The document summarizes research on characterizing and modeling damage in the polymer material acrylonitrile butadiene styrene (ABS). Uniaxial tensile tests were performed on ABS specimens at temperatures ranging from 60°C to 170°C. The tests showed the material's mechanical properties degrade with increasing temperature. A damage model was developed to describe the reduction in residual strength based on measurements of ultimate stress in virgin and damaged conditions. Damage was found to gradually increase from 0 for virgin material to 1 for complete damage, progressing through three stages. The model provides a way to predict damage for ABS structures under different loading conditions.
Predicting the Nonlinear Material Behaviour under Monotonic and Cyclic loadin...IJERA Editor
Nonlinearity naturally arises in a true, rigorous mathematical formulation of physical problems. One of the most
common nonlinearity is the material nonlinearity where the stress-strain response behaves nonlinearly. The main
objective of this paper is to predict the material nonlinearity with the use of constitutive material model. To this
end, the specimen is modeled with the eight nodded solid elements. One end of the specimen is fixed while the
prescribed displacement is specified at the other end. The Chaboche model parameters are fitted first by
matching the experimental stress-strain curve [4] with the finite element simulations. After that the response of
the specimen is predicted when subjected to different displacement amplitudes i.e. completely reversed loading,
cyclic tension loading and fluctuating ramp loading
Strength of material lab, Exp 2: Tensile test Osaid Qasim
by using our “UTM” machine that
operates on the basis of applying a load in our specimen , so if
we take this force and compare it with change in the length of
specimen “Deformation” we can obtain a (Load-Deformation
diagram) , and by applying this force and divide it by the
specimen cross sectional area we get the Stress ( σ), and divide
the “Deformation” by the original length of the specimen we
will get the Strain (ϵ) , and comparing the stress with strain
results a very Important curve that is characteristic of the
properties of the material and it’s the (Stress-Strain Diagram),
Predicting the Nonlinear Material Behaviour under Monotonic and Cyclic loadin...IJERA Editor
Nonlinearity naturally arises in a true, rigorous mathematical formulation of physical problems. One of the most
common nonlinearity is the material nonlinearity where the stress-strain response behaves nonlinearly. The main
objective of this paper is to predict the material nonlinearity with the use of constitutive material model. To this
end, the specimen is modeled with the eight nodded solid elements. One end of the specimen is fixed while the
prescribed displacement is specified at the other end. The Chaboche model parameters are fitted first by
matching the experimental stress-strain curve [4] with the finite element simulations. After that the response of
the specimen is predicted when subjected to different displacement amplitudes i.e. completely reversed loading,
cyclic tension loading and fluctuating ramp loading
Strength of material lab, Exp 2: Tensile test Osaid Qasim
by using our “UTM” machine that
operates on the basis of applying a load in our specimen , so if
we take this force and compare it with change in the length of
specimen “Deformation” we can obtain a (Load-Deformation
diagram) , and by applying this force and divide it by the
specimen cross sectional area we get the Stress ( σ), and divide
the “Deformation” by the original length of the specimen we
will get the Strain (ϵ) , and comparing the stress with strain
results a very Important curve that is characteristic of the
properties of the material and it’s the (Stress-Strain Diagram),
The section will cover the behaviour of materials by introducing the stress-strain curve. The concepts of elastic and plastic deformation will be covered. This will then lead to a discussion of the micro-structure of materials and a physical explanation of what is happening to a polycrystalline material as it is loaded to failure.
Intro
Principle
How it works
Types of dynamic Experiments
Instrumentation
Construction
Preparation of samples
Types of analysers
DMA of glass transition of polymers
Advantages
Applications
Limitations
Latest Research
References
Abstract. Ensuring of permanent and continuous working process of oil-gas and field equipment alongside with the other factors, depends also on reliability of sealing units. A problem of deterioration modeling of a sealing element of a packer including into an oil field equipment complex is considered in this paper.
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)
Material Parameter and Effect of Thermal Load on Functionally Graded CylindersIJMER
The present study investigates the creep in a thick-walled composite cylinders made
up of aluminum/aluminum alloy matrix and reinforced with silicon carbide particles. The distribution
of SiCp is assumed to be either uniform or decreasing linearly from the inner to the outer radius of
the cylinder. The creep behavior of the cylinder has been described by threshold stress based creep
law with a stress exponent of 5. The composite cylinders are subjected to internal pressure which is
applied gradually and steady state condition of stress is assumed. The creep parameters required to
be used in creep law, are extracted by conducting regression analysis on the available experimental
results. The mathematical models have been developed to describe steady state creep in the composite
cylinder by using von-Mises criterion. Regression analysis is used to obtain the creep parameters
required in the study. The basic equilibrium equation of the cylinder and other constitutive equations
have been solved to obtain creep stresses in the cylinder. The effect of varying particle size, particle
content and temperature on the stresses in the composite cylinder has been analyzed. The study
revealed that the stress distributions in the cylinder do not vary significantly for various combinations
of particle size, particle content and operating temperature except for slight variation observed for
varying particle content. Functionally Graded Materials (FGMs) emerged and led to the development
of superior heat resistant materials.
The section will cover the behaviour of materials by introducing the stress-strain curve. The concepts of elastic and plastic deformation will be covered. This will then lead to a discussion of the micro-structure of materials and a physical explanation of what is happening to a polycrystalline material as it is loaded to failure.
Intro
Principle
How it works
Types of dynamic Experiments
Instrumentation
Construction
Preparation of samples
Types of analysers
DMA of glass transition of polymers
Advantages
Applications
Limitations
Latest Research
References
Abstract. Ensuring of permanent and continuous working process of oil-gas and field equipment alongside with the other factors, depends also on reliability of sealing units. A problem of deterioration modeling of a sealing element of a packer including into an oil field equipment complex is considered in this paper.
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)
Material Parameter and Effect of Thermal Load on Functionally Graded CylindersIJMER
The present study investigates the creep in a thick-walled composite cylinders made
up of aluminum/aluminum alloy matrix and reinforced with silicon carbide particles. The distribution
of SiCp is assumed to be either uniform or decreasing linearly from the inner to the outer radius of
the cylinder. The creep behavior of the cylinder has been described by threshold stress based creep
law with a stress exponent of 5. The composite cylinders are subjected to internal pressure which is
applied gradually and steady state condition of stress is assumed. The creep parameters required to
be used in creep law, are extracted by conducting regression analysis on the available experimental
results. The mathematical models have been developed to describe steady state creep in the composite
cylinder by using von-Mises criterion. Regression analysis is used to obtain the creep parameters
required in the study. The basic equilibrium equation of the cylinder and other constitutive equations
have been solved to obtain creep stresses in the cylinder. The effect of varying particle size, particle
content and temperature on the stresses in the composite cylinder has been analyzed. The study
revealed that the stress distributions in the cylinder do not vary significantly for various combinations
of particle size, particle content and operating temperature except for slight variation observed for
varying particle content. Functionally Graded Materials (FGMs) emerged and led to the development
of superior heat resistant materials.
