Pub Date : 2022-05-16DOI: 10.31399/asm.cp.smst2022p0018
P. Eyer, A. Trauth, K. Weidenmann
Shape memory alloys (SMA) stand out due to the ability that they can be deformed and then return to their initial shape by heating. This process results in a high actuation energy density. All SMA manufacturing methods, regardless of which matrix material is used, result in heat input into the SMA, which could induce a phase transformation and therefore disable the actuator function. In this regard, options to increase the transition temperatures of NiTi alloys above the processing temperatures are fundamental. In this study, the influence of the pre-tension on the transformation temperatures of SMA wires was investigated as a way to prevent phase transformation due to heat impact during the production of SMA-polymer-actuators. Applying a pre-tension of 400 MPa to the NiTi wire, the austenite start temperature could be increased by a factor of 1.9 whereas it could be increased by a factor of 2.2 with a pre-tension of 550 MPa. Therefore, after preloading the wires, a phase transformation should not be induced when the wire contacts the polymer droplets. However, the shift of the phase transformation has to be further investigated.
{"title":"Influence of Stress on the Transition Behaviour of NiTi Shape Memory Alloys for Actuator Applications","authors":"P. Eyer, A. Trauth, K. Weidenmann","doi":"10.31399/asm.cp.smst2022p0018","DOIUrl":"https://doi.org/10.31399/asm.cp.smst2022p0018","url":null,"abstract":"Shape memory alloys (SMA) stand out due to the ability that they can be deformed and then return to their initial shape by heating. This process results in a high actuation energy density. All SMA manufacturing methods, regardless of which matrix material is used, result in heat input into the SMA, which could induce a phase transformation and therefore disable the actuator function. In this regard, options to increase the transition temperatures of NiTi alloys above the processing temperatures are fundamental. In this study, the influence of the pre-tension on the transformation temperatures of SMA wires was investigated as a way to prevent phase transformation due to heat impact during the production of SMA-polymer-actuators. Applying a pre-tension of 400 MPa to the NiTi wire, the austenite start temperature could be increased by a factor of 1.9 whereas it could be increased by a factor of 2.2 with a pre-tension of 550 MPa. Therefore, after preloading the wires, a phase transformation should not be induced when the wire contacts the polymer droplets. However, the shift of the phase transformation has to be further investigated.","PeriodicalId":119283,"journal":{"name":"SMST 2022: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126387718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-16DOI: 10.31399/asm.cp.smst2022p0047
Nathan Rendon, Emma Daharsh, W. LePage
Failure in device-grade NiTi is often due to nonmetallic inclusions in the NiTi, along with phase transformation in the surrounding NiTi. While progress has been made through metallurgy for high-purity NiTi, along with fatigue life experiments (e.g., total life with respect to mean strain), there remains a lack of understanding about how the fatigue life of NiTi devices is determined in the presence of inclusion defects. To better understand inclusions, this work is probing the initiation and growth of fatigue cracks in and around particle- void assemblies. The approach utilizes a combination of fatigue testing, scanning electron microscopy (SEM), both optical and SEM digital image correlation (DIC), and focused ion beam milling (FIB). Initial results have revealed that cracks tend to form first around smaller "teardrop" inclusions instead of larger "stringer" inclusions. The crack-forming inclusions tend to have nonmetallic inclusions that remain intact. This is in contrast with the larger, "stringer" inclusion that has nonmetallic particles that are not intact. Additional work is being done to better understand these findings. Additionally, ongoing studies with energy-dispersive X- ray spectroscopy (EDX) are identifying the composition of the various inclusion types.
