Shape memory alloys have the ability to return to their original shape after being deformed by heating or cooling. This document discusses shape memory alloys and their structural applications. It provides an introduction to shape memory alloys, describes their properties and types. Examples of using shape memory alloys for reinforcement, prestressing, bracing, damping, and self-rehabilitation of structures are presented. Two experimental programs are summarized that studied using shape memory alloys for buckling control and improving the bond between shape memory alloy rebar and concrete.
Shape Memory Alloy is one type of Smart Material.It can Remember its Original Shape.It has 2 way memory,i.e:- it can Remember 2 Shape,one in Low temperature and other in high temperature.
Shape Memory Alloy is one type of Smart Material.It can Remember its Original Shape.It has 2 way memory,i.e:- it can Remember 2 Shape,one in Low temperature and other in high temperature.
Smart Materials ppt, Smart or intelligent materials are materials that have to respond to stimuli and environmental changes, Detailed Engineering Project Research on Smart Materials, smart and composite materials, smart materials in construction, smart materials in engineering, its about smart or say intelligent materials
A shape memory alloy(SMA) is an alloy that remembers its “original shape” and that when deformed returns to its original “pre-deformed” shape when heated
Metal matrix composites (MMCs) possess significantly improved properties including highspecific strength; specific modulus, damping capacity and good wear resistance compared to unreinforced alloys. There has been an increasing interest in composites containing low density and low cost reinforcements. Among various discontinuous dispersoids used, fly ash is one of the most inexpensive and low density reinforcement available in large quantities as solid waste by-product during combustion of coal in thermal power plants. Hence, composites with fly ash as reinforcement are likely to overcome the cost barrier for wide spread applications in automotive and small engine applications.
This presentation is an introduction to Smart Materials including Piezoelectric materials, Shape memory materials, Magnetorheological, PH sensitive polymers, and Chromogenic systems.You can find the other sessions on my Linkedin or Slideshare pages as well.
Smart Materials ppt, Smart or intelligent materials are materials that have to respond to stimuli and environmental changes, Detailed Engineering Project Research on Smart Materials, smart and composite materials, smart materials in construction, smart materials in engineering, its about smart or say intelligent materials
A shape memory alloy(SMA) is an alloy that remembers its “original shape” and that when deformed returns to its original “pre-deformed” shape when heated
Metal matrix composites (MMCs) possess significantly improved properties including highspecific strength; specific modulus, damping capacity and good wear resistance compared to unreinforced alloys. There has been an increasing interest in composites containing low density and low cost reinforcements. Among various discontinuous dispersoids used, fly ash is one of the most inexpensive and low density reinforcement available in large quantities as solid waste by-product during combustion of coal in thermal power plants. Hence, composites with fly ash as reinforcement are likely to overcome the cost barrier for wide spread applications in automotive and small engine applications.
This presentation is an introduction to Smart Materials including Piezoelectric materials, Shape memory materials, Magnetorheological, PH sensitive polymers, and Chromogenic systems.You can find the other sessions on my Linkedin or Slideshare pages as well.
dental ceramics silicate ceramics and oxidceramics/ oral surgery courses Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
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Optimization of Process Parameters in Turning Operation of AISI-1016 Alloy St...IOSR Journals
This paper investigates the parameters affecting the roughness of surfaces produced in the turning
process for the material AISI-1016 Steel. Design of experiments was conducted for the analysis of the influence
of the turning parameters such as cutting speed, feed rate and depth of cut on the surface roughness. The
results of the machining experiments for AISI-1016 were used to characterize the main factors affecting
surface roughness by the Analysis of Variance (ANOVA) method. The feed rate was found to be the most
significant parameter influencing the surface roughness in the turning process.
Parametric analysis and multi objective optimization of cutting parameters in...eSAT Journals
Abstract Modern manufacturers, seeking to remain competitive in the market, rely on their Manufacturing engineers and production personnel to quickly and effectively set up manufacturing processes for new products. This paper presents the multi response optimization of turning parameters for Turning on AISI 4340 Alloy Steel. Experiments are designed and conducted based on Taguchi’s L27 Orthogonal array design. This paper discusses an investigation into the use of Taguchi parameter Design and Regression analysis to predict and optimize the Surface Roughness, Metal Removal Rate and Power Consumption in turning operations using CVD Cutting Tool. The Analysis of Variance (ANOVA) is employed to analyze the influence of Process Parameters during Turning. This paper also remarks the advantages of multi-objective optimization approach over the single-objective one. The useful results have been obtained by this research for other similar type of studies and can be helpful for further research works on the Tool life and Vibration of tools etc. Keywords: Turning, Ra, MRR, PC, Taguchi, Anova etc…
Taguchi Method for Optimization of Cutting Parameters in Turning OperationsIDES Editor
Surface roughness an indicator of surface quality is
one of the prime customer requirements for machined parts.
