Volume 1: Development and Characterization of Multifunctional Materials; Modeling, Simulation, and Control of Adaptive Systems; Integrated System Design and Implementation最新文献
Various researchers have investigated the behavior of a linear mechanical oscillator weakly coupled to a nonlinear mechanical attachment that has essential stiffness nonlinearity. Under certain conditions, the essentially nonlinear attachment acts as a nonlinear energy sink (NES) and one-way energy transfer from the main structure to the attachment can be achieved. Since an essentially nonlinear attachment does not possess any preferential resonance frequency, they have increased robustness against detuning, enabling frequency-wise wideband performance. In this work, the interactions between an essentially nonlinear piezoelectric attachment and an electromechanically coupled two-degree-of-freedom (2-DOF) aeroelastic typical section are studied. The governing equations of the electromechanically coupled typical section with piezoelectric coupling added to the plunge DOF are presented. An equivalent electrical model of the coupled aeroelastic system is presented and combined to a nonlinear shunt circuit. The performance of the piezoelectric NES to modify the aeroelastic behavior of the typical section is discussed using the short-circuit condition as a reference case. Furthermore, the robustness of the piezoelectric NES against detuning is also investigated by changing some parameters of the typical section.
{"title":"Essentially Nonlinear Piezoelectric Attachment for Aeroelastic Flutter Suppression","authors":"Gabriela Mayumi de Freitas Otsubo, C. D. Marqui","doi":"10.1115/SMASIS2018-8094","DOIUrl":"https://doi.org/10.1115/SMASIS2018-8094","url":null,"abstract":"Various researchers have investigated the behavior of a linear mechanical oscillator weakly coupled to a nonlinear mechanical attachment that has essential stiffness nonlinearity. Under certain conditions, the essentially nonlinear attachment acts as a nonlinear energy sink (NES) and one-way energy transfer from the main structure to the attachment can be achieved. Since an essentially nonlinear attachment does not possess any preferential resonance frequency, they have increased robustness against detuning, enabling frequency-wise wideband performance. In this work, the interactions between an essentially nonlinear piezoelectric attachment and an electromechanically coupled two-degree-of-freedom (2-DOF) aeroelastic typical section are studied. The governing equations of the electromechanically coupled typical section with piezoelectric coupling added to the plunge DOF are presented. An equivalent electrical model of the coupled aeroelastic system is presented and combined to a nonlinear shunt circuit. The performance of the piezoelectric NES to modify the aeroelastic behavior of the typical section is discussed using the short-circuit condition as a reference case. Furthermore, the robustness of the piezoelectric NES against detuning is also investigated by changing some parameters of the typical section.","PeriodicalId":392289,"journal":{"name":"Volume 1: Development and Characterization of Multifunctional Materials; Modeling, Simulation, and Control of Adaptive Systems; Integrated System Design and Implementation","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123113436","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}
Although there have been numerous efforts into harnessing the snap through dynamics of bistable structures with piezoelectric transducers to achieve large energy conversion, these same dynamics are undesirable under morphing applications where stationary control of the structure’s configuration is paramount. To suppress cross-well vibrations that primarily result from periodic excitation at low frequencies, a novel control strategy is proposed and implemented on the piezoelectrically generated bistable laminate, which consists of only Macro Fiber Composites (MFC) in a [0MFC/90MFC]T layup. While under cross-well regimes such as chaotic or limit cycle oscillations, a single MFC is actuated past the laminate’s limit voltage to eliminate one of its potential wells and force it into the remaining stable state. Simultaneously, a Positive Position Feedback (PPF) controller suppresses the resulting single-well oscillations through the other MFC. This dual control strategy is demonstrated with an electromechanical model through the suppression of various cross-well regimes, and results in significant reduction of amplitude. The active control capability of the laminate prevents snap through instability when under large enough external vibrations and adds to its multifunctionality along with morphing and broadband energy harvesting.
