The document discusses inelastic material behavior and yield criteria. It introduces nonlinear stress-strain relationships and various yield criteria models used for ductile and brittle materials, including maximum principal stress, Tresca shear stress, and von Mises distortional energy criteria. It also covers Hooke's law for isotropic elasticity and defines strain energy density. Key concepts discussed are nonlinear response, idealized stress-strain curves, general yield criteria concepts, and conditions for material yielding under multiaxial stress states.
This document discusses four common failure theories used to predict failure of materials under complex stress conditions:
1. Maximum shear stress (Tresca) theory, which states failure occurs when the maximum shear stress equals the yield shear stress.
2. Maximum principal stress (Rankine) theory, which uses the maximum principal stress.
3. Maximum normal strain (Saint Venant's) theory, which uses the maximum normal strain.
4. Maximum shear strain (distortion energy) theory, which uses the maximum shear strain. The document provides details on applying these theories including using Mohr's circle to determine principal stresses and strains.
Theory of Failure and failure analysis.pptchethansg8
This document discusses four common failure theories used to predict failure of materials under complex stress conditions:
1. Maximum shear stress (Tresca) theory, which states failure occurs when the maximum shear stress equals the yield shear stress.
2. Maximum principal stress (Rankine) theory, which uses the maximum principal stress.
3. Maximum normal strain (Saint Venant's) theory, which uses the maximum normal strain.
4. Maximum shear strain (distortion energy) theory, which uses the maximum shear strain. The document provides details on applying these theories including using Mohr's circle to determine principal stresses and strains.
1. The document discusses four common failure theories used in engineering: maximum shear stress theory, maximum principal stress theory, maximum normal strain theory, and maximum shear strain theory.
2. It provides details on the maximum shear stress (Tresca) theory, which states that failure occurs when the maximum shear stress equals the yield point stress under simple tension.
3. An example problem is presented involving determining the required diameter of a circular shaft using the maximum shear stress theory with a safety factor of 3, given the material properties and loads on the shaft.
This summary provides the key details about four failure theories in 3 sentences:
The document discusses four common failure theories: 1) Maximum shear stress (Tresca) theory, which predicts failure when maximum shear stress equals yield stress, applies to ductile materials. 2) Maximum principal stress (Rankine) theory, which predicts failure when largest principal stress reaches ultimate stress. 3) Maximum normal strain (Saint Venant) theory, which predicts failure when maximum normal strain equals yield strain. 4) Maximum shear strain (distortion energy) theory, which predicts failure when distortion energy per unit volume equals strain energy at failure. The theories attempt to predict failure of materials subjected to multiaxial stress states.
This document provides an overview of topics in elasticity that are relevant for a finite element analysis course. It summarizes stress and strain concepts, including definitions of normal, shearing, and elasticity strains. It also reviews linear elastic constitutive relationships through Hooke's law and the elasticity matrix for isotropic materials. Finally, it introduces strain energy density and notes that energy methods are important techniques in finite element analysis that satisfy equilibrium or compatibility in a global sense rather than pointwise.
This document provides an overview of topics in elasticity that are relevant for a finite element analysis course. It summarizes stress and strain concepts, including definitions of normal, shearing, and elasticity strains. It also reviews constitutive theory, describing Hooke's law and special cases for isotropic materials. Finally, it discusses strain energy and density and provides an overview of energy methods in elasticity, distinguishing between methods that assume equilibrium or compatibility.
This document provides an overview of topics in elasticity that are relevant for a finite element analysis course. It summarizes stress and strain concepts, including definitions of normal, shearing strains, and Hooke's law. It also describes constitutive relations for isotropic materials, including equations for plane stress and plane strain. Finally, it introduces strain energy density and provides an overview of energy methods in elasticity, noting that these methods satisfy equilibrium or compatibility in a global sense rather than pointwise.
This document discusses linear and non-linear elasticity concepts relevant to rock mechanics. It defines key terms like stress, strain, elastic moduli, and principal stresses/strains. It describes how stress and strain relate for isotropic materials using Hooke's law and elastic constants. It also covers the stress tensor, Mohr's circle, strain energy, and the differences between linear, perfectly elastic, elastic with hysteresis, and permanently deforming non-linear elastic models.
This document discusses four common failure theories used to predict failure of materials under complex stress conditions:
1. Maximum shear stress (Tresca) theory, which states failure occurs when the maximum shear stress equals the yield shear stress.
2. Maximum principal stress (Rankine) theory, which uses the maximum principal stress.
3. Maximum normal strain (Saint Venant's) theory, which uses the maximum normal strain.
4. Maximum shear strain (distortion energy) theory, which uses the maximum shear strain. The document provides details on applying these theories including using Mohr's circle to determine principal stresses and strains.
Theory of Failure and failure analysis.pptchethansg8
This document discusses four common failure theories used to predict failure of materials under complex stress conditions:
1. Maximum shear stress (Tresca) theory, which states failure occurs when the maximum shear stress equals the yield shear stress.
2. Maximum principal stress (Rankine) theory, which uses the maximum principal stress.
3. Maximum normal strain (Saint Venant's) theory, which uses the maximum normal strain.
4. Maximum shear strain (distortion energy) theory, which uses the maximum shear strain. The document provides details on applying these theories including using Mohr's circle to determine principal stresses and strains.
