This document discusses adaptive structures that use piezoelectric materials as actuators. It begins by describing the constitutive relations for piezoelectric materials, accounting for mechanical, thermal, and electrical strains. It then presents models for beam and plate structures actuated by piezoelectric patches, including a block force model for beams and models incorporating the Euler-Bernoulli beam theory and classical laminate plate theory. The models are used to analyze how piezoelectric actuators can induce extension, bending, twisting and other deformations in beam and plate structures.
This document provides an overview of experimental strain analysis techniques, specifically focusing on strain gages, photoelasticity, and moire methods. It describes how strain gages use changes in electrical resistance to measure strain, and how they are usually connected to a Wheatstone bridge circuit to improve measurement sensitivity. Photoelasticity and moire methods allow full-field displays of strain distributions by exploiting the birefringent properties of certain materials, in which refractive index depends on polarization orientation.
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 summarizes research on Casimir torque in the weak coupling approximation. It examines manifestations of Casimir torque between planar objects characterized by delta function potentials. The key findings are:
1) An exact calculation of the Casimir torque between a finite rectangular plate above a semi-infinite plate is presented and agrees well with the proximity force approximation when the plate separation is small compared to their sizes.
2) Cusps in the torque arise when the corners of the finite plate pass over the edge of the semi-infinite plate.
3) A similar calculation is done for a disk above a semi-infinite plate, again finding good agreement with the proximity force approximation.
In this section the concept of stress will be introduced, and this will be applied to components that are in a state of tension, compression, and shear. Strain measurement methods will also be briefly discussed.
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.
1) The document discusses bending of curved beams and determining stresses in components like crane hooks and circular rings. Equations are derived for stresses in curved beams based on assumptions of plane sections remaining plane and Hooke's law.
2) Stresses in circular rings subjected to tension or compression from diametric loads are analyzed. Maximum stresses occur where the load is applied.
3) Stresses in chain links subjected to tensile loads are similarly analyzed, finding maximum stresses on the inner and outer surfaces and along the straight and curved portions.
4) Deflection of curved beams due to applied bending moments is also briefly discussed.
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This document provides an overview of experimental strain analysis techniques, specifically focusing on strain gages, photoelasticity, and moire methods. It describes how strain gages use changes in electrical resistance to measure strain, and how they are usually connected to a Wheatstone bridge circuit to improve measurement sensitivity. Photoelasticity and moire methods allow full-field displays of strain distributions by exploiting the birefringent properties of certain materials, in which refractive index depends on polarization orientation.
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 summarizes research on Casimir torque in the weak coupling approximation. It examines manifestations of Casimir torque between planar objects characterized by delta function potentials. The key findings are:
1) An exact calculation of the Casimir torque between a finite rectangular plate above a semi-infinite plate is presented and agrees well with the proximity force approximation when the plate separation is small compared to their sizes.
2) Cusps in the torque arise when the corners of the finite plate pass over the edge of the semi-infinite plate.
3) A similar calculation is done for a disk above a semi-infinite plate, again finding good agreement with the proximity force approximation.
In this section the concept of stress will be introduced, and this will be applied to components that are in a state of tension, compression, and shear. Strain measurement methods will also be briefly discussed.
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.
1) The document discusses bending of curved beams and determining stresses in components like crane hooks and circular rings. Equations are derived for stresses in curved beams based on assumptions of plane sections remaining plane and Hooke's law.
2) Stresses in circular rings subjected to tension or compression from diametric loads are analyzed. Maximum stresses occur where the load is applied.
3) Stresses in chain links subjected to tensile loads are similarly analyzed, finding maximum stresses on the inner and outer surfaces and along the straight and curved portions.
4) Deflection of curved beams due to applied bending moments is also briefly discussed.
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
The document presents an analytical method called the dynamic stiffness matrix approach to analyze the torsional vibrations and buckling of thin-walled beams of open section that are resting on an elastic foundation. The method is used to study a thin-walled beam that is clamped at one end and simply supported at the other. Numerical results for the natural frequencies and buckling loads are obtained for different values of warping and elastic foundation parameters.
IJCER (www.ijceronline.com) International Journal of computational Engineerin...ijceronline
This document summarizes an article that presents an analytical model for the electromechanical dynamics of a simply-supported micro-plate subjected to electrostatic excitation. The model derives equations of motion for the plate and uses Galerkin's method to obtain closed-form solutions for static deflection and natural frequencies. The effect of applied voltage, gap height, and plate dimensions on natural frequencies is illustrated. A reduced-order model is also developed and compared to the distributed parameter model.
- Saint-Venant's principle states that the stress and strain distribution on a cross-section of a loaded material will be independent of the applied load if the cross-section is located away from the point of load application.
- The principle of superposition allows breaking down structures into individual load cases and adding their effects to determine the total stress, strain, or deflection.
- Statically indeterminate structures require additional compatibility equations relating deformations to solve for member forces.
Strengthofmaterialsbyskmondal 130102103545-phpapp02Priyabrata Behera
This document contains a table of contents for a book on strength of materials with 16 chapters covering topics like stress and strain, bending, torsion, columns, and failure theories. It also contains introductory material on stress, strain, Hooke's law, true stress and strain, volumetric strain, Young's modulus, shear modulus, and bulk modulus. Key definitions provided include normal stress, shear stress, tensile strain, compressive strain, engineering stress and strain, true stress and strain, Hooke's law, and the relationships between elastic constants.
This document discusses strain gages and how they work to measure strain. It provides the following key points:
- Strain gages use the principle that a material's electrical resistance changes with its physical deformation. They measure this small resistance change to determine strain.
- Strain gages are most commonly arranged in a Wheatstone bridge circuit to convert the small resistance change into a measurable voltage change.