{"title":"Towards Understanding the Initiation and Growth of Fatigue Failures at Defects and Inclusions in NiTi","authors":"Nathan Rendon, Emma Daharsh, W. LePage","doi":"10.31399/asm.cp.smst2022p0047","DOIUrl":"https://doi.org/10.31399/asm.cp.smst2022p0047","url":null,"abstract":"\u0000 Failure in device-grade NiTi is often due to nonmetallic inclusions in the NiTi, along with phase transformation in the surrounding NiTi. While progress has been made through metallurgy for high-purity NiTi, along with fatigue life experiments (e.g., total life with respect to mean strain), there remains a lack of understanding about how the fatigue life of NiTi devices is determined in the presence of inclusion defects. To better understand inclusions, this work is probing the initiation and growth of fatigue cracks in and around particle- void assemblies. The approach utilizes a combination of fatigue testing, scanning electron microscopy (SEM), both optical and SEM digital image correlation (DIC), and focused ion beam milling (FIB). Initial results have revealed that cracks tend to form first around smaller \"teardrop\" inclusions instead of larger \"stringer\" inclusions. The crack-forming inclusions tend to have nonmetallic inclusions that remain intact. This is in contrast with the larger, \"stringer\" inclusion that has nonmetallic particles that are not intact. Additional work is being done to better understand these findings. Additionally, ongoing studies with energy-dispersive X- ray spectroscopy (EDX) are identifying the composition of the various inclusion types.","PeriodicalId":119283,"journal":{"name":"SMST 2022: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121706986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-16DOI: 10.31399/asm.cp.smst2022fm02
Listings of the SMST 2022 Organizing Committee and Extended Abstract Reviewers.
SMST 2022组委会和扩展摘要审稿人名单。
{"title":"SMST 2022 Organizing Committee and Extended Abstract Reviewers","authors":"","doi":"10.31399/asm.cp.smst2022fm02","DOIUrl":"https://doi.org/10.31399/asm.cp.smst2022fm02","url":null,"abstract":"\u0000 Listings of the SMST 2022 Organizing Committee and Extended Abstract Reviewers.","PeriodicalId":119283,"journal":{"name":"SMST 2022: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122285213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-16DOI: 10.31399/asm.cp.smst2022p0087
Neha S. John, Bailey Ashmore, Michael T Wall, R. Wheeler, M. L. Young, A. Giri
In this work, a new method of processing shape memory alloys was utilized to understand the effects of disrupting the martensitic long range order and forming amorphous nanodomains with martensitic short range order. Based on the obtained results, strain glass alloy states were analyzed and confirmed using various characterization methods to determine trends and compare two alloys, Ni49.5Ti50.5 and Ni50.8Ti49.2. For Ni49.5Ti50.5 a 33% thickness reduction was required to obtain a cold work-induced strain glass state, while for Ni50.8Ti49.2 a 24% reduction was required.
{"title":"Comparative Analysis of Process-Induced Strain Glass States in Austenitic and Martensitic NiTi Shape Memory Alloy Plates","authors":"Neha S. John, Bailey Ashmore, Michael T Wall, R. Wheeler, M. L. Young, A. Giri","doi":"10.31399/asm.cp.smst2022p0087","DOIUrl":"https://doi.org/10.31399/asm.cp.smst2022p0087","url":null,"abstract":"\u0000 In this work, a new method of processing shape memory alloys was utilized to understand the effects of disrupting the martensitic long range order and forming amorphous nanodomains with martensitic short range order. Based on the obtained results, strain glass alloy states were analyzed and confirmed using various characterization methods to determine trends and compare two alloys, Ni49.5Ti50.5 and Ni50.8Ti49.2. For Ni49.5Ti50.5 a 33% thickness reduction was required to obtain a cold work-induced strain glass state, while for Ni50.8Ti49.2 a 24% reduction was required.","PeriodicalId":119283,"journal":{"name":"SMST 2022: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129957221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-16DOI: 10.31399/asm.cp.smst2022p0020
K. Safaei, M. Nematollahi, P. Bayati, F. Kordizadeh, H. Abedi, Nasrin Taheri Andani, B. Poorganji, M. Elahinia, Mohsen Taheri Andani, O. Benafan
In this work, the authors introduce an approach in additive manufacturing that enables control of the crystallographic texture through controlling the build orientation in the laser powder bed fusion (LPBF) method. The LPBF parameters play a key role in tailoring the microstructure of the as-fabricated parts. The proposed approach provides the capability of altering/enhancing the properties of the as-printed NiTi shape memory alloys by controlling the texture. The anisotropy may not be preferred for applications with complex and multi-axial loading regimes; however, the approach can be suitable for application with the main loading direction such as torque tube actuators.
