This document discusses fatigue failure in metals. It defines fatigue as weakness caused by repeated cyclic loading. There are two types of fatigue loading: low-cycle loading with high stresses that cause plastic deformation, and high-cycle loading with lower elastic stresses. Fatigue failure requires sufficient tensile stresses, stress variations through cycling, and a large number of cycles. The document outlines fatigue testing methods, the stages of fatigue propagation including crack initiation and propagation, analyzing fatigue failures, and methods for preventing fatigue such as surface treatments and removing stress concentrators.
This presentation is by Flt Lt Dinesh Gupta, Associate Professor (Mechanical Engineering) NIET, Alwar (Rajasthan). It covers topic on Fluctuating Stresses related to Machine Design subject.
Fatigue is important as it is the largest cause of failure in metals, estimated to comprise approximately 90% of all metallic failures; polymers and ceramics are also susceptible to this type of failure.
This presentation is by Flt Lt Dinesh Gupta, Associate Professor (Mechanical Engineering) NIET, Alwar (Rajasthan). It covers topic on Fluctuating Stresses related to Machine Design subject.
Fatigue is important as it is the largest cause of failure in metals, estimated to comprise approximately 90% of all metallic failures; polymers and ceramics are also susceptible to this type of failure.
Mumbai University.
Mechanical Engineering
SEM III
Material Technology
Module 2.2
Fatigue Failure:
Definition of fatigue and significance of cyclic stress, Mechanism of fatigue and theories of fatigue failure, Fatigue testing, Test data presentation and statistical evolution, S-N Curve and its interpretation, Influence of important factors on fatigue, Notch effect, surface effect, Effect of pre-stressing, corrosion fatigue, Thermal fatigue.
This PPT discusses Fatigue and Fracture mechanism, some history and problems. It has included on research paper. You can refer the literature review for further study of the topic.
Recrystallization is the process in which deformed grains of the crystal structure are replaced by a new set of stress-free grains that nucleate and grow until all the original grains have been consumed. The process is accomplished by heating the material to temperatures above that of crystallization.
Mumbai University.
Mechanical Engineering
SEM III
Material Technology
Module 2.2
Fatigue Failure:
Definition of fatigue and significance of cyclic stress, Mechanism of fatigue and theories of fatigue failure, Fatigue testing, Test data presentation and statistical evolution, S-N Curve and its interpretation, Influence of important factors on fatigue, Notch effect, surface effect, Effect of pre-stressing, corrosion fatigue, Thermal fatigue.
This PPT discusses Fatigue and Fracture mechanism, some history and problems. It has included on research paper. You can refer the literature review for further study of the topic.
Recrystallization is the process in which deformed grains of the crystal structure are replaced by a new set of stress-free grains that nucleate and grow until all the original grains have been consumed. The process is accomplished by heating the material to temperatures above that of crystallization.
Simulation of Critical Crack Length Propagation Using Fracture Mechanicsijceronline
The focus of this paper is to investigate and analyze the study on the plate of steel, Aluminum and Epoxy with a center crack. Linear elastic fracture mechanics principles have been used for calculating Stress Intensity Factor, Critical crack length, Increment in crack, Mean stress and strain Amplitude at critical fatigue load cycles. Above calculations will be done on the plate with centre crack of various materials (steel, aluminum and epoxy) to predict crack length to evaluate and to compare the results with theoretical calculations. .Conclusions/results obtained on the basis of analysis.
Fatigue in aerospace materials.
Materials Science and Engineering.
Metallography and failure analysis.
Research and development.
Credit: Prof. Dr. Anjum Tauqir (R)
This lecture constitutes an introduction to creep and to the creep response of aluminium and its alloys. It provides basic information on creep and its mechanisms; it gives a description of the more extensively used mathematical relations among creep variables (time, stress and temperature); it illustrates the creep response of pure Aluminium and of Al-Mg alloys; it provides a synthesis of the information available in the literature on the creep behaviour of a number of new alloys and composites in the form of a series of figures elaborated on the basis of the data reported in same sources. Basic knowledge of physics and chemistry and some familiarity with TALAT lectures 1201 through 1205 is assumed.
Forklift Classes Overview by Intella PartsIntella Parts
Discover the different forklift classes and their specific applications. Learn how to choose the right forklift for your needs to ensure safety, efficiency, and compliance in your operations.
For more technical information, visit our website https://intellaparts.com
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.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
Democratizing Fuzzing at Scale by Abhishek Aryaabh.arya
Presented at NUS: Fuzzing and Software Security Summer School 2024
This keynote talks about the democratization of fuzzing at scale, highlighting the collaboration between open source communities, academia, and industry to advance the field of fuzzing. It delves into the history of fuzzing, the development of scalable fuzzing platforms, and the empowerment of community-driven research. The talk will further discuss recent advancements leveraging AI/ML and offer insights into the future evolution of the fuzzing landscape.
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
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.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
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.
