SlideShare a Scribd company logo

CHARACTERIZATION OF SHAPE MEMORY ALLOY FOR VIBRATION ATTENUATION IN SMART STRUCTURES

•
•
K
Kandhan Siva

The document discusses the characterization of shape memory alloy (SMA) properties and the development of a virtual control system for monitoring SMA-based smart structures. Key points include: - An experiment was conducted to determine the relationship between Young's modulus of Nitinol wire and actuation current by applying cyclic loads at different currents. This provided an empirical equation to model SMA stiffness as a function of current. - An SMA wire was embedded in a glass fiber reinforced polymer beam to create a smart beam. Testing found the beam's natural frequency increased by up to 4.2% with current due to increased SMA and beam stiffness. A 28% reduction in vibration amplitude was also achieved. - Anal

Related slideshows

Shape Memory Alloy Based Actuators - Technology Intro
Shape Memory Alloy Based Actuators - Technology Intro Shape Memory Alloy Based Actuators - Technology Intro
Shape Memory Alloy Based Actuators - Technology Intro
 
SMA presentation
SMA presentationSMA presentation
SMA presentation
 
Shape memory alloys
Shape memory alloysShape memory alloys
Shape memory alloys
 
1 of 38
Download to read offline
CHARACTERIZATION OF SHAPE MEMORY ALLOY (SMA) AND DEVELOPMENT OF VIRTUAL CONTROL SYSTEM FOR ACTIVE MONITORING OF SMA BASED SMART STRUCTURES Presentation by KANDHAN.S 16MD07 ME Engineering Design, PSG college of Technology Guided by Dr. M. YUVARAJA Associate Professor, Department of Mechanical Engineering, PSG college of Technology PSG College of Technology Dept. of Mechanical Engineering Project Phase : II Review Date : 25-May-2018
Origin of this project POWER DEFICIT IN INDIA Ministry of New and Renewable Energy (MNRE) RENEWABLE ENERGY FOR URBAN WIND ENERGY SMALL HORIZONTAL AXIS WIND TURBINE VIBRATION CONTROL SHAPE MEMORY ALLOY CHARACTERISATION OF SUPER ELASTIC PROPERTIES OF SMA FOR DEVELOPMENT OF CONTROL SYSTEM
Understanding SMA F30’ C F60’ CHigh High stiffness state High low stiffness state High Heating HighIncreasein Young'sModulusfrom 20MPato50MPPa Unlike other metal whose Young’s modulus decreases with increase in temperature, SMA’s Young’s Modulus increases with increase in temperature due to solid phase transformation from martensite to austenite as shown in figure above
Problem definition Vibration characteristics of smart structure containing SMA in embedded form is not well established, since the Young’s modulus change of SMA with respect to actuation current is not explicitly known, thus there arises a need to establish a relation between them which in turn seeks characterization of SMA under various thermo- mechanical conditions
Major Literature survey  H. N. Bhargaw 𝐞𝐭 𝒂𝒍 [𝟏] discuss about Thermo-electric behaviour of NiTi shape memory alloy Young's modulus change with respect to current is not available  B.-S. Jung et 𝒂𝒍[𝟐] investigates large deflecting smart materials by fabricating smart structure using shape memory alloy wire embedded hybrid composite Vibration characteristics of GFRP composite beam using SMA wire was not performed  Yuvaraja M et 𝒂𝒍[𝟑] discuss a vibration characteristics of a flexible GFRP composite beam using SMA wire The study shows vibration characteristics of GFRP composite beam using SMA wire attached externally
Objective • To characterize SMA properties by finding a valid empirical relation between variation in Young’s Modulus variation with respect to actuation current for an application as an actuator in SMA embedded GFRP beam (Smart structure) • To develop a virtual feedback control system for SMA embedded in GFRP smart structure for vibration attenuation.