1. The document discusses four common failure theories used in engineering: maximum shear stress theory, maximum principal stress theory, maximum normal strain theory, and maximum shear strain theory.
2. It provides details on the maximum shear stress (Tresca) theory, which states that failure occurs when the maximum shear stress equals the yield point stress under simple tension.
3. An example problem is presented involving determining the required diameter of a circular shaft using the maximum shear stress theory with a safety factor of 3, given the material properties and loads on the shaft.
This summary provides the key details about four failure theories in 3 sentences:
The document discusses four common failure theories: 1) Maximum shear stress (Tresca) theory, which predicts failure when maximum shear stress equals yield stress, applies to ductile materials. 2) Maximum principal stress (Rankine) theory, which predicts failure when largest principal stress reaches ultimate stress. 3) Maximum normal strain (Saint Venant) theory, which predicts failure when maximum normal strain equals yield strain. 4) Maximum shear strain (distortion energy) theory, which predicts failure when distortion energy per unit volume equals strain energy at failure. The theories attempt to predict failure of materials subjected to multiaxial stress states.
This document provides an overview of topics in elasticity that are relevant for a finite element analysis course. It summarizes stress and strain concepts, including definitions of normal, shearing, and elasticity strains. It also reviews linear elastic constitutive relationships through Hooke's law and the elasticity matrix for isotropic materials. Finally, it introduces strain energy density and notes that energy methods are important techniques in finite element analysis that satisfy equilibrium or compatibility in a global sense rather than pointwise.
This document provides an overview of topics in elasticity that are relevant for a finite element analysis course. It summarizes stress and strain concepts, including definitions of normal, shearing, and elasticity strains. It also reviews constitutive theory, describing Hooke's law and special cases for isotropic materials. Finally, it discusses strain energy and density and provides an overview of energy methods in elasticity, distinguishing between methods that assume equilibrium or compatibility.
This document provides an overview of topics in elasticity that are relevant for a finite element analysis course. It summarizes stress and strain concepts, including definitions of normal, shearing strains, and Hooke's law. It also describes constitutive relations for isotropic materials, including equations for plane stress and plane strain. Finally, it introduces strain energy density and provides an overview of energy methods in elasticity, noting that these methods satisfy equilibrium or compatibility in a global sense rather than pointwise.
This document discusses linear and non-linear elasticity concepts relevant to rock mechanics. It defines key terms like stress, strain, elastic moduli, and principal stresses/strains. It describes how stress and strain relate for isotropic materials using Hooke's law and elastic constants. It also covers the stress tensor, Mohr's circle, strain energy, and the differences between linear, perfectly elastic, elastic with hysteresis, and permanently deforming non-linear elastic models.
1. The general procedure for the finite element method involves discretizing the domain into elements, selecting displacement functions to approximate displacements within each element, and establishing relationships between displacements, strains, and stresses to set up the governing equations.
2. A displacement-based approach is used where shape functions are chosen to describe the displacement field within an element and ensure continuity of displacements between elements.
3. The strain-displacement and stress-strain relationships are developed using the shape functions and material properties to create the elemental stiffness matrix which are then assembled in the global finite element model.
1. The general procedure for the finite element method involves discretizing the domain into elements, selecting displacement functions to approximate displacements within each element, and establishing relationships between displacements, strains, and stresses to set up the governing equations.
2. A displacement function is assumed for each element to describe the displacement at any point within the element in terms of nodal displacements. Shape functions are developed from the displacement functions.
3. The strain-displacement relationship is developed by taking derivatives of the displacement functions. Stress is related to strain through constitutive equations for linear elastic behavior.
The document discusses stress-strain curves, which plot the stress and strain of a material sample under load. It describes the typical stress-strain behavior of ductile materials like steel and brittle materials like concrete. For ductile materials, the curve shows an elastic region, yield point, strain hardening region, and ultimate strength before failure. The yield point marks the transition between elastic and plastic deformation. The document also discusses factors that influence a material's yield stress, such as temperature and strain rate, and implications for structural engineering like reduced buckling strength after yielding.
Linear elasticity theory assumes small deformations and the existence of an unstressed reference state. It relates stress and strain through generalized Hooke's law, with the elastic constants tensor. The stress power is the time derivative of the internal energy density, which defines an elastic potential. The stress is the derivative of this potential with respect to strain, and the elastic constants tensor is the second derivative of the potential.
This document discusses static failure theories for analyzing machine components under loading. It begins by asking why parts fail and explaining that failure depends on the material properties and type of loading. It then covers different failure modes and the need for separate theories for ductile and brittle materials. The key static failure theories presented are maximum normal stress theory, maximum shear stress theory, distortion energy theory, and their applications to ductile and brittle materials. Examples are provided to illustrate Mohr's circle analysis and applying the theories.
Mechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materials
This chapter discusses stress and strain in materials subjected to tension or compression. It defines stress as the load applied over the cross-sectional area. Strain is defined as the change in length over the original length. Hooke's law states that stress is proportional to strain for elastic materials. Young's modulus is the constant of proportionality between stress and strain. The chapter also discusses stress and strain calculations for materials with non-uniform cross-sections, as well as examples of stress and strain problems.
mechanics of materials presentation - vtuSuryaRS10
This document discusses concepts related to mechanics of materials including stress, elastic constants, thermal stresses, and the relationships between them. It defines stress as the intensity of internally distributed forces that resist external forces. It explains the four elastic constants - Young's modulus, shear modulus, bulk modulus, and Poisson's ratio. Thermal stresses that develop due to restraint against thermal expansion when temperature changes are also discussed. Complete restraint causes compressive thermal stresses proportional to the temperature change and coefficient of thermal expansion.
This Report presents a review of the definition of the equivalent crack concept by defining the relationship between two correlated theories, which are fracture mechanics and damage mechanics based on Mazars static damage model and derived in the framework of the thermodynamics of irreversible processes, an energetic equivalence between the two descriptions is proposed. This paper also presents an example of combined damage and fracture calculation on a concrete specimen, the energy consumption during crack propagation, modelled with damage mechanics, is computed. Finally, the paper provide a comparison for the fracture energy according to the damage model with experiments and linear elastic fracture mechanics
The document discusses plasticity theory and yield criteria. It introduces Hooke's law and its limitations under large strains. Generalized Hooke's law is presented for isotropic and anisotropic materials. Common stress-strain curves are shown including elastic-plastic and strain hardening responses. Several yield criteria are covered, including maximum principal stress, Tresca, and von Mises criteria. The von Mises criterion uses a second invariant of stress to predict yielding of ductile materials. An example compares predictions of yielding using Tresca and von Mises criteria for a given stress state in aluminum.
1) Fracture mechanics is the study of crack propagation in materials under stress. It considers failure as cracks growing through a structure rather than simultaneous failure.
2) Linear elastic fracture mechanics describes crack growth in elastic materials, while elastic-plastic fracture mechanics describes ductile crack growth in metals.
3) Fracture mechanics models failure using energy and strength criteria, considering the energy required to form new crack surface area.
Ekeeda is an online portal which creates and provides exclusive content for all branches engineering.To have more updates you can goto www.ekeeda.com..or you can contact on 8433429809...
This document discusses constitutive models for elastoplastic materials. It describes how elastoplastic materials behave elastically up to a certain stress limit, after which both elastic and plastic behavior occurs. The document outlines stress-strain curves for hypothetical materials under different loading conditions and discusses yield criteria and hardening rules used in plasticity models to describe the evolution of material behavior. It also summarizes common plasticity models including von Mises and Tresca and the assumptions underlying incremental plasticity theories.
Theory of Plasticity is a very important topic in solid mechanics & Strength of Materials. It is very very useful for Mechanical & Civil Engineering students.
The document discusses yield criteria, which is the relationship between stresses that predicts material yielding. It describes two common yield criteria: the von Mises yield criterion and Tresca criterion. The von Mises criterion states that yielding occurs when the second invariant of the deviatoric stress tensor exceeds a critical value. The Tresca criterion states that yielding occurs when the difference between the maximum and minimum principal stresses exceeds a critical value. The document provides equations and examples to explain these criteria. It concludes that the Tresca criterion guarantees no yield, so it is commonly used for safe design, while von Mises is widely used for plasticity analysis since it guarantees yielding.
Maximum principal stress theory.
Maximum shear stress theory.
Maximum shear strain theory.
Maximum strain energy theory.
Maximum shear strain energy theory.
2018SOE07-Kim-Computation of Added resistance of ships by using a frequency-d...SahilJawa3
This document summarizes research on using a frequency-domain Rankine panel method to compute the added resistance of ships in waves. It presents the background and motivation for accurately predicting added resistance. It reviews previous related work using frequency-domain and time-domain Rankine panel methods. It then describes the boundary value problem, basis potential evaluation, frequency-domain formulation, and higher-order B-spline panel numerical method used in the presented research. The research aims to efficiently and accurately predict added resistance for ship design and operation under IMO greenhouse gas emission regulations.
This document presents research on the static stability of an asymmetric sandwich beam with a viscoelastic core. The beam is subjected to an axial pulsating load and a one-dimensional temperature gradient. Equations of motion and boundary conditions are derived using Hamilton's energy principle. A set of Hill's equations is obtained using the Galerkin method to analyze the effects of various parameters on the non-dimensional static buckling loads. Parameters investigated include shear properties, geometric properties, core loss factors, and the thermal gradient.
1. The general procedure for the finite element method involves discretizing the domain into elements, selecting displacement functions to approximate displacements within each element, and establishing relationships between displacements, strains, and stresses to set up the governing equations.
2. A displacement-based approach is used where shape functions are chosen to describe the displacement field within an element and ensure continuity of displacements between elements.
3. The strain-displacement and stress-strain relationships are developed using the shape functions and material properties to create the elemental stiffness matrix which are then assembled in the global finite element model.
1. The general procedure for the finite element method involves discretizing the domain into elements, selecting displacement functions to approximate displacements within each element, and establishing relationships between displacements, strains, and stresses to set up the governing equations.
2. A displacement function is assumed for each element to describe the displacement at any point within the element in terms of nodal displacements. Shape functions are developed from the displacement functions.
3. The strain-displacement relationship is developed by taking derivatives of the displacement functions. Stress is related to strain through constitutive equations for linear elastic behavior.
The document discusses stress-strain curves, which plot the stress and strain of a material sample under load. It describes the typical stress-strain behavior of ductile materials like steel and brittle materials like concrete. For ductile materials, the curve shows an elastic region, yield point, strain hardening region, and ultimate strength before failure. The yield point marks the transition between elastic and plastic deformation. The document also discusses factors that influence a material's yield stress, such as temperature and strain rate, and implications for structural engineering like reduced buckling strength after yielding.