- Different strain gage configurations (1, 2, or 4 gages) are used depending on the type of strain being measured and whether temperature compensation is required.
- Common applications discussed include using strain gages to measure bending stress, torsional stress, shear stress, and torque. Equations
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 plate and shell elements for structural analysis. Plate elements are used to model flat surfaces, while shell elements model curved surfaces. Kirchhoff plate theory and Reissner-Mindlin plate theory are described for modeling plate bending, with the latter including transverse shear deformations. The derivation of a rectangular plate bending element is shown, involving assumed displacement fields and strain-curvature relationships. Shell elements can be formulated by combining plate and plane stress elements. Limitations of Kirchhoff shell elements for nearly coplanar or folded plate structures are noted.
This document provides an overview of statics concepts including:
- Forces on particles in 2D and 3D space including addition and resolution of forces
- Equilibrium of particles and rigid bodies using free body diagrams
- Moments of forces about points and axes
- Force couples and equivalent force systems
- Example problems are provided to demonstrate applying concepts to determine tensions, components of forces, moments, and equivalent single forces.
This document provides an overview of topics in strength of materials and mechanics of solids. It includes 51 pages on topics like stress and strain, shear force and bending moment diagrams in beams, torsion, deflection of beams, thin shells and principal stresses, trusses, and more. The table of contents lists 13 main topics covered across two pages, including sub-topics like different types of beams, shafts, springs, and methods for solving various problems.
Effect of Piezoelectric Layer on Beam Parameters using Zigzag TheoryIDES Editor
An efficient higher order theory is presented for
static analysis of multilayered composite beams with
piezoelectric layers embedded or bonded to the surface, under
static electromechanical load. In this theory, the in-plane
displacement field is taken as a combination of a layer-wise
linear variation and a cubic variation across the thickness.
Transverse normal strains are neglected. The electric field is
also approximated as piecewise linear across the sub layers.
The displacement field is expressed in terms of only three
primary displacement variables excluding electric potential
variables by enforcing the conditions of zero transverse shear
stress at top and bottom of the beam and its continuity at layer
interfaces under general electromechanical loading. The effect
of thickness of the piezo-layer is observed for various loading
conditions. Also, the effect of beam lay-up on various
parameters is studied.
This document contains the teaching schedule and lecture topics for a course on complex strains taught by Dr. Alessandro Palmeri. The course covers various topics related to complex stress and strain analysis, including beam shear stresses, shear centres, virtual forces, compatibility methods, moment distribution methods, column stability, unsymmetric bending, and complex stress/strain analysis. Lectures are delivered by Dr. Palmeri and other staff members. Tutorial sessions are also included to provide examples and applications of the taught concepts. The schedule lists the topics to be covered in each week across the 12-week term, with exams occurring in the final two weeks.
1. The document discusses structures, loads, stresses, strains and material properties related to mechanics of materials.
2. It defines key terms like stress, strain, elastic modulus and explains stress-strain relationships. Common stress types like tensile, compressive, shear and their effects are described.
3. Examples of different structures like cylinders, spheres, arches, towers and bridges are provided to illustrate stress distributions and effects of loads. Material properties of common materials are also listed.
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.
Torsional vibrations and buckling of thin WALLED BEAMSSRINIVASULU N V
The document discusses the torsional vibrations and buckling of thin-walled beams on elastic foundation using a dynamic stiffness matrix method. It develops analytical equations to model the behavior of clamped-simply supported beams under an axial load and resting on an elastic foundation. Numerical results are presented for natural frequencies and buckling loads for different values of warping and foundation parameters. The dynamic stiffness matrix approach can accurately analyze beams with non-uniform cross-sections and complex boundary conditions.
This document contains conceptual problems and questions about static equilibrium and elasticity. It includes the following:
1) True/false questions about the conditions for static equilibrium.
2) A question about the tension in different parts of a wire made of aluminum and steel.
3) Derivations of the expression for Young's modulus based on an atomic model and an estimate of the atomic force constant.
4) Questions involving calculating tensions, normal forces, and torque in situations involving objects in equilibrium, such as masts on sailboats and cylinders on steps.
5) Questions involving static equilibrium conditions to solve for quantities like the location of a person's center of gravity and the height a ladder can
This document provides an introduction to elastic-plastic fracture mechanics (EPFM). It discusses the key concepts of EPFM including crack tip opening displacement (CTOD) and the J-integral. CTOD and J-integral are used to characterize fracture toughness in large-scale plastic deformation, unlike linear elastic fracture mechanics (LEFM) which is only valid for small plastic zones. Measurement methods and applications of CTOD and J-integral are also covered along with background on plasticity theory and LEFM concepts.
This document provides an overview of beam and column design concepts. It discusses types of beam supports, beams, shear force and bending moment diagrams, stresses in beams from bending and shear, and beam deflection calculations. It also covers column buckling, including the Euler buckling formula and Johnson's equation. The document provides examples of calculating stresses, strains, deflections, and buckling loads for different beam and column scenarios.
This document summarizes a research paper on modeling the sound radiation from a baffled composite rectangular panel with a line constraint. It presents the following key points:
1) Researchers used receptance theory to model a composite panel with springs attached along a line, representing a constraint. This allowed calculating new natural frequencies and mode shapes of the constrained system.
2) The response of the constrained panel to a point force was determined using the new mode shapes. Sound pressure radiated from the vibrating panel was then estimated using Rayleigh's integral.
3) Sound power calculations integrated the sound pressure over a hemispherical surface in the far field to obtain the total power radiated by the constrained vibrating panel.
1) The document discusses the seismic behavior of frame structures equipped with passive dampers. It covers damping reduction factors, complex damping theory applied to adjacent buildings connected by dampers, peak interstory velocity profiles, nonlinear viscous damping ratios, and behavior factors for damped structures.