INVESTIGATION ON MECHANICAL PROPERTIES OF HEMP-E GLASS FIBER REINFORCED POLYM...IAEME Publication
Natural fiber composite is currently a leading module in the world of composites. It is due to many of its features such as freely available, easy processing, low cost, ability to replace usage of Glass fiber (Synthetic fiber), better strength properties and ecofriendly. They find useful applications in various fields from domestic to automotive sector as of now. Natural fibers with good content of lignocellulose, low density, and better elongation percentage are chosen for manufacturing of composites of above mentioned applications. Unidirectional & Continuous natural fiber composites are said to be anisotropic and having predominant mechanical properties.
Characterization of Mechanical, Thermal, and Electrical Properties of Carbon ...drboon
In this paper, the mechanical, thermal and electrical properties of carbon fiber modified thermoplastic polyimide were numerically analyzed by finite element analysis. A three-dimensional model was created, in which continuous carbon fibers are aligning and paralleling to each other and uniformly distributing in the polymer matrix. The behaviors of the composites in two extreme situations, i.e., parallel or perpendicular to carbon fiber direction, were simulated. The effects of the volume fraction of carbon fiber content on the physical properties were investigated. It shows clearly that carbon fibers significantly improve the mechanical strength, and thermal and electrical conductivities. The future work includes investigation of the physical properties of the conductive network of the composites with random carbon fiber orientation, and different fillers, such as graphite, and carbon nanotubes.
Mechanical properties of polymer composite materialseSAT Journals
Abstract In this paper, composite materials and its properties are discussed in detail. It is also discussed their importance and replacement for metals because of their properties like low weight, corrosion resistance etc. Now-a-days, there is a great importance of usage of these materials in various applications in all Engg. Fields. The paper also brings out the manufacturing techniques and costs involved.
Here the composite material was fabricated using sugarcane bagasse, jute fibre & with glass fibre as a hybrid material and the mechanical properties of this material was studied.
Study of Damage to ABS Specimens Submitted To Uniaxial Loadingtheijes
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.
Theoretical work submitted to the Journal should be original in its motivation or modeling structure. Empirical analysis should be based on a theoretical framework and should be capable of replication. It is expected that all materials required for replication (including computer programs and data sets) should be available upon request to the authors.
The International Journal of Engineering & Science would take much care in making your article published without much delay with your kind cooperation.
Multi resolution defect transformation of the crack under different anglesIJRES Journal
It is used to analyze the crack of different angles by the method of finite element. In the same material, the same crack is applied different angles, crack with 15 degree Angle differences, and applying Ⅰ type load on the material. The effective elastic modulus under the different angles of crack are obtained by finite element. With comparative judgment method, it provides the relationship between the modulus of elasticity and crack different angles, and a method crack material defects of transformation. On based on the transformation of energy equivalent principle, there are a lot of crack defects of materials for different degrees of defects, so as to simplify the material crack, provide a simple way for material fatigue analysis.
This paper addresses the fracture toughness ( ), or also known as critical stress intensity Factor, according to
conditions of Lineal Elastic Fracture Mechanics (LEFM). The characterization of the mechanical properties in
tensile and fracture toughness of structural steel pipes API-5L used in hydrocarbons transportation was
performed. For fracture toughness, the material was tested through fatigue crack propagation on standardized
compact specimen (CT) according to ASTM E-399 norm. A thickness (B) equal to and a crack size (a) equal
to 0.5w were used. With the porpoise of establishing the adequate conditions at the crack tip, the specimens were
subjected to fatigue pre-cracking by application of repeated cycles of load in tensile-tensile and constant load
amplitude with a load ratio of R = 0.1. The experimental Compliance method was used based on data obtained
from load vs. Crack Mouth Opening Displacement (CMOD). The results show a Stress Intensity factor of 35.88
MPa√m for a 25 mm crack size specimen. The device used for testing is a MTS-810 machine with capacity of
100KN and 6 kHz sampling rate, which meets the conditions of the ASTM E-399 standard. The cracking
susceptibility of steel is influenced by the size, morphology and distribution of non-metallic inclusions,
thermochemical interaction with the environment and microstructure.
Comparative study of the mechanical behavior of polymer materials: between A...theijes
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.
Comparative study of the mechanical behavior of polymer materials: between AB...theijes
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.
Strength of material lab, Exp 3&4: Compression and impact testsOsaid Qasim
- Utilization the UTM machine and know the different
ways that could test the material’s properties.
2- Knowing the different types of failure in the compression.
3- Determining Young's modulus “E” and Passion’s ratio
“υ” and Yield/Proof stress σ y.
1. Finding the impact load effect on the materials.
2. Finding the relative toughness of the different materials.
3. Distinguish between static and dynamic loads and how differently they
effect in the material.
4.Knowing the different methods to preform the impact test (Charpy,
IZOD, Impact tensile).