{"title":"Suppression of Cross-Well Oscillations With Active Control of a Bistable Laminate","authors":"Andrew J Lee, Antai Xie, D. Inman","doi":"10.1115/SMASIS2018-7919","DOIUrl":"https://doi.org/10.1115/SMASIS2018-7919","url":null,"abstract":"Although there have been numerous efforts into harnessing the snap through dynamics of bistable structures with piezoelectric transducers to achieve large energy conversion, these same dynamics are undesirable under morphing applications where stationary control of the structure’s configuration is paramount. To suppress cross-well vibrations that primarily result from periodic excitation at low frequencies, a novel control strategy is proposed and implemented on the piezoelectrically generated bistable laminate, which consists of only Macro Fiber Composites (MFC) in a [0MFC/90MFC]T layup. While under cross-well regimes such as chaotic or limit cycle oscillations, a single MFC is actuated past the laminate’s limit voltage to eliminate one of its potential wells and force it into the remaining stable state. Simultaneously, a Positive Position Feedback (PPF) controller suppresses the resulting single-well oscillations through the other MFC. This dual control strategy is demonstrated with an electromechanical model through the suppression of various cross-well regimes, and results in significant reduction of amplitude. The active control capability of the laminate prevents snap through instability when under large enough external vibrations and adds to its multifunctionality along with morphing and broadband energy harvesting.","PeriodicalId":392289,"journal":{"name":"Volume 1: Development and Characterization of Multifunctional Materials; Modeling, Simulation, and Control of Adaptive Systems; Integrated System Design and Implementation","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130242224","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}
The buckling characteristics of thin functionally graded (FG) nano-plates subjected to both thermal loads and biaxial linearly varying forces is investigated. Eringen’s nonlocal elasticity theory is employed to account for the nano-scale phenomena in the plates. Hamilton’s principle and the constitutive relations are used to derive the partial differential governing equations of motion for the thin plates that are modeled using Kirchhoff’s plate theory. The mechanical properties of the FG nano-plates are assumed to vary smoothly across the thickness of the plate following a power law. Three types of thermal loads are presented and the spectral collocation method is utilized to solve for the critical buckling loads. The accuracy of the numerical solution of the proposed model is verified by comparing the results with those available in the literature. A comprehensive parametric study is carried out, and the effects of the nonlocal scale parameter, power law index, aspect ratio, slopes of the axial loads, boundary conditions, assumed temperature distributions, and the difference between the ceramic-rich and metal-rich surfaces on the nonlocal critical buckling loads of the nano-plates are examined. The results reveal that these parameters have significant influence on the stability behavior of the FG nano-plates.
{"title":"Nonlocal Buckling Characteristics of Functionally Graded Nano-Plates Subjected to Thermal Loads and Biaxial Linearly Varying Forces","authors":"M. Sari, S. Ghaffari, S. Ceballes, A. Abdelkefi","doi":"10.1115/SMASIS2018-8107","DOIUrl":"https://doi.org/10.1115/SMASIS2018-8107","url":null,"abstract":"The buckling characteristics of thin functionally graded (FG) nano-plates subjected to both thermal loads and biaxial linearly varying forces is investigated. Eringen’s nonlocal elasticity theory is employed to account for the nano-scale phenomena in the plates. Hamilton’s principle and the constitutive relations are used to derive the partial differential governing equations of motion for the thin plates that are modeled using Kirchhoff’s plate theory. The mechanical properties of the FG nano-plates are assumed to vary smoothly across the thickness of the plate following a power law. Three types of thermal loads are presented and the spectral collocation method is utilized to solve for the critical buckling loads. The accuracy of the numerical solution of the proposed model is verified by comparing the results with those available in the literature. A comprehensive parametric study is carried out, and the effects of the nonlocal scale parameter, power law index, aspect ratio, slopes of the axial loads, boundary conditions, assumed temperature distributions, and the difference between the ceramic-rich and metal-rich surfaces on the nonlocal critical buckling loads of the nano-plates are examined. The results reveal that these parameters have significant influence on the stability behavior of the FG nano-plates.","PeriodicalId":392289,"journal":{"name":"Volume 1: Development and Characterization of Multifunctional Materials; Modeling, Simulation, and Control of Adaptive Systems; Integrated System Design and Implementation","volume":"203 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114586104","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 trade-off exists in compliant morphing structures between weight, adaptability, and load-carrying capacity. A truss-like structure utilizing a selectively stiff, bi-stable element is proposed to provide a solution to this problem. The design space of the element is explored in a parameter study using a finite element model. The element is embedded in a rib to correlate its behavior to that of the element in isolation. Finally, an aeroelastic analysis is conducted on the rib to determine the response of the structure to aerodynamic loading.
{"title":"Monolithic Morphing Rib With Selective Stiffness From Embeddable Bi-Stable Elements","authors":"D. M. Boston, A. F. Arrieta, José R Rivas-Padilla","doi":"10.1115/SMASIS2018-8256","DOIUrl":"https://doi.org/10.1115/SMASIS2018-8256","url":null,"abstract":"A trade-off exists in compliant morphing structures between weight, adaptability, and load-carrying capacity. A truss-like structure utilizing a selectively stiff, bi-stable element is proposed to provide a solution to this problem. The design space of the element is explored in a parameter study using a finite element model. The element is embedded in a rib to correlate its behavior to that of the element in isolation. Finally, an aeroelastic analysis is conducted on the rib to determine the response of the structure to aerodynamic loading.","PeriodicalId":392289,"journal":{"name":"Volume 1: Development and Characterization of Multifunctional Materials; Modeling, Simulation, and Control of Adaptive Systems; Integrated System Design and Implementation","volume":"2017 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123613046","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}
Wei Zhang, Jonathan Hong, Saad Ahmed, Z. Ounaies, M. Frecker
Nowadays, soft grippers, which use compliant mechanisms instead of stiff components to achieve grasping action, are being utilized in an increasing range of engineering fields, such as food industry, medical care and biological sample collection, for their material selection, high conformability and gentle contact with target objects compared to traditional stiff grippers. In this study, a three-fingered gripper is designed based on a simple actuation mechanism but with high conformability to the object and produces relatively high actuation force per unit mass. The electrostrictive PVDF-based terpolymer is applied as the self-folding actuation mechanism. Finite element analysis (FEA) models are developed to predict the deformation of the folded shape and grasping force of the gripper with two grasp modes, i.e. enveloping grasp and parallel grasp. The FEA models achieved good agreement with experiments. Design optimization is then formulated and a parametric design is conducted with objectives to maximize free deflection and blocked force of the gripper. The design variables are the thicknesses of the active and passive materials, and the nature of the passive layer. It is found that there exists an optimal terpolymer thickness for a given scotch tape substrate thickness to achieve maximum free deflection, and the blocked force always increases as either thickness of terpolymer or scotch tape increases. As the length of the notch increases, free deflection also increases due to more pronounced folding behavior of the actuator, but the blocked force decreases since the actuator is less stiff. The tradeoff between free deflection and blocked force is critical for the final decision on the optimal design for a particular application.
{"title":"Parametric Design of a Soft Gripper Actuated Using the Electrostrictive PVDF-Based Terpolymer","authors":"Wei Zhang, Jonathan Hong, Saad Ahmed, Z. Ounaies, M. Frecker","doi":"10.1115/SMASIS2018-7966","DOIUrl":"https://doi.org/10.1115/SMASIS2018-7966","url":null,"abstract":"Nowadays, soft grippers, which use compliant mechanisms instead of stiff components to achieve grasping action, are being utilized in an increasing range of engineering fields, such as food industry, medical care and biological sample collection, for their material selection, high conformability and gentle contact with target objects compared to traditional stiff grippers. In this study, a three-fingered gripper is designed based on a simple actuation mechanism but with high conformability to the object and produces relatively high actuation force per unit mass. The electrostrictive PVDF-based terpolymer is applied as the self-folding actuation mechanism. Finite element analysis (FEA) models are developed to predict the deformation of the folded shape and grasping force of the gripper with two grasp modes, i.e. enveloping grasp and parallel grasp. The FEA models achieved good agreement with experiments. Design optimization is then formulated and a parametric design is conducted with objectives to maximize free deflection and blocked force of the gripper. The design variables are the thicknesses of the active and passive materials, and the nature of the passive layer. It is found that there exists an optimal terpolymer thickness for a given scotch tape substrate thickness to achieve maximum free deflection, and the blocked force always increases as either thickness of terpolymer or scotch tape increases. As the length of the notch increases, free deflection also increases due to more pronounced folding behavior of the actuator, but the blocked force decreases since the actuator is less stiff. The tradeoff between free deflection and blocked force is critical for the final decision on the optimal design for a particular application.","PeriodicalId":392289,"journal":{"name":"Volume 1: Development and Characterization of Multifunctional Materials; Modeling, Simulation, and Control of Adaptive Systems; Integrated System Design and Implementation","volume":"1999 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125722751","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}