2) Complex damping theory models a damped structure using a generalized single-degree-of-freedom system and complex frequencies and modes. This allows modeling of energy dissipation through damping.
3) Nonlinear viscous dampers can be modeled using an equivalent linear damper. The equivalent damping ratio depends on the maximum displacement and approaches the design damping ratio as the displacement decreases toward the design level.
The document presents an analytical method called the dynamic stiffness matrix approach to analyze the torsional vibrations and buckling of thin-walled beams of open section that are resting on an elastic foundation. The method is used to study a thin-walled beam that is clamped at one end and simply supported at the other. Numerical results for the natural frequencies and buckling loads are obtained for different values of warping and elastic foundation parameters.
IJCER (www.ijceronline.com) International Journal of computational Engineerin...ijceronline
This document summarizes an article that presents an analytical model for the electromechanical dynamics of a simply-supported micro-plate subjected to electrostatic excitation. The model derives equations of motion for the plate and uses Galerkin's method to obtain closed-form solutions for static deflection and natural frequencies. The effect of applied voltage, gap height, and plate dimensions on natural frequencies is illustrated. A reduced-order model is also developed and compared to the distributed parameter model.
- Saint-Venant's principle states that the stress and strain distribution on a cross-section of a loaded material will be independent of the applied load if the cross-section is located away from the point of load application.
- The principle of superposition allows breaking down structures into individual load cases and adding their effects to determine the total stress, strain, or deflection.
- Statically indeterminate structures require additional compatibility equations relating deformations to solve for member forces.
Strengthofmaterialsbyskmondal 130102103545-phpapp02Priyabrata Behera
This document contains a table of contents for a book on strength of materials with 16 chapters covering topics like stress and strain, bending, torsion, columns, and failure theories. It also contains introductory material on stress, strain, Hooke's law, true stress and strain, volumetric strain, Young's modulus, shear modulus, and bulk modulus. Key definitions provided include normal stress, shear stress, tensile strain, compressive strain, engineering stress and strain, true stress and strain, Hooke's law, and the relationships between elastic constants.
This document discusses strain gages and how they work to measure strain. It provides the following key points:
- Strain gages use the principle that a material's electrical resistance changes with its physical deformation. They measure this small resistance change to determine strain.
- Strain gages are most commonly arranged in a Wheatstone bridge circuit to convert the small resistance change into a measurable voltage change.
- Different strain gage configurations (1, 2, or 4 gages) are used depending on the type of strain being measured and whether temperature compensation is required.
- Common applications discussed include using strain gages to measure bending stress, torsional stress, shear stress, and torque. Equations
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 plate and shell elements for structural analysis. Plate elements are used to model flat surfaces, while shell elements model curved surfaces. Kirchhoff plate theory and Reissner-Mindlin plate theory are described for modeling plate bending, with the latter including transverse shear deformations. The derivation of a rectangular plate bending element is shown, involving assumed displacement fields and strain-curvature relationships. Shell elements can be formulated by combining plate and plane stress elements. Limitations of Kirchhoff shell elements for nearly coplanar or folded plate structures are noted.
This document provides an overview of statics concepts including:
- Forces on particles in 2D and 3D space including addition and resolution of forces
- Equilibrium of particles and rigid bodies using free body diagrams
- Moments of forces about points and axes
- Force couples and equivalent force systems
- Example problems are provided to demonstrate applying concepts to determine tensions, components of forces, moments, and equivalent single forces.
This document provides an overview of topics in strength of materials and mechanics of solids. It includes 51 pages on topics like stress and strain, shear force and bending moment diagrams in beams, torsion, deflection of beams, thin shells and principal stresses, trusses, and more. The table of contents lists 13 main topics covered across two pages, including sub-topics like different types of beams, shafts, springs, and methods for solving various problems.
Effect of Piezoelectric Layer on Beam Parameters using Zigzag TheoryIDES Editor
An efficient higher order theory is presented for
static analysis of multilayered composite beams with
piezoelectric layers embedded or bonded to the surface, under
static electromechanical load. In this theory, the in-plane
displacement field is taken as a combination of a layer-wise
linear variation and a cubic variation across the thickness.
Transverse normal strains are neglected. The electric field is
also approximated as piecewise linear across the sub layers.
The displacement field is expressed in terms of only three
primary displacement variables excluding electric potential
variables by enforcing the conditions of zero transverse shear
stress at top and bottom of the beam and its continuity at layer
interfaces under general electromechanical loading. The effect
of thickness of the piezo-layer is observed for various loading
conditions. Also, the effect of beam lay-up on various
parameters is studied.
This document contains the teaching schedule and lecture topics for a course on complex strains taught by Dr. Alessandro Palmeri. The course covers various topics related to complex stress and strain analysis, including beam shear stresses, shear centres, virtual forces, compatibility methods, moment distribution methods, column stability, unsymmetric bending, and complex stress/strain analysis. Lectures are delivered by Dr. Palmeri and other staff members. Tutorial sessions are also included to provide examples and applications of the taught concepts. The schedule lists the topics to be covered in each week across the 12-week term, with exams occurring in the final two weeks.
1. The document discusses structures, loads, stresses, strains and material properties related to mechanics of materials.
2. It defines key terms like stress, strain, elastic modulus and explains stress-strain relationships. Common stress types like tensile, compressive, shear and their effects are described.
3. Examples of different structures like cylinders, spheres, arches, towers and bridges are provided to illustrate stress distributions and effects of loads. Material properties of common materials are also listed.
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.
Torsional vibrations and buckling of thin WALLED BEAMSSRINIVASULU N V
The document discusses the torsional vibrations and buckling of thin-walled beams on elastic foundation using a dynamic stiffness matrix method. It develops analytical equations to model the behavior of clamped-simply supported beams under an axial load and resting on an elastic foundation. Numerical results are presented for natural frequencies and buckling loads for different values of warping and foundation parameters. The dynamic stiffness matrix approach can accurately analyze beams with non-uniform cross-sections and complex boundary conditions.
This document contains conceptual problems and questions about static equilibrium and elasticity. It includes the following:
1) True/false questions about the conditions for static equilibrium.
2) A question about the tension in different parts of a wire made of aluminum and steel.
3) Derivations of the expression for Young's modulus based on an atomic model and an estimate of the atomic force constant.
4) Questions involving calculating tensions, normal forces, and torque in situations involving objects in equilibrium, such as masts on sailboats and cylinders on steps.
5) Questions involving static equilibrium conditions to solve for quantities like the location of a person's center of gravity and the height a ladder can
This document provides an introduction to elastic-plastic fracture mechanics (EPFM). It discusses the key concepts of EPFM including crack tip opening displacement (CTOD) and the J-integral. CTOD and J-integral are used to characterize fracture toughness in large-scale plastic deformation, unlike linear elastic fracture mechanics (LEFM) which is only valid for small plastic zones. Measurement methods and applications of CTOD and J-integral are also covered along with background on plasticity theory and LEFM concepts.
This document provides an overview of beam and column design concepts. It discusses types of beam supports, beams, shear force and bending moment diagrams, stresses in beams from bending and shear, and beam deflection calculations. It also covers column buckling, including the Euler buckling formula and Johnson's equation. The document provides examples of calculating stresses, strains, deflections, and buckling loads for different beam and column scenarios.
This document summarizes a research paper on modeling the sound radiation from a baffled composite rectangular panel with a line constraint. It presents the following key points:
1) Researchers used receptance theory to model a composite panel with springs attached along a line, representing a constraint. This allowed calculating new natural frequencies and mode shapes of the constrained system.
2) The response of the constrained panel to a point force was determined using the new mode shapes. Sound pressure radiated from the vibrating panel was then estimated using Rayleigh's integral.
3) Sound power calculations integrated the sound pressure over a hemispherical surface in the far field to obtain the total power radiated by the constrained vibrating panel.
1) The document discusses the seismic behavior of frame structures equipped with passive dampers. It covers damping reduction factors, complex damping theory applied to adjacent buildings connected by dampers, peak interstory velocity profiles, nonlinear viscous damping ratios, and behavior factors for damped structures.
2) Complex damping theory models a damped structure using a generalized single-degree-of-freedom system and complex frequencies and modes. This allows modeling of energy dissipation through damping.
3) Nonlinear viscous dampers can be modeled using an equivalent linear damper. The equivalent damping ratio depends on the maximum displacement and approaches the design damping ratio as the displacement decreases toward the design level.
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
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.
Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024Sinan KOZAK
Sinan from the Delivery Hero mobile infrastructure engineering team shares a deep dive into performance acceleration with Gradle build cache optimizations. Sinan shares their journey into solving complex build-cache problems that affect Gradle builds. By understanding the challenges and solutions found in our journey, we aim to demonstrate the possibilities for faster builds. The case study reveals how overlapping outputs and cache misconfigurations led to significant increases in build times, especially as the project scaled up with numerous modules using Paparazzi tests. The journey from diagnosing to defeating cache issues offers invaluable lessons on maintaining cache integrity without sacrificing functionality.
Discover the latest insights on Data Driven Maintenance with our comprehensive webinar presentation. Learn about traditional maintenance challenges, the right approach to utilizing data, and the benefits of adopting a Data Driven Maintenance strategy. Explore real-world examples, industry best practices, and innovative solutions like FMECA and the D3M model. This presentation, led by expert Jules Oudmans, is essential for asset owners looking to optimize their maintenance processes and leverage digital technologies for improved efficiency and performance. Download now to stay ahead in the evolving maintenance landscape.
Prediction of Electrical Energy Efficiency Using Information on Consumer's Ac...PriyankaKilaniya
Energy efficiency has been important since the latter part of the last century. The main object of this survey is to determine the energy efficiency knowledge among consumers. Two separate districts in Bangladesh are selected to conduct the survey on households and showrooms about the energy and seller also. The survey uses the data to find some regression equations from which it is easy to predict energy efficiency knowledge. The data is analyzed and calculated based on five important criteria. The initial target was to find some factors that help predict a person's energy efficiency knowledge. From the survey, it is found that the energy efficiency awareness among the people of our country is very low. Relationships between household energy use behaviors are estimated using a unique dataset of about 40 households and 20 showrooms in Bangladesh's Chapainawabganj and Bagerhat districts. Knowledge of energy consumption and energy efficiency technology options is found to be associated with household use of energy conservation practices. Household characteristics also influence household energy use behavior. Younger household cohorts are more likely to adopt energy-efficient technologies and energy conservation practices and place primary importance on energy saving for environmental reasons. Education also influences attitudes toward energy conservation in Bangladesh. Low-education households indicate they primarily save electricity for the environment while high-education households indicate they are motivated by environmental concerns.
Null Bangalore | Pentesters Approach to AWS IAMDivyanshu
#Abstract:
- Learn more about the real-world methods for auditing AWS IAM (Identity and Access Management) as a pentester. So let us proceed with a brief discussion of IAM as well as some typical misconfigurations and their potential exploits in order to reinforce the understanding of IAM security best practices.
- Gain actionable insights into AWS IAM policies and roles, using hands on approach.
#Prerequisites:
- Basic understanding of AWS services and architecture
- Familiarity with cloud security concepts
- Experience using the AWS Management Console or AWS CLI.