Linear elasticity theory assumes small deformations and the existence of an unstressed reference state. It relates stress and strain through generalized Hooke's law, with the elastic constants tensor. The stress power is the time derivative of the internal energy density, which defines an elastic potential. The stress is the derivative of this potential with respect to strain, and the elastic constants tensor is the second derivative of the potential.
This document discusses static failure theories for analyzing machine components under loading. It begins by asking why parts fail and explaining that failure depends on the material properties and type of loading. It then covers different failure modes and the need for separate theories for ductile and brittle materials. The key static failure theories presented are maximum normal stress theory, maximum shear stress theory, distortion energy theory, and their applications to ductile and brittle materials. Examples are provided to illustrate Mohr's circle analysis and applying the theories.
Mechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materialsMechanical properties of materials
This chapter discusses stress and strain in materials subjected to tension or compression. It defines stress as the load applied over the cross-sectional area. Strain is defined as the change in length over the original length. Hooke's law states that stress is proportional to strain for elastic materials. Young's modulus is the constant of proportionality between stress and strain. The chapter also discusses stress and strain calculations for materials with non-uniform cross-sections, as well as examples of stress and strain problems.
mechanics of materials presentation - vtuSuryaRS10
This document discusses concepts related to mechanics of materials including stress, elastic constants, thermal stresses, and the relationships between them. It defines stress as the intensity of internally distributed forces that resist external forces. It explains the four elastic constants - Young's modulus, shear modulus, bulk modulus, and Poisson's ratio. Thermal stresses that develop due to restraint against thermal expansion when temperature changes are also discussed. Complete restraint causes compressive thermal stresses proportional to the temperature change and coefficient of thermal expansion.
This Report presents a review of the definition of the equivalent crack concept by defining the relationship between two correlated theories, which are fracture mechanics and damage mechanics based on Mazars static damage model and derived in the framework of the thermodynamics of irreversible processes, an energetic equivalence between the two descriptions is proposed. This paper also presents an example of combined damage and fracture calculation on a concrete specimen, the energy consumption during crack propagation, modelled with damage mechanics, is computed. Finally, the paper provide a comparison for the fracture energy according to the damage model with experiments and linear elastic fracture mechanics
The document discusses plasticity theory and yield criteria. It introduces Hooke's law and its limitations under large strains. Generalized Hooke's law is presented for isotropic and anisotropic materials. Common stress-strain curves are shown including elastic-plastic and strain hardening responses. Several yield criteria are covered, including maximum principal stress, Tresca, and von Mises criteria. The von Mises criterion uses a second invariant of stress to predict yielding of ductile materials. An example compares predictions of yielding using Tresca and von Mises criteria for a given stress state in aluminum.
1) Fracture mechanics is the study of crack propagation in materials under stress. It considers failure as cracks growing through a structure rather than simultaneous failure.
2) Linear elastic fracture mechanics describes crack growth in elastic materials, while elastic-plastic fracture mechanics describes ductile crack growth in metals.
3) Fracture mechanics models failure using energy and strength criteria, considering the energy required to form new crack surface area.
Ekeeda is an online portal which creates and provides exclusive content for all branches engineering.To have more updates you can goto www.ekeeda.com..or you can contact on 8433429809...
This document discusses constitutive models for elastoplastic materials. It describes how elastoplastic materials behave elastically up to a certain stress limit, after which both elastic and plastic behavior occurs. The document outlines stress-strain curves for hypothetical materials under different loading conditions and discusses yield criteria and hardening rules used in plasticity models to describe the evolution of material behavior. It also summarizes common plasticity models including von Mises and Tresca and the assumptions underlying incremental plasticity theories.
Theory of Plasticity is a very important topic in solid mechanics & Strength of Materials. It is very very useful for Mechanical & Civil Engineering students.
The document discusses yield criteria, which is the relationship between stresses that predicts material yielding. It describes two common yield criteria: the von Mises yield criterion and Tresca criterion. The von Mises criterion states that yielding occurs when the second invariant of the deviatoric stress tensor exceeds a critical value. The Tresca criterion states that yielding occurs when the difference between the maximum and minimum principal stresses exceeds a critical value. The document provides equations and examples to explain these criteria. It concludes that the Tresca criterion guarantees no yield, so it is commonly used for safe design, while von Mises is widely used for plasticity analysis since it guarantees yielding.
Maximum principal stress theory.
Maximum shear stress theory.
Maximum shear strain theory.
Maximum strain energy theory.
Maximum shear strain energy theory.
2018SOE07-Kim-Computation of Added resistance of ships by using a frequency-d...SahilJawa3
This document summarizes research on using a frequency-domain Rankine panel method to compute the added resistance of ships in waves. It presents the background and motivation for accurately predicting added resistance. It reviews previous related work using frequency-domain and time-domain Rankine panel methods. It then describes the boundary value problem, basis potential evaluation, frequency-domain formulation, and higher-order B-spline panel numerical method used in the presented research. The research aims to efficiently and accurately predict added resistance for ship design and operation under IMO greenhouse gas emission regulations.
This document presents research on the static stability of an asymmetric sandwich beam with a viscoelastic core. The beam is subjected to an axial pulsating load and a one-dimensional temperature gradient. Equations of motion and boundary conditions are derived using Hamilton's energy principle. A set of Hill's equations is obtained using the Galerkin method to analyze the effects of various parameters on the non-dimensional static buckling loads. Parameters investigated include shear properties, geometric properties, core loss factors, and the thermal gradient.
ACEP Magazine edition 4th launched on 05.06.2024Rahul
This document provides information about the third edition of the magazine "Sthapatya" published by the Association of Civil Engineers (Practicing) Aurangabad. It includes messages from current and past presidents of ACEP, memories and photos from past ACEP events, information on life time achievement awards given by ACEP, and a technical article on concrete maintenance, repairs and strengthening. The document highlights activities of ACEP and provides a technical educational article for members.
Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...IJECEIAES
Climate change's impact on the planet forced the United Nations and governments to promote green energies and electric transportation. The deployments of photovoltaic (PV) and electric vehicle (EV) systems gained stronger momentum due to their numerous advantages over fossil fuel types. The advantages go beyond sustainability to reach financial support and stability. The work in this paper introduces the hybrid system between PV and EV to support industrial and commercial plants. This paper covers the theoretical framework of the proposed hybrid system including the required equation to complete the cost analysis when PV and EV are present. In addition, the proposed design diagram which sets the priorities and requirements of the system is presented. The proposed approach allows setup to advance their power stability, especially during power outages. The presented information supports researchers and plant owners to complete the necessary analysis while promoting the deployment of clean energy. The result of a case study that represents a dairy milk farmer supports the theoretical works and highlights its advanced benefits to existing plants. The short return on investment of the proposed approach supports the paper's novelty approach for the sustainable electrical system. In addition, the proposed system allows for an isolated power setup without the need for a transmission line which enhances the safety of the electrical network
A SYSTEMATIC RISK ASSESSMENT APPROACH FOR SECURING THE SMART IRRIGATION SYSTEMSIJNSA Journal
The smart irrigation system represents an innovative approach to optimize water usage in agricultural and landscaping practices. The integration of cutting-edge technologies, including sensors, actuators, and data analysis, empowers this system to provide accurate monitoring and control of irrigation processes by leveraging real-time environmental conditions. The main objective of a smart irrigation system is to optimize water efficiency, minimize expenses, and foster the adoption of sustainable water management methods. This paper conducts a systematic risk assessment by exploring the key components/assets and their functionalities in the smart irrigation system. The crucial role of sensors in gathering data on soil moisture, weather patterns, and plant well-being is emphasized in this system. These sensors enable intelligent decision-making in irrigation scheduling and water distribution, leading to enhanced water efficiency and sustainable water management practices. Actuators enable automated control of irrigation devices, ensuring precise and targeted water delivery to plants. Additionally, the paper addresses the potential threat and vulnerabilities associated with smart irrigation systems. It discusses limitations of the system, such as power constraints and computational capabilities, and calculates the potential security risks. The paper suggests possible risk treatment methods for effective secure system operation. In conclusion, the paper emphasizes the significant benefits of implementing smart irrigation systems, including improved water conservation, increased crop yield, and reduced environmental impact. Additionally, based on the security analysis conducted, the paper recommends the implementation of countermeasures and security approaches to address vulnerabilities and ensure the integrity and reliability of the system. By incorporating these measures, smart irrigation technology can revolutionize water management practices in agriculture, promoting sustainability, resource efficiency, and safeguarding against potential security threats.
Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
KuberTENes Birthday Bash Guadalajara - K8sGPT first impressionsVictor Morales
K8sGPT is a tool that analyzes and diagnoses Kubernetes clusters. This presentation was used to share the requirements and dependencies to deploy K8sGPT in a local environment.
Harnessing WebAssembly for Real-time Stateless Streaming PipelinesChristina Lin
Traditionally, dealing with real-time data pipelines has involved significant overhead, even for straightforward tasks like data transformation or masking. However, in this talk, we’ll venture into the dynamic realm of WebAssembly (WASM) and discover how it can revolutionize the creation of stateless streaming pipelines within a Kafka (Redpanda) broker. These pipelines are adept at managing low-latency, high-data-volume scenarios.
Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapte...University of Maribor
Slides from talk presenting:
Aleš Zamuda: Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapter and Networking.
Presentation at IcETRAN 2024 session:
"Inter-Society Networking Panel GRSS/MTT-S/CIS
Panel Session: Promoting Connection and Cooperation"
IEEE Slovenia GRSS
IEEE Serbia and Montenegro MTT-S
IEEE Slovenia CIS
11TH INTERNATIONAL CONFERENCE ON ELECTRICAL, ELECTRONIC AND COMPUTING ENGINEERING
3-6 June 2024, Niš, Serbia
3. First Law of thermodynamics
Law : The net external work and heat into the system is equal
to increase in potential and kinetic energies
W H U K
Variation of work δW of the external forces that act on the volume
V with surface S is equal to δWs and δWB
S B
xx xy xz yx yy yz zx zy zz x y z
V
W W W
u v w u v w u v w B u B v B w dV
x y z
4. First Law of thermodynamics
2 2 2
xx xx yy yy zz zz xy xy yz yz zx zx
V
W dV
which simplifies to
𝑈 =
𝑉
𝑈𝑜𝑑𝑉
Internal Energy per unit
volume
𝛿𝑈 =
𝑉
𝛿𝑈𝑜𝑑𝑉
Variation of internal
energy
5. First Law of thermodynamics
.