For efficient use of machine tools, optimum cutting
parameters are required. The turning process parameter
optimization is highly complex and time consuming. In this
paper taguchi parameter optimization methodology is applied
to optimize cutting parameters in turning. The turning
parameters evaluated are, cutting velocity, feed rate, depth of
cut, and nose radius of tool and hardness of the material each
at two levels. The results of analysis show that feed rate,
cutting velocity and nose radius have present significant
contribution on the surface roughness and depth of cut and
hardness of material have less significant contribution on the
surface roughness.
PARAMETRIC OPTIMIZATION OF NEAR DRY ELECTRICAL DISCHARGE MACHINING PROCESS FO...IAEME Publication
Present dissertation work has attempted to optimize the various significant process parameters for near dry EDM process by Taguchi method and design of experiments. The response variables are material removal rate (MRR), the surf ace roughness (SR) and tool wear rate (TWR). A low cost mist delivery system (MQL fluid dispenser) to supply the mist (liquid-gas mixture) at a controlled rate has been developed to conduct the experiments and has served it’s purpose exceptionally well during the experimentation. The AISISAE D-2 tool steel has been used as a work-piece material. The kerosene air mixture has been used as a dielectric medium. The various process parameters selected for the study were discharge current, gap voltage, pulse on time, duty factor, air pressure and electrode material. A standard L 18 orthogonal array was selected for design of experiments. The results obtained from the experimental runs were analyzed by using Minitab15 software
a brief descriptive of shape memory alloy, a brief introduction of shape memory alloy and its functions and its types and applications and its future uses
leaf spring is a simple form of spring commonly used for the suspension in wheeled vehicles. Originally called a a laminated or carriage spring and sometimes referred to as a semi-elliptical spring or cart spring, it is one of the oldest forms of springing, dating back to medieval times.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Automobile Management System Project Report.pdfKamal Acharya
The proposed project is developed to manage the automobile in the automobile dealer company. The main module in this project is login, automobile management, customer management, sales, complaints and reports. The first module is the login. The automobile showroom owner should login to the project for usage. The username and password are verified and if it is correct, next form opens. If the username and password are not correct, it shows the error message.
When a customer search for a automobile, if the automobile is available, they will be taken to a page that shows the details of the automobile including automobile name, automobile ID, quantity, price etc. “Automobile Management System” is useful for maintaining automobiles, customers effectively and hence helps for establishing good relation between customer and automobile organization. It contains various customized modules for effectively maintaining automobiles and stock information accurately and safely.
When the automobile is sold to the customer, stock will be reduced automatically. When a new purchase is made, stock will be increased automatically. While selecting automobiles for sale, the proposed software will automatically check for total number of available stock of that particular item, if the total stock of that particular item is less than 5, software will notify the user to purchase the particular item.
Also when the user tries to sale items which are not in stock, the system will prompt the user that the stock is not enough. Customers of this system can search for a automobile; can purchase a automobile easily by selecting fast. On the other hand the stock of automobiles can be maintained perfectly by the automobile shop manager overcoming the drawbacks of existing system.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
TECHNICAL TRAINING MANUAL GENERAL FAMILIARIZATION COURSEDuvanRamosGarzon1
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The Single Aisle is the most advanced family aircraft in service today, with fly-by-wire flight controls.
The A318, A319, A320 and A321 are twin-engine subsonic medium range aircraft.