- For hands on lab create account on [killercoda.com](https://killercoda.com/cloudsecurity-scenario/)
# Scenario Covered:
- Basics of IAM in AWS
- Implementing IAM Policies with Least Privilege to Manage S3 Bucket
- Objective: Create an S3 bucket with least privilege IAM policy and validate access.
- Steps:
- Create S3 bucket.
- Attach least privilege policy to IAM user.
- Validate access.
- Exploiting IAM PassRole Misconfiguration
-Allows a user to pass a specific IAM role to an AWS service (ec2), typically used for service access delegation. Then exploit PassRole Misconfiguration granting unauthorized access to sensitive resources.
- Objective: Demonstrate how a PassRole misconfiguration can grant unauthorized access.
- Steps:
- Allow user to pass IAM role to EC2.
- Exploit misconfiguration for unauthorized access.
- Access sensitive resources.
- Exploiting IAM AssumeRole Misconfiguration with Overly Permissive Role
- An overly permissive IAM role configuration can lead to privilege escalation by creating a role with administrative privileges and allow a user to assume this role.
- Objective: Show how overly permissive IAM roles can lead to privilege escalation.
- Steps:
- Create role with administrative privileges.
- Allow user to assume the role.
- Perform administrative actions.
- Differentiation between PassRole vs AssumeRole
Try at [killercoda.com](https://killercoda.com/cloudsecurity-scenario/)
DEEP LEARNING FOR SMART GRID INTRUSION DETECTION: A HYBRID CNN-LSTM-BASED MODELijaia
As digital technology becomes more deeply embedded in power systems, protecting the communication
networks of Smart Grids (SG) has emerged as a critical concern. Distributed Network Protocol 3 (DNP3)
represents a multi-tiered application layer protocol extensively utilized in Supervisory Control and Data
Acquisition (SCADA)-based smart grids to facilitate real-time data gathering and control functionalities.
Robust Intrusion Detection Systems (IDS) are necessary for early threat detection and mitigation because
of the interconnection of these networks, which makes them vulnerable to a variety of cyberattacks. To
solve this issue, this paper develops a hybrid Deep Learning (DL) model specifically designed for intrusion
detection in smart grids. The proposed approach is a combination of the Convolutional Neural Network
(CNN) and the Long-Short-Term Memory algorithms (LSTM). We employed a recent intrusion detection
dataset (DNP3), which focuses on unauthorized commands and Denial of Service (DoS) cyberattacks, to
train and test our model. The results of our experiments show that our CNN-LSTM method is much better
at finding smart grid intrusions than other deep learning algorithms used for classification. In addition,
our proposed approach improves accuracy, precision, recall, and F1 score, achieving a high detection
accuracy rate of 99.50%.
Redefining brain tumor segmentation: a cutting-edge convolutional neural netw...IJECEIAES
Medical image analysis has witnessed significant advancements with deep learning techniques. In the domain of brain tumor segmentation, the ability to
precisely delineate tumor boundaries from magnetic resonance imaging (MRI)
scans holds profound implications for diagnosis. This study presents an ensemble convolutional neural network (CNN) with transfer learning, integrating
the state-of-the-art Deeplabv3+ architecture with the ResNet18 backbone. The
model is rigorously trained and evaluated, exhibiting remarkable performance
metrics, including an impressive global accuracy of 99.286%, a high-class accuracy of 82.191%, a mean intersection over union (IoU) of 79.900%, a weighted
IoU of 98.620%, and a Boundary F1 (BF) score of 83.303%. Notably, a detailed comparative analysis with existing methods showcases the superiority of
our proposed model. These findings underscore the model’s competence in precise brain tumor localization, underscoring its potential to revolutionize medical
image analysis and enhance healthcare outcomes. This research paves the way
for future exploration and optimization of advanced CNN models in medical
imaging, emphasizing addressing false positives and resource efficiency.
3. ADAPTIVE STRUCTURES
Constitutive Relations
ð The constitutive relations are based on the assumption that the
total strain in the actuator is the sum of the mechanical strain
induced by the stress, the thermal strain due to temperature and
the controllable actuation strain due to the electric voltage.
?T
d
?T
a
e
T
T
α
σ
ε
ε
σ
+
+
=
+
+
=
S
E
C
E
4. ADAPTIVE STRUCTURES
Constitutive Relations
ð Re-writing the stress-strain equation:
ðIn a plane perpendicular to the piezo-polarization, it has isotropic
properties, i.e. transversely isotropic material in the plane 1-2.
ðFor orthotropic material, there is no temperature shear strain.
However there is a shear strain induced due to the electrical fields E1
and E2.
T
E
E
E
d
d
d
d
d
S
S
S
S
S
S
S
S
S
S
S
S
∆
+
+
=
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
3
2
1
3
2
1
15
15
33
31
31
12
31
23
3
2
1
66
55
44
33
32
31
23
22
21
13
12
11
12
31
23
3
2
1
α
α
α
τ
τ
τ
σ
σ
σ
γ
γ
γ
ε
ε
ε
5. ADAPTIVE STRUCTURES
Constitutive Relations
ð For piezoceramics, the actuation strain is:
ðd33, d31 and d15 are called piezoelectric strain coefficients of a
mechanical free piezo element.
ðd31 characterizes strain in the 1 an 2 directions to an electrical
field E3 in the 3 direction
ðd33 relates strain in the 3 direction due to field in the 3 direction
ðd15 characterizes 2-3 and 3-1 shear strains due a field E2 and E1,
respectively.
