ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems最新文献

{"title":"Preliminary Experimental Investigation of Control Parameters for the Electroresistive Heating of SMA Knitted Textiles","authors":"Rachel Marbaker, B. Utter, K. Eschen, J. Abel","doi":"10.1115/smasis2019-5666","DOIUrl":"https://doi.org/10.1115/smasis2019-5666","url":null,"abstract":"\u0000 Knitted textiles manufactured from shape memory alloy (SMA) monofilaments possess advanced capabilities for distributed and complex actuation and are suited for a range of emerging needs in aerospace, biomedical, and robotics applications. In general, high currents for short periods of time provide sufficient electroresistive (Joule) heat to cause SMA wires to transform to austenite. However, SMA knitted textiles are difficult to electroresistively heat because the interlocking knit structure short-circuits the flow of current, causing localized overheating and isolating the transformation of the material along the current path. One approach for heating SMA knitted textiles is to drive pulses of high current between pairs of electrodes positioned across horizontal courses (rows) of knitted loops. This research presents a preliminary experimental investigation of the effects of factors related to electroresistive heating for SMA knitted textiles. A design of experiments analysis with two levels of four factors was conducted using a 24–1 fractional factorial design. The factors included the voltage of the power supply connected to the current amplifiers; a geometric factor defining the horizontal spacing of the electrodes attached to the knit sample; and two waveform factors: On Cycles and Off/On Cycles, which defined the length of time each current amplifier was enabled and disabled. Actuation performance was quantified by the actuation displacement and actuation force of the knit sample. Preliminary results suggest that voltage is the most influential factor, but also indicate that interactions between the geometric and waveform factors have significant effects on the heating and actuation performance. The characterization of these factor interactions has the potential to inform optimal electroresistive heating approaches for SMA knitted textiles, enabling integration into applications such as wearable technologies where convective heating is not practical.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127085404","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}

{"title":"Exfoliated-Graphite/Latex Piezoresistive System for Mapping Plantar Pressure","authors":"A. Riegel, Jonathan Gray, E. Zegeye","doi":"10.1115/smasis2019-5696","DOIUrl":"https://doi.org/10.1115/smasis2019-5696","url":null,"abstract":"\u0000 Diabetics often have neuropathy that prevents them from noticing developing foot ulcers. Pressure sensors can detect areas with abnormally high pressure, allowing earlier detection, prevention, and treatment of developing ulcers. Accurate pressure sensors are often limited to bulky or stationary systems, or have other limitations such as lack of accuracy, slow response times, and cost. This paper explains the fabrication of a prototype system using a bilayer flexible sensor for better accuracy in measuring pressure. The sensor is made of an exfoliated graphite film on a latex substrate and is layered with rubber padding to allow deformation. It is connected to an electronic system that reads changing resistance due to pressure and maps the applied pressure. This system might be a low cost, accurate, and durable alternative to current systems.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122401078","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}

{"title":"Nonreciprocal Wave Transmission in Metastable Modular Metastructures Utilizing Asymmetric Dual-Threshold Snap-Through","authors":"Xiang Liu, G. Cai, Kon-Well Wang","doi":"10.1115/smasis2019-5572","DOIUrl":"https://doi.org/10.1115/smasis2019-5572","url":null,"abstract":"\u0000 In this research, the nonreciprocal wave transmission features in one-dimensional and two-dimensional metastable modular metastructures are studied. Unlike previous work, in which the nonreciprocal transmission in metastable metastructures is realized by utilizing the supratransmission phenomenon when the excitation frequency is inside the linearized bandgap, a new approach is explored to achieve nonreciprocal wave transmission exploiting metastability and asymmetric dual-threshold snap-through. It is found that because of the asymmetry of potential energy wells of the equilibria, there will be two excitation amplitude thresholds for a metastable component when it is initially at the high-potential-energy equilibrium with excitation frequency within the passband. When the excitation amplitude increases and exceeds the first threshold, the metastable component will snap to the low-potential-energy equilibrium and maintain intrawell motion around this stable point, which will cause a significant decrease of the wave transmission. And when the excitation amplitude exceeds the second threshold, the metastable component will start to perform interwell motion, and now the wave transmission will increase suddenly. By using this “dual-threshold” phenomenon, nonreciprocal wave transmission in a one-dimensional structure is realized by connecting a metastable chain with a linear periodic part. Because of the wave attenuation effect of the linear part of the system, the excitation amplitude thresholds on different sides of the one-dimensional structure will be discrepant. Therefore, nonreciprocal wave transmission can be developed when the excitation amplitude is within certain ranges. It is interesting to note that the direction of nonreciprocal wave transmission can be changed by setting the excitation amplitude to different values. By changing the configuration of the metastable chain, the operation frequency and excitation amplitude ranges of the nonreciprocal transmission can be tuned. For a two-dimensional metastable metastructure, nonreciprocal wave transmission can be realized by adjusting the parameters of some metastable modules in the metastructure in the manner that the potential energy and energy thresholds of the adjusted modules and the unadjusted modules are different, but the passbands of the adjusted modules and the unadjusted modules will overlap in some frequency regions. Numerical studies provide clear insight of the proposed nonreciprocal wave transmission approach.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":"111 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115197005","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}

{"title":"Analytical Modeling and Simulation of the Blocked Force and Large Deformation of Multifunctional Segmented Lithium Ion Battery Unimorph Actuator","authors":"Cody Gonzalez, Jun Ma, M. Frecker, C. Rahn","doi":"10.1115/smasis2019-5560","DOIUrl":"https://doi.org/10.1115/smasis2019-5560","url":null,"abstract":"\u0000 A self-powered, and self-actuating lithium ion battery (LIB) has the potential to achieve large deformation while still maintaining actuation force. The energy storage capability allows for continual actuation without an external power source once charged. Reshaping the actuator requires a nonuniform distribution of charge and/or bending stiffness. Spatially varying the state of charge and bending stiffness along the length of a segmented unimorph configuration have the effect of improving the tailorability of the deformed actuator. In this paper, an analytical model is developed to predict the actuation properties of the segmented unimorph beam to determine its usefulness as an actuator. The model predicts the free deflection, blocked deflection, and blocked force at the tip as a function of spatially varying state of charge and bending stiffness. The main contribution of the paper is the development of blocked deflection over the length of the segmented unimorph, which has not yet been considered in the literature. The model is verified using experimental data and commercial finite element analysis.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":"515 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116209338","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}

{"title":"Coupled Electro-Thermo-Mechanical Modeling of Shape Memory Polymers","authors":"Midhan Siwakoti, Russell W. Mailen","doi":"10.1115/smasis2019-5693","DOIUrl":"https://doi.org/10.1115/smasis2019-5693","url":null,"abstract":"\u0000 Shape memory polymers (SMPs) are extensively studied for self-folding origami due to their large strain recovery, low cost, and low activation energy. SMPs utilize viscoelastic material behavior to change shape in response to an applied stimulus, for instance light or electricity. Electrical actuation is desirable due to its higher energy density and shorter response time. Previous studies reported empirical results on shape recovery of conductive polymer composites actuated by specific applied voltage or current conditions, which required rigorous experimentation. Here, we introduce a finite element framework capable of predicting the coupled electro-thermo-mechanical response of electrically actuated SMPs. As inputs, this framework requires material properties, such as electrical conductivity and viscoelastic parameters. The viscoelastic response is implemented using a Prony series model that is fit to experimental dynamic mechanical analysis (DMA) data. Using this framework, we predict the shape recovery behavior of electrically actuated SMPs subject to various thermal, electrical, and mechanical loads and evaluate the sensitivity of the response to the material properties. Additionally, we show the effects of material pre-straining conditions and localized conductive pathways on shape recovery and self-folding. This computational framework provides a fundamental understanding of the electro-thermo-mechanical response of electrically actuated SMPs and can be used to design electrically actuated self-folding origami for aerospace applications.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":"365 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114048933","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}

{"title":"Methodology for Minimizing Operational Influences of the Test Rig During Long-Term Investigations of SMA Wires","authors":"Benedict Theren, Dennis Otibar, Antonia Weirich, J. Brandenburg, B. Kuhlenkötter","doi":"10.1115/smasis2019-5513","DOIUrl":"https://doi.org/10.1115/smasis2019-5513","url":null,"abstract":"\u0000 The Chair of Production Systems conducts many reliability and fatigue tests of SMA actuators. A properly functioning test rig is essential for these often tedious investigations. The authors found deviations in the experimental results over high amount of experiments e.g. in the case of a batch change of the test material or in the case of exchanging wear parts. It is not clear whether this change was actually measured or is caused by a deviation of the measuring equipment. The influences of different load parameters on structural and functional fatigue are only partially quantified, which makes it difficult to assess the general plausibility of the results. In this paper the authors propose an experimental design by means of design of experiments (DoE), which determines the qualitative influence of the independent variables (IV) mechanical load, activation time, voltage, current and energy input on the dependent variable (DV) fatigue. The results of this initially performed experimental design serve as a reference point during the operation of the test rig in the event that experimental results do not appear plausible. In this case, the reference experimental design can be repeated. Since the influence of each IV is represented separately by the DoE, not only a fundamental deviation can be determined, but also the IV which deviates from the reference can be determined directly.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115119275","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}

{"title":"Perceived Value Change via 3D Printed Bistable Structures","authors":"W. K. Chan, Katherine S. Riley, A. F. Arrieta","doi":"10.1115/smasis2019-5694","DOIUrl":"https://doi.org/10.1115/smasis2019-5694","url":null,"abstract":"\u0000 A key aspect of color change is altering perceived value or intensity. This paper presents a methodology to achieve value change through mechanical means via the deflection of bistable structures. We create mechanical pixel-based, reversible color change using 3D printed switchable bistability. Switchable bistability arises from the combination of pre-strain and shape memory, enabling us to access multiple elastically programmed shapes at elevated temperatures with fast morphing and low actuation forces, while retaining high stiffness at room temperature. Building on our previous study that achieved bistability through FDM printing with directional pre-stress, finite element analysis is conducted to design a pixel-like structure that acts as a unit cell with color change capabilities. Quantitative and qualitative analysis is conducted through image processing techniques in order to prove the viability of this approach to creating value change through geometric deformation of bistable structures. By leveraging this technique, there are numerous potential applications in fields including robotics, architecture, and interior design.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133333806","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}

{"title":"Investigation of the Lifetime of Antagonistic Shape Memory Wires With Focus on Accelerated Resetting","authors":"Antonia Weirich, Benedict Theren, Dennis Otibar, B. Kuhlenkötter","doi":"10.1115/smasis2019-5511","DOIUrl":"https://doi.org/10.1115/smasis2019-5511","url":null,"abstract":"\u0000 The antagonistic setup of shape memory actuators enables a multitude of further applications than designs with only one shape memory element. In these actuators, two opposed shape memory elements work against each other and also ensure mutual resetting. This setup allows easily controlled and powersaving actuators for applications with two end positions such as locks or latches. It not only eliminates mechanical resetting, for example by a spring, but also offers a simple realization of holding the end positions energy-free and thereby conserving the shape memory effect.\u0000 In order to maximize the potential of this actuator design, the authors investigate the interdependencies between antagonistic wires. This paper focuses on the effect of resetting a previously activated NiTi wire by another, similar antagonistic wire before it cooled down completely. On the one hand, very early resetting can have a negative effect on both the cooling and especially the activated wire. This is mainly noticeable in a shortened lifetime of the actuator elements. On the other hand, applying mechanical strain by activating the opposed wire can accelerate phase transformation within the cooling wire. The authors performed corresponding fatigue tests with different cooling times in the antagonistic setup, in order to narrow down a timeframe for the optimized usability of an antagonistic wire actuator.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133542445","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}

{"title":"Direct Printing of a Flexible Strain Sensor for Distributed Monitoring of Deformation in Inflatable Structures","authors":"Mohammed Al-Rubaiai, Tsuruta Ryohei, T. Nam, U. Gandhi, Xiaobo Tan","doi":"10.1115/smasis2019-5713","DOIUrl":"https://doi.org/10.1115/smasis2019-5713","url":null,"abstract":"\u0000 Inflatable structures provide significant volume and weight savings for future space and soft robotic applications. Structural health monitoring (SHM) of these structures is essential to ensuring safe operation, providing early warnings of damage, and measuring structural changes over time. In this paper, we propose the design of a single flexible strain sensor for distributed monitoring of an inflatable tube, in particular, the detection and localization of a kink should that occur. Several commercially available conductive materials, including 3D-printing filaments, conductive paint, and conductive fabrics are explored for their strain-sensing performance, where the resistance change under uniaxial tension is measured, and the corresponding gauge factor (GF) is characterized. Flexible strain sensors are then fabricated and integrated with an inflatable structure fabric using screen-printing or 3D-printing techniques, depending on the nature of the raw conductive material. Among the tested materials, the conductive paint shows the highest stability, with GF of 15 and working strain range of 2.28%. Finally, the geometry of the sensor is designed to enable distributed monitoring of an inflatable tube. In particular, for a given deformation magnitude, the sensor output shows a monotonic relationship with the location where the deformation is applied, thus enabling the monitoring of the entire tube with a single sensor.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129705152","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}

{"title":"Dynamic Response of an Electrospun PVDF-Fe3O4 Piezoelectric Composite Microfiber","authors":"K. C. Chinnam, A. Casalotti, G. Lanzara","doi":"10.1115/smasis2019-5686","DOIUrl":"https://doi.org/10.1115/smasis2019-5686","url":null,"abstract":"\u0000 In this paper the dynamic response of an electrospun nanocomposite piezoelectric microfiber is investigated. The microfiber is formed by magnetic nanoparticles dispersed in Polyvinylidene (PVDF) matrix. Focus is given on the influence of an AC electric field on the dynamic response of the microfiber. In particular, the resonance frequency of the fiber was assessed under an increasing AC electric field at a wide range of frequencies. The electromechanical test results show that the resonance frequency of the fiber is influenced by the applied voltage and, for this case study, it decreases with increasing voltage. The results reported in this paper suggest that, once the mechanism behind such response is fully understood, composite piezoelectric microfibers can be used to fine-tune the resonance frequency of hosting devices.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120992146","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}