The family offers a choice of engines
NO1 Uk best vashikaran specialist in delhi vashikaran baba near me online vas...Amil Baba Dawood bangali
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Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
1. SHAPE MEMORY ALLOY
AND ITS STRUCTURAL
APPLICATIONS
GUIDED BY,
Ms . AMRITHA E K
ASSISTANT PROFESSOR
CIVIL ENGINEERING DEPARTMENT
UEC
PRESENTED BY,
KRISHNA PRIYA V V
ROLL NO : 02
S3, M Tech
UEC
9/30/2016Dept. of CE , UEC 1
2. 9/30/2016Dept. of CE , UEC 2
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
CONTENT
Introduction
History
Properties
Types of SMAs
Working principle
Application
3. 9/30/2016Dept. of CE , UEC 3
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
A shape-memory alloys (SMA, smart metal, memory metal,
memory alloy, muscle wire, smart alloy) are metal alloys that
can be deformed at one temperature but when heated or
cooled, return to their “original” shape
The alloy appears to have a memory
The most effective and widely used alloys are NiTi, CuZnAl,
and CuAlNi
SMA also exhibits superelastic (pseudoelastic) behavior
INTRODUCTION
4. 9/30/2016Dept. of CE , UEC 4
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
CONTD…
Extraordinary properties are due to the temperature and stress
dependent phase transformation from a low-symmetry to a
highly symmetric crystallographic structure
Very high actuation strain, stress, and work output
Excellent self-centering ability, good energy dissipation
capacity, high corrosion resistance, and high fatigue life
Applications of SMAs in various disciplines including
biomedical, aerospace, automotive, and other industries
5. 9/30/2016Dept. of CE , UEC 5
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
)
Fig 1 (a) Shape memory effect; (b) superelastic effect
(Ozbulut et al.2015)
6. 9/30/2016Dept. of CE , UEC 6
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
HISTORY
1932: Chang and Read recorded the first observation of the shape
memory transformation
1938: Greninger and Mooradian observed the formation and
disappearance of martensitic phase by varying the temperature of a
Cu-Zn alloy
1951: Shape memory effect was observed
1962-63: Ni-Ti alloys were first developed by the United States
Naval Ordnance Laboratory
Mid-1990s – Memory metals start to become widespread in
medicine and soon move to other applications
7. 9/30/2016Dept. of CE , UEC 7
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
PROPERTIES OF SMA
Figure 2 Transformation temperatures
(Motavalli et al.2009)
(Motavalli et al.2009)
8. 9/30/2016Dept. of CE , UEC 8
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
CONTD…
Temperatures at which the SMA changes its crystallographic
structure are characteristic of the alloy and can be tuned by
varying the elemental ratios
Ms-the temperature at which the structure starts to change from
austenite to martensite upon cooling
Mf-the temperature at which the transition is finished
As and Af are the temperatures at which the reverse
transformation from martensite to austenite start and finish,
respectively
9. 9/30/2016Dept. of CE , UEC 9
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
Pseudo-Elasticity
Occurs without temperature change
Based on stress induced mechanism
This property allows the SMA’s to bear large amounts of stress
without undergoing permanent deformation.
CONTD…
11. 9/30/2016Dept. of CE , UEC 11
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
Table 1. Property values of selected shape memory alloys
CONTD…
(Motavalli et al.2009)
12. 9/30/2016Dept. of CE , UEC 12
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
BASIC WORKING PRINCIPLE
A molecular
rearrangement in the
SMA’s austenite and
martensite phase is
responsible for its
unique properties
Martensite is relatively
soft and occurs at lower
temperatures
Fig 3 : Temperature vs Load graph
(Motavalli et al.2009)
13. 9/30/2016Dept. of CE , UEC 13
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
CONTD…
The shape of austenite structure is cubic
No change in size or shape is visible in shape memory alloys
until the Martensite is deformed
To fix the parent shape, the metal must be held in position and
heated to about 500°C
The high temperature causes the atoms to arrange themselves
into the most compact and regular pattern possible resulting in a
rigid cubic arrangement (austenite phase)
15. 9/30/2016Dept. of CE , UEC 15
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
APPLICATIONS
Applications in civil engineering/ structure
1. Reinforcement
SMA’s are particularly beneficial for construction in
seismic regions.
If SMA is used as reinforcement, it will yield when
subjected to high seismic loads but will not retain
significant permanent deformations.
16. 9/30/2016Dept. of CE , UEC 16
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
2. Prestressing
The benefits of employing SMAs in prestressing
include:
-No involvement of jacking or strand-cutting
-No elastic shortening, friction, and anchorage losses
over time
SMA strands are used in pre tensioning and post
tensioning
CONTD…
17. 9/30/2016Dept. of CE , UEC 17
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
3.Braces for frame structures
The SMA wire braces are installed diagonally in the
frame structures.