Evaluation of Damage by the Reliability of the Traction Test on Polymer Test ...inventy
In recent decades, polymers have undergone a remarkable historical development and their use has been greatly imposed by gradually dethroning most of the secular materials. These polymer materials have always distinguished themselves by their simple shaping and inexpensive price, their versatility, lightness, and chemical stability but despite their massive use in everyday life as well as in advanced technologies. Generally, these materials still not understood which requires a thorough knowledge of their chemical, physical, rheological and mechanical properties. This paper, we study the mechanical behavior of an amorphous polymer: Acrylonitrile Butadiene Styrene “ABS” by means of uniaxial tensile testing on pierced test pieces with different notch lengths ranging between 1 to 14mm.The proposed approach consists in analyzing the evolution of the global geometry of the obtained strain curves by taking into account the zones and characteristic points of these curves as well as the effect of the damage on the mechanical behavior of the polymer ABS, in order to visualize the evolution of the damage by a static model
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
numerical investigation on induced residual stress of al albite metal matrix ...INFOGAIN PUBLICATION
The aim of the work was to investigate residual stress formed during fabrication of Al/albite metal matrix composites (MMCs) using finite element analysis. Optical images of MMCs were extracted from scanning electron microscope (SEM) after fabrication by stir-casting. The collected images and properties were used to determine residuals stresses at the interface using COMSOL multi physics tool. The imported MMCs images modelled and meshed for 5458, 6318 and 7149 elements for 5%, 10% and 15% particle reinforced composites respectively. Geometrical and thermal constraints are applied at the boundaries and difference in temperature T 620 C as a thermal constraint. FE results in the COMSOL multi physics show that residual stress in composites material tested are in the range of 1.55 MPa to 2.84 MPa. Al/albite with 15% albite reinforcement possesses lowest residual stress formation in all 27 cases studied with value of 1.55 MPa
Structural Integrity Analysis: Chapter 3 Mechanical Properties of MaterialsIgor Kokcharov
Structural Integrity Analysis features a collection of selected topics on structural design, safety, reliability, redundancy, strength, material science, mechanical properties of materials, composite materials, welds, finite element analysis, stress concentration, failure mechanisms and criteria. The engineering approaches focus on understanding and concept visualization rather than theoretical reasoning. The structural engineering profession plays a key role in the assurance of safety of technical systems such as metallic structures, buildings, machines, and transport. The third chapter explains the engineering tests and fundamentals of mechanical properties of materials.
Numerical modeling of the welding defect influence on fatigue life of the wel...inventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Examples of Homogenization Techniques in the Material Modeling Under the Effe...Sardasht S. Weli
Explosions become a very attractive research area in the last decades.
This is due to the increase of accidental and intentional explosions.
Historical structure were not designed and built against the extreme loading events.
Homogenization Techniques were developed to assess the masonry response.
A Novel Method for Prevention of Bandwidth Distributed Denial of Service AttacksIJERD Editor
Distributed Denial of Service (DDoS) Attacks became a massive threat to the Internet. Traditional
Architecture of internet is vulnerable to the attacks like DDoS. Attacker primarily acquire his army of Zombies,
then that army will be instructed by the Attacker that when to start an attack and on whom the attack should be
done. In this paper, different techniques which are used to perform DDoS Attacks, Tools that were used to
perform Attacks and Countermeasures in order to detect the attackers and eliminate the Bandwidth Distributed
Denial of Service attacks (B-DDoS) are reviewed. DDoS Attacks were done by using various Flooding
techniques which are used in DDoS attack.
The main purpose of this paper is to design an architecture which can reduce the Bandwidth
Distributed Denial of service Attack and make the victim site or server available for the normal users by
eliminating the zombie machines. Our Primary focus of this paper is to dispute how normal machines are
turning into zombies (Bots), how attack is been initiated, DDoS attack procedure and how an organization can
save their server from being a DDoS victim. In order to present this we implemented a simulated environment
with Cisco switches, Routers, Firewall, some virtual machines and some Attack tools to display a real DDoS
attack. By using Time scheduling, Resource Limiting, System log, Access Control List and some Modular
policy Framework we stopped the attack and identified the Attacker (Bot) machines
Hearing loss is one of the most common human impairments. It is estimated that by year 2015 more
than 700 million people will suffer mild deafness. Most can be helped by hearing aid devices depending on the
severity of their hearing loss. This paper describes the implementation and characterization details of a dual
channel transmitter front end (TFE) for digital hearing aid (DHA) applications that use novel micro
electromechanical- systems (MEMS) audio transducers and ultra-low power-scalable analog-to-digital
converters (ADCs), which enable a very-low form factor, energy-efficient implementation for next-generation
DHA. The contribution of the design is the implementation of the dual channel MEMS microphones and powerscalable
ADC system.
Influence of tensile behaviour of slab on the structural Behaviour of shear c...IJERD Editor
-A composite beam is composed of a steel beam and a slab connected by means of shear connectors
like studs installed on the top flange of the steel beam to form a structure behaving monolithically. This study
analyzes the effects of the tensile behavior of the slab on the structural behavior of the shear connection like slip
stiffness and maximum shear force in composite beams subjected to hogging moment. The results show that the
shear studs located in the crack-concentration zones due to large hogging moments sustain significantly smaller
shear force and slip stiffness than the other zones. Moreover, the reduction of the slip stiffness in the shear
connection appears also to be closely related to the change in the tensile strain of rebar according to the increase
of the load. Further experimental and analytical studies shall be conducted considering variables such as the
reinforcement ratio and the arrangement of shear connectors to achieve efficient design of the shear connection
in composite beams subjected to hogging moment.
Gold prospecting using Remote Sensing ‘A case study of Sudan’IJERD Editor
Gold has been extracted from northeast Africa for more than 5000 years, and this may be the first
place where the metal was extracted. The Arabian-Nubian Shield (ANS) is an exposure of Precambrian
crystalline rocks on the flanks of the Red Sea. The crystalline rocks are mostly Neoproterozoic in age. ANS
includes the nations of Israel, Jordan. Egypt, Saudi Arabia, Sudan, Eritrea, Ethiopia, Yemen, and Somalia.
Arabian Nubian Shield Consists of juvenile continental crest that formed between 900 550 Ma, when intra
oceanic arc welded together along ophiolite decorated arc. Primary Au mineralization probably developed in
association with the growth of intra oceanic arc and evolution of back arc. Multiple episodes of deformation
have obscured the primary metallogenic setting, but at least some of the deposits preserve evidence that they
originate as sea floor massive sulphide deposits.
The Red Sea Hills Region is a vast span of rugged, harsh and inhospitable sector of the Earth with
inimical moon-like terrain, nevertheless since ancient times it is famed to be an abode of gold and was a major
source of wealth for the Pharaohs of ancient Egypt. The Pharaohs old workings have been periodically
rediscovered through time. Recent endeavours by the Geological Research Authority of Sudan led to the
discovery of a score of occurrences with gold and massive sulphide mineralizations. In the nineties of the
previous century the Geological Research Authority of Sudan (GRAS) in cooperation with BRGM utilized
satellite data of Landsat TM using spectral ratio technique to map possible mineralized zones in the Red Sea
Hills of Sudan. The outcome of the study mapped a gossan type gold mineralization. Band ratio technique was
applied to Arbaat area and a signature of alteration zone was detected. The alteration zones are commonly
associated with mineralization. The alteration zones are commonly associated with mineralization. A filed check
confirmed the existence of stock work of gold bearing quartz in the alteration zone. Another type of gold
mineralization that was discovered using remote sensing is the gold associated with metachert in the Atmur
Desert.
