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":"78 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":"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}
Structural health monitoring (SHM) has originally been used for static structures. With the development of high-speed data acquisition technology, SHM systems can monitor structures in seconds. Advanced SHM systems for use in dynamic environments require operation in the microsecond timescale. One promising approach is the electromechanical impedance (EMI) technique. The EMI method monitors the impedance of a structure, and damage is indicated by changes in the impedance. Standard impedance measuring hardware are not practical for microsecond detection due to their slow sampling speeds. Faster impedance measuring techniques have been developed and allow for customizable excitation signals. Researchers have also considered taking measurements at higher frequencies to decrease the measurement time. Past works indicate sensitivity to damage is limited above 600 kHz. The goal of this study is to evaluate the sensitivity of the EMI method to damage with a high voltage excitation signal. It was hypothesized that increasing the voltage would increase damage sensitivity at higher frequencies. In this study, the amplitude of the excitation signal was increased using a high frequency voltage amplifier. A PZT disk bonded to a cantilevered aluminum beam was used as the test structure. Damage was created by decreasing the length of the beam. Finite element (FE) simulation was also employed to achieve a better understanding of the experiment. From the results of the experiment and FE model, using a higher excitation voltage has proven not to increase the sensitivity level of the EMI method. Higher voltages do improve the precision of the measurement by increasing the signal to noise ratio.
{"title":"Evaluation of SHM With the Electromechanical Impedance Method Using a High Voltage Excitation Signal in High Frequencies","authors":"Eric C. Nolan, M. Safaei, S. Anton","doi":"10.1115/smasis2019-5556","DOIUrl":"https://doi.org/10.1115/smasis2019-5556","url":null,"abstract":"\u0000 Structural health monitoring (SHM) has originally been used for static structures. With the development of high-speed data acquisition technology, SHM systems can monitor structures in seconds. Advanced SHM systems for use in dynamic environments require operation in the microsecond timescale. One promising approach is the electromechanical impedance (EMI) technique. The EMI method monitors the impedance of a structure, and damage is indicated by changes in the impedance. Standard impedance measuring hardware are not practical for microsecond detection due to their slow sampling speeds. Faster impedance measuring techniques have been developed and allow for customizable excitation signals. Researchers have also considered taking measurements at higher frequencies to decrease the measurement time. Past works indicate sensitivity to damage is limited above 600 kHz. The goal of this study is to evaluate the sensitivity of the EMI method to damage with a high voltage excitation signal. It was hypothesized that increasing the voltage would increase damage sensitivity at higher frequencies. In this study, the amplitude of the excitation signal was increased using a high frequency voltage amplifier. A PZT disk bonded to a cantilevered aluminum beam was used as the test structure. Damage was created by decreasing the length of the beam. Finite element (FE) simulation was also employed to achieve a better understanding of the experiment. From the results of the experiment and FE model, using a higher excitation voltage has proven not to increase the sensitivity level of the EMI method. Higher voltages do improve the precision of the measurement by increasing the signal to noise ratio.","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":"130788520","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}
Philipp J. Mehner, Anthony Beck, M. Busek, A. Voigt, U. Marschner, A. Richter
We propose a planar hydrogel-based micro-valve design which is modeled as a library element for Matlab Simulink. For this test case, a pressure pump (voltage source) in series with a micro-valve model (variable fluidic resistance) is built up. The micro-valve subsystem is separated in four main parts. Based on the applied temperature stimulus, the equilibrium length is determined according to an experimentally verified fit function. Furthermore, the equilibrium length considers a static hysteresis effect which is modeled in analogy to the saturation of magnetization in electric transformers. In a second step, the transient behavior follows a first order differential equation, but the cooperate diffusion coefficient is size dependent affecting the rise time of the system. This causes a faster swelling than deswelling of the hydrogel. In the third section, the stiffness property is implemented to calculate the maximum sealing pressure and the resulting gap between the hydrogel and the wall. The fluidic resistance of the micro-valve considers a three-dimensional geometry and is calculated based on a look-up table, extracted from a fluid-structure-interaction (FSI) model generated from a finite element structure. The proposed model allows a full description of the fluidic hydrogel-based micro-valve and is part of an upcoming microfluidic toolbox for Matlab Simulink containing passive elements and optional chemical reactions like mixing fluids and enzyme reactions for future applications.
{"title":"Description of a Hydrogel-Based Micro-Valve As a Library Element for Matlab Simulink","authors":"Philipp J. Mehner, Anthony Beck, M. Busek, A. Voigt, U. Marschner, A. Richter","doi":"10.1115/smasis2019-5614","DOIUrl":"https://doi.org/10.1115/smasis2019-5614","url":null,"abstract":"\u0000 We propose a planar hydrogel-based micro-valve design which is modeled as a library element for Matlab Simulink. For this test case, a pressure pump (voltage source) in series with a micro-valve model (variable fluidic resistance) is built up. The micro-valve subsystem is separated in four main parts. Based on the applied temperature stimulus, the equilibrium length is determined according to an experimentally verified fit function. Furthermore, the equilibrium length considers a static hysteresis effect which is modeled in analogy to the saturation of magnetization in electric transformers. In a second step, the transient behavior follows a first order differential equation, but the cooperate diffusion coefficient is size dependent affecting the rise time of the system. This causes a faster swelling than deswelling of the hydrogel. In the third section, the stiffness property is implemented to calculate the maximum sealing pressure and the resulting gap between the hydrogel and the wall. The fluidic resistance of the micro-valve considers a three-dimensional geometry and is calculated based on a look-up table, extracted from a fluid-structure-interaction (FSI) model generated from a finite element structure.\u0000 The proposed model allows a full description of the fluidic hydrogel-based micro-valve and is part of an upcoming microfluidic toolbox for Matlab Simulink containing passive elements and optional chemical reactions like mixing fluids and enzyme reactions for future applications.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":"4 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":"130969004","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 presents an optimal Electrical Impedance Tomography (EIT) drive pattern for real-time gesture recognition, which can reduce the measurement time and realize a performance trade-off between the accuracy and the time response. This method is achieved by feature selection and model explanation. We designed eleven hand gestures to verify the proposed approach. Compared to the 8-electrode method, the optimal electrode drive pattern achieved a recognition accuracy of 97.5% with seven electrodes and the measurement time was reduced by 60%. To illustrate the universality of this method, we performed a contact detection experiment. By setting seven labels on the conductive panel and using optimal electrode drive pattern, the detection accuracy reached 100% with seven electrodes and the measurement time was reduced by 85%.
{"title":"An Electrical Impedance Tomography Drive Pattern for Fast and Accurate Gesture Recognition With Less Electrodes","authors":"Gang Ma, Zhiliang Hao, Xuan Wu, XiaojieĀ Wang","doi":"10.1115/smasis2019-5550","DOIUrl":"https://doi.org/10.1115/smasis2019-5550","url":null,"abstract":"\u0000 This paper presents an optimal Electrical Impedance Tomography (EIT) drive pattern for real-time gesture recognition, which can reduce the measurement time and realize a performance trade-off between the accuracy and the time response. This method is achieved by feature selection and model explanation. We designed eleven hand gestures to verify the proposed approach. Compared to the 8-electrode method, the optimal electrode drive pattern achieved a recognition accuracy of 97.5% with seven electrodes and the measurement time was reduced by 60%. To illustrate the universality of this method, we performed a contact detection experiment. By setting seven labels on the conductive panel and using optimal electrode drive pattern, the detection accuracy reached 100% with seven electrodes and the measurement time was reduced by 85%.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":"141 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":"131695042","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 paper at hand focuses on the modeling and design of an experimental demonstrator of a blade segment, twisted through Shape Memory Alloy technology. The demonstrator will be used for the wind tunnel tests planned within the Project of SABRE (H2020 Eu Program), aimed at investigating the effects produced by blade oriented morphing technologies, both in fixed and rotary wing configurations. The design approach adopted for a SMA twist concept is herein described in its different phases, moving from the definition of the preliminary layout, its fitting to the reference blade mechanical features, the preliminary structural analysis to confine its operational envelope, up to the simulation of the SMA actuation through a SMA torque element. The results are presented in terms of operational envelope limits and transmitted twist.
{"title":"Modeling and Design of an Experimental Demonstrator of Blade Twist Through the SMA Technology","authors":"S. Ameduri, A. Concilio, B. Galasso","doi":"10.1115/smasis2019-5573","DOIUrl":"https://doi.org/10.1115/smasis2019-5573","url":null,"abstract":"\u0000 The paper at hand focuses on the modeling and design of an experimental demonstrator of a blade segment, twisted through Shape Memory Alloy technology. The demonstrator will be used for the wind tunnel tests planned within the Project of SABRE (H2020 Eu Program), aimed at investigating the effects produced by blade oriented morphing technologies, both in fixed and rotary wing configurations. The design approach adopted for a SMA twist concept is herein described in its different phases, moving from the definition of the preliminary layout, its fitting to the reference blade mechanical features, the preliminary structural analysis to confine its operational envelope, up to the simulation of the SMA actuation through a SMA torque element. The results are presented in terms of operational envelope limits and transmitted twist.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":"14 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":"129613352","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}
Soft actuators have been studied and analyzed as a new solution for soft robotic technologies. These types of actuators have many advantages due to their predictable deformations and their ease of control, enabling them to hold and move delicate objects performing complex movements in confined spaces. Soft actuators can be made using different manufacturing processes, but the most common is mold casting. However, this manufacturing process involves several steps, increasing the manufacturing time and hindering changes in the design. This paper presents a novel design of a 3D printed soft pneumatic actuator based on additive manufacturing, achieving design versatility and performance. The produced actuator has seven that can be individually controlled. The actuators were made using fused deposition modeling (FDM) technology in one continuous process and without support material. The mechanical performance of the soft actuators was demonstrated, analyzing the deformation in the z-axis based on input pressure.
{"title":"3D Printed Segmented Flexible Pneumatic Actuator","authors":"D. Gonzalez, J. García, B. Newell","doi":"10.1115/smasis2019-5645","DOIUrl":"https://doi.org/10.1115/smasis2019-5645","url":null,"abstract":"\u0000 Soft actuators have been studied and analyzed as a new solution for soft robotic technologies. These types of actuators have many advantages due to their predictable deformations and their ease of control, enabling them to hold and move delicate objects performing complex movements in confined spaces. Soft actuators can be made using different manufacturing processes, but the most common is mold casting. However, this manufacturing process involves several steps, increasing the manufacturing time and hindering changes in the design. This paper presents a novel design of a 3D printed soft pneumatic actuator based on additive manufacturing, achieving design versatility and performance. The produced actuator has seven that can be individually controlled. The actuators were made using fused deposition modeling (FDM) technology in one continuous process and without support material. The mechanical performance of the soft actuators was demonstrated, analyzing the deformation in the z-axis based on input pressure.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":"8 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":"128859034","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 investigates the optimal geometric parameters for a bioinspired peristaltic piezocomposite pump with the use of an electromechanical Euler-Bernoulli beam model. The peristaltic pump is a self-contained propulsion system involving a series of piezo-active soft cymbal-like segments that are connected with passive soft connective segments. A series of phased excitations in expansion and contraction applied to different active segments of the channel create a traveling wave along the axis of the channel, which in return “propels” the fluid in one direction. A parametric analysis, based on the Euler-Bernoulli beam model, is conducted to improve the effectiveness of the cymbal-like piezocomposite actuators. Area change of the cymbal-like actuators, which is correlated to the propulsion power, is studied based on the analysis of the moment, curvature, and area change due to excitation. Area change is also used to evaluate the effectiveness, and to decide the optimal geometric parameters of the piezocomposite actuators.
{"title":"A Bioinspired Piezocomposite Peristaltic Pump: An Electromechanical Euler-Bernoulli Beam Model and Parametric Analysis","authors":"Xin Shan, O. Bilgen","doi":"10.1115/smasis2019-5559","DOIUrl":"https://doi.org/10.1115/smasis2019-5559","url":null,"abstract":"\u0000 This paper investigates the optimal geometric parameters for a bioinspired peristaltic piezocomposite pump with the use of an electromechanical Euler-Bernoulli beam model. The peristaltic pump is a self-contained propulsion system involving a series of piezo-active soft cymbal-like segments that are connected with passive soft connective segments. A series of phased excitations in expansion and contraction applied to different active segments of the channel create a traveling wave along the axis of the channel, which in return “propels” the fluid in one direction. A parametric analysis, based on the Euler-Bernoulli beam model, is conducted to improve the effectiveness of the cymbal-like piezocomposite actuators. Area change of the cymbal-like actuators, which is correlated to the propulsion power, is studied based on the analysis of the moment, curvature, and area change due to excitation. Area change is also used to evaluate the effectiveness, and to decide the optimal geometric parameters of the piezocomposite actuators.","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":"129185902","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, D. Shumway, Tae-Heon Yang, Young-Min Kim, J. Koo
Current wearable technologies strive to incorporate more medical functionalities in wearable devices for tracking health conditions and providing information for timely medical treatments. Beyond tracking of a wearer’s physical activities and basic vital signs, the advancement of wearable healthcare devices aspires to continuously monitor health parameters, such as cardiovascular indicators. To properly monitor cardiovascular health, the wearables should accurately measure blood pressure in real-time. However, current devices on the market are not validated for continuous monitoring of blood pressure at a clinical level. To develop wearable healthcare devices such applications, they must be validated by considering various parameters, such as the effects of varying skin properties. Being located between the blood vessel and the wearable device, the skin can affect the sensor readings of the device. The primary goal of this study is to investigate the effect of skin property on the radial pulse measurements. To this end, a range of artificial vein-inserted skin samples with varying properties is fabricated using Magneto-Rheological Elastomers (MRE), materials whose mechanical properties can be altered by external magnetic fields. The samples include layers to simulate the structure of skin and a silicone vein for the pulse to pass through. Note that they are not intended to represent real human skin-vein properties but created to vary a range of stiffness properties to carry out the study. Experiments are performed using a cam system capable of generating realistic human pulse waveforms to pass through the samples. During the indentation testing, the sample is compressed using a dynamic mechanical analyzer (DMA) to record experienced surface pressure, allowing the pulse patterns to be studied. Various samples are used to probe the effects of base resin hardness, iron content, and magnetic field. A pressure sensor incorporated in the cam simulator is used to benchmark the internal pulse pressure of the vein while the DMA indents the sample in order to note the pulse pressures being passed through the sample. Test results show that the properties of the skin influence the resulting pulse behaviors, particularly the ratio of the recorded pulse pressures from the sensor and the DMA.
{"title":"Investigation of Variable Stiffness Effects on Radial Pulse Measurements Using Magneto-Rheological Elastomers","authors":"Kyle A. Weaver, D. Shumway, Tae-Heon Yang, Young-Min Kim, J. Koo","doi":"10.1115/smasis2019-5708","DOIUrl":"https://doi.org/10.1115/smasis2019-5708","url":null,"abstract":"\u0000 Current wearable technologies strive to incorporate more medical functionalities in wearable devices for tracking health conditions and providing information for timely medical treatments. Beyond tracking of a wearer’s physical activities and basic vital signs, the advancement of wearable healthcare devices aspires to continuously monitor health parameters, such as cardiovascular indicators. To properly monitor cardiovascular health, the wearables should accurately measure blood pressure in real-time. However, current devices on the market are not validated for continuous monitoring of blood pressure at a clinical level. To develop wearable healthcare devices such applications, they must be validated by considering various parameters, such as the effects of varying skin properties. Being located between the blood vessel and the wearable device, the skin can affect the sensor readings of the device. The primary goal of this study is to investigate the effect of skin property on the radial pulse measurements. To this end, a range of artificial vein-inserted skin samples with varying properties is fabricated using Magneto-Rheological Elastomers (MRE), materials whose mechanical properties can be altered by external magnetic fields. The samples include layers to simulate the structure of skin and a silicone vein for the pulse to pass through. Note that they are not intended to represent real human skin-vein properties but created to vary a range of stiffness properties to carry out the study. Experiments are performed using a cam system capable of generating realistic human pulse waveforms to pass through the samples. During the indentation testing, the sample is compressed using a dynamic mechanical analyzer (DMA) to record experienced surface pressure, allowing the pulse patterns to be studied. Various samples are used to probe the effects of base resin hardness, iron content, and magnetic field. A pressure sensor incorporated in the cam simulator is used to benchmark the internal pulse pressure of the vein while the DMA indents the sample in order to note the pulse pressures being passed through the sample. Test results show that the properties of the skin influence the resulting pulse behaviors, particularly the ratio of the recorded pulse pressures from the sensor and the DMA.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":"39 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":"117082525","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}
In this paper the design of a linear long-stroke quasi-constant force compliant mechanism (CM) is presented and discussed. Starting from a flexure-based slider-crank mechanism, providing the required constant force within a rather limited deflection range, the paper reports about the shape optimization carried out with the specific aim of extending the available CM operative range. The proposed device is suitable in several precision manipulation systems, which require to maintain a constant-force at their contact interface with the manipulated object. Force regulation is generally achieved by means of complex control algorithms and related sensory apparatus, resulting in a flexible behavior but also in high costs. A valid alternative may be the use of a purposely designed CM, namely a purely mechanical system whose shape and dimensions are optimized so as to provide a force-deflection behavior characterized by zero stiffness. In the first design step, the Pseudo-Rigid Body (PRB) method is exploited to synthesize the sub-optimal compliant configuration, i.e. the one characterized by lumped compliance. Secondly, an improved design alternative is evaluated resorting to an integrated software framework, comprising Matlab and ANSYS APDL, and capable of performing non-linear structural optimizations. The new embodiment makes use of a variable thickness beam, whose shape and dimensions have been optimized so as to provide a constant reaction force in an extended range. Finally, a physical prototype of the beam-based configuration is produced and tested, experimentally validating the proposed design method.
{"title":"On the Design of a Long-Stroke Beam-Based Compliant Mechanism Providing Quasi-Constant Force","authors":"Pietro Bilancia, A. Geraci, G. Berselli","doi":"10.1115/smasis2019-5519","DOIUrl":"https://doi.org/10.1115/smasis2019-5519","url":null,"abstract":"\u0000 In this paper the design of a linear long-stroke quasi-constant force compliant mechanism (CM) is presented and discussed. Starting from a flexure-based slider-crank mechanism, providing the required constant force within a rather limited deflection range, the paper reports about the shape optimization carried out with the specific aim of extending the available CM operative range. The proposed device is suitable in several precision manipulation systems, which require to maintain a constant-force at their contact interface with the manipulated object. Force regulation is generally achieved by means of complex control algorithms and related sensory apparatus, resulting in a flexible behavior but also in high costs. A valid alternative may be the use of a purposely designed CM, namely a purely mechanical system whose shape and dimensions are optimized so as to provide a force-deflection behavior characterized by zero stiffness. In the first design step, the Pseudo-Rigid Body (PRB) method is exploited to synthesize the sub-optimal compliant configuration, i.e. the one characterized by lumped compliance. Secondly, an improved design alternative is evaluated resorting to an integrated software framework, comprising Matlab and ANSYS APDL, and capable of performing non-linear structural optimizations. The new embodiment makes use of a variable thickness beam, whose shape and dimensions have been optimized so as to provide a constant reaction force in an extended range. Finally, a physical prototype of the beam-based configuration is produced and tested, experimentally validating the proposed design method.","PeriodicalId":235262,"journal":{"name":"ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems","volume":"231 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":"125278513","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}
Additive manufacturing is an enabling technology that is rapidly advancing with the development of new printers, materials, and processes. The purpose of this research was to design a part that could function similar to a pneumatic piston-cylinder producing small force outputs between 5 and 10 N. The research presented in this paper looks at various types of 3D printing methods to produce flexible linear bellows actuators to achieve this functionality. In particular, stereolithography, fused deposition modeling, digital light processing, and Polyjet printing were examined to produce a variety of test actuators. A successful flexible part was designed and produced using Polyjet printing, the steady state and dynamic responses of constructed actuators were measured and characterized at various loading conditions. The displacement trends at different load conditions followed a non-linear path, exhibiting highly elastic deformation typical of the flexible resins used in this project.
{"title":"Production and Characterization of a Fully 3D Printed Flexible Bellows Actuator","authors":"Alfonso Costas, B. Newell, J. García","doi":"10.1115/smasis2019-5644","DOIUrl":"https://doi.org/10.1115/smasis2019-5644","url":null,"abstract":"\u0000 Additive manufacturing is an enabling technology that is rapidly advancing with the development of new printers, materials, and processes. The purpose of this research was to design a part that could function similar to a pneumatic piston-cylinder producing small force outputs between 5 and 10 N. The research presented in this paper looks at various types of 3D printing methods to produce flexible linear bellows actuators to achieve this functionality. In particular, stereolithography, fused deposition modeling, digital light processing, and Polyjet printing were examined to produce a variety of test actuators. A successful flexible part was designed and produced using Polyjet printing, the steady state and dynamic responses of constructed actuators were measured and characterized at various loading conditions. The displacement trends at different load conditions followed a non-linear path, exhibiting highly elastic deformation typical of the flexible resins used in this project.","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":"129770369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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