As the frame structures deform under excitation, SMA
braces dissipate energy through stress-induced
Martensite transformation (in the superelastic SMA
case) or Martensite reorientation (in the Martensite
SMA case)
CONTD…
18. 9/30/2016Dept. of CE , UEC 18
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
Fig. 4 Schematic of the setup of the SMA
brace reinforced frame structure
CONTD…
Fig. 5. Schematic of the SMA braces
for a two-story steel frame
(Motavalli et al.2009)(Motavalli et al.2009)
19. 9/30/2016Dept. of CE , UEC 19
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
CONTD…
Fig 6 Schematic of the SMA braces for a frame
structure
(Motavalli et al.2009)
20. 9/30/2016Dept. of CE , UEC 20
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
4.Damping element for Bridges(restrainer)
One of the main problems of bridges during earthquakes is
their unseating because of excessive relative hinge opening
and displacement
These limitations can be overcome by introducing SMA
restrainers as they have larger elastic strain range and can
be brought back to its original position even after
deformation
CONTD…
21. 9/30/2016Dept. of CE , UEC 21
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
Fig. 7 Schematic of the SMA damper for a
stay-cable bridge
(Motavalli et al.2009)
CONTD…
22. 9/30/2016Dept. of CE , UEC 22
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
Fig. 8. Schematic of the setup of SMA restrainer for a
simple-supported bridge
CONTD…
(Motavalli et al.2009)
23. 9/30/2016Dept. of CE , UEC 23
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
5.SMA for structural self-Rehabilitation
The IRC(Intelligent Reinforced Concrete ) uses stranded
Martensite SMA wires for post-tensioning
By monitoring the electric resistance change of the SMA wires,
the strain distribution inside the concrete can be obtained
This self-rehabilitation can handle macro-sized cracks
The concrete structure is intelligent since it has the ability to
sense and the ability to self-rehabilitate
CONTD…
24. 9/30/2016Dept. of CE , UEC 24
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
6.SMA as FRP
SMA-FRP reinforcing bars behave in a ductile manner
and are capable of dissipating energy
It was found that SMA-FRP bars have more potential to
improve the ductility and energy dissipation capability
of concrete structures compared to conventional FRP
bars
CONTD…
25. 9/30/2016Dept. of CE , UEC 25
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
7.SMA as fibers
Due to the propagation of micro-cracks, strength of
concrete decreases
This may be prevented by using prestrained SMA wires
that are embedded in the concrete matrix
Upon activation, these wires regain their original shape,
and consequently, initial compressive stresses are
transmitted to the concrete matrix
CONTD…
27. 9/30/2016Dept. of CE , UEC 27
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
EXPERIMENTAL PROGRAM ON SMA
1. Buckling Control Using Shape-memory Alloy Cables
To provide additional insight into the high potential shown
by SMAs for new structural applications, namely in bracing
systems
Achieved by using original cable-restraining systems based
in SMAs
The proposed cable-restraining systems take advantage of
either superelasticity or the SME
28. 9/30/2016Dept. of CE , UEC 28
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
CONTD…
Passive Control Of Buckling With SMAs
• The system that is analyzed in this section is based on a
simply supported aluminium column with a total height (l) of
500 mm and a rectangular cross section of 15 × 2 mm2
•In this system, two SE cables, each having a circular cross
section with a 0.406-mm diameter, laterally restrain the column
•The system has a horizontal deviator at mid height, which is
equipped with two pulleys, one in each extremity
29. 9/30/2016Dept. of CE , UEC 29
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
CONTD…
)
Fig 9 The proposed cable restrained system (Santos et al.2016)
30. 9/30/2016Dept. of CE , UEC 30
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
CONTD…
)
Fig 10 . Critical buckling mode shapes(Santos et al.2016)
31. 9/30/2016Dept. of CE , UEC 31
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
Active Control Of Buckling With SMAs
•A restrained column with martensitic NiTi wires is used with
the 36-mm deviator
•The compressive force is introduced with the same
experimental apparatus as in the passive control system
•The system is also provided with two laser-displacement
sensors to monitor the vertical and horizontal displacements of
the column
CONTD…
32. 9/30/2016Dept. of CE , UEC 32
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
•The stress in the wire is applied to the system by temperature-
induced phase transformations in a two-way NiTi SMA, martensitic