Reducing Corrosion Rate by Welding DesignIJERD Editor
The paper addresses the importance of welding design to prevent corrosion at steel. Welding is
used to join pipe, profiles at bridges, spindle, and a lot more part of engineering construction. The
problems happened associated with welding are common issues in these fields, especially corrosion.
Corrosion can be reduced with many methods, they are painting, controlling humidity, and also good
welding design. In the research, it can be found that reducing residual stress on the welding can be
solved in corrosion rate reduction problem.
Preheating on 500oC and 600oC give better condition to reduce corosion rate than condition after
preheating 400oC. For all welding groove type, material with 500oC and 600oC preheating after 14 days
corrosion test is 0,5%-0,69% lost. Material with 400oC preheating after 14 days corrosion test is 0,57%-0,76%
lost.
Welding groove also influence corrosion rate. X and V type welding groove give better condition to reduce
corrosion rate than use 1/2V and 1/2 X welding groove. After 14 days corrosion test, the samples with
X welding groove type is 0,5%-0,57% lost. The samples with V welding groove after 14 days corrosion test is
0,51%-0,59% lost. The samples with 1/2V and 1/2X welding groove after 14 days corrosion test is 0,58%-
0,71% lost.
Router 1X3 – RTL Design and VerificationIJERD Editor
Routing is the process of moving a packet of data from source to destination and enables messages
to pass from one computer to another and eventually reach the target machine. A router is a networking device
that forwards data packets between computer networks. It is connected to two or more data lines from different
networks (as opposed to a network switch, which connects data lines from one single network). This paper,
mainly emphasizes upon the study of router device, it‟s top level architecture, and how various sub-modules of
router i.e. Register, FIFO, FSM and Synchronizer are synthesized, and simulated and finally connected to its top
module.
Active Power Exchange in Distributed Power-Flow Controller (DPFC) At Third Ha...IJERD Editor
This paper presents a component within the flexible ac-transmission system (FACTS) family, called
distributed power-flow controller (DPFC). The DPFC is derived from the unified power-flow controller (UPFC)
with an eliminated common dc link. The DPFC has the same control capabilities as the UPFC, which comprise
the adjustment of the line impedance, the transmission angle, and the bus voltage. The active power exchange
between the shunt and series converters, which is through the common dc link in the UPFC, is now through the
transmission lines at the third-harmonic frequency. DPFC multiple small-size single-phase converters which
reduces the cost of equipment, no voltage isolation between phases, increases redundancy and there by
reliability increases. The principle and analysis of the DPFC are presented in this paper and the corresponding
simulation results that are carried out on a scaled prototype are also shown.
Mitigation of Voltage Sag/Swell with Fuzzy Control Reduced Rating DVRIJERD Editor
Power quality has been an issue that is becoming increasingly pivotal in industrial electricity
consumers point of view in recent times. Modern industries employ Sensitive power electronic equipments,
control devices and non-linear loads as part of automated processes to increase energy efficiency and
productivity. Voltage disturbances are the most common power quality problem due to this the use of a large
numbers of sophisticated and sensitive electronic equipment in industrial systems is increased. This paper
discusses the design and simulation of dynamic voltage restorer for improvement of power quality and
reduce the harmonics distortion of sensitive loads. Power quality problem is occurring at non-standard
voltage, current and frequency. Electronic devices are very sensitive loads. In power system voltage sag,
swell, flicker and harmonics are some of the problem to the sensitive load. The compensation capability
of a DVR depends primarily on the maximum voltage injection ability and the amount of stored
energy available within the restorer. This device is connected in series with the distribution feeder at
medium voltage. A fuzzy logic control is used to produce the gate pulses for control circuit of DVR and the
circuit is simulated by using MATLAB/SIMULINK software.
Study on the Fused Deposition Modelling In Additive ManufacturingIJERD Editor
Additive manufacturing process, also popularly known as 3-D printing, is a process where a product
is created in a succession of layers. It is based on a novel materials incremental manufacturing philosophy.
Unlike conventional manufacturing processes where material is removed from a given work price to derive the
final shape of a product, 3-D printing develops the product from scratch thus obviating the necessity to cut away
materials. This prevents wastage of raw materials. Commonly used raw materials for the process are ABS
plastic, PLA and nylon. Recently the use of gold, bronze and wood has also been implemented. The complexity
factor of this process is 0% as in any object of any shape and size can be manufactured.
Spyware triggering system by particular string valueIJERD Editor
This computer programme can be used for good and bad purpose in hacking or in any general
purpose. We can say it is next step for hacking techniques such as keylogger and spyware. Once in this system if
user or hacker store particular string as a input after that software continually compare typing activity of user
with that stored string and if it is match then launch spyware programme.
A Blind Steganalysis on JPEG Gray Level Image Based on Statistical Features a...IJERD Editor
This paper presents a blind steganalysis technique to effectively attack the JPEG steganographic
schemes i.e. Jsteg, F5, Outguess and DWT Based. The proposed method exploits the correlations between
block-DCTcoefficients from intra-block and inter-block relation and the statistical moments of characteristic
functions of the test image is selected as features. The features are extracted from the BDCT JPEG 2-array.
Support Vector Machine with cross-validation is implemented for the classification.The proposed scheme gives
improved outcome in attacking.
Secure Image Transmission for Cloud Storage System Using Hybrid SchemeIJERD Editor
- Data over the cloud is transferred or transmitted between servers and users. Privacy of that
data is very important as it belongs to personal information. If data get hacked by the hacker, can be
used to defame a person’s social data. Sometimes delay are held during data transmission. i.e. Mobile
communication, bandwidth is low. Hence compression algorithms are proposed for fast and efficient
transmission, encryption is used for security purposes and blurring is used by providing additional
layers of security. These algorithms are hybridized for having a robust and efficient security and
transmission over cloud storage system.
Application of Buckley-Leverett Equation in Modeling the Radius of Invasion i...IJERD Editor
A thorough review of existing literature indicates that the Buckley-Leverett equation only analyzes
waterflood practices directly without any adjustments on real reservoir scenarios. By doing so, quite a number
of errors are introduced into these analyses. Also, for most waterflood scenarios, a radial investigation is more
appropriate than a simplified linear system. This study investigates the adoption of the Buckley-Leverett
equation to estimate the radius invasion of the displacing fluid during waterflooding. The model is also adopted
for a Microbial flood and a comparative analysis is conducted for both waterflooding and microbial flooding.