=
Λ
3
2
1
15
15
33
31
31
0
0
0
0
0
0
0
0
0
0
0
0
0
E
E
E
d
d
d
d
d
6. ADAPTIVE STRUCTURES
Block Force Model
•
If an electric field V is applied, then the maximum
actuator strain (free strain) will be:
•
The maximum block force (zero strain condition) is:
=
Λ
=
c
t
V
d31
max
ε
V
b
E
d
F c
c
b 31
=
7. ADAPTIVE STRUCTURES
Block Force Model
ð A piezo patch attached to the beam structure results
in an axial force F in the beam due to potential V. The
reactive force in the piezo element will be –F. Then the
strain in the piezo becomes
c
c
c
c
c
c
E
t
b
F
t
V
d
l
l
−
=
∆
= 31
ε
8. ADAPTIVE STRUCTURES
Block Force Model
ð Force-strain relation for constant field V:
ðThis plot can also be used to determine the properties
of piezo materials experimentally.
c
c
c
c
t
b
F
E
V
t
d
1
max
max
max
31
ε
ε
=
=
9. ADAPTIVE STRUCTURES
Pure Extension
ð Two identical patches mounted on the surface of a
beam, one on either side can produce pure extension
ðFor pure extension, same potential is applied to top
and bottom actuators. The induced force is
ðFb is the block force for each piezo patch.
ðIf piezo stiffness (beam stiffness),
actuation force becomes zero though actuation strain
equals free strain;
ðIf the actuation strain becomes zero
though actuation force equals block force
b
b
c
c A
E
A
E >>
b
b
b
b
b
c
c
c
c
c
c
c
b
b
b
b
b
c
c
b
b
c
c
b
b
c
t
b
E
A
E
t
b
E
A
E
A
E
A
E
A
E
F
A
E
A
E
A
E
A
E
t
V
d
F
=
=
+
=
+
=
;
2
2
31
b
b
c
c A
E
A
E <<
10. ADAPTIVE STRUCTURES
Pure Bending
ð For pure bending, an equal and opposite potential is
applied to top and bottom actuators
ðThe induced bending is
ðMb is the block moment for each piezo patch.
ðIf actuation moment becomes zero
ðIf actuation strain becomes zero
2
31
2
2
2
=
+
=
+
=
b
c
c
c
c
c
c
c
b
b
b
b
b
c
c
b
b
c
c
b
b
b
c
t
t
b
E
I
E
I
E
I
E
I
E
M
I
E
I
E
I
E
I
E
t
t
V
d
M
b
b
c
c I
E
I
E >>
b
b
c
c I
E
I
E <<
11. ADAPTIVE STRUCTURES
Euler-Bernoulli Beam Model
ðBeam, adhesive and actuator form a continuous
structure
ðBernoulli´s assumption: a plane section normal to the
beam axis remains plane and normal to the beam axis
after bending
ðLinear distribution of strain in actuator and host
structure
ðGenerally gives more accurate results than uniform
strain model
( )
( ) ( )
( ) ( ) net
xx
net
z
E
z
z
z
z
z
ε
σ
ε
ε
κ
κ
ε
ε
=
Λ
−
=
=
−
= xx
0 -w,
,
12. ADAPTIVE STRUCTURES
Bernoulli-Euler Beam Model
ð Axial force and bending moment expressions are:
where
ð F is the axial force in the beam
ð M is the bending moment in the beam
ð b(z) is the beam width
=
+
+
Λ
Λ
xx
w
E
E
E
E
M
M
F
F
,
0
2
1
1
0 ε
( ) ( )
( ) ( )
( ) width
beam
is
2
h
2
h
-
2
h
2
h
-
z
b
zdz
z
z
b
M
dz
z
z
b
F
xx
xx
∫
∫
=
=
σ
σ
13. ADAPTIVE STRUCTURES
Euler–Bernoulli Beam Model
ð Axial force and bending moment due to induced
stress:
ð If the placement of the actuators is symmetric, the
coupling term will be zero; if not, this term will be non-
zero: extension-bending coupling
( ) ( ) 2
1
0
,
2
2
,
,
j
dz
z
z
E
z
b
E
h
h
j
j =
= ∫
−
( ) ( ) ( ) ( ) ( ) ( )
∫
∫ Λ
=
Λ
= Λ
Λ
2
h
2
h
-
2
h
2
h
-
, zdz
z
z
E
z
b
M
dz
z
z
E
z
b
F
14. ADAPTIVE STRUCTURES
Uniform Strain and Euler-Bernoulli Beam Models
ðThe thickness ratio, T, determines if the strain variation
across the piezo affects the analysis:
ðfor small T, the uniform strain model overpredicts
strain (curvature)
ðfor large T, the predicted induced bending
curvatures are identical for both models
c
b
t
t
T =
15. ADAPTIVE STRUCTURES
Plate with Induced Strain Actuation
ðInduced strain actuation is used to control the extension,
bending and twisting of a plate
ðUsing tailored anisotropic plates with distributed piezo
actuators, the control of specific static deformation can be
augmented
16. ADAPTIVE STRUCTURES
Plate with Induced Strain Actuation
ð Assumptions to develop a consistent plate model:
ð Actuators and substrates are integrated as plies of
a laminated plate
ð A consistent deformation is assumed in the
actuators and substrates
ð Generally, a thin classical laminated plate theory is