Methodology Literature survey Selection of suitable SMA Characterization of Nitinol properties Experimentation in UTM Obtaining Young’s Modulus change as a function of actuation current Experimental analysis of SMA embedded GFRP beam Natural frequency shift as a function of actuation current Mathematical modal of SMA embedded GFRP beam Theoretical natural frequency shift as a function of actuation current Validation Development of virtual feedback control system
Selection of SMA • Ni-Ti based alloy (Ni-Ti: 50.5-49.5%) is chosen due to their stability, practicability, superior thermo- mechanic performance, the high level of recoverable plastic strain that can be induced and It also has excellent biocompatibility and corrosion resistance • Ni-Ti based alloy in form of wires because it is easy to cut and connect, and can be conveniently activated by Joule heating. It is lightweight with high power to mass ratio and high energy density in the order of 107 J/m3 • DYNALLOY, Inc. Flexinol® Made of nickel-titanium small diameter wires have been specially processed to have large, stable amounts of memory strain for many cycles is our source of Ni-Ti wires. • Among different sized Ni-Ti wires provided by Flexinol wire diameter of 0.5 mm is chosen for application.
Experimental setup overview Power supply kit
Grippers used in experimentation Fig 1.1 Gripper containing rubber pad Surpassing 20 N the wire got slipped from the gripper and no longer the readings are valid. This due the oxidizing coating of SMA which make it so slippery hence this gripper is neglected. The steel jaw grippers eliminated the slippage problem but current conducted by the SMA wire passes through these gripper this might affect the sensitive load cell hence this gripper is also neglected. Fig 1.2 Gripper containing hardened steel jaws
Gripper by adaptive design 1. Non conduction bushes make sure that the load cell is not getting affected. 2. Metallic Bobbins make sure that wire will not get slipped. 1 2Fig 1.3 Conventional gripper containing for testing wires
Design and fabrication of gripper Insert Pin Shaft Collar • Taking maximum possible stress 895 MPa acting on wire of diameter 0.5 mm will produce a force of 166.6 N. • Taking factor of safety of 1.8, the design force is set as 300 N • Based on this force, design calculations are made Fig 1.4 UTM color pin arrangement Fig 1.5 drafted drawings of gripper
Design check of gripper
Design check of gripper…
Fabrication of gripper Sheetmetalprocessing MachiningofTeflon Machiningofbobbins Drillingofbobbins
Final assembled gripper Fig 1.7 Grippers attached to UTMFig 1.6 Gripper assembly
Experimentation on Nitinol wire • The experimental setup consists of a UTM ZWICK / ROEL 2.5 KN, test wire Nitinol (Ni-Ti: 50.5-49.5%) and power supply kit. • The cyclic load of 50N tensile is applied. The experiment is conducted at different actuation current ratings at steady state conditions. Fig 1.8 UTM ZWICK / ROEL 2.5 KN Fig 1.9 Cyclic load
Nitinol wire specifications for testing NITINOL WIRE TESTING SPECS PARAMETERS SPECIFICATIONS WIRE DIAMETER 0.5 mm GAUGE LENGTH OF WIRE 180 mm RATE OF LOADING [5] (as per ASTM F 2516 ) During hysteresis cycle (Load to 6% strain and unload) During failure test cycle (upto failure) 0.04 mm/min 0.4 mm/min MAXIMUM APPLIED LOAD 50 N NO OF CYCLES 2 MINIMUM CURRENT 0 Ampere MAXIMUM CURRENT 2.5 Ampere MINIMUM TEMPERATURE Room temperature (32 ºC) MAXIMUM TEMPERATURE 90ºC
Experimental set up
Stress and strain curve of Nitinol wire as a function of actuation current 0 50 100 150 200 250 300 0 0.005 0.01 0.015 0.02 0.025 0.03 Stress,MPa Strain at 0 Aat 0.5 A at 1 A at 2.5 A at 1.5 A at 2 A
Young’s Modulus of Nitinol wire as a function of actuation current E= -6.7699I2 + 31.077I + 17.738 0 10 20 30 40 50 60 0 0.5 1 1.5 2 2.5 3 3.5 E,GPa Current I, A 0 10 20 30 40 50 60 70 80 90 100 0 1 2 3 4 Temperature,'C Input current, A Fig 2.1 Temperature vs actuation current Fig 2.0 Young’s modulus of Nitinol wire as a function of actuation current