actuator wire, which can remember both high- and low-temperature
shapes
•A Sorensen programmable direct-current (DC) power supply
(PPS), model XHR 40–25 (Sorensen Systems,
Northborough,Massachusetts), was used to allow the Joule heating
of the NiTi wire actuators
CONTD…
33. 9/30/2016Dept. of CE , UEC 33
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
)
Fig. 11 A view of the experimental setup(Santos et al.2016)
34. 9/30/2016Dept. of CE , UEC 34
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
•A passive control restraining solution that uses the SE cables
to increase the buckling resistance of a compressed column
while employing the SE effect to dissipate energy and promote
recentering
•The critical buckling load was increased by a factor of 2.0
and 2.85
•An active control system based on a PID control algorithm
that detected the onset of buckling and applied control forces
in the cables that counteracted the buckling motion
CONTD…
35. 9/30/2016Dept. of CE , UEC 35
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
CONTD…
•This control approach enabled the increase of the critical
buckling load by a factor of 2.6
•These two promising control approaches can be further
combined in hybrid restraining solutions for subsequent
studies
36. 9/30/2016Dept. of CE , UEC 36
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
2. Bond Behavior Of Smooth And Sand-coated Shape
Memory Alloy (SMA) Rebar In Concrete
The experimental program conducted in this study involved a
series of 56 push out test specimens (concrete cylinders) with
different parameters
Push out test was selected since it was simple to conduct
Ni–Ti SMA rebar (nitinol) has been used as reinforcement to
investigate the bond behaviour
4different concrete mixes were evaluating the effect of
concrete compressive strength on the bondbehavior of SMA rebar
37. 9/30/2016Dept. of CE , UEC 37
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
Fig. 12 Test setup for bond behavior SMA rebar with concrete (Billah et al. 2015)
38. 9/30/2016Dept. of CE , UEC 38
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
)
Fig.13 Specimens (smooth) (a) before testing, (b) after testing and (c) inside view
(Billah et al. 2015)
39. 9/30/2016Dept. of CE , UEC 39
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
The results from 56 pushout tests lead to the following
conclusions:
1. The stress–slip curve of SMA rebar can be divided/idealized
into four stages: elastic stage, ascending stage, linearly
descending stage and residual stage
Fig. 14. Load–slip curves for pushout test of smooth SMA rebar (Billah et al. 2015)
40. 9/30/2016Dept. of CE , UEC 40
SHAPE MEMORY ALLOYAND ITS STRUCTURALAPPLICATIONS
2. The bond strength of both smooth and sand coated SMA rebar
is significantly influenced by the concrete strength, bar diameter
and embedment length but is independent of concrete cover
3. The application of sand coating increased the bond strength
between concrete and SMA rebar by developing friction and
interlocking forces in addition to the adhesion mechanism
4. The coarser the sand size, the more is the improvement in bond
strength
CONTD…
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5. The surface roughness of SMA rebar significantly affects the
failure pattern as well as the bond strength
6. Concrete with smooth SMA rebars resulted in simple push
out failure whereas sand coated rebars resulted in splitting
failure
CONTD…
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3. Experimental Results of A Niti Shape Memory Alloy (SMA)-
based Recentering Beam-column Connection
Use of superelastic nickel–titanium (NiTi) shape memory
alloys (SMAs)to induce the recentering force on the connection
with the goal of creating a simplified ductile recentering system
The connection was designed to recenter under large drift
demands to fully exploit the unique ability of NiTi to
spontaneously recover up to 8% strain
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CONTD…
Four experimental tests were carried out
Test A was performed using ordinary steel tendons to set a
benchmark to compare performance
Test B was performed using martensitic NiTi tendons, which
do not revert to their initial shape until heat is applied
Test C was performed using superelastic SMA tendons,
which revert to their initial shape spontaneously
Test D was performed using superelastic SMA tendons in
parallel with low-strength aluminium bars
The aluminium bars were added to provide additional energy
dissipation
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The results demonstrated that a NiTi SMA-based connection can
be developed to have excellent ductility, energy dissipation, and
recentering
For the test connection layout, a 0.5% prestrain was applied to all
NiTi tendons.