Results shown from the analysis doesn’t only records a success in determining the radial distance of the leading
edge of water during the flooding process, but also gives a clearer understanding of the applicability of
microbes to enhance oil production through in-situ production of bio-products like bio surfactans, biogenic
gases, bio acids etc.
Gesture Gaming on the World Wide Web Using an Ordinary Web CameraIJERD Editor
- Gesture gaming is a method by which users having a laptop/pc/x-box play games using natural or
bodily gestures. This paper presents a way of playing free flash games on the internet using an ordinary webcam
with the help of open source technologies. Emphasis in human activity recognition is given on the pose
estimation and the consistency in the pose of the player. These are estimated with the help of an ordinary web
camera having different resolutions from VGA to 20mps. Our work involved giving a 10 second documentary to
the user on how to play a particular game using gestures and what are the various kinds of gestures that can be
performed in front of the system. The initial inputs of the RGB values for the gesture component is obtained by
instructing the user to place his component in a red box in about 10 seconds after the short documentary before
the game is finished. Later the system opens the concerned game on the internet on popular flash game sites like
miniclip, games arcade, GameStop etc and loads the game clicking at various places and brings the state to a
place where the user is to perform only gestures to start playing the game. At any point of time the user can call
off the game by hitting the esc key and the program will release all of the controls and return to the desktop. It
was noted that the results obtained using an ordinary webcam matched that of the Kinect and the users could
relive the gaming experience of the free flash games on the net. Therefore effective in game advertising could
also be achieved thus resulting in a disruptive growth to the advertising firms.
Hardware Analysis of Resonant Frequency Converter Using Isolated Circuits And...IJERD Editor
-LLC resonant frequency converter is basically a combo of series as well as parallel resonant ckt. For
LCC resonant converter it is associated with a disadvantage that, though it has two resonant frequencies, the
lower resonant frequency is in ZCS region[5]. For this application, we are not able to design the converter
working at this resonant frequency. LLC resonant converter existed for a very long time but because of
unknown characteristic of this converter it was used as a series resonant converter with basically a passive
(resistive) load. . Here, it was designed to operate in switching frequency higher than resonant frequency of the
series resonant tank of Lr and Cr converter acts very similar to Series Resonant Converter. The benefit of LLC
resonant converter is narrow switching frequency range with light load[6] . Basically, the control ckt plays a
very imp. role and hence 555 Timer used here provides a perfect square wave as the control ckt provides no
slew rate which makes the square wave really strong and impenetrable. The dead band circuit provides the
exclusive dead band in micro seconds so as to avoid the simultaneous firing of two pairs of IGBT’s where one
pair switches off and the other on for a slightest period of time. Hence, the isolator ckt here is associated with
each and every ckt used because it acts as a driver and an isolation to each of the IGBT is provided with one
exclusive transformer supply[3]. The IGBT’s are fired using the appropriate signal using the previous boards
and hence at last a high frequency rectifier ckt with a filtering capacitor is used to get an exact dc
waveform .The basic goal of this particular analysis is to observe the wave forms and characteristics of
converters with differently positioned passive elements in the form of tank circuits.
Simulated Analysis of Resonant Frequency Converter Using Different Tank Circu...IJERD Editor
LLC resonant frequency converter is basically a combo of series as well as parallel resonant ckt. For
LCC resonant converter it is associated with a disadvantage that, though it has two resonant frequencies, the
lower resonant frequency is in ZCS region [5]. For this application, we are not able to design the converter
working at this resonant frequency. LLC resonant converter existed for a very long time but because of
unknown characteristic of this converter it was used as a series resonant converter with basically a passive
(resistive) load. . Here, it was designed to operate in switching frequency higher than resonant frequency of the
series resonant tank of Lr and Cr converter acts very similar to Series Resonant Converter. The benefit of LLC
resonant converter is narrow switching frequency range with light load[6] . Basically, the control ckt plays a
very imp. role and hence 555 Timer used here provides a perfect square wave as the control ckt provides no
slew rate which makes the square wave really strong and impenetrable. The dead band circuit provides the
exclusive dead band in micro seconds so as to avoid the simultaneous firing of two pairs of IGBT’s where one
pair switches off and the other on for a slightest period of time. Hence, the isolator ckt here is associated with
each and every ckt used because it acts as a driver and an isolation to each of the IGBT is provided with one
exclusive transformer supply[3]. The IGBT’s are fired using the appropriate signal using the previous boards
and hence at last a high frequency rectifier ckt with a filtering capacitor is used to get an exact dc
waveform .The basic goal of this particular analysis is to observe the wave forms and characteristics of
converters with differently positioned passive elements in the form of tank circuits. The supported simulation
is done through PSIM 6.0 software tool
Amateurs Radio operator, also known as HAM communicates with other HAMs through Radio
waves. Wireless communication in which Moon is used as natural satellite is called Moon-bounce or EME
(Earth -Moon-Earth) technique. Long distance communication (DXing) using Very High Frequency (VHF)
operated amateur HAM radio was difficult. Even with the modest setup having good transceiver, power
amplifier and high gain antenna with high directivity, VHF DXing is possible. Generally 2X11 YAGI antenna
along with rotor to set horizontal and vertical angle is used. Moon tracking software gives exact location,
visibility of Moon at both the stations and other vital data to acquire real time position of moon.
“MS-Extractor: An Innovative Approach to Extract Microsatellites on „Y‟ Chrom...IJERD Editor
Simple Sequence Repeats (SSR), also known as Microsatellites, have been extensively used as
molecular markers due to their abundance and high degree of polymorphism. The nucleotide sequences of
polymorphic forms of the same gene should be 99.9% identical. So, Microsatellites extraction from the Gene is
crucial. However, Microsatellites repeat count is compared, if they differ largely, he has some disorder. The Y
chromosome likely contains 50 to 60 genes that provide instructions for making proteins. Because only males
have the Y chromosome, the genes on this chromosome tend to be involved in male sex determination and
development. Several Microsatellite Extractors exist and they fail to extract microsatellites on large data sets of
giga bytes and tera bytes in size. The proposed tool “MS-Extractor: An Innovative Approach to extract
Microsatellites on „Y‟ Chromosome” can extract both Perfect as well as Imperfect Microsatellites from large
data sets of human genome „Y‟. The proposed system uses string matching with sliding window approach to
locate Microsatellites and extracts them.