Results and Discussion • As input current increases the temperature of wire increases which incurs the solid phase transformation from low temperature, low stiffness martinsite phase to high temperature, high stiffness austinite phase this causes the Young’s Modulus change in wire. • Taking loading line’s slope, Young’s Modulus of wire at corresponding input currents are found • The plots shows the slope is steeper till 1 Ampere after which only gradual change in Young’s Modulus is attained. • Young’s Modulus of SMA is made as function of current, E(SMA) = -6.7699 I2 + 31.077 I + 17.738 (1)
Fabrication of SMA embedded GFRP beam Pre-preparation • Preparation of mould box • Cleaning and application of releasing agent • Cutting of CSM mat to required dimesnions • Resin preparation Fabrication • Laying galssfiber and SMA • squeegeeing • Curing Post-preparation • Remove part from mould • Trim to required dimensions • Finishing Fig 2.4 GFRP beamFig 2.2 Aluminum die Fig 2.3 Layup of glassfiber mat
Experimental analysis of SMA Embedded GFRP smart beam • An experimentation is made to understand how Young’s Modulus shift of SMA affects the structural stiffness of a smart beam containing SMA as wire embedded inside GFRP (Glass Fiber Reinforced Polymer) with a volume fraction of SMA to GFRP is at ratio of 0.0067. • GFRP (Glass Fiber Reinforced Polymer) beam is made using 5 layers of 300gsm glass fiber and 22ml of epoxy resin. SMA wire of diameter 0.5mm is embedded inside the beam on its neutral axis High SMA wire terminals High GFRP beam
Experimental analysis of SMA Embedded GFRP smart beam • The set up consists of SMA embedded GFRP beam, accelerometer for vibration pick up, DAQ interfaced with LabVIEW software to analysis frequency response and power supply kit to vary the current in SMA wire
Natural frequency of Smart beam as a function of actuation current 155 157 159 161 163 165 167 169 171 173 0 0.5 1 1.5 2 2.5 3 Frequency,Hz Current, A Experimental plot
Analytical expressions… • For a simple elastic beam problem with uniform cross section the natural frequency is given by [7], • f(n) = 1 2𝜋 3𝐸 𝑐𝑜𝑚𝑏𝑖𝑛𝑒𝑑 𝐼 𝐿3 𝑚 (2) • The combined equivalent young’s modulus with embedded SMA wires, obtained according to the classical composite-beam theory can be given as [8],
Analytical expressions… • E(combined) = E(GFRP) (1- V(f)) + V(f) E(SMA) (3) V(f) = volume of SMA / volume of GFRP Sub Equation (1) in (3) • E(combined) = E(GFRP) (1- V(f)) + V(f) (-6.7699 I2 + 31.077 I + 17.738) (4)
Analytical expressions… • E(combined) = ( - 0.13 T(GFRP) + 18.367) (1- V(f)) + V(f)(-6.7699I2 + 31.077I + 17.738) (5) Where T(GFRP) = 4.9286 I2 – 5.0071 I + 30.964 (6) • f(n) = 1 2𝜋 3𝐸 𝑐𝑜𝑚𝑏𝑖𝑛𝑒𝑑 𝐼𝑚 𝐿3 𝑚 • f(n) = 𝟏 𝟐𝝅 𝟑( − 𝟎.𝟏𝟑 𝑻 ( 𝑮𝑭𝑹𝑷) + 𝟏𝟖.𝟑𝟔𝟕) (𝟏− 𝑽 ( 𝒇)) + 𝑽 ( 𝒇)(− 𝟔.𝟕𝟔𝟗𝟗𝑰 𝟐 + 𝟑𝟏.𝟎𝟕𝟕𝑰 + 𝟏𝟕.𝟕𝟑𝟖))𝑰𝒎 𝑳 𝟑 𝒎 • f(n) = -4.132I2 + 5.2305I + 167.31 Parameters Values V(f) 0.0067 𝐿 247.5 mm m 47 grams b 4.5 mm d 38 mm 𝐼m 1.8290667E-8 mm^4 b d 𝐿
Theoretical natural frequency plot 152 154 156 158 160 162 164 166 168 170 0 0.5 1 1.5 2 2.5 3 Naturalfrequency,Hz Current, A Natural Frequency vs Current Series1 F(n) = -4.132I2 + 5.2305I + 167.31
Results and discussion 155 157 159 161 163 165 167 169 171 173 0 0.5 1 1.5 2 2.5 3 Frequency,Hz Current, A Natural frequency vs Current Experimental plot Analytical plot • As the current increase the Young’s Modulus of SMA increases and overall Young’s Modulus of smart beam increases. thus increases in natural frequency of smart beam is observed till 1 ampere after which decrease in natural frequency is found. • Once the current exceeding 1 ampere the overall temperature of beam increases but Young’s Modulus of GFRP decreases with increases in temperature. Thus stiffness of overall beam reduces and decreases in natural frequency is observed and expressed in analytical form and validated with experimental plot with the maximum error of 3 %.
Significance of natural frequency shift -1 0 1 2 3 4 5 6 7 8 9 0.85 0.9 0.95 1 1.05 1.1 1.15 1.2 Magnificationfactor ω ∕ ωn 4.2 % increases in natural frequency At 0 A At 1 A28 % reduction in amplitude
Virtual control over natural frequency of the system
Conclusions • In this work experimental analysis of Nitinol wire is performed to determine its young’s modulus change as function of actuation current. This expression can be used in applications of smart structures containing SMA. • The results obtained from above study is used in experimental analysis of SMA embedded GFRP smart beam and the increases in natural frequency shift of 4.2% and significant amplitude reduction of 28 % is found. This can be applied to control the natural frequency of a system at active condition depending on the requirement. E(SMA) = -6.7699 I2 + 31.077 I + 17.738
ACTIVITY PLANNED / ACTUAL December January February March April 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 DEVELOPMENT OF PROPOSED GRIPPER PLANNED ACTUAL EXPERIMENTATION IN UTM PLANNED ACTUAL FINDING EMPIRICAL RELATION BETWEEN INPUT CURRENT, YOUNG'S MODULES AND STIFFNESS PLANNED ACTUAL ANALYTICAL MODAL PLANNED ACTUAL EXPERIMENTAL VALIDATION WITH SMA EMBEDDED BEAM PLANNED ACTUAL PLANNED ACTUAL Gantt Chart
References… 1. H. N. Bhargaw, M. Ahmed, P. Sinha, September 2012, “Thermo-electric behaviour of NiTi shape memory alloy”, Trans. Nonferrous Met. Soc. China 23(2013) 2329−2335. 2. Kin-tak Lau, January 2002, “Vibration characteristics of SMA composite beams with different boundary conditions” Materials and Design 23 (2002) 741–749. 3. Sia Nemat-Nasser, Wei-Guo Guo, July 2005, “Superelastic and cyclic response of NiTi SMA at various strain rates and temperatures”, Mechanics of Materials 38 (2006) 463–474. 4. Toshibumi FUKUTA1, Masanori IIBA2, Yoshikazu KITAGAWA3, and Yuji SAKAI, August 1-6, 2004, “Experimental Study On Stress-Strain Property Of Shape Memory Alloy And Its Application To Self- Restoration Of Structural Members” 13th World Conference on Earthquake Engineering Vancouver, B.C., Canada. 5. J.M. McNaney, V. Imbeni, Y. Jung b, Panayiotis Papadopoulos, R.O. Ritchie, September 2002, “An experimental study of the superelastic effect in a shape-memory Nitinol alloy under biaxial loading”, Mechanics of Materials 35 (2003) 969–986.