Prestraining of the NiTi SMA tendons was effective in increasing
the recentering capability, and the overall behaviour of the
connection
• NiTi tendons possess significant superelastic properties that can
fully recenter a connection at drift levels below 1% and adequately
recenter a connection at drift levels above 1%
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4. RC Beams Reinforced With SMA Rebars
A concrete beam reinforced with shape memory alloys (SMA)
wires was tested and compared with a conventionally reinforced
concrete (RC) beam
For the tests, NiTi (Nickel/Titanium) wires approximately
4.3mm in diameter were used to reinforce the underside of a
concrete beam with a span of 1.14m
The surfaces of the SMA wires were sand-blasted and coated
with quartz sand using an epoxy adhesive
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Figure 15.Beam reinforced with SMA wires in the test set-up (Motavalli et al.2009)
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Figure 16.MTest cycles on the test beams (Motavalli et al.2009)
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REAL WORLD APPLICATION OF SMA
1.Retrofitting Of The Basilica Of San Francesco At Assisi,
Italy
Earthquake induced vibrations may cause severe damage in
particular to historical buildings, like the Basilica of San
Francesco at Assisi
The Basilica was restored after being strongly damaged by an
earthquake of 1997
The structural interaction of the basilica’s transept south gable
with the main structure needed to be modified
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Figure 17 .Back view of the historic gable (Photo: FIP Industriale)
(Motavalli et al.2009)
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Figure 18. Shape memory alloy device (Photo: FIP Industriale)
(Motavalli et al.2009)
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Figure 19. Principal load displacement behavior of SMAD
(Motavalli et al.2009)
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2. Retrofitting Of The Bell Tower Of The Church Of
Sangiorgio At Trignano, Italy
Seismic upgrade of the bell tower of the Church of San Giorgio
at Trignano became necessary after being struck by a 4.8 Richter
magnitude earthquake in 1996 and represents one of the first
known applications of SMAs to civil engineering
Retrofit design of the 17 meters tall masonry tower was carried
out under the framework of the ISTECH project
After a 4.5 Richter magnitude earthquake with the same
epicenter in 2000, subsequent investigations of the retrofitted bell
tower found no evidence of damage .
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Figure 18.St. Giorgio bell tower (Motavalli et al.2009)
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Figure 20.Bell tower with tendons and principle load-displacementbehavior of
incorporatedSMA devices (Motavalli et al.2009)
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3. Repair Of A Cracked Region Of A Highway Bridge In
Michigan, Usa
The concerned bridge in Michigan on highway no. US-31
has suffered cracks due to insufficient shear resistance
attributed to improper cut-off of longitudinal flexural
reinforcement
The resulting shear cracks in the web of the reinforced
concrete T-beam had an average width of 0.55 mm
Iron-manganese-silicon-chromium (FeMnSiCr) SMA was
used for the rods of diameter 10.4 mm
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Figure 21.Assembly of SMA rods for external strengthening of a
bridge (Motavalli et al.2009)
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LIMITS OF SMA
1.Cost
Due to the size of civil engineering structures and the acting
of relatively high forces, a large amount of material is needed
Ni-Ti based alloys show an extremely good shape memory
effect but the high material costs prevent it from being used
more extensively
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CONTD…
2. Stress Induced Martensite in Shape Memory Effect
The re-transformation from austenite to martensite and the
associated loss in stiffness is unwanted when using shape
memory effect for permanent tensioning
Stress induced martensite can be avoided by providing a
suitable transformation temperature profile
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CONCLUSIONS
The shape memory effect (SME) enables martensite Nitinol
materials to be used as actuators and also enables their
applications in active and semi-active controls of civil structures
Structural self-rehabilitation using reinforced martensite
SMAs is an example of active structural control
Sand coated SMA rebar shows high bond strength
NiTi SMA-based connection can be developed to have
excellent ductility, energy dissipation, and recentering
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REFERENCE
• Filipe Amarante dos Santos, 2016,”Buckling Control Using
Shape-Memory Alloy Cables”, American Society of Civil
Engineers
• A. H. M. MuntasirBillah, A.M.ASCE; and M. ShahriaAlam,
M.ASCE2, 2016,
“Performance-Based Seismic Design of Shape Memory
Alloy–Reinforced Concrete Bridge Piers. I: Development of
Performance-Based Damage States”, ASCE
• Osman E. Ozbulut, A.M.ASCE1; Sherif Daghash; and
Muhammad M. Sherif,2015,”Shape Memory Alloy Cables for
Structural Applications”, American Society of Civil Engineers
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• Mostafa Tazarv and M. Saiid Saiidi, F.ASCE,.
2014,“Reinforcing NiTi Superelastic SMA for Concrete
Structures “, American Society of Civil Engineers
• Michael V. Nathal and George L. Stefko ,2013,“Smart
Materials and Active Structures”, American Society of Civil
Engineers
• Matthew S. Speicher , Reginald DesRoches, Roberto T.
Leon,2011,”Experimental results of a NiTi shape memory alloy
(SMA)-based recentering beam-column connection”, Elsevier Ltd
• G. Song, N. Ma, H.-N. Li, 2006,” Applications of shape
memory alloys in civil structures”, Elsevier Ltd
• L. Janke , C. Czaderski , M. Motavalli and J. Ruth ,2005,”
Applications of shape memory alloys in civil engineering
structures - Overview, limits and new ideas”, Elsevier Ltd
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THANK YOU