adopted
ð For systems actuated in extension:
ðAssume strains are constant across the thickness
of actuators and plate
ð For systems actuated in pure bending:
ð Assume strains vary linearly through the thickness
17. ADAPTIVE STRUCTURES
Plate with Induced Strain Actuation
ð Strain in the system:
ð Mid-plane strain:
ð Curvature:
{ }
T
T
xy
y
x
x
v
y
u
y
v
x
u
∂
∂
+
∂
∂
∂
∂
∂
∂
=
= 0
0
0
0
ε
ε
ε
ε
κ
ε
ε z
+
= 0
{ }
T
T
xy
y
x
y
x
w
y
w
x
w
∂
∂
∂
−
∂
∂
−
∂
∂
−
=
=
2
2
2
2
2
2
κ
κ
κ
κ
18. ADAPTIVE STRUCTURES
Plate with Induced Strain Actuation
ð Constitutive relation for any ply:
ð is the transformed reduced stiffness of the
plate
ðThe second term represents an equivalent stress
due to the actuation
ð Stress vector:
ðActuation strain vector
{ }
T
xy
y
x τ
σ
σ
σ =
( )
Λ
−
= ε
σ Q
{ }
T
xy
y
x Λ
Λ
Λ
=
Λ
Q
19. ADAPTIVE STRUCTURES
Plate with Induced Strain Actuation
ð Net forces and moments
=
xy
y
x
xy
y
x
z
y
x
z
y
x
D
D
D
D
D
D
D
D
D
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
A
A
A
A
A
A
A
A
A
M
M
M
N
N
N
κ
κ
κ
γ
ε
ε
0
0
0
6
26
16
26
22
11
16
12
11
6
26
16
26
22
11
16
12
11
6
26
16
26
22
11
16
12
11
6
26
16
26
22
11
16
12
11
21. ADAPTIVE STRUCTURES
Shells
ð Strain-Displacement Relations
ε κ
ε κ
ε τ
θ θ
θ
x x
x
u
x
w
x
v w
R R
w
R
v
v
x R
u
R
w
x R
v
x
=
∂
∂
= −
∂
∂
=
∂
∂
θ
+ = −
∂
∂
θ
+
∂
∂
θ
=
∂
∂
+
∂
∂
θ
= −
∂
∂∂
θ
+
∂
∂
; ;
; ;
;
2
2
2
2
2 2
2
1 1
1 2 2
22. ADAPTIVE STRUCTURES
Piezo Patch Contributions
ð Finite Patches
M M M H x H x H H
M M M H x H x H H
N N N H x H x H H S x S
N N N H x H x H H S x S
x x x
x x x
p pinner pouter
p pinner pouter
p pinner pouter
p pinner pouter
= + − −
= + − −
= + − −
= + − −
1 2 1 2
1 2 1 2
1 2 1 2 1 2 1 2
1 2 1 2 1 2 1 2
( ) ( ) ( ) ( )
( ) ( ) ( ) ( )
( ) ( ) ( ) ( ) ( ) $ ( )
( ) ( ) ( ) ( ) ( ) $ ( )
, ,
, ,
θ θ
θ θ
θ θ θ
θ θ θ
θ θ θ
θ θ θ
23. ADAPTIVE STRUCTURES
Concluding Remarks
ðAnalytical models for beam, plate and shell type
elements have been presented.
ðThe weak form of the equations of motion are desirable
since they circumvent the need to differentiate terms with
patch force and moment terms.
ðThe analytical models provide a physical appreciation
of the interaction between the structure and the actuating
piezo patches
24. ADAPTIVE STRUCTURES
Finite Element Models
Œ Piezoelectric Finite Elements
F Solid, Plate and Beam Models
• Simple Plate Finite Element Model
Ž Actuation and Sensing Examples
F Bimorph beam
F Adaptive Composite Plate
25. ADAPTIVE STRUCTURES
Solid Elements
Allik and Hughes (1970)
u,v,w, ϕ : linear
16 dof
Static condensation of the electric dof
Gandhi and Hagood (1997)
u,v,w, ϕ : linear
16 dof + internal dof
Nonlinear constitutive relations
26. ADAPTIVE STRUCTURES
Solid Elements
Tzou and Tseng (1990)
u,v,w,ϕ : linear + quadratic incompatible modes
32 dof
Static condensation of the electric dof
Ha and Keilers (1992)
u,v,w,ϕ : linear + quadratic incompatible modes
32 dof
Equivalent single layer model
Static condensation of incompatible modes
27. ADAPTIVE STRUCTURES
Solid Elements
Chin and Varadan (1994)
u,v,w,ϕ : linear
32 dof
Lagrange method
Allik and Webman (1974)
u,v,w,ϕ : quadratic
80 dof
Sonar transducers
28. ADAPTIVE STRUCTURES
Shell Elements
Lammering (1991)
u,v,w,β
x, β
y : linear
28 dof
Shallow shell theory
Upper-lower nodal electric potential dof
Thirupati et al (1997)
u,v,w,φ
: quadratic
32 dof
3D degenerated shell theory
Piezo effect as initial strain problem
29. ADAPTIVE STRUCTURES
Shell Elements
Varadan et al (1993)
u,w,φ: linear
9 dof
Lagrange formulation
Mooney transducers
Tzou and Ye (1993)
u,v,w,φ: in-plane quadratic, thickness linear
48 dof
Layerwise constant shear angle theory
Laminated piezo shell continuum
30. ADAPTIVE STRUCTURES
Plate Elements
Suleman and Venkayya (1995)
u,v,w, θx,θy,θz : bilinear
φ
: linear
24 dof
Mindlin plate element C0
1 dof per piezo patch/layer
Ray et al (1994)
w: cubic
φ
: linear
104 dof
Linear potential in thickness
1 dof per piezo patch/layer
31. ADAPTIVE STRUCTURES
Plate Elements