References… 7. Costantino Menna, Ferdinando Auricchio, Domenico Asprone, “Applications of Shape Memory Alloys in Structural Engineering”, ISBN 978-0-08-099920-3. 8. Irschik, H.,2002. A Review on static and dynamic shape control of structures by piezoelectric actuation,Engineering Sturctures 24, p 5-11. 9. Chen, S.H., Wang, Z.D., Liu, X. H.,1997, Active Vibration contol and suppression for intelligent Sturctures, Journal of Sound and Vibration 20,p 167-77. 10. Yuvaraja M, Senthilkumar M Procedia Engineering 64 ( 2013 ) 571 – 581,Comparative study on Vibration Characteristics of a Flexible GFRP Composite beam using SMA and PZT Actuators
Thanks for your patience

More Related Content

CHARACTERIZATION OF SHAPE MEMORY ALLOY FOR VIBRATION ATTENUATION IN SMART STRUCTURES

  • 1. CHARACTERIZATION OF SHAPE MEMORY ALLOY (SMA) AND DEVELOPMENT OF VIRTUAL CONTROL SYSTEM FOR ACTIVE MONITORING OF SMA BASED SMART STRUCTURES Presentation by KANDHAN.S 16MD07 ME Engineering Design, PSG college of Technology Guided by Dr. M. YUVARAJA Associate Professor, Department of Mechanical Engineering, PSG college of Technology PSG College of Technology Dept. of Mechanical Engineering Project Phase : II Review Date : 25-May-2018
  • 2. Origin of this project POWER DEFICIT IN INDIA Ministry of New and Renewable Energy (MNRE) RENEWABLE ENERGY FOR URBAN WIND ENERGY SMALL HORIZONTAL AXIS WIND TURBINE VIBRATION CONTROL SHAPE MEMORY ALLOY CHARACTERISATION OF SUPER ELASTIC PROPERTIES OF SMA FOR DEVELOPMENT OF CONTROL SYSTEM
  • 3. Understanding SMA F30’ C F60’ CHigh High stiffness state High low stiffness state High Heating HighIncreasein Young'sModulusfrom 20MPato50MPPa Unlike other metal whose Young’s modulus decreases with increase in temperature, SMA’s Young’s Modulus increases with increase in temperature due to solid phase transformation from martensite to austenite as shown in figure above
  • 4. Problem definition Vibration characteristics of smart structure containing SMA in embedded form is not well established, since the Young’s modulus change of SMA with respect to actuation current is not explicitly known, thus there arises a need to establish a relation between them which in turn seeks characterization of SMA under various thermo- mechanical conditions
  • 5. Major Literature survey  H. N. Bhargaw 𝐞𝐭 𝒂𝒍 [𝟏] discuss about Thermo-electric behaviour of NiTi shape memory alloy Young's modulus change with respect to current is not available  B.-S. Jung et 𝒂𝒍[𝟐] investigates large deflecting smart materials by fabricating smart structure using shape memory alloy wire embedded hybrid composite Vibration characteristics of GFRP composite beam using SMA wire was not performed  Yuvaraja M et 𝒂𝒍[𝟑] discuss a vibration characteristics of a flexible GFRP composite beam using SMA wire The study shows vibration characteristics of GFRP composite beam using SMA wire attached externally
  • 6. Objective • To characterize SMA properties by finding a valid empirical relation between variation in Young’s Modulus variation with respect to actuation current for an application as an actuator in SMA embedded GFRP beam (Smart structure) • To develop a virtual feedback control system for SMA embedded in GFRP smart structure for vibration attenuation.
  • 7. Methodology Literature survey Selection of suitable SMA Characterization of Nitinol properties Experimentation in UTM Obtaining Young’s Modulus change as a function of actuation current Experimental analysis of SMA embedded GFRP beam Natural frequency shift as a function of actuation current Mathematical modal of SMA embedded GFRP beam Theoretical natural frequency shift as a function of actuation current Validation Development of virtual feedback control system
  • 8. Selection of SMA • Ni-Ti based alloy (Ni-Ti: 50.5-49.5%) is chosen due to their stability, practicability, superior thermo- mechanic performance, the high level of recoverable plastic strain that can be induced and It also has excellent biocompatibility and corrosion resistance • Ni-Ti based alloy in form of wires because it is easy to cut and connect, and can be conveniently activated by Joule heating. It is lightweight with high power to mass ratio and high energy density in the order of 107 J/m3 • DYNALLOY, Inc. Flexinol® Made of nickel-titanium small diameter wires have been specially processed to have large, stable amounts of memory strain for many cycles is our source of Ni-Ti wires. • Among different sized Ni-Ti wires provided by Flexinol wire diameter of 0.5 mm is chosen for application.