Relation between strain components and strain energy Uo
0 2 2 2
xx xx yy yy zz zz xy xy xz xz yz yz
U
Strain energy density function Uo depends on strain components,
the coordinates and the temperature
0 0 , , , , , , , , ,
xx yy zz xy xz yz
U U x y z T
Variations in strain components and the function Uo are related by
0 0 0 0 0 0
0 xx yy zz xy xz yz
xx yy zz xy xz yz
U U U U U U
U
6. Hooke’s law: Isotropic Elasticity
Isotropy : Directional independence
Homogeneity : Spatial independence
A material can be anisotropic and homogeneous or inhomogeneous and
anisotropic
Isotropic material - Two independent constants are required to describe
the material
1
( )
1
( )
1
( )
1 1
2
1 1
2
xx xx yy zz
yy yy xx zz
zz zz xx yy
xy xy xy
yz yz yz
E
E
E
G E
G E
Strain-stress relations are given
as :-
7. Hooke’s law: Isotropic Elasticity contd.
[(1 ) ( )]
(1 )(1 2 )
[(1 ) ( )]
(1 )(1 2 )
[(1 ) ( )]
(1 )(1 2 )
, ,
1 1 1
xx xx yy zz
yy yy xx zz
zz zz xx yy
xy xy xz xz yz yz
E
E
E
E E E
Alternatively the stress- strain relation can also be
written as :
8. Hooke’s law: Isotropic Elasticity contd.
In the case of plane stress,
0
zz xz yz
2
2
( )
1
( )
1
1
xx xx yy
yy xx yy
xy xy
E
E
E
In the case of plane strain,
0
zz xz yz
[(1 ) ]
(1 )(1 2 )
[ (1 ) ]
(1 )(1 2 )
( )
(1 )(1 2 )
, 0
(1 )
xx xx yy
yy xx yy
zz xx yy
xy xy xz yz
E
E
E
E
10. Objectives
Nonlinear material behavior
Yield criteria
Yielding in ductile materials
Sections
4.1 Limitations of Uniaxial Stress- Strain data
4.2 Nonlinear Material Response
4.3 Yield Criteria : General Concepts
4.4 Yielding of Ductile Materials
4.6 General Yielding
11. Introduction
When a material is elastic, it returns to the same state (at
macroscopic, microscopic and atomistic levels) upon removal
of all external load
Any material is not elastic can be assumed to be inelastic
E.g.. Viscoelastic, Viscoplastic, and plastic
To use the measured quantities like yield strength etc. we
need some criteria
The criteria are mathematical concepts motivated by strong
experimental observations
E.g. Ductile materials fail by shear stress on planes of
maximum shear stress
Brittle materials by direct tensile loading without much
yielding
Other factors affecting material behavior
- Temperature
- Rate of loading
- Loading/ Unloading cycles
16. Models for Uniaxial stress-strain
All constitutive equations are models that are supposed to
represent the physical behavior as described by experimental
stress-strain response
Experimental Stress strain curvesIdealized stress strain curves
Elastic- perfectly plastic
response
17. Models for Uniaxial stress-strain contd.
. Linear elastic response Elastic strain hardening response
20. The Yield Criteria : General concepts
General Theory of Plasticity defines
Yield criteria : predicts material yield under multi-axial state of
stress
Flow rule : relation between plastic strain increment and stress
increment
Hardening rule: Evolution of yield surface with strain
Yield Criterion is a mathematical postulate and is defined by a
yield function ,
( )
ij
f f Y
where Y is the yield strength in uniaxial load, and is correlated
with the history of stress state.
Maximum Principal Stress Criterion:- used for brittle materials
Maximum Principal Strain Criterion:- sometimes used for brittle materials
Strain energy density criterion:- ellipse in the principal stress plane
Maximum shear stress criterion (a.k.a Tresca):- popularly used for ductile materials
Von Mises or Distortional energy criterion:- most popular for ductile materials
Some Yield criteria developed over the years are:
21. Maximum Principal Stress Criterion
Originally proposed by Rankine
1 2 3
max , ,
f Y
1 Y
2 Y
3 Y
Yield surface is:
22. Maximum Principal Strain
This was originally proposed by St. Venant
1 1 2 3 0
f Y
1 2 3 Y
2 1 2 3 0
f Y
2 1 3 Y
3 3 1 2 0
f Y
3 1 2 Y
or
or
or
Hence the effective stress may be defined as
max
e i j k
i j k
The yield function may be defined as
e
f Y
23. Strain Energy Density Criterion
.
This was originally proposed by Beltrami
Strain energy density is found as
2 2 2
0 1 1 1 1 2 1 3 2 3
1
2 0
2
U
E
Strain energy density at yield in uniaxial tension test
2
0
2
Y
Y
U
E
Yield surface is given by
2 2 2 2
1 1 1 1 2 1 3 2 3
2 0
Y
2 2
e
f Y
2 2 2
1 1 1 1 2 1 3 2 3
2
e
24. Maximum Shear stress (Tresca) Criterion
.