{"title":"Controlling Crystallographic Texture and Thermomechanical Properties of NiTi Shape Memory Alloy through Laser Powder Bed Fusion Technique","authors":"K. Safaei, M. Nematollahi, P. Bayati, F. Kordizadeh, H. Abedi, Nasrin Taheri Andani, B. Poorganji, M. Elahinia, Mohsen Taheri Andani, O. Benafan","doi":"10.31399/asm.cp.smst2022p0020","DOIUrl":"https://doi.org/10.31399/asm.cp.smst2022p0020","url":null,"abstract":"\u0000 In this work, the authors introduce an approach in additive manufacturing that enables control of the crystallographic texture through controlling the build orientation in the laser powder bed fusion (LPBF) method. The LPBF parameters play a key role in tailoring the microstructure of the as-fabricated parts. The proposed approach provides the capability of altering/enhancing the properties of the as-printed NiTi shape memory alloys by controlling the texture. The anisotropy may not be preferred for applications with complex and multi-axial loading regimes; however, the approach can be suitable for application with the main loading direction such as torque tube actuators.","PeriodicalId":119283,"journal":{"name":"SMST 2022: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124481194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-16DOI: 10.31399/asm.cp.smst2022p0049
Parikshith K. Kumar, Steve K. Huang
Nitinol as a material is often considered stable at temperatures below 100 °C since these temperatures are significantly lower than the theoretical temperature range of [0.3-0.5] Tm (Tm = absolute melting temperature) at which temperature viscoplastic phenomena become active. However, when considering a constrained device, factors such as the peak pre-strain and the associated stress coupled with the exposed temperature and time may have a significant impact on the mechanical behavior of Nitinol. This in-turn can impact the performance and the shelf life of a constrained device. This effort investigates the effect of constant applied uniaxial strain (at different test temperatures over different exposure times) on the superelastic unloading response of Nitinol. To quantify this behavior on a more practical level, tests were conducted by constraining apical samples to different peak bending strains and exposed to an accelerated aging environment. The results from the testing suggest that the tensile response of the Nitinol is impacted by the strain and the time of dwell at a specific temperature under constrained conditions.
{"title":"Effect of Pre-Strain, Temperature and Time on the Shelf Life Behavior of Nitinol","authors":"Parikshith K. Kumar, Steve K. Huang","doi":"10.31399/asm.cp.smst2022p0049","DOIUrl":"https://doi.org/10.31399/asm.cp.smst2022p0049","url":null,"abstract":"\u0000 Nitinol as a material is often considered stable at temperatures below 100 °C since these temperatures are significantly lower than the theoretical temperature range of [0.3-0.5] Tm (Tm = absolute melting temperature) at which temperature viscoplastic phenomena become active. However, when considering a constrained device, factors such as the peak pre-strain and the associated stress coupled with the exposed temperature and time may have a significant impact on the mechanical behavior of Nitinol. This in-turn can impact the performance and the shelf life of a constrained device. This effort investigates the effect of constant applied uniaxial strain (at different test temperatures over different exposure times) on the superelastic unloading response of Nitinol. To quantify this behavior on a more practical level, tests were conducted by constraining apical samples to different peak bending strains and exposed to an accelerated aging environment. The results from the testing suggest that the tensile response of the Nitinol is impacted by the strain and the time of dwell at a specific temperature under constrained conditions.","PeriodicalId":119283,"journal":{"name":"SMST 2022: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122490089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-16DOI: 10.31399/asm.cp.smst2022p0024
Andre L. Montagnoli, Neha S. John, M. L. Young, F. Tad Calkins, D. Nicholson
Shape memory alloys (SMAs) have gained attention in recent years as a powerful mechanism for mechanical actuation in space applications. One issue facing this technology is that most commercially available SMAs yield a high amount of energy loss due to their relatively large hysteresis, which can translate into an increase in the overall cost of the mission. Low hysteresis shape memory alloys (LHSMAs), which exhibit a much narrower hysteresis, are needed to minimize this energy loss. Previous studies have shown that elemental additions of Cu, Co, and Pd to the NiTi-based SMA can result in shape memory alloys with a much lower thermal hysteresis, due to better phase compatibility. This present work investigated seven alloy compositions to identify LHSMAs with less than 20 °C hysteresis and develop processing routes for these LHSMAs to determine potential candidates for space actuation applications.
