposite corners where bending was maximum.
The specimen in Fig. 761 had a single notch at top and broke after
20,500 cycles at 434 MPa (63 ksi); note the small shear lip around the
region of fast fracture at bottom.
The specimen in Fig. 762 was notched at two corners that were along
an axis not in the plane of bending and broke after 50,000 cycles at
338 MPa (49 ksi); the two resulting fatigue cracks therefore had
somewhat distorted shapes.
The specimen in Fig. 763 was notched at four sites--two in the bending
plane and two in a plane 60° from it--and broke after 10,260 cycles at
434 MPa (63 ksi). The four notches produced fatigue zones, which
formed two major crack fronts that nearly penetrated the section.
5. 2) Microscopic Examination / Microfractography
The information thus gathered at the macroscopic level has to be
integrated with the observations on detailed examination at the
microscopic level so that meaningful conclusions can be drawn regarding
the cause of failure.
Microscopic examination is carried out using optical microscopes and
electron microscopes, the choice dictated by the magnification and
resolution desired.
Microscopic examination is carried out on the fracture surface to study
the fracture features and also on a section transverse to the fracture
surface to study the internal structure of the material.
The latter is a destructive test and should be carried out only at the end
after recording all the microfractographic features.
The additional information one can obtain through microscopy includes:
Microstructure of the material through metallography
Path of fracture
Mode of fracture
Length of the crack that pre-existed and propagated by fatigue
Length of the fatigue crack before it became critical
Presence of inclusions, pits, or other flaws at the origin
Striation spacing of the fatigue crack
Presence of corrosion products
6. The fracture surfaces are generally rough and cannot be easily studied
entirely by an optical microscope because of its limited depth of focus
and resolution.
For microfractography, instruments with better depth of focus and
resolution are necessary. These requirements are met by the electron
microscope of which there are two types:
The scanning electron microscope (SEM)
The transmission electron microscope (TEM)
7. Possible combinations of mating dimple shapes resulting from
different stress states, which cause the crack tip to deform by various
modes
10. Example 3:
Fig. 17 Surface of tensile-test fracture in specimen of low-carbon, high-
oxygen iron that was broken at room temperature. Many of the equiaxed
dimples contain spheroidal particles of FeO. The rectangle marks the area
shown at higher magnification in Fig. 18 and 19. SEM, 500×
Fig. 18 Enlargement of the area within the rectangle in Fig. 17, showing the
surface contours of the dimple cavities of the very ductile fracture. Dimly
visible in the central dimple is a globular particle of FeO; the particle is
shown more clearly in Fig. 19. SEM, 2400×
11. Example-4: Stereo pair of scanning electron microscope fractographs of the
surface of a tensile-test fracture obtained at room temperature
The alloy was a low-carbon iron to which an appreciable amount of Fe2O3
had been added to form an aggregate of FeO inclusions. The dimples that
are characteristics of ductile rupture are evident here, and many of these
dimples contain one or more globular oxide inclusions that are readily
apparent. There appear to be two sizes of these oxide inclusions--some
being about 6 μm in diameter and other about 3 μm in diameter. Unlike
many inclusions displayed in other fractographs, which have relatively
smooth, unbroken contours several of the particles shown here possess
sizable surface defects. Some of these defects may be exposed internal
shrinkage cavities. The surfaces of the dimples show contours that vaguely
resemble fatigue-striation marks. The differences in topographic contours of
the dimples displayed in this stereo pair of fractographs can be appreciated
by viewing the fractographs stereographically, which provides a three
dimensional effect. It then becomes apparent that the dimples are chimney
like cavities with nearly vertical walls in many instances and with bottoms at
great depth that appear black and without detail. The FeO inclusions appear
to cling to the cavity walls, many at a point part way to the bottom of the
"chimney." Most of the separating walls between adjacent chimneys are
extremely thin, which makes it surprising that these walls did not rupture at
a point closer to the bottom of the chimney. 1200×
12. Example- 5: Sequence of SEM fractographs:
Sequence of SEM fractographs, at increasing magnifications (80×, 950×,
and 5000×, respectively), that show a fracture in an iron alloy containing
0.14% S and 0.04% O. The fracture was obtained by bending at room
temperature. Several spheroidal oxide inclusions are visible, most of them
having diameters in the range of 1 to 3 μm. The rectangle in Fig. 6 indicates
the area that is shown at higher magnification in Fig. 7, and the rectangle in
Fig. 7 indicates the area that is shown at still higher magnification in Fig. 8.