  • 10. Grippers used in experimentation Fig 1.1 Gripper containing rubber pad Surpassing 20 N the wire got slipped from the gripper and no longer the readings are valid. This due the oxidizing coating of SMA which make it so slippery hence this gripper is neglected. The steel jaw grippers eliminated the slippage problem but current conducted by the SMA wire passes through these gripper this might affect the sensitive load cell hence this gripper is also neglected. Fig 1.2 Gripper containing hardened steel jaws
  • 11. Gripper by adaptive design 1. Non conduction bushes make sure that the load cell is not getting affected. 2. Metallic Bobbins make sure that wire will not get slipped. 1 2Fig 1.3 Conventional gripper containing for testing wires
  • 12. Design and fabrication of gripper Insert Pin Shaft Collar • Taking maximum possible stress 895 MPa acting on wire of diameter 0.5 mm will produce a force of 166.6 N. • Taking factor of safety of 1.8, the design force is set as 300 N • Based on this force, design calculations are made Fig 1.4 UTM color pin arrangement Fig 1.5 drafted drawings of gripper
  • 13. Design check of gripper
  • 14. Design check of gripper…
  • 16. Final assembled gripper Fig 1.7 Grippers attached to UTMFig 1.6 Gripper assembly
  • 17. Experimentation on Nitinol wire • The experimental setup consists of a UTM ZWICK / ROEL 2.5 KN, test wire Nitinol (Ni-Ti: 50.5-49.5%) and power supply kit. • The cyclic load of 50N tensile is applied. The experiment is conducted at different actuation current ratings at steady state conditions. Fig 1.8 UTM ZWICK / ROEL 2.5 KN Fig 1.9 Cyclic load
  • 18. Nitinol wire specifications for testing NITINOL WIRE TESTING SPECS PARAMETERS SPECIFICATIONS WIRE DIAMETER 0.5 mm GAUGE LENGTH OF WIRE 180 mm RATE OF LOADING [5] (as per ASTM F 2516 ) During hysteresis cycle (Load to 6% strain and unload) During failure test cycle (upto failure) 0.04 mm/min 0.4 mm/min MAXIMUM APPLIED LOAD 50 N NO OF CYCLES 2 MINIMUM CURRENT 0 Ampere MAXIMUM CURRENT 2.5 Ampere MINIMUM TEMPERATURE Room temperature (32 ºC) MAXIMUM TEMPERATURE 90ºC
  • 20. Stress and strain curve of Nitinol wire as a function of actuation current 0 50 100 150 200 250 300 0 0.005 0.01 0.015 0.02 0.025 0.03 Stress,MPa Strain at 0 Aat 0.5 A at 1 A at 2.5 A at 1.5 A at 2 A
  • 21. Young’s Modulus of Nitinol wire as a function of actuation current E= -6.7699I2 + 31.077I + 17.738 0 10 20 30 40 50 60 0 0.5 1 1.5 2 2.5 3 3.5 E,GPa Current I, A 0 10 20 30 40 50 60 70 80 90 100 0 1 2 3 4 Temperature,'C Input current, A Fig 2.1 Temperature vs actuation current Fig 2.0 Young’s modulus of Nitinol wire as a function of actuation current
  • 22. Results and Discussion • As input current increases the temperature of wire increases which incurs the solid phase transformation from low temperature, low stiffness martinsite phase to high temperature, high stiffness austinite phase this causes the Young’s Modulus change in wire. • Taking loading line’s slope, Young’s Modulus of wire at corresponding input currents are found • The plots shows the slope is steeper till 1 Ampere after which only gradual change in Young’s Modulus is attained. • Young’s Modulus of SMA is made as function of current, E(SMA) = -6.7699 I2 + 31.077 I + 17.738 (1)