{"title":"Development and Mechanical Testing of Low Hysteresis Shape Memory Alloys","authors":"Andre L. Montagnoli, Neha S. John, M. L. Young, F. Tad Calkins, D. Nicholson","doi":"10.31399/asm.cp.smst2022p0024","DOIUrl":"https://doi.org/10.31399/asm.cp.smst2022p0024","url":null,"abstract":"\u0000 Shape memory alloys (SMAs) have gained attention in recent years as a powerful mechanism for mechanical actuation in space applications. One issue facing this technology is that most commercially available SMAs yield a high amount of energy loss due to their relatively large hysteresis, which can translate into an increase in the overall cost of the mission. Low hysteresis shape memory alloys (LHSMAs), which exhibit a much narrower hysteresis, are needed to minimize this energy loss. Previous studies have shown that elemental additions of Cu, Co, and Pd to the NiTi-based SMA can result in shape memory alloys with a much lower thermal hysteresis, due to better phase compatibility. This present work investigated seven alloy compositions to identify LHSMAs with less than 20 °C hysteresis and develop processing routes for these LHSMAs to determine potential candidates for space actuation applications.","PeriodicalId":119283,"journal":{"name":"SMST 2022: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies","volume":"143 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131318816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-16DOI: 10.31399/asm.cp.smst2022p0069
C. Landis, S. Kyriakides, Dongjie Jiang
A new thermomechanical constitutive modeling approach for shape memory alloys (SMAs) that undergo a martensite to austenite phase transformation and the associated pseudoelastic and shape memory responses is presented. The novelty of this new formulation is that a single transformation surface is implemented in order to capture the forward and reverse phase transformations, as well as the reorientation and detwinning of the martensite phase. The framework is akin to the usual flow theory plasticity with kinematic hardening, however in addition to the transformation strain there is also a transformation entropy that is directly related to the martensite volume fraction appearing in prior theories. A transformation surface in effective stress and effective temperature space is introduced and an associated flow rule governs the evolution of the transformation strain and entropy. In order to capture the multitude of SMA behaviors, a transformation potential function is introduced in transformation strain and entropy space for the derivation of the back stresses and back temperatures that define the kinematic hardening behavior. It is this potential function that governs all of the important behaviors within the model. After the description of the general theory, specific forms for the transformation surface and the transformation potential are devised and results for the behaviors captured by the model are provided for a range of thermomechanical loadings. The model is then implemented in finite element calculations to investigate the structural response of shape memory alloy tubes, bars, and beams.
{"title":"A New Constitutive Modeling Approach for Shape Memory Alloys","authors":"C. Landis, S. Kyriakides, Dongjie Jiang","doi":"10.31399/asm.cp.smst2022p0069","DOIUrl":"https://doi.org/10.31399/asm.cp.smst2022p0069","url":null,"abstract":"\u0000 A new thermomechanical constitutive modeling approach for shape memory alloys (SMAs) that undergo a martensite to austenite phase transformation and the associated pseudoelastic and shape memory responses is presented. The novelty of this new formulation is that a single transformation surface is implemented in order to capture the forward and reverse phase transformations, as well as the reorientation and detwinning of the martensite phase. The framework is akin to the usual flow theory plasticity with kinematic hardening, however in addition to the transformation strain there is also a transformation entropy that is directly related to the martensite volume fraction appearing in prior theories. A transformation surface in effective stress and effective temperature space is introduced and an associated flow rule governs the evolution of the transformation strain and entropy. In order to capture the multitude of SMA behaviors, a transformation potential function is introduced in transformation strain and entropy space for the derivation of the back stresses and back temperatures that define the kinematic hardening behavior. It is this potential function that governs all of the important behaviors within the model. After the description of the general theory, specific forms for the transformation surface and the transformation potential are devised and results for the behaviors captured by the model are provided for a range of thermomechanical loadings. The model is then implemented in finite element calculations to investigate the structural response of shape memory alloy tubes, bars, and beams.","PeriodicalId":119283,"journal":{"name":"SMST 2022: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116066092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-16DOI: 10.31399/asm.cp.smst2022p0063
Yannic Zwinscher, F. Hoffmann, Simon Horn, R. Krieg, R. Theiss, P. Dültgen, Niclas Klumpen, C. Brecher, S. Neus
Passive vibration isolation is a key element to achieve precise results in milling processes and to increase tool durability. Damping of vibrations near to the cutting edge is considered highly effective as well as hard to implement because of the limited damping properties of conventional materials in the available space. The use of damping elements made of NiTi shape memory alloys (SMA) represents an innovative approach. Their use is based on the ability to convert mechanical energy into thermal energy through the pseudoelastic effect, whereby the pronounced conversion hysteresis of the material provides information about the usable damping potential. Studies on the properties of pseudoelastic SMA under compressive loading are only sporadically available in comparison to tensile loading. In this paper, the stress-compression curves and the hysteresis energy of tests results are compared with the results of finite element simulations. The simulation results based on the material model used so far is a good basis for the further development of damping elements.
{"title":"Simulation of Pseudoelastic NiTi Shape Memory Alloys under Compressive Loading to Assess the Potential use in Vibration Damping in the Tool Interface","authors":"Yannic Zwinscher, F. Hoffmann, Simon Horn, R. Krieg, R. Theiss, P. Dültgen, Niclas Klumpen, C. Brecher, S. Neus","doi":"10.31399/asm.cp.smst2022p0063","DOIUrl":"https://doi.org/10.31399/asm.cp.smst2022p0063","url":null,"abstract":"\u0000 Passive vibration isolation is a key element to achieve precise results in milling processes and to increase tool durability. Damping of vibrations near to the cutting edge is considered highly effective as well as hard to implement because of the limited damping properties of conventional materials in the available space. The use of damping elements made of NiTi shape memory alloys (SMA) represents an innovative approach. Their use is based on the ability to convert mechanical energy into thermal energy through the pseudoelastic effect, whereby the pronounced conversion hysteresis of the material provides information about the usable damping potential. Studies on the properties of pseudoelastic SMA under compressive loading are only sporadically available in comparison to tensile loading. In this paper, the stress-compression curves and the hysteresis energy of tests results are compared with the results of finite element simulations. The simulation results based on the material model used so far is a good basis for the further development of damping elements.","PeriodicalId":119283,"journal":{"name":"SMST 2022: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124940583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-16DOI: 10.31399/asm.cp.smst2022p0004
O. Benafan, D. Gaydosh, G. Bigelow, R. Noebe, F. Calkins, D. Nicholson
Aerodynamic devices, such as vortex generators, are often used to reenergize flow and improve aerodynamic performance of aircraft control surfaces. Often the static, non-moving surfaces are designed for specific flight conditions and decrease performance, such as increasing drag and fuel consumption, at other conditions. One example is vortex generators (VGs), small vanes located throughout the aircraft surfaces. VGs are typically not required for the entire flight profile but are essential for conditions such as low speeds during take-off and landing. The static nature of standard VGs stems from the inability to adapt conventional actuators due to mass, complexity, or footprint constraints given their small size and placement on outer surfaces of the aircraft. Shape memory alloys (SMAs) present an opportunity to enable actuation of such devices with a minimal mass and dimension, while still providing high energy densities. Additionally, SMAs can be passively used as sensors if carefully "tuned" to respond to the altitude temperature differential and passively actuate without the need for heaters, active controls, or additional sensors and instrumentation. In this work, the authors report on the development of low temperature SMAs for passively actuating VGs based on temperature changes from ground to cruise altitudes.
{"title":"Shape Memory Alloy Actuated Vortex Generators: Alloy Design","authors":"O. Benafan, D. Gaydosh, G. Bigelow, R. Noebe, F. Calkins, D. Nicholson","doi":"10.31399/asm.cp.smst2022p0004","DOIUrl":"https://doi.org/10.31399/asm.cp.smst2022p0004","url":null,"abstract":"\u0000 Aerodynamic devices, such as vortex generators, are often used to reenergize flow and improve aerodynamic performance of aircraft control surfaces. Often the static, non-moving surfaces are designed for specific flight conditions and decrease performance, such as increasing drag and fuel consumption, at other conditions. One example is vortex generators (VGs), small vanes located throughout the aircraft surfaces. VGs are typically not required for the entire flight profile but are essential for conditions such as low speeds during take-off and landing. The static nature of standard VGs stems from the inability to adapt conventional actuators due to mass, complexity, or footprint constraints given their small size and placement on outer surfaces of the aircraft. Shape memory alloys (SMAs) present an opportunity to enable actuation of such devices with a minimal mass and dimension, while still providing high energy densities. Additionally, SMAs can be passively used as sensors if carefully \"tuned\" to respond to the altitude temperature differential and passively actuate without the need for heaters, active controls, or additional sensors and instrumentation. In this work, the authors report on the development of low temperature SMAs for passively actuating VGs based on temperature changes from ground to cruise altitudes.","PeriodicalId":119283,"journal":{"name":"SMST 2022: Extended Abstracts from the International Conference on Shape Memory and Superelastic Technologies","volume":"76 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120919350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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