The 6-μm-diam oxysulfide particle in Fig. 8 shows a shrinkage cavity plus a
white spot from an electron beam impingement in fluorescent x-ray analysis.
It is quite evident that, during the process of microvoid coalescence, the iron
matrix has become detached from the globular inclusions at the metal-to-
oxide and metal-to-sulfide interfaces, leaving these inclusions unaffected by
the applied stresses and severe deformation taking place around them.
14. Example- 7: Sequence of SEM fractographs:
Fig. 14 Intergranular fracture that was generated in a specimen of oxygen-
embrittled Armco iron by a Charpy impact test at room temperature. The
grain features appear sharp and clean. Note the secondary cracks, which
follow grain boundaries. See also Fig. 15 and 16 for views of other regions
of this fracture. SEM, 55×
Fig. 15 View of another region of the surface of the impact fracture shown in
Fig. 14, showing facets that resulted from a combination of intergranular
rupture and transcrystalline cleavage. Note the array of small river patterns
at the bottom edge of the large facet at center. See also Fig. 16. SEM, 655×
Fig. 16 View of a third region of the surface of the impact fracture shown in
Fig. 14 and 15. Note the almost perfect grain-boundary surfaces and the
sharp edges and points at which the separated-grain facets meet. The
secondary cracks are equally clean separations. SEM, 670×
15. Example-8:
Fracture of SiC initiated at corrosion pits. The boron- and carbon-doped SiC
was injection molded and pressure less sintered. The sample was then
coated with 2 mg/cm2 (0.07 oz/ft2) Na2SO4 and exposed for 48 hat 1000
°C (1830 °F) in 0.1% SO2/O2 gas. Corrosion products were removed with a
solution of 10% HF inwater and the sample was broken in four-point
bending at a strain rate of 0.5 mm/min (0.02 in./min).
Fig. 1278: Fracture surface shows radial crack lines emanating from the
origin, which was a corrosion pit (top).
SEM (30° tilt), 115×.
Fig. 1279: Close-up of pit-ceramic interface reveals preferential grain-
boundary attack in advance of the pit.
SEM (30° tilt), 4300×
(J.L. Smialek and N.S. Jacobson, NASA Lewis Research Center)
17. Metallography of Fracture Specimen:
The metallurgical microscope is yet another instrument very useful to
the failure analyst.
After collecting all the information through fractography of the failed
component, a section of the component can be cut transverse to the
fracture surface.
This section is then polished and examined in the metallurgical
microscope, both before and after etching. Inclusions present in the
material are observed on the as-polished surface.
The inclusion rating can be determined by standard quantitative
microscopy techniques.
By differences in color, reflectivity, and refractive index, they can also
be identified with some prior experience.
The polished specimen is then etched with suitable etchants to reveal
the microstructure of the material.
Abnormalities in the microstructure that may have been responsible for
the failure can be identified at this stage.
The path of a crack, whether it is intergranular or transgranular, and
branched or not branched, will be clear in the microstructure.
Cracks due to stress corrosion, hydrogen embrittlement, and liquid
metal embrittlement are generally intergranular with some exceptional
situations.
Fatigue cracks are transgranular. If a stress-corrosion crack
propagates by fatigue, the transition from intergranular to transgranular
mode can be seen in the microstructure.
18. Stress-corrosion cracks in certain stainless steels are transgranular
with extensive branching.
Plastic deformation of the component prior to fracture can be
recognized in the microstructure by the elongated grains.
Abnormal grain growth, segregation of brittle or weak phases at the
grain boundaries, and recrystallization are some of the other features
that can be identified by metallography.
Figure shows the intergranular and transgranular modes of crack
propagation, revealed by metallography.
Figure: Optical microstructure showing transgranular crack propagation