This was originally proposed by Tresca
2
e
Y
f
Yield function is defined as
where the effective stress is
max
e
2 3
1
3 1
2
1 2
3
2
2
2
Magnitude of the extreme values of the stresses
are
Conditions in which yielding
can occur in a
multi-axial stress state
2 3
3 1
1 2
Y
Y
Y
25. Distortional Energy Density (von Mises)
Criterion
Originally proposed by von Mises & is the most popular for ductile materials
Total strain energy density = SED due to volumetric change +SED due to distortion
2 2 2 2
1 2 3 1 2 2 3 3 1
0
18 12
U
G
2 2 2
1 2 2 3 3 1
12
D
U
G
The yield surface is given by
2
2
1
3
J Y
2 2 2 2
1 2 2 3 3 1
1 1
6 3
f Y
26. Distortional Energy Density (von Mises)
Criterion contd.
Alternate form of the yield function
2 2
e
f Y
where the effective stress is
2 2 2
1 2 2 3 3 1 2
1
3
2
e J
2 2 2 2 2 2
1
3
2
e xx yy yy zz zz xx xy yz xz
J2 and the octahedral shear stress are related by
2
2
3
2
oct
J
Hence the von Mises yield criterion can be written as
2
3
oct
f Y
27. Problems
4.7: The design loads of a member made of a brittle
material produce the following nonzero stress
components at the critical section in the member
𝜎𝑥𝑥 = −60𝑀𝑃𝑎, 𝜎𝑦𝑦 = 80𝑀𝑃𝑎, 𝑎𝑛𝑑 𝜎𝑥𝑦 = 70𝑀𝑃𝑎. The
ultimate strength of the material is 460MPa.
Determine the factor of safety used in the design.
a. Apply the maximum principal stress criterion
b. Apply the maximum principal strain criterion
and use 𝜐 = 0.20
28. Problems
4.10: A member made of steel (𝐸 =
200𝐺𝑃𝑎 𝑎𝑛𝑑 𝜐 = 0.29) is subjected to state of
plane strain when the design loads are applied. At
the critical point in the member, three state of the
stress components are 𝜎𝑥𝑥 = 60𝑀𝑃𝑎, 𝜎𝑦𝑦 =
240𝑀𝑃𝑎, 𝑎𝑛𝑑 𝜎𝑥𝑦 = −80𝑀𝑃𝑎. The material has a
yield stress 𝑌 = 490. Based on the maximum shear-
stress criterion determine the factor of safety.
4.11: Solve problem 4.10 using octahedral shear-
stress criterion.
29. General Yielding
The failure of a material is when the structure cannot support
the intended function
For some special cases, the loading will continue to increase
even beyond the initial load
At this point, part of the member will still be in elastic range.
When the entire member reaches the inelastic range, then the
general yielding occurs
2
,
6
Y Y
bh
P Ybh M Y
P Y
P Ybh P
2
1.5
4
P Y
bh
M Y M
30. Elastic Plastic Bending
Consider a beam made up of elastic-perfectly plastic material
subjected to bending. We want to find the maximum bending
moment the beam can sustain
1 ( )
,
( )
zz Y
Y
k a
where
Y
b
E
( )
2
Y
h
y c
k
0 ( )
Z zz
F dA d
/2
0
/2
0
2 2 0
2 2 ( )
Y
Y
Y
Y
y h
x ZZ y
y
y h
EP zz
y
M M ydA Y dA
or
M M ydA Y ydA e
31. Elastic Plastic Bending contd.
2
2 2
3 1 3 1
(4.43)
6 2 2 2 2
EP Y
Ybh
M M
k k
3
2
EP Y P
M M M
2
, /6
Y
where M Ybh
as k becomes large
32. Fully Plastic Bending
Definition: Bending required to
cause yielding either in tension
or compression over the entire
cross section
0
z zz
F dA
Equilibrium condition
Fully plastic moment is
2
P
t b
M Ybt
33. Comparison of failure yield criteria
For a tensile specimen
of ductile steel the
following six quantities
attain their critical
values at the same load
PY
1. Maximum principal stress reaches the yield strength Y
2. Maximum principal strain reaches the value
3. Strain energy Uo absorbed by the material per unit volume reaches
the value
4. The maximum shear stress reaches the
tresca shear strength
5. The distortional energy density UD reaches
6. The octahedral shear stress
max
( / )
Y
P A
max max
( / )
E
/
Y Y E
2
0 / 2
Y
U Y E
max
( / 2 )
Y
P A
( / 2)
Y Y
2
/ 6
DY
U Y G
2 /3 0.471
oct Y Y
The practical application of mathematics and science to create, design, test, improve, and develop knowledge, research, money, business, economics, and technology.
This is why engineering is such a challenging and demanding field of study: It involves areas of expertise that continue to evolve independently yet are required to perform together as part of the engineering process. Thus, an engineer must be expert in many areas, must know how to communicate knowledge between those areas, and must apply that knowledge to create, design, study, research, and invent all kinds of things. It is not uncommon for engineers to begin their careers as mathematicians, applied scientists, or even economists
The practical application of mathematics and science to create, design, test, improve, and develop knowledge, research, money, business, economics, and technology.
This is why engineering is such a challenging and demanding field of study: It involves areas of expertise that continue to evolve independently yet are required to perform together as part of the engineering process. Thus, an engineer must be expert in many areas, must know how to communicate knowledge between those areas, and must apply that knowledge to create, design, study, research, and invent all kinds of things. It is not uncommon for engineers to begin their careers as mathematicians, applied scientists, or even economists
The practical application of mathematics and science to create, design, test, improve, and develop knowledge, research, money, business, economics, and technology.
