Inerter-based vibration energy harvesters (VEHs) have been widely studied to harvest energy from large-scale structural vibrations. Recently, there have been efforts to increase the operation frequency bandwidth of VEHs by introducing a variety of stiffness and inertia nonlinearity. This paper proposes a new inerter-based VEH comprising an epicyclic-gearing inerter and a pendulum vibration absorber. The centrifugal force of the pendulum introduces a new type of inertia nonlinearity that broadens the frequency bandwidth. This inerter-pendulum VEH (IPVEH) is incorporated in a single-degree-of-freedom structure to demonstrate its performance and the equations of motion of the system are derived. The method of multiple scales is applied to derive the amplitude–frequency response relationship of the harvested power in the primary resonance. The harvested power is optimized through tuning the harvester’s electrical damping and the optimum power is benchmarked with that of conventional linear inerter-based VEHs. The results show that the IPVEH has larger bandwidth and harvested power and the improvement is correlated with the strength of its inertia nonlinearity.
{"title":"Broadband and Enhanced Energy Harvesting Using Inerter Pendulum Vibration Absorber","authors":"Aakash Gupta, Wei-Che Tai","doi":"10.1115/detc2020-22200","DOIUrl":"https://doi.org/10.1115/detc2020-22200","url":null,"abstract":"\u0000 Inerter-based vibration energy harvesters (VEHs) have been widely studied to harvest energy from large-scale structural vibrations. Recently, there have been efforts to increase the operation frequency bandwidth of VEHs by introducing a variety of stiffness and inertia nonlinearity. This paper proposes a new inerter-based VEH comprising an epicyclic-gearing inerter and a pendulum vibration absorber. The centrifugal force of the pendulum introduces a new type of inertia nonlinearity that broadens the frequency bandwidth. This inerter-pendulum VEH (IPVEH) is incorporated in a single-degree-of-freedom structure to demonstrate its performance and the equations of motion of the system are derived. The method of multiple scales is applied to derive the amplitude–frequency response relationship of the harvested power in the primary resonance. The harvested power is optimized through tuning the harvester’s electrical damping and the optimum power is benