Li-Chih Tsai, Maysam Rezaee, M. Haider, A. Yazdi, N. Salowitz
Thin film and micro-fabricated devices are increasingly being used in actuators, sensors, and processors deployed in smart materials. The physical survival of these devices is paramount to their usefulness but existing methods for testing and analysis are limited and challenging due to their properties. The most common test involve the manual application and removal of (unspecified) tape but does not provide a result in scientific units and has large variation (> 35%). This paper presents a study into the effects of parameters of tape application and peeling on the adhesion strength of the tape. This information was then used to create a test methodology using commonly available laboratory equipment, which would control these parameters to minimize variation and produce repeatable quantitative results. Experiments using this test methodology were performed with tape directly adhered to several different substrates as well as tape adhered to a thin film which was then peeled off of a backing. Ongoing work is seeking to identify and address different forms of failure including adhesive failure, cohesive failure, or survival.
{"title":"Quantitative Measurement of Thin Film Adhesion Force","authors":"Li-Chih Tsai, Maysam Rezaee, M. Haider, A. Yazdi, N. Salowitz","doi":"10.1115/smasis2019-5615","DOIUrl":"https://doi.org/10.1115/smasis2019-5615","url":null,"abstract":"\u0000 Thin film and micro-fabricated devices are increasingly being used in actuators, sensors, and processors deployed in smart materials. The physical survival of these devices is paramount to their usefulness but existing methods for testing and analysis are limited and challenging due to their properties. The most common test involve the manual application and removal of (unspecified) tape but does not provide a result in scientific units and has large variation (> 35%). This paper presents a study into the effects of parameters of tape application and peeling on the adhesion strength of the tape. This information was then used to create a test methodology using commonly available laboratory equipment, which would control these parameters to minimize variation and produce repeatable quantitative results. Experiments using this test methodology were performed with tape directly adhered to several different substrates as well as tape adhered to a thin film which was then peeled off of a backing. Ongoing work is seeking to identify and address different forms of failure including adhesive failure, cohesive failure, or survival.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128496668","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}
Madalyn Mikkelsen, Michayal Mathew, P. Walgren, Brent R. Bielefeldt, Pedro B. C. Leal, D. Hartl, A. F. Arrieta
Morphing airfoils present an effective approach to managing the different requirements in each segment of a mission profile (e.g., takeoff/landing, cruise, and active maneuvering). In this work, an approach to morphing airfoil design that couples aerodynamic performance and internal structural configuration is detailed. The internal structural topology is formulated using a Lindenmayer System (L-System) coupled with a graph-based interpreter known as Spatial Interpretation for Development of Reconfigurable Structures (SPIDRS). The L-System encodes design variables that are interpreted via SPIDRS graphical operations and governs the development of the internal configuration (composed of elastic structural members and actuators). The global optimization uses a weakly coupled fluid-structure interaction (FSI) scheme for a first-order estimation of the aeroelastic loads that are critical for airfoil aerodynamic performance and structural integrity. Each airfoil is evaluated in two states: a standard non-actuated state to determine performance in standard operating conditions (e.g., cruise) and a high lift state, where internal shape memory alloy actuators are deformed to create a high lift configuration for the airfoil (e.g., takeoff/landing). Evaluating the aerodynamic performance of airfoils in these two states results in a series of potential solutions that best manage the tradeoff between aerodynamic metrics for both evaluated cases.
{"title":"Morphing Airfoil Design via L-System Generated Topology Optimization","authors":"Madalyn Mikkelsen, Michayal Mathew, P. Walgren, Brent R. Bielefeldt, Pedro B. C. Leal, D. Hartl, A. F. Arrieta","doi":"10.1115/smasis2019-5695","DOIUrl":"https://doi.org/10.1115/smasis2019-5695","url":null,"abstract":"\u0000 Morphing airfoils present an effective approach to managing the different requirements in each segment of a mission profile (e.g., takeoff/landing, cruise, and active maneuvering). In this work, an approach to morphing airfoil design that couples aerodynamic performance and internal structural configuration is detailed. The internal structural topology is formulated using a Lindenmayer System (L-System) coupled with a graph-based interpreter known as Spatial Interpretation for Development of Reconfigurable Structures (SPIDRS). The L-System encodes design variables that are interpreted via SPIDRS graphical operations and governs the development of the internal configuration (composed of elastic structural members and actuators). The global optimization uses a weakly coupled fluid-structure interaction (FSI) scheme for a first-order estimation of the aeroelastic loads that are critical for airfoil aerodynamic performance and structural integrity. Each airfoil is evaluated in two states: a standard non-actuated state to determine performance in standard operating conditions (e.g., cruise) and a high lift state, where internal shape memory alloy actuators are deformed to create a high lift configuration for the airfoil (e.g., takeoff/landing). Evaluating the aerodynamic performance of airfoils in these two states results in a series of potential solutions that best manage the tradeoff between aerodynamic metrics for both evaluated cases.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125264454","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}
Silicone materials are very appropriate for dielectric elastomer (DE) transducer applications due to their distinguished mechanical and electrical characteristics like high elasticity and an efficient electromechanical behavior. Since the material parameter permittivity influences significantly the work output, Wacker Chemie AG developed a new silicone named ELASTOSIL® Film 5030 with increased permittivity for improving the work output. Within this contribution, the mechanical characteristics including the hyperelasticity and electromechanically coupled behavior is compared to standard silicone material ELASTOSIL® Film 2030 from Wacker Young’s modulus of both materials are obtained conducting tensile tests, while the electromechanical behavior is characterized by investigating a planar single layer DE transducer. The new material has a similar Young’s modulus compared to the standard material. Furthermore, the electrically actuated deformation of the planar single layer DE transducers made form new silicone is proportional larger to its permittivity and inversely proportional to its Young’s modulus under same electrical field applied.
{"title":"Silicone Material With Enhanced Permittivity Used for Dielectric Elastomer Transducers","authors":"Ozan Çabuk, J. Maas","doi":"10.1115/smasis2019-5730","DOIUrl":"https://doi.org/10.1115/smasis2019-5730","url":null,"abstract":"\u0000 Silicone materials are very appropriate for dielectric elastomer (DE) transducer applications due to their distinguished mechanical and electrical characteristics like high elasticity and an efficient electromechanical behavior. Since the material parameter permittivity influences significantly the work output, Wacker Chemie AG developed a new silicone named ELASTOSIL® Film 5030 with increased permittivity for improving the work output. Within this contribution, the mechanical characteristics including the hyperelasticity and electromechanically coupled behavior is compared to standard silicone material ELASTOSIL® Film 2030 from Wacker Young’s modulus of both materials are obtained conducting tensile tests, while the electromechanical behavior is characterized by investigating a planar single layer DE transducer. The new material has a similar Young’s modulus compared to the standard material. Furthermore, the electrically actuated deformation of the planar single layer DE transducers made form new silicone is proportional larger to its permittivity and inversely proportional to its Young’s modulus under same electrical field applied.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121373830","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}
D. R. Seifert, Wesley A. Chapkin, G. Frank, J. Baur
This article presents the design, fabrication, and testing of multimaterial articulating cylinders with optimized periodic substructures. Genetic Optimization (NSGA-II) is used to obtain promising archetypes, which are rapidly post-processed, additively manufactured, and tested for bending and torsional rigidity. Objectives are set as structural stiffness in torsion and bending, subject to stress and maximum radial displacement constraints. A multimaterial printer allows for two material (stiff and compliant) design. Pareto Optimal structures are down selected and post processed into manufacturable designs, which are then printed. Bending and torsional rigidities are obtained via a series of static load tests, in which a known load is applied and a bending or twisting angle is measured. Design archetypes are compared via load-rotation curves. Performance in both loading environments is related back to the characteristic substructure.
{"title":"Design, Fabrication, and Testing of Optimized Flexible Cylinders","authors":"D. R. Seifert, Wesley A. Chapkin, G. Frank, J. Baur","doi":"10.1115/smasis2019-5601","DOIUrl":"https://doi.org/10.1115/smasis2019-5601","url":null,"abstract":"\u0000 This article presents the design, fabrication, and testing of multimaterial articulating cylinders with optimized periodic substructures. Genetic Optimization (NSGA-II) is used to obtain promising archetypes, which are rapidly post-processed, additively manufactured, and tested for bending and torsional rigidity. Objectives are set as structural stiffness in torsion and bending, subject to stress and maximum radial displacement constraints. A multimaterial printer allows for two material (stiff and compliant) design. Pareto Optimal structures are down selected and post processed into manufacturable designs, which are then printed. Bending and torsional rigidities are obtained via a series of static load tests, in which a known load is applied and a bending or twisting angle is measured. Design archetypes are compared via load-rotation curves. Performance in both loading environments is related back to the characteristic substructure.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122774970","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}
Wearable motion sensors find a great number of applications in the biomedical field by recording real-time movements and transferring data to mobile electronics. Patients with hyperkinetic movements is a group of interest for such sensors to survey their conditions for long periods. Longer and more frequent recording intervals are necessary to diagnose and treat patients’ disease. Mobile battery-operated motion sensors have a limited recording span, and they need to be charged frequently, which is inconvenient for most of the patients. In this study, vibration energy harvesters are employed to extend the battery life of motion sensors: one step closer to make autonomous sensors without chargers. A vibration energy harvester is designed for a motion sensor to harvest energy from involuntary movements of patients with hyperkinetic movements. An analytical model for charging and discharging cycles is developed to predict the battery life based on the amount of harvested power. Preliminary data from commercial devices are used as a foundation for the design and the current feasibility study.
{"title":"A Wearable Biomedical Motion Sensor Employing a Vibration Energy Harvester","authors":"H. Sharghi, J. Daneault, O. Bilgen","doi":"10.1115/smasis2019-5634","DOIUrl":"https://doi.org/10.1115/smasis2019-5634","url":null,"abstract":"\u0000 Wearable motion sensors find a great number of applications in the biomedical field by recording real-time movements and transferring data to mobile electronics. Patients with hyperkinetic movements is a group of interest for such sensors to survey their conditions for long periods. Longer and more frequent recording intervals are necessary to diagnose and treat patients’ disease. Mobile battery-operated motion sensors have a limited recording span, and they need to be charged frequently, which is inconvenient for most of the patients. In this study, vibration energy harvesters are employed to extend the battery life of motion sensors: one step closer to make autonomous sensors without chargers. A vibration energy harvester is designed for a motion sensor to harvest energy from involuntary movements of patients with hyperkinetic movements. An analytical model for charging and discharging cycles is developed to predict the battery life based on the amount of harvested power. Preliminary data from commercial devices are used as a foundation for the design and the current feasibility study.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125806300","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}
Colin M Basham, Megan E. Pitz, J. Najem, S. A. Sarles, Sakib Hasan
Two-terminal adaptive materials and circuit elements that mimic the signal processing, learning, and computing capabilities of biological synapses are essential for next-generation computing systems. To this end, we have recently developed resistive (ion channel) and capacitive (lipid bilayer) memory elements that mimic the composition, structure, and plasticity of biological synapses. Unlike solid-state counterparts, these biomolecular systems are low-power, analog, less noisy, biocompatible, and capable of exhibiting multiple timescales of short-term synaptic plasticity. However, lipid membranes lack structural stability and modularity necessary for a long-lasting adaptive material system. To address this issue, we propose the replacement of phospholipids with amphiphilic polymers to create artificial membranes, which have been demonstrated to be more durable than phospholipids. With the focus on memory capacitors, we demonstrate that polymeric bilayers can exhibit pinched hysteresis in the Q-v plane because of voltage-induced geometrical changes. Further, we demonstrate that the memcapacitive response is altered based on the surrounding oil medium; smaller oil molecules are retained at higher volume in the membrane, so that thicker bilayers have lower nominal capacitance but can vary this value by over 400%. Finally, we present a physics-based model that enables us to predict the device’s areal voltage-dependent response. Polymeric bilayers represent a significant enhancement in the field of soft-matter, geometrically-reconfigurable memcapacitors, and their highly customizable compositions will allow for a finely tuned electrical response that has a future in brain-inspired materials and circuits.
{"title":"Memcapacitive Devices in Neuromorphic Circuits via Polymeric Biomimetic Membranes","authors":"Colin M Basham, Megan E. Pitz, J. Najem, S. A. Sarles, Sakib Hasan","doi":"10.1115/smasis2019-5648","DOIUrl":"https://doi.org/10.1115/smasis2019-5648","url":null,"abstract":"\u0000 Two-terminal adaptive materials and circuit elements that mimic the signal processing, learning, and computing capabilities of biological synapses are essential for next-generation computing systems. To this end, we have recently developed resistive (ion channel) and capacitive (lipid bilayer) memory elements that mimic the composition, structure, and plasticity of biological synapses. Unlike solid-state counterparts, these biomolecular systems are low-power, analog, less noisy, biocompatible, and capable of exhibiting multiple timescales of short-term synaptic plasticity. However, lipid membranes lack structural stability and modularity necessary for a long-lasting adaptive material system. To address this issue, we propose the replacement of phospholipids with amphiphilic polymers to create artificial membranes, which have been demonstrated to be more durable than phospholipids. With the focus on memory capacitors, we demonstrate that polymeric bilayers can exhibit pinched hysteresis in the Q-v plane because of voltage-induced geometrical changes. Further, we demonstrate that the memcapacitive response is altered based on the surrounding oil medium; smaller oil molecules are retained at higher volume in the membrane, so that thicker bilayers have lower nominal capacitance but can vary this value by over 400%. Finally, we present a physics-based model that enables us to predict the device’s areal voltage-dependent response. Polymeric bilayers represent a significant enhancement in the field of soft-matter, geometrically-reconfigurable memcapacitors, and their highly customizable compositions will allow for a finely tuned electrical response that has a future in brain-inspired materials and circuits.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127325236","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}
A continuous-surface morphing airfoil is desirable for commercial aircraft in order to improve fuel efficiency, and due to the potential to morph the wing into a high-lift configuration for take-off and landing. Piezocomposite actuators have shown to be a feasible strategy for camber morphing in small unmanned fixed-wing aircraft with a Reynold’s number in the range of 50,000 to 250,000. As an extension, this paper presents a theoretical framework and results for morphing in single and multi-segment natural laminar flow airfoils with a maximum Reynold’s number of 825,000. The airfoils presented employ a continuous inextensible surface. To achieve morphing, piezocomposite actuating elements are applied on the suction and pressure surfaces of the airfoils. The geometric properties of the airfoils are determined using a genetic algorithm optimization method with a migration strategy in order to maintain population diversity. The algorithm optimizes independently the substrate thicknesses for the nominal airfoil, the leading edge, and the piezocomposite bonded surfaces. In addition, positions and voltages for each piezocomposite actuators are optimized. The genetic algorithm uses an objective function to maximize the change in coefficient of lift to morph the airfoil from its baseline (i.e. cruise) state to the high-lift state. Analysis is performed using a coupled fluid-structure interaction method assuming static aero-elastic behavior. Optimization is followed by a parametric analysis to examine lift, drag, and lift-to-drag ratio of the airfoils over their full operational range. The optimization is performed on a symmetric, asymmetric, and the aft element of a slotted multi-segment airfoil to examine the capabilities of induced-strain actuation at high dynamic pressures.
{"title":"A Variable Camber Piezocomposite Trailing-Edge for Subsonic Aircraft: Multidisciplinary Design Optimization","authors":"C. Wright, O. Bilgen","doi":"10.1115/smasis2019-5604","DOIUrl":"https://doi.org/10.1115/smasis2019-5604","url":null,"abstract":"\u0000 A continuous-surface morphing airfoil is desirable for commercial aircraft in order to improve fuel efficiency, and due to the potential to morph the wing into a high-lift configuration for take-off and landing. Piezocomposite actuators have shown to be a feasible strategy for camber morphing in small unmanned fixed-wing aircraft with a Reynold’s number in the range of 50,000 to 250,000. As an extension, this paper presents a theoretical framework and results for morphing in single and multi-segment natural laminar flow airfoils with a maximum Reynold’s number of 825,000. The airfoils presented employ a continuous inextensible surface. To achieve morphing, piezocomposite actuating elements are applied on the suction and pressure surfaces of the airfoils. The geometric properties of the airfoils are determined using a genetic algorithm optimization method with a migration strategy in order to maintain population diversity. The algorithm optimizes independently the substrate thicknesses for the nominal airfoil, the leading edge, and the piezocomposite bonded surfaces. In addition, positions and voltages for each piezocomposite actuators are optimized. The genetic algorithm uses an objective function to maximize the change in coefficient of lift to morph the airfoil from its baseline (i.e. cruise) state to the high-lift state. Analysis is performed using a coupled fluid-structure interaction method assuming static aero-elastic behavior. Optimization is followed by a parametric analysis to examine lift, drag, and lift-to-drag ratio of the airfoils over their full operational range. The optimization is performed on a symmetric, asymmetric, and the aft element of a slotted multi-segment airfoil to examine the capabilities of induced-strain actuation at high dynamic pressures.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130698058","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}
Susanne-Marie Kirsch, F. Welsch, L. Ehl, Nicolas Michaelis, Paul Motzki, A. Schütze, S. Seelecke
Elastocaloric cooling uses solid-state NiTi-based shape memory alloy (SMA) as a non-volatile cooling medium and enables a novel environment-friendly cooling technology without global warming potential. Due to the high specific latent heats activated by mechanical loading/unloading, large temperature changes can be generated in the material. Accompanied by a small required work input, a high coefficient of performance is achievable. Recently, a fully-functional and illustrative continuous operating elastocaloric fluid cooling system based on SMA is developed and realized, using a novel mechanical concept for individual loading and unloading of multiple SMA wire bundles. The fluid-based heat transfer system is designed for efficient heat exchange between the stationary heat source/sink and the SMA elements, operates without any additional heat transfer medium. Rotation frequency and fluid flow-rate are adjustable during operation, which allows adapting the operation point to power- or efficiency-optimized demands. The versatile placement of the in- and outlets allows different duct lengths and counter-flow or parallel-flow experiments. To investigate the air flow parameters at the in- and outlets, as well as the crossflow between the hot and cold side, a measurement system is developed and integrated. In this contribution, the first measurement results of the output temperatures for inlet air flow variation in combination with different rotation frequencies are presented.
弹性冷却利用固态镍钛形状记忆合金（SMA）作为非挥发性冷却介质，实现了一种新型环保冷却技术，且不会造成全球变暖。由于机械加载/卸载激活了高比潜热，材料中可产生较大的温度变化。由于所需的功输入较小，因此可以实现较高的性能系数。最近，我们开发并实现了一个基于 SMA 的全功能连续运行弹性热流体冷却系统，该系统采用新颖的机械概念，可对多个 SMA 线束进行单独加载和卸载。基于流体的传热系统设计用于固定热源/散热器和 SMA 元件之间的高效热交换，无需任何额外的传热介质即可运行。在运行过程中，旋转频率和流体流速均可调节，从而使运行点适应功率或效率优化的要求。进气口和出气口的多用途布置允许不同的管道长度以及逆流或平行流实验。为了研究进气口和出气口的气流参数以及冷热侧之间的交叉气流，开发并集成了一套测量系统。在本文中，将首次介绍进气口气流变化与不同旋转频率相结合时输出温度的测量结果。
{"title":"Continuous Operating Elastocaloric Heating and Cooling Device: Air Flow Investigation and Experimental Parameter Study","authors":"Susanne-Marie Kirsch, F. Welsch, L. Ehl, Nicolas Michaelis, Paul Motzki, A. Schütze, S. Seelecke","doi":"10.1115/smasis2019-5633","DOIUrl":"https://doi.org/10.1115/smasis2019-5633","url":null,"abstract":"\u0000 Elastocaloric cooling uses solid-state NiTi-based shape memory alloy (SMA) as a non-volatile cooling medium and enables a novel environment-friendly cooling technology without global warming potential. Due to the high specific latent heats activated by mechanical loading/unloading, large temperature changes can be generated in the material. Accompanied by a small required work input, a high coefficient of performance is achievable.\u0000 Recently, a fully-functional and illustrative continuous operating elastocaloric fluid cooling system based on SMA is developed and realized, using a novel mechanical concept for individual loading and unloading of multiple SMA wire bundles. The fluid-based heat transfer system is designed for efficient heat exchange between the stationary heat source/sink and the SMA elements, operates without any additional heat transfer medium. Rotation frequency and fluid flow-rate are adjustable during operation, which allows adapting the operation point to power- or efficiency-optimized demands.\u0000 The versatile placement of the in- and outlets allows different duct lengths and counter-flow or parallel-flow experiments. To investigate the air flow parameters at the in- and outlets, as well as the crossflow between the hot and cold side, a measurement system is developed and integrated. In this contribution, the first measurement results of the output temperatures for inlet air flow variation in combination with different rotation frequencies are presented.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130822649","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}
Global energy demand continues to drive oil and gas exploration in increasingly challenging environments. The extreme temperatures and pressures drilling fluids are subjected to require optimum design of their rheology. Among the numerous components used in the design of drilling fluids are surfactants. Surfactants play an important role in the emulsification of immiscible liquids as well as the alteration of cuttings wettability to facilitate transport to the surface. Nonionic surfactants, depending on their chemical group allow the inversion of oil-in-water emulsions (O/W) to water-in-oil (W/O) and vice-versa depending on the direction of temperature change. In this study, emulsion-suspension samples were prepared with different nonionic surfactants at Oil:Water ratios of 50:50 and 60:40. The mechanical properties of the samples was assessed using a scientific rheometer at temperatures ranging from 0–90 °C. Phase inversion from oil-in-water to water-in-oil was observed for samples stabilized by polyoxyethylene oleyl ether surfactants. Build up in the apparent viscosity of the samples was observed following phase inversion, mainly resulting from the formation of nanosized dispersed water droplets. Findings in the study highlighted the possibility of obtaining different drilling fluid types during downhole circulation, thereby paving a path for the design optimization of drilling fluids used in offshore operations.
{"title":"Phase Inversion of Complex Fluids With Implications to Drilling Fluids","authors":"G. Numkam, B. Akbari","doi":"10.1115/smasis2019-5715","DOIUrl":"https://doi.org/10.1115/smasis2019-5715","url":null,"abstract":"\u0000 Global energy demand continues to drive oil and gas exploration in increasingly challenging environments. The extreme temperatures and pressures drilling fluids are subjected to require optimum design of their rheology. Among the numerous components used in the design of drilling fluids are surfactants. Surfactants play an important role in the emulsification of immiscible liquids as well as the alteration of cuttings wettability to facilitate transport to the surface.\u0000 Nonionic surfactants, depending on their chemical group allow the inversion of oil-in-water emulsions (O/W) to water-in-oil (W/O) and vice-versa depending on the direction of temperature change. In this study, emulsion-suspension samples were prepared with different nonionic surfactants at Oil:Water ratios of 50:50 and 60:40. The mechanical properties of the samples was assessed using a scientific rheometer at temperatures ranging from 0–90 °C.\u0000 Phase inversion from oil-in-water to water-in-oil was observed for samples stabilized by polyoxyethylene oleyl ether surfactants. Build up in the apparent viscosity of the samples was observed following phase inversion, mainly resulting from the formation of nanosized dispersed water droplets.\u0000 Findings in the study highlighted the possibility of obtaining different drilling fluid types during downhole circulation, thereby paving a path for the design optimization of drilling fluids used in offshore operations.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132687614","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}
Over the past decade, shape memory alloy (SMA) in the form of wires and cables have been extensively studied for various structural engineering applications. There are numerous application areas where pure compression (or coupled with tension) is the primary load bearing scenario, which requires larger size SMA bars. However, the compression behavior of SMA bars is not well known, and little is reported in the literature. In that perspective, this paper presents an experimental study on large diameter superelastic Nickel-Titanium (NiTi) bars subjected to a cyclic compression load. A total of nine SMA bars having slenderness ratios ranging from 60 to 90 were tested. Hysteretic stress-strain responses are plotted and critical buckling load, energy dissipation and residual strain of SMA bars with different slenderness ratios are presented.
{"title":"Experimental Investigation on the Cyclic Compression Behavior of Superelastic NiTi SMA Bars","authors":"A. Asfaw, G. Xing, O. Ozbulut","doi":"10.1115/smasis2019-5654","DOIUrl":"https://doi.org/10.1115/smasis2019-5654","url":null,"abstract":"Over the past decade, shape memory alloy (SMA) in the form of wires and cables have been extensively studied for various structural engineering applications. There are numerous application areas where pure compression (or coupled with tension) is the primary load bearing scenario, which requires larger size SMA bars. However, the compression behavior of SMA bars is not well known, and little is reported in the literature. In that perspective, this paper presents an experimental study on large diameter superelastic Nickel-Titanium (NiTi) bars subjected to a cyclic compression load. A total of nine SMA bars having slenderness ratios ranging from 60 to 90 were tested. Hysteretic stress-strain responses are plotted and critical buckling load, energy dissipation and residual strain of SMA bars with different slenderness ratios are presented.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115154134","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：