Importance of Measurements in Smart GridIJERD Editor
- The need to get reliable supply, independence from fossil fuels, and capability to provide clean
energy at a fixed and lower cost, the existing power grid structure is transforming into Smart Grid. The
development of a smart energy distribution grid is a current goal of many nations. A Smart Grid should have
new capabilities such as self-healing, high reliability, energy management, and real-time pricing. This new era
of smart future grid will lead to major changes in existing technologies at generation, transmission and
distribution levels. The incorporation of renewable energy resources and distribution generators in the existing
grid will increase the complexity, optimization problems and instability of the system. This will lead to a
paradigm shift in the instrumentation and control requirements for Smart Grids for high quality, stable and
reliable electricity supply of power. The monitoring of the grid system state and stability relies on the
availability of reliable measurement of data. In this paper the measurement areas that highlight new
measurement challenges, development of the Smart Meters and the critical parameters of electric energy to be
monitored for improving the reliability of power systems has been discussed.
Study of Macro level Properties of SCC using GGBS and Lime stone powderIJERD Editor
One of the major environmental concerns is the disposal of the waste materials and utilization of
industrial by products. Lime stone quarries will produce millions of tons waste dust powder every year. Having
considerable high degree of fineness in comparision to cement this material may be utilized as a partial
replacement to cement. For this purpose an experiment is conducted to investigate the possibility of using lime
stone powder in the production of SCC with combined use GGBS and how it affects the fresh and mechanical
properties of SCC. First SCC is made by replacing cement with GGBS in percentages like 10, 20, 30, 40, 50 and
by taking the optimum mix with GGBS lime stone powder is blended to mix in percentages like 5, 10, 15, 20 as
a partial replacement to cement. Test results shows that the SCC mix with combination of 30% GGBS and 15%
limestone powder gives maximum compressive strength and fresh properties are also in the limits prescribed by
the EFNARC.
A tale of scale & speed: How the US Navy is enabling software delivery from l...sonjaschweigert1
Rapid and secure feature delivery is a goal across every application team and every branch of the DoD. The Navy’s DevSecOps platform, Party Barge, has achieved:
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Development teams can ship efficiently and ensure applications are cyber ready for Navy Authorizing Officials (AOs). In this webinar, Sigma Defense and Anchore will give attendees a look behind the scenes and demo secure pipeline automation and security artifacts that speed up application ATO and time to production.
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LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
Key Trends Shaping the Future of Infrastructure.pdfCheryl Hung
Keynote at DIGIT West Expo, Glasgow on 29 May 2024.
Cheryl Hung, ochery.com
Sr Director, Infrastructure Ecosystem, Arm.
The key trends across hardware, cloud and open-source; exploring how these areas are likely to mature and develop over the short and long-term, and then considering how organisations can position themselves to adapt and thrive.
Observability Concepts EVERY Developer Should Know -- DeveloperWeek Europe.pdfPaige Cruz
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While the dev and ops silo continues to crumble….many organizations still relegate monitoring & observability as the purview of ops, infra and SRE teams. This is a mistake - achieving a highly observable system requires collaboration up and down the stack.
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Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
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Dev Dives: Train smarter, not harder – active learning and UiPath LLMs for do...UiPathCommunity
💥 Speed, accuracy, and scaling – discover the superpowers of GenAI in action with UiPath Document Understanding and Communications Mining™:
See how to accelerate model training and optimize model performance with active learning
Learn about the latest enhancements to out-of-the-box document processing – with little to no training required
Get an exclusive demo of the new family of UiPath LLMs – GenAI models specialized for processing different types of documents and messages
This is a hands-on session specifically designed for automation developers and AI enthusiasts seeking to enhance their knowledge in leveraging the latest intelligent document processing capabilities offered by UiPath.
Speakers:
👨🏫 Andras Palfi, Senior Product Manager, UiPath
👩🏫 Lenka Dulovicova, Product Program Manager, UiPath
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
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https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
PHP Frameworks: I want to break free (IPC Berlin 2024)Ralf Eggert
In this presentation, we examine the challenges and limitations of relying too heavily on PHP frameworks in web development. We discuss the history of PHP and its frameworks to understand how this dependence has evolved. The focus will be on providing concrete tips and strategies to reduce reliance on these frameworks, based on real-world examples and practical considerations. The goal is to equip developers with the skills and knowledge to create more flexible and future-proof web applications. We'll explore the importance of maintaining autonomy in a rapidly changing tech landscape and how to make informed decisions in PHP development.
This talk is aimed at encouraging a more independent approach to using PHP frameworks, moving towards a more flexible and future-proof approach to PHP development.
PHP Frameworks: I want to break free (IPC Berlin 2024)
Thermo mechanical characterization and damage of polymer materials:Application material Acrylonitrile Butadiene Styrene (ABS)
1. International Journal of Engineering Research and Development
e-ISSN: 2278-067X, p-ISSN: 2278-800X, www.ijerd.com
Volume 11, Issue 03 (March 2015), PP.53-59
53
Thermo mechanical characterization and damage of polymer
materials:Application material Acrylonitrile Butadiene
Styrene (ABS)
M.Barakat1
, I.Makadir1
, M.Elghorba1
1
Controls and Characterization Laboratory Mechanics of Materials and Structures,
National School of Electricity and Mechanics, Route d'El Jadida. BP 8118 Oasis Casablanca, Maroc
Abstract:Plastic materials occupy a large part in our daily lives because of their ease of installation and
relatively low production costs. The rapid technical development and we live brings more and more mechanical
engineers to face the problems of damage to materials. However, these problems are even more serious than
fatigue cracking often leads to a sudden break often cause accidents. This unfortunately happens all too
frequently, due to insufficient knowledge either room service conditions or even damage parameters. This work
presents new developments in the field of fracture mechanics and the objective is the evaluation of defects and
thus a better estimate of the reliability of the polymeric material structures
Keywords:polymer breakdown, damage, traction, ABS
I. INTRODUCTION
The polymers offer many features that make it appealing, one can distinguish their corrosion features, their
lightness, their low cost, their insulating character their ductility, numerous methods available to implement and
shape simultaneously.
Or, if one attaches only to their mechanical properties, their behavior is complex and is a major barrier [1], as
potential users find it difficult to be considered when sizing and optimization steps. However, because of the
presence of voids in the material, or even damage, cracks can start and propagate to a size causing the collapse
of the [2] structure.
To assess the level of damage to a structure subjected to a solicitation, two models exist: the mechanics of the
mechanical damage of the rupture [3] and this work is a contribution to the study of the failure mechanism an
ABS plate under uniaxial stress through the tensile test.
II. THEORY
The polymers offer many features that make it appealing, one can distinguish their corrosion features, their
lightness, their low cost, their insulating character their ductility, numerous methods available to implement and
shape simultaneously.