2. Presentation structure
1. Fatigue basics
2. Requirements for Fatigue Failure of Metals
3. Stress Cycles
4. FatigueTesting
5. Construction of S-N curve
6. Stages of Fatigue Process
7. Analysis of Fatigue Failure
8. Prevention of Fatigue Failure
3. 1. Fatigue basics
- Repeated cyclic loadings -
..Weakness/tiredness
- 2 types of loadings:
1. )low-cycle loading
N < 105
- high loads, el. + also some
plastic strain
2. )high-cycle loading
N > 105
- lower stresses
- totally elastic strain
FL- fatigue limit (endless
number of cycles) 105 106
Cycles to failure N
STRESS↑
107
FL
4. 2. Requirements for Fatigue Failure of Metals
3 necessary factors :
1. Sufficient amount of
tensile stresses,
2. enough variations in
the applied stress
(cycling),
3. Sufficient large
number of cycles.
5. 3. Stress cycle
Cycle types:
1. Completely Reversed
Stress cycle,
(amplitude is symmetrical
about mean zero)
2. Repeated Stress
Cycle,
(stresses are not equal)
3. Irregular or random
stress cycle.
(real conditions, wings etc.)
6. Finding fatigue properties-
laboratorysimulation tests.
-duplicate as nearly as
possible the service stress
conditions (stress level,
time frequency..)
Rotating- bending test
machine -compressionand
tensile stresses arecharged
onthe specimenas it is
bent androtatedatthe
sametime.
Presenting inS – N curve
4. Fatigue testing
7. - Requires 8 – 12
specimens,
- first testing on high
level of stress (2/3 of Rm),
- applying lower levels of
stress until specimen
reaches and define
Fatigue Limit.
5.Construction ofS-N curve
8. Three stagesofFatigue
propagation:
I stage –crackinitiation,
cyclic hardening (annealed
steel
Rm/Re> 1,4),
cyclic softening(hardened
steel, martensite,work
hardened Rm/Re< 1,2),
II stage - crack nucleation
andgrowthofcrackon small
material volume(surface),
III stage –crackpropagation
andfinalfailure onoverload.
6.Stages of Fatigue Process
I. CRACK INITIATION (growth 0,25nm/cycle)
9. Three stagesofFatigue
propagation:
I stage –crackinitiation,
cyclic hardening (annealed
steel
Rm/Re> 1,4),
cyclic softening(hardened
steel, martensite,work
hardened Rm/Re< 1,2),
II stage - crack nucleation
andgrowthofcrackon small
material volume(surface),
III stage –crackpropagation
andfinalfailure onoverload.
6.1Stages of Fatigue Process
II. CRACK NUCLEATION (stable growth)
Fatigue striations
∆l/cycle
10. Three stagesofFatigue
propagation:
I stage –crackinitiation,
cyclic hardening (annealed
steel
Rm/Re> 1,4),
cyclic softening(hardened
steel, martensite,work
hardened Rm/Re< 1,2),
II stage - crack nucleation
andgrowthofcrackon small
material volume(surface),
III stage –crackpropagation
andfinalfailure onoverload.
6.2Stages of Fatigue Process
III. CRACK PROPAGATION (unstable growth)
III. Unstable stage
overload
INITIATION SITE
11. - Differences of
Low and high
nominal stress,
- differences of
stress types,
- differences of
fracture surface.
7.Analysis of Fatigue failure
Typical fatigue failure
caused by fatigue forces
LOW σ
HIGH σ
12. - Difference of
Low and high
nominal stress,
- differences of
stress types,
- differences of
fracture surface.
7.1Analysis of Fatigue failure
Stress type dependence
Torsional fatigue
Rotating bending
fatigue
13. - Differences of
Low and high
nominal stress,
- differences of
stress types,
- differences of
fracture surface.
7.2Analysis of Fatigue failure
Ductile and brittle
material differences
SMOOTH
NOTCHED
14. 8. Prevention of Fatigue Failure
High velocity
1.SURFACETREATMENTS
-Surface rolling –(compressive
stressapplyingbetween the
rollers andmaterial)
-Polishing – (reducing surface
scratches)
-Shot peening- (putting
surfaceinto compression)
-Carburizing - (surface
treatment)
2. REMOVESTRESS
CONCENTRATORS
-Design- (removing of sharp
edges)
-TIG dressing –(weld
treatment)
Crankshaft
polishing
High velocity shooting
against the surface
Surface rolling
15. 8. Prevention of Fatigue Failure
1.SURFACETREATMENTS
-Surface rolling –(compressive
stressapplyingbetween the
rollers andmaterial)
-Polishing – (reducing surface
scratches)
-Shot peening- (putting
surfaceinto compression)
-Carburizing - (surface
treatment)
2. REMOVESTRESS
CONCENTRATORS
-Design- (removing of sharp
edges)
-TIG dressing –(weld
treatment)
TIG – Dressing :
Removing of weld
toe intrusions