Yin and Shen (1997)
u,v,w, β
x,β
y, φ: quadratic
54 dof
Mindlin plate theory C0
Linear voltage but transverse field dof
32. ADAPTIVE STRUCTURES
Beam Elements
Shen (1994)
U: linear
W: cubic hermite
Β: linear
8 dof
Timoshenko beam theory with Hu-Washizu
Principle (Mixed)
Offset nodes
33. ADAPTIVE STRUCTURES
Summary of Available Elements
Elements Shape and approximations
Solid 4-nodes linear tetrahedron
8-nodes linear hexahedron
20-nodes quadratichexahedron
available
available
available
Shell 3-nodes linear axisymmetric flat triangle
8-nodes quadratic axisymm. quadrangle
4-nodes linear flat quadrangle
8-nodes 3D-degenerated quadratic quad
12-nodes 3D-degenerated quadratic prism
available
available
available
not available
available
Plate 3-nodes linear triangle
4-nodes linear quadrangle
8-nodes quadrangle
9-nodes quadrangle
not available
available
available
available
Beam 2-nodes linear element
3-nodes quadratic element
available
not available
35. ADAPTIVE STRUCTURES
Kinetic, Potential and Electrical Energies
•The Hamiltonian for the system is
[ ] 0
2
1
=
+
Π
−
∫ dt
W
T
t
t
e
δ
dV
T
S
dV
u
u
T c
c
V
T
V
T
∫
∫ =
Π
=
2
1
;
2
1 &
&
ρ
p
e
e
V
e dV
T
S
W
T
p
∫
=
2
1
39. ADAPTIVE STRUCTURES
Strain-Displacement Relations
=
= e
s
e
s
e
s
q
q
S
S
S
b
0
0
b
el
s
i
s
i
s
i
s
i
s
i
s
i
s
i
s
i
s
i
s
i
s
i
s
i
s
i n
i
N
x
N
N
x
N
x
N
z
x
N
z
y
N
z
x
N
z
x
N
y
N
y
N
x
N
,
,
1
;
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
L
=
−
∂
∂
∂
∂
∂
∂
∂
∂
−
∂
∂
−
∂
∂
∂
∂
∂
∂
∂
∂
∂
∂
=
b
42. ADAPTIVE STRUCTURES
Equations of Motion
=
+
+
+
+
∆
∆
0
0
0
0
K
0
0
0
K
K
K
K
0
0
0
0
K
0
0
0
M
T T
e
c
g
e
c
e
c
ee
ec
ce
e
c
cc
e
c
cc
P
U
U
U
U
U
U
U
U
U
U
48
4 7
6
48
4 7
6
4 8
4 7
6
48
4 7
6
&
&
&
&
48
4 7
6
stiffness
nonlinear
stiffness
thermal
stiffness
piezo
stiffness
linear
inertia
55. ADAPTIVE STRUCTURES
ACTIVE CONTROL
1
i
n
_1
2
Ou t
por
t2
C
C M a t
r
i
x
M u x
M u x
x
' = A
x
+Bu
y = Cx
+Du
Pl
a t
e M odel
St
a t
e Noi
s e
Sou r
ce
Sys t
em
Vi
s u a l
i
za t
i
on
Ou t
pu tNoi
s e
Sou r
ce
Ou t
po
+
+
Su m
Dyn
a m i
c M odelofPl
a t
e w i
t
h Pi
ezoel
ect
r
i
c Sen
s or
s a n
d A
ct
u a t
or
s
62. ADAPTIVE STRUCTURES
A composite shell element with electromechanical properties
and with principal radii of curvature Rx and Ry has been
formulated and implemented.
This 8-noded isoparametric finite element has five degrees
of freedom at each node, which includes three displacements
and two rotations .
To derive the equations of motion for the laminated
composite shell, in an acoustic field with piezoelectrically
coupled electromechanical properties, we use the
generalized form of Hamilton’
s principle
[ ] 0
2
1
=
−
+
Π
−
∫ dt
W
W
T
t
t
p
e
δ
COMPOSITE SHELL
63. ADAPTIVE STRUCTURES
[ ] 0
2
1
=
+
Π
−
∫ dt
W
T
t
t
p
p
p
δ
0
1
2
2
2
2
=
∂
∂
−
∇
t
p
c
p
•
To derive the equations of motion for the acoustic cavity, we use the
generalized form of Hamilton’
s principle
boundary
vibrating
a
at
boundary
rigid
a
at
0
2
2
t
w
n
p
n
p
a
∂
∂
−
=
∂
∂
=
∂
∂
ρ
With the following boundary conditions:
ACOUSTIC CAVITY MODEL
65. ADAPTIVE STRUCTURES
( )
( )
( )
>
<
= −
−
−
−
o
z
z
d
o
z
z
d
f
z
z
e
P
z
z
e
P
z
P
o
o
for
for
( )
>
−
−
<
−
−
=
θ
θ
θ
θ
θ
θ
θ
θ
θ
θ
θ
θ
θ
θ
θ
for
for
2
2
1
1
k
j
o
o
k
j
o
f
e
P
e
P
P
Axial distribution:
Circumferential Distribution:
ASSUMED PRESSURE DISTRIBUTION
70. ADAPTIVE STRUCTURES
NOISE REDUCTION
0
20
40
60
80
100
120
140
ANGULAR POSITION (Deg)
NOISE
REDUCTION
(dB)
45 90
θ = 0
Frequency 90 Hz
Actuation 400 V
Case 2 - Line Pattern
Frequency 90 Hz
No Actuation
Frequency 90 Hz
Actuation 400 V
Case 1 - Chess Pattern
Symmetric
360
135 180 225 270 270
External Pressure
Distribution
θ = 180
RESULTS
71. ADAPTIVE STRUCTURES
´ Analytical and finite element models with
electromechanical properties have been presented.
´ Application of piezoelectric patches to control pane
flutter has been demonstrated.
´ Internal noise reduction using a stiffened fuselage
with piezo pacthes achieved considerable reduction in
noise levels.
CONCLUSIONS