Or, if one attaches only to their mechanical properties, their behavior is complex and is a major barrier [1], as
potential users find it difficult to be considered when sizing and optimization steps. However, because of the
presence of voids in the material, or even damage, cracks can start and propagate to a size causing the collapse
of the [2] structure.
To assess the level of damage to a structure subjected to a solicitation, two models exist: the mechanics of the
mechanical damage of the rupture [3] and this work is a contribution to the study of the failure mechanism an
ABS plate under uniaxial stress through the tensile test:
γ D=( γ ur/ γ u)m
γD=( σD/ σD0) , γur=( σur/ σD0) , γu=( σu/ σD0)
or σD0 is the endurance limit of virgin material, σD is the limit of endurance instant of the material (after n
loading cycles) σur is the instantaneous value of the monotonic tensile strength of the material, σu is the
maximum strength monotonous traction of virgin material, m is an empirical constant. [6] model Bui Quoc [7]
provides a correlation between the tensile strength monotonic and cyclic loading, the resistance of a material to
a static effect diminishes if it has undergone previous cyclical nature of the application efforts of the static force
[8].We are talking about the reduction of the residual strength of [9] material. σur (equal to σer for polymers) is
the ultimate residual stress damaged material after n cycles of loading, σu (equal to σe for polymers) is the
Eq (1)
2. Thermomechanical characterization and damage of polymer materials: Application material…
54
ultimate tensile strength of the virgin material, β is the fraction of life and γ = σm / σD0 is the load level (mean
stress σm cyclical) [10]. for polymers, the ultimate stress σu and the stress at the yield σe are identical [11].
Thus, the parameter m is a parameter material with m = 1 for amorphous polymers [12]. The formulation of the
damage proposed by Bui Quoc is different from that previously presented by Miner [13]:
D=(1-γ D)/ (1-γ D
*
)
γD= σD/ σD0,γD
*
= σm/ σD0
σD: the endurance limit
σD*: Critical endurance limit
The damage model resulting fraction is a function of the life of the load and the mechanical properties of the
virgin material [14]:
or γu = σu /σD0 is a parameter characterizing the virgin material.
III. EXPERIMENTAL
The tensile tests conducted during the study are provided to characterize the material in terms of its mechanical
properties, determine its mechanical properties such as yield strength, Young's modulus, ultimate stress, etc. the
purpose of this section is to identify a pattern of behavior of the material that will be useful later in the
numerical modeling part.
For this purpose, uniaxial tensile test series were performed on specimens halters. [14], according to the
procedure already described in the previous chapter mode. And considering the guidelines prescribed by ASTM
D638-03 [15]. To characterize the function of the material temperature behavior, several series of tests were
performed in a temperature range from 60 ° C to 170 ° C, through the glass transition temperature which is in
the vicinity 110 ° C for each temperature value, the stress-strain curve is drawn to meet the measurands in
question for analyzing the thermomechanical behavior of the material. For each temperature, the evolution of
the ultimate stress against deformation, so that the change in the Young's modulus were reported.
Figure 1: Test piece dumbbell during a tensile test (left), Rupture of a dumbbell specimen types
ASTM D638-03 after static tensile test (right)
IV. RESULTS
In order to characterize the material as a function of the mechanical properties, we conduct tensile testing to
extract the various characteristics such as yield strength, Young's modulus, ultimate stress .After Treaty curves
produced by the machine traction, and after statistical analysis of the results, we can draw the average curve as
follows:
Eq (2)
Eq (3)
3. Thermomechanical characterization and damage of polymer materials: Application material…
55
Figure 2: Evolution of the stress versus strain
Tensile tests enable us to trace the evolution of the stress-strain curve up to failure and highlight the typical
behavior of polymers in large deformation. At the beginning of the trials, a linear zone is like rating reflecting
the proportionality between the applied force and elongation (field of elastic deformation), it allows us to obtain
the Young's modulus and yield strength. The obtained value of the Young's modulus is E = 2 GPa, a value
comparable with that provided by the literature (from 1.4 GPa to 3.1 GPa), and thus the value of the ultimate
stress which is σu = 32MPa, so that the elastic limit which is σ0,2% = 29,77MPa. The material starts to deform
beyond the value of 32MPa which has the boundary of the constraint after which more of linear proportionality
was observed between the stress and strain; this area is followed by an intrinsic softening portion corresponding
to the non-linear plastic deformation and continues with an increase in stress to a maximum after which it
decreases to a stabilization of the value as the elongation increases.
Effect of temperature on the behavior of ABS
The behavior of polymers depends strongly on the temperature. They are the site of behavioral transitions that
can be associated with different molecular relaxations. From the macroscopic point of view, this translates into
more brutal behavior changes in certain temperature ranges. Its influence is apparent on the physical
characteristics of the polymers in the behavioral study, specifically when it comes to the study of shaping
processes that require significant heat input and efforts must mécanique.Il note however that the behavior of
polymers is closely related to a known temperature range glass transition temperature Tg, below which, the
configuration of the macromolecular chains is widely immobile.Pour characterization of behavior of the
material according to the temperature, several sets of tests were performed in a temperature range from 60 ° C to
170 ° C, passing through the glass transition temperature which is in the vicinity of 110 ° C, for each
temperature value, the curve stress-strain is drawn to meet the measurands in question for analyzing the
thermomechanical behavior of the material.
0
5
10
15
20
25
30
35
0 1 2 3 4 5
Contrainte(Mpa)
Déformation (%)
1 mm/min
4. Thermomechanical characterization and damage of polymer materials: Application material…
56
Figure 3: evolution of the ultimate stress versus temperature
From figure which represents the evolution of the ultimate in function of temperature, we can distinguish three
important areas:From figure which represents the evolution of the ultimate in function of temperature, we can
distinguish three important areas:
• T g (= 110 ° C):
The curve of a progressively decreases gradually as the temperature rises but always keeping the mechanical
properties in this area because the polymer molecules are well aligned rows which gives the general ABS good
rigidity, good mechanical strength and low deformability
• Tg ˂ T ˂ Tf (= 150 ° C)
In this area the stress continues to decrease rapidly via the temperature increase up to reach a significant value of
the temperature (Tm = 150 ° C). In this state the crystalline phase does not change and its structure is identical
to what it was at T g (= 110 ° C), the amorphous phase is subjected to thermal activation change causing
movement of the molecules, a breaking the bonds of low energy between the molecules and increase the volume
of the polymer. This results in a greater ease of movement of the molecules.