This is why engineering is such a challenging and demanding field of study: It involves areas of expertise that continue to evolve independently yet are required to perform together as part of the engineering process. Thus, an engineer must be expert in many areas, must know how to communicate knowledge between those areas, and must apply that knowledge to create, design, study, research, and invent all kinds of things. It is not uncommon for engineers to begin their careers as mathematicians, applied scientists, or even economists
The practical application of mathematics and science to create, design, test, improve, and develop knowledge, research, money, business, economics, and technology.
This is why engineering is such a challenging and demanding field of study: It involves areas of expertise that continue to evolve independently yet are required to perform together as part of the engineering process. Thus, an engineer must be expert in many areas, must know how to communicate knowledge between those areas, and must apply that knowledge to create, design, study, research, and invent all kinds of things. It is not uncommon for engineers to begin their careers as mathematicians, applied scientists, or even economists
The practical application of mathematics and science to create, design, test, improve, and develop knowledge, research, money, business, economics, and technology.
This is why engineering is such a challenging and demanding field of study: It involves areas of expertise that continue to evolve independently yet are required to perform together as part of the engineering process. Thus, an engineer must be expert in many areas, must know how to communicate knowledge between those areas, and must apply that knowledge to create, design, study, research, and invent all kinds of things. It is not uncommon for engineers to begin their careers as mathematicians, applied scientists, or even economists
The practical application of mathematics and science to create, design, test, improve, and develop knowledge, research, money, business, economics, and technology.
This is why engineering is such a challenging and demanding field of study: It involves areas of expertise that continue to evolve independently yet are required to perform together as part of the engineering process. Thus, an engineer must be expert in many areas, must know how to communicate knowledge between those areas, and must apply that knowledge to create, design, study, research, and invent all kinds of things. It is not uncommon for engineers to begin their careers as mathematicians, applied scientists, or even economists
The practical application of mathematics and science to create, design, test, improve, and develop knowledge, research, money, business, economics, and technology.
This is why engineering is such a challenging and demanding field of study: It involves areas of expertise that continue to evolve independently yet are required to perform together as part of the engineering process. Thus, an engineer must be expert in many areas, must know how to communicate knowledge between those areas, and must apply that knowledge to create, design, study, research, and invent all kinds of things. It is not uncommon for engineers to begin their careers as mathematicians, applied scientists, or even economists
The practical application of mathematics and science to create, design, test, improve, and develop knowledge, research, money, business, economics, and technology.
This is why engineering is such a challenging and demanding field of study: It involves areas of expertise that continue to evolve independently yet are required to perform together as part of the engineering process. Thus, an engineer must be expert in many areas, must know how to communicate knowledge between those areas, and must apply that knowledge to create, design, study, research, and invent all kinds of things. It is not uncommon for engineers to begin their careers as mathematicians, applied scientists, or even economists
The practical application of mathematics and science to create, design, test, improve, and develop knowledge, research, money, business, economics, and technology.
This is why engineering is such a challenging and demanding field of study: It involves areas of expertise that continue to evolve independently yet are required to perform together as part of the engineering process. Thus, an engineer must be expert in many areas, must know how to communicate knowledge between those areas, and must apply that knowledge to create, design, study, research, and invent all kinds of things. It is not uncommon for engineers to begin their careers as mathematicians, applied scientists, or even economists
The practical application of mathematics and science to create, design, test, improve, and develop knowledge, research, money, business, economics, and technology.
This is why engineering is such a challenging and demanding field of study: It involves areas of expertise that continue to evolve independently yet are required to perform together as part of the engineering process. Thus, an engineer must be expert in many areas, must know how to communicate knowledge between those areas, and must apply that knowledge to create, design, study, research, and invent all kinds of things. It is not uncommon for engineers to begin their careers as mathematicians, applied scientists, or even economists
The practical application of mathematics and science to create, design, test, improve, and develop knowledge, research, money, business, economics, and technology.
This is why engineering is such a challenging and demanding field of study: It involves areas of expertise that continue to evolve independently yet are required to perform together as part of the engineering process. Thus, an engineer must be expert in many areas, must know how to communicate knowledge between those areas, and must apply that knowledge to create, design, study, research, and invent all kinds of things. It is not uncommon for engineers to begin their careers as mathematicians, applied scientists, or even economists
The practical application of mathematics and science to create, design, test, improve, and develop knowledge, research, money, business, economics, and technology.
This is why engineering is such a challenging and demanding field of study: It involves areas of expertise that continue to evolve independently yet are required to perform together as part of the engineering process. Thus, an engineer must be expert in many areas, must know how to communicate knowledge between those areas, and must apply that knowledge to create, design, study, research, and invent all kinds of things. It is not uncommon for engineers to begin their careers as mathematicians, applied scientists, or even economists
The practical application of mathematics and science to create, design, test, improve, and develop knowledge, research, money, business, economics, and technology.
This is why engineering is such a challenging and demanding field of study: It involves areas of expertise that continue to evolve independently yet are required to perform together as part of the engineering process. Thus, an engineer must be expert in many areas, must know how to communicate knowledge between those areas, and must apply that knowledge to create, design, study, research, and invent all kinds of things. It is not uncommon for engineers to begin their careers as mathematicians, applied scientists, or even economists