Elastic meta-structures, with wave propagation control capabilities, have been widely investigated for mechanical vibrations suppression and acoustics attenuation applications. Periodic architected lattices, combined with mechanical or electromechanical resonators, are utilized to form frequency bands over which the propagation of elastic waves is forbidden, known as bandgaps. The characteristics of these bandgaps, in terms of frequency range and bandwidth, are determined by the local resonators as well as characteristics of the individual cells out of which the structure is composed. In this study, the effectiveness of local stress fields as a tool for bandgap tuning in active, elastic meta-structures is investigated. A finite beam undergoing axial and flexural deformations, with a spatially periodic axial loads acting on it, is chosen to demonstrate the concept. The beam is first divided into several sections where localized stress-fields are varied periodically. Lateral and longitudinal deformations of the beam are described, respectively, by the Timoshenko beam theory and the Elementary rod theory. The Frequency-domain Spectral Element Method is then employed to calculate the forced-vibration response of the structure. The effects of the local state-of-stress on the width and frequency of the resulting bandgaps are investigated.
{"title":"Investigation of Elastic Meta-Structures With Periodic Localized Stress-Fields","authors":"M. Albakri, P. Tarazaga","doi":"10.1115/SMASIS2018-8147","DOIUrl":"https://doi.org/10.1115/SMASIS2018-8147","url":null,"abstract":"Elastic meta-structures, with wave propagation control capabilities, have been widely investigated for mechanical vibrations suppression and acoustics attenuation applications. Periodic architected lattices, combined with mechanical or electromechanical resonators, are utilized to form frequency bands over which the propagation of elastic waves is forbidden, known as bandgaps. The characteristics of these bandgaps, in terms of frequency range and bandwidth, are determined by the local resonators as well as characteristics of the individual cells out of which the structure is composed.\u0000 In this study, the effectiveness of local stress fields as a tool for bandgap tuning in active, elastic meta-structures is investigated. A finite beam undergoing axial and flexural deformations, with a spatially periodic axial loads acting on it, is chosen to demonstrate the concept. The beam is first divided into several sections where localized stress-fields are varied periodically. Lateral and longitudinal deformations of the beam are described, respectively, by the Timoshenko beam theory and the Elementary rod theory. The Frequency-domain Spectral Element Method is then employed to calculate the forced-vibration response of the structure. The effects of the local state-of-stress on the width and frequency of the resulting bandgaps are investigated.","PeriodicalId":392289,"journal":{"name":"Volume 1: Development and Characterization of Multifunctional Materials; Modeling, Simulation, and Control of Adaptive Systems; Integrated System Design and Implementation","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123919117","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}
Kyle A. Weaver, J. Koo, Tae-Heon Yang, Young-Min Kim
Artificial and synthetic skins are widely used in the medical field; used in applications ranging from skin grafts to suture training pads. There is a growing need for artificial skins with tunable properties. However, current artificial skins do not take into account the variability of mechanical properties between individual humans as well as the age-dependent properties of human skin. Furthermore, there has been little development in artificial skins based on these properties. Thus, the primary purpose of this research is to develop variable stiffness artificial skin samples using magnetorheological elastomers (MREs) whose properties that can be controlled using external magnetic fields. In this study, multiple MRE skin samples were fabricated with varying filler particle volume contents. Using a precision dynamic mechanical analyzer, a series of indenting experiments were performed on the samples to characterize their mechanical properties. The samples were tested using a spherical indenter that indented a total depth of 1 mm with a speed of 0.01 mm/s and unloaded at the same rate. The results show that the modulus or stiffness increases significantly as the iron percent (w/w) in the sample increases. Additionally, the stiffness of the sample increases proportional to the intensity of the applied external magnetic field. To assess the MRE samples’ variability of properties, the testing results were compared with in vivo human skin testing data. The results show the MRE samples are feasible to represent the age-dependent stiffness demonstrated in in vivo human skin testing. The MRE materials studied will be further studied as a variable-stiffness skin model in medical devices, such as radial pulse simulators.
{"title":"Capturing Age-Dependent Properties of Human Skin Using Magnetorheological Elastomers","authors":"Kyle A. Weaver, J. Koo, Tae-Heon Yang, Young-Min Kim","doi":"10.1115/SMASIS2018-8015","DOIUrl":"https://doi.org/10.1115/SMASIS2018-8015","url":null,"abstract":"Artificial and synthetic skins are widely used in the medical field; used in applications ranging from skin grafts to suture training pads. There is a growing need for artificial skins with tunable properties. However, current artificial skins do not take into account the variability of mechanical properties between individual humans as well as the age-dependent properties of human skin. Furthermore, there has been little development in artificial skins based on these properties. Thus, the primary purpose of this research is to develop variable stiffness artificial skin samples using magnetorheological elastomers (MREs) whose properties that can be controlled using external magnetic fields. In this study, multiple MRE skin samples were fabricated with varying filler particle volume contents. Using a precision dynamic mechanical analyzer, a series of indenting experiments were performed on the samples to characterize their mechanical properties. The samples were tested using a spherical indenter that indented a total depth of 1 mm with a speed of 0.01 mm/s and unloaded at the same rate. The results show that the modulus or stiffness increases significantly as the iron percent (w/w) in the sample increases. Additionally, the stiffness of the sample increases proportional to the intensity of the applied external magnetic field. To assess the MRE samples’ variability of properties, the testing results were compared with in vivo human skin testing data. The results show the MRE samples are feasible to represent the age-dependent stiffness demonstrated in in vivo human skin testing. The MRE materials studied will be further studied as a variable-stiffness skin model in medical devices, such as radial pulse simulators.","PeriodicalId":392289,"journal":{"name":"Volume 1: Development and Characterization of Multifunctional Materials; Modeling, Simulation, and Control of Adaptive Systems; Integrated System Design and Implementation","volume":"287 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129762762","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}
Bistable structures have several applications in different areas, such as aircraft morphing wings, morphing wind turbine blades, and vibration energy harvesting, due to their unique properties. Bistable structures can be used in morphing wings and wind turbine blades since they are able to alleviate large loads by snapping from one stable position to the other one. A piezoelectric actuator can be used to bring the bistable structure back to its original position after the load is alleviated. In this paper, the transient response of a piezoelectrically actuated bistable beam is investigated experimentally for different force inputs. The goal of these experiments is to explore the ability of a commercial piezoelectric actuator to induce snap-through motion in a bistable structure. The feasibility of performing snap-through motion, and the required energy are found for different excitation force amplitudes and frequencies.
{"title":"Transient Motion of a Piezoelectrically-Actuated Bistable Beam","authors":"M. Zarepoor, O. Bilgen","doi":"10.1115/SMASIS2018-7989","DOIUrl":"https://doi.org/10.1115/SMASIS2018-7989","url":null,"abstract":"Bistable structures have several applications in different areas, such as aircraft morphing wings, morphing wind turbine blades, and vibration energy harvesting, due to their unique properties. Bistable structures can be used in morphing wings and wind turbine blades since they are able to alleviate large loads by snapping from one stable position to the other one. A piezoelectric actuator can be used to bring the bistable structure back to its original position after the load is alleviated. In this paper, the transient response of a piezoelectrically actuated bistable beam is investigated experimentally for different force inputs. The goal of these experiments is to explore the ability of a commercial piezoelectric actuator to induce snap-through motion in a bistable structure. The feasibility of performing snap-through motion, and the required energy are found for different excitation force amplitudes and frequencies.","PeriodicalId":392289,"journal":{"name":"Volume 1: Development and Characterization of Multifunctional Materials; Modeling, Simulation, and Control of Adaptive Systems; Integrated System Design and Implementation","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124518808","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}
This paper studies the vibration mitigation of a sandwich beam with tip mass using piezoelectric active control. The core of the sandwich beam is made of foam and the face sheets are made of steel with a bonded piezoelectric actuator and sensor. The three-layer sandwich beam is clamped at one end and carries a payload at the other end. The tip mass is such that its center of mass is offset from the point of attachment. The extended higher-order sandwich panel (HSAPT) theory is employed in conjunction with the Hamilton’s principle to derive the governing equations of motion and boundary conditions. The obtained partial differential equations are solved using the generalized differential quadrature (GDQ) method. Free and forced vibration analyses are carried out and the results are compared with those obtained from the use of the commercial finite element software ANSYS. Derivative feedback control algorithm is employed to control the vibration of the system. Parametric studies are conducted to examine the arrangement impact of the piezoelectric sensors and actuators on the system vibrational behavior.
{"title":"Piezoelectric Vibration Control of a Sandwich Beam With Tip Mass","authors":"Eshagh Farzaneh, O. Barry, P. Tarazaga","doi":"10.1115/SMASIS2018-8127","DOIUrl":"https://doi.org/10.1115/SMASIS2018-8127","url":null,"abstract":"This paper studies the vibration mitigation of a sandwich beam with tip mass using piezoelectric active control. The core of the sandwich beam is made of foam and the face sheets are made of steel with a bonded piezoelectric actuator and sensor. The three-layer sandwich beam is clamped at one end and carries a payload at the other end. The tip mass is such that its center of mass is offset from the point of attachment. The extended higher-order sandwich panel (HSAPT) theory is employed in conjunction with the Hamilton’s principle to derive the governing equations of motion and boundary conditions. The obtained partial differential equations are solved using the generalized differential quadrature (GDQ) method. Free and forced vibration analyses are carried out and the results are compared with those obtained from the use of the commercial finite element software ANSYS. Derivative feedback control algorithm is employed to control the vibration of the system. Parametric studies are conducted to examine the arrangement impact of the piezoelectric sensors and actuators on the system vibrational behavior.","PeriodicalId":392289,"journal":{"name":"Volume 1: Development and Characterization of Multifunctional Materials; Modeling, Simulation, and Control of Adaptive Systems; Integrated System Design and Implementation","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131381880","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}
K. Fuchi, A. Gillman, Alexander Cook, Alexander M. Pankonien, P. Buskohl
This article investigates a method of designing fractal origami tessellations through eigen analysis. Foldable structures with hierarchical geometric features could be beneficial in applications where a graded functionality is desired. A representative unit in an origami tessellation is modeled as networked truss elements with torsional springs at fold lines. Eigen analysis and nonlinear mechanics analysis of the representative unit with fractal boundary conditions reveal the foldability of a given fractal origami crease pattern out of its flat state. This configuration can be used to construct a folded fractal origami tessellation with a desired number of fractal levels, which can then be used to evaluate its functional merit. The design process is demonstrated for the design of a fractal origami tessellation with tailored boundary shape change (from rectangular to trapezoidal) through folding, that could be used as an enabling mechanism for an adaptive wing section.
{"title":"Designing Fractal Origami Tessellations Through Eigen Analysis","authors":"K. Fuchi, A. Gillman, Alexander Cook, Alexander M. Pankonien, P. Buskohl","doi":"10.1115/SMASIS2018-8020","DOIUrl":"https://doi.org/10.1115/SMASIS2018-8020","url":null,"abstract":"This article investigates a method of designing fractal origami tessellations through eigen analysis. Foldable structures with hierarchical geometric features could be beneficial in applications where a graded functionality is desired. A representative unit in an origami tessellation is modeled as networked truss elements with torsional springs at fold lines. Eigen analysis and nonlinear mechanics analysis of the representative unit with fractal boundary conditions reveal the foldability of a given fractal origami crease pattern out of its flat state. This configuration can be used to construct a folded fractal origami tessellation with a desired number of fractal levels, which can then be used to evaluate its functional merit. The design process is demonstrated for the design of a fractal origami tessellation with tailored boundary shape change (from rectangular to trapezoidal) through folding, that could be used as an enabling mechanism for an adaptive wing section.","PeriodicalId":392289,"journal":{"name":"Volume 1: Development and Characterization of Multifunctional Materials; Modeling, Simulation, and Control of Adaptive Systems; Integrated System Design and Implementation","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116934181","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}
Volume 1: Development and Characterization of Multifunctional Materials; Modeling, Simulation, and Control of Adaptive Systems; Integrated System Design and Implementation
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