• T ˃ Tm (150 ° C)
The material is completely degraded and it's already noticed in the course of the curve beyond the value T = 150
° C and ABS loses all its mechanical characteristics. The crystalline phase no longer exists because T> Tf, there
is no longer an amorphous phase. All molecules (those from the amorphous phase and that from the crystalline
phase) form balls. The nodes entanglement disappear crawling, the material flows like a fluid. The polymer is
malleable little mechanical strength, low stiffness ... Testing at the vicinity of the melting temperature was not
constructive specimen melts before the start of the test, and flows from the jaws the machine due to its weight,
and got no results later, the figure shows that the specimens were subjected to temperatures higher than 170 ° C:
Figure 4 specimens after tensile test at temperatures above 170 ° C
0
5
10
15
20
25
50 70 90 110 130 150 170 190
Contrainteultime(Mpa)
Température (°C)
5. Thermomechanical characterization and damage of polymer materials: Application material…
57
Figure 5: Test subject to tensile tests as a function of temperature
• Assessment of the damage:
All theoretical models of damage require confrontation with results from experiments, hence the need for a
standardized formulation of the damage. In the literature, several authors whose BuiQuoc proposed a model of
the normalized damage based on the variation of the residual resistance between virgin and her critical
condition:
In the case of cyclic loading, fatigue, fractions 𝛾 𝐷
and𝛾 𝐷
∗
are defined as:
𝛄 𝐃
=
𝛔 𝐃
𝛔 𝐃𝟎
, 𝑒𝑡𝛄 𝐃
∗
=
𝛔 𝐃
∗
𝛔 𝐃𝟎
𝜎 𝐷 the limit of endurance instant, 𝜎 𝐷
∗
the limit of endurance criticism, 𝜎 𝐷0 the endurance limit of virgin material.
In the case of a static load, the fraction𝛾 𝐷
characterizes the residual strength of the material after a damaging
stress. In this case of uniaxial tension coupled with a notch effect, the fraction may be defined showing the static
characteristics as follows:
𝛄 𝐃 =
𝛔 𝐮𝐫
𝛔 𝐮
𝜎 𝑢𝑟the residual ultimate limit,𝜎 𝑢the ultimate stress static pull of virgin material.
the parameter 𝛾 𝐷
∗
is a characteristic of the critical tensile strength. In the case of a uniaxial tensile test, it was
defined by showing the critical resistance to tensile breaking as follows:
𝛄 𝐃
∗
=
𝛔 𝐮𝐫
∗
𝛔 𝐮
𝜎 𝑢𝑟
∗
the ultimate stress critical.
The expression of the damage made by the equation (Eq6) can be rewritten as:
𝐃 𝐄𝐱𝐩 =
𝟏−𝛄 𝐃
𝟏−𝛄 𝐃
∗ =
𝟏−
𝛔 𝐮𝐫
𝛔 𝐮
𝟏−
𝛔 𝐮𝐫
∗
𝛔 𝐮
Thus defined, the normalized damage is calculated through experimental measurements on perforated
specimens. And its value is between 0 and 1.
The following curve shows the variation of damage depending on the dimensionless ratio of the temperature.
Eq (4)
Eq (5)
Eq (6)
Eq (7)
Eq (8)
𝑫 𝑬𝒙𝒑 =
𝟏 − 𝜸 𝑫
𝟏 − 𝜸 𝑫
∗
6. Thermomechanical characterization and damage of polymer materials: Application material…
58
Figure6 : damage evolution depending on the fraction of life β = T (initial) / T (final)
The above curve represents the change in terms of damage to temperature versus dimensionless ratio of the
temperature as we notice that each curve can be divided into three parts that define stages and the following
table summarizes the different features:
The results clearly show for each temperature (90 ° C, 110 ° C, 150 ° C), the development of standardized
experimental damage according to β = T (initial) / T (final). Whatever the temperature, the damage gradually
increases from 0 (virgin material) to its normalized value of 1.
In phase 1, ABS keeps a good mechanical strength. This is attributed to the morphology of the crack, which
has a continuity of matter through micro fibrils [TIJSS, 1995] and gives the material a nearly intact residual
strength.
In phase 2, this area is a progressive increase in damage.
Finally Phase 3 for β greater than 0.9, the damage is rapidly accelerating until it breaks. By analogy to
cracking, the beginning of this stage is the condition of instability leading to rupture.
Indeed for low , the material still has good resistance, which in terms of industrial removes any gain an
accurate assessment of the damage. By cons, for heavy loads, large, the level attained damage can lead to
material failure (critical injury: a phase of instability of the material making it unfit for service). Hence the need
to accurately predict the damage for high .
0
0.2
0.4
0.6
0.8
1
1.2
0 0.2 0.4 0.6 0.8 1 1.2
DommageD
T initiale/T finale
90°C
110°C
150°C
90°C 110°C 150°C
Stade I
β = (0 ; 0,6)
D= (0 ;0,88)
β = (0 ; 0,44)
D= (0 ; 0,76)
β =(0 ;0,30)
D=(0 ;0,6)
Stade II
β = (0,6 ; 0,88)
D=(0,88 ;0,94)
β =(0,44 ;0,84)
D=(0,76 ;0,96)
β =(0,30 ;0,92)
D=(0,6 ;0,92)
Stade III
β = (0,88 ; 1)
D= (0,94 ;1)
β =(0,84 ;1)
D=(0,96 ;1)
β =(0,92 ;1)
D=(0,92 ;1)
7. Thermomechanical characterization and damage of polymer materials: Application material…
59
IV. CONCLUSION
The thermal damage tests were preceded by thermophysical characterization tests to determine the
glass transition temperature of ABS, as well as its melting temperature. Then tensile tests on fracture under
controlled temperature were carried out in order to note the influence of temperature on the structural behavior
of the material;
• The glass transition temperature of ABS is Tg = 110 ° C,
• Its melting point is Tf = 196.19 ° C
• For temperatures vary between 20 ° C and 170 ° C, a degradation of the mechanical properties is observed, a
drop of the ultimate stress of the 99.5% in order from room temperature to 170 ° C,
• Elongation proportionally increases with the temperature, growth accelerates after the passage of the Tg.
REFERENCES
[1]. Sanchez-Santana U., Comportement dynamique des matériaux et structures après sollicitation en
fatigue. Thèse de doctorat, Université des sciences et technologies de Lille, 2007.
[2]. Criens R.M. and Moslé H.G., Faillure of plastics, edited by W. Brostow and R.D. Corneliunssen
Hauser, 1986.
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