  • 23. Fabrication of SMA embedded GFRP beam Pre-preparation • Preparation of mould box • Cleaning and application of releasing agent • Cutting of CSM mat to required dimesnions • Resin preparation Fabrication • Laying galssfiber and SMA • squeegeeing • Curing Post-preparation • Remove part from mould • Trim to required dimensions • Finishing Fig 2.4 GFRP beamFig 2.2 Aluminum die Fig 2.3 Layup of glassfiber mat
  • 24. Experimental analysis of SMA Embedded GFRP smart beam • An experimentation is made to understand how Young’s Modulus shift of SMA affects the structural stiffness of a smart beam containing SMA as wire embedded inside GFRP (Glass Fiber Reinforced Polymer) with a volume fraction of SMA to GFRP is at ratio of 0.0067. • GFRP (Glass Fiber Reinforced Polymer) beam is made using 5 layers of 300gsm glass fiber and 22ml of epoxy resin. SMA wire of diameter 0.5mm is embedded inside the beam on its neutral axis High SMA wire terminals High GFRP beam
  • 25. Experimental analysis of SMA Embedded GFRP smart beam • The set up consists of SMA embedded GFRP beam, accelerometer for vibration pick up, DAQ interfaced with LabVIEW software to analysis frequency response and power supply kit to vary the current in SMA wire
  • 26. Natural frequency of Smart beam as a function of actuation current 155 157 159 161 163 165 167 169 171 173 0 0.5 1 1.5 2 2.5 3 Frequency,Hz Current, A Experimental plot
  • 27. Analytical expressions… • For a simple elastic beam problem with uniform cross section the natural frequency is given by [7], • f(n) = 1 2𝜋 3𝐸 𝑐𝑜𝑚𝑏𝑖𝑛𝑒𝑑 𝐼 𝐿3 𝑚 (2) • The combined equivalent young’s modulus with embedded SMA wires, obtained according to the classical composite-beam theory can be given as [8],
  • 28. Analytical expressions… • E(combined) = E(GFRP) (1- V(f)) + V(f) E(SMA) (3) V(f) = volume of SMA / volume of GFRP Sub Equation (1) in (3) • E(combined) = E(GFRP) (1- V(f)) + V(f) (-6.7699 I2 + 31.077 I + 17.738) (4)
  • 29. Analytical expressions… • E(combined) = ( - 0.13 T(GFRP) + 18.367) (1- V(f)) + V(f)(-6.7699I2 + 31.077I + 17.738) (5) Where T(GFRP) = 4.9286 I2 – 5.0071 I + 30.964 (6) • f(n) = 1 2𝜋 3𝐸 𝑐𝑜𝑚𝑏𝑖𝑛𝑒𝑑 𝐼𝑚 𝐿3 𝑚 • f(n) = 𝟏 𝟐𝝅 𝟑( − 𝟎.𝟏𝟑 𝑻 ( 𝑮𝑭𝑹𝑷) + 𝟏𝟖.𝟑𝟔𝟕) (𝟏− 𝑽 ( 𝒇)) + 𝑽 ( 𝒇)(− 𝟔.𝟕𝟔𝟗𝟗𝑰 𝟐 + 𝟑𝟏.𝟎𝟕𝟕𝑰 + 𝟏𝟕.𝟕𝟑𝟖))𝑰𝒎 𝑳 𝟑 𝒎 • f(n) = -4.132I2 + 5.2305I + 167.31 Parameters Values V(f) 0.0067 𝐿 247.5 mm m 47 grams b 4.5 mm d 38 mm 𝐼m 1.8290667E-8 mm^4 b d 𝐿
  • 30. Theoretical natural frequency plot 152 154 156 158 160 162 164 166 168 170 0 0.5 1 1.5 2 2.5 3 Naturalfrequency,Hz Current, A Natural Frequency vs Current Series1 F(n) = -4.132I2 + 5.2305I + 167.31
  • 31. Results and discussion 155 157 159 161 163 165 167 169 171 173 0 0.5 1 1.5 2 2.5 3 Frequency,Hz Current, A Natural frequency vs Current Experimental plot Analytical plot • As the current increase the Young’s Modulus of SMA increases and overall Young’s Modulus of smart beam increases. thus increases in natural frequency of smart beam is observed till 1 ampere after which decrease in natural frequency is found. • Once the current exceeding 1 ampere the overall temperature of beam increases but Young’s Modulus of GFRP decreases with increases in temperature. Thus stiffness of overall beam reduces and decreases in natural frequency is observed and expressed in analytical form and validated with experimental plot with the maximum error of 3 %.
  • 32. Significance of natural frequency shift -1 0 1 2 3 4 5 6 7 8 9 0.85 0.9 0.95 1 1.05 1.1 1.15 1.2 Magnificationfactor ω ∕ ωn 4.2 % increases in natural frequency At 0 A At 1 A28 % reduction in amplitude
  • 33. Virtual control over natural frequency of the system
  • 34. Conclusions • In this work experimental analysis of Nitinol wire is performed to determine its young’s modulus change as function of actuation current. This expression can be used in applications of smart structures containing SMA. • The results obtained from above study is used in experimental analysis of SMA embedded GFRP smart beam and the increases in natural frequency shift of 4.2% and significant amplitude reduction of 28 % is found. This can be applied to control the natural frequency of a system at active condition depending on the requirement. E(SMA) = -6.7699 I2 + 31.077 I + 17.738
  • 35. ACTIVITY PLANNED / ACTUAL December January February March April 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 DEVELOPMENT OF PROPOSED GRIPPER PLANNED ACTUAL EXPERIMENTATION IN UTM PLANNED ACTUAL FINDING EMPIRICAL RELATION BETWEEN INPUT CURRENT, YOUNG'S MODULES AND STIFFNESS PLANNED ACTUAL ANALYTICAL MODAL PLANNED ACTUAL EXPERIMENTAL VALIDATION WITH SMA EMBEDDED BEAM PLANNED ACTUAL PLANNED ACTUAL Gantt Chart
  • 36. References… 1. H. N. Bhargaw, M. Ahmed, P. Sinha, September 2012, “Thermo-electric behaviour of NiTi shape memory alloy”, Trans. Nonferrous Met. Soc. China 23(2013) 2329−2335. 2. Kin-tak Lau, January 2002, “Vibration characteristics of SMA composite beams with different boundary conditions” Materials and Design 23 (2002) 741–749. 3. Sia Nemat-Nasser, Wei-Guo Guo, July 2005, “Superelastic and cyclic response of NiTi SMA at various strain rates and temperatures”, Mechanics of Materials 38 (2006) 463–474. 4. Toshibumi FUKUTA1, Masanori IIBA2, Yoshikazu KITAGAWA3, and Yuji SAKAI, August 1-6, 2004, “Experimental Study On Stress-Strain Property Of Shape Memory Alloy And Its Application To Self- Restoration Of Structural Members” 13th World Conference on Earthquake Engineering Vancouver, B.C., Canada. 5. J.M. McNaney, V. Imbeni, Y. Jung b, Panayiotis Papadopoulos, R.O. Ritchie, September 2002, “An experimental study of the superelastic effect in a shape-memory Nitinol alloy under biaxial loading”, Mechanics of Materials 35 (2003) 969–986.
  • 37. References… 7. Costantino Menna, Ferdinando Auricchio, Domenico Asprone, “Applications of Shape Memory Alloys in Structural Engineering”, ISBN 978-0-08-099920-3. 8. Irschik, H.,2002. A Review on static and dynamic shape control of structures by piezoelectric actuation,Engineering Sturctures 24, p 5-11. 9. Chen, S.H., Wang, Z.D., Liu, X. H.,1997, Active Vibration contol and suppression for intelligent Sturctures, Journal of Sound and Vibration 20,p 167-77. 10. Yuvaraja M, Senthilkumar M Procedia Engineering 64 ( 2013 ) 571 – 581,Comparative study on Vibration Characteristics of a Flexible GFRP Composite beam using SMA and PZT Actuators
  • 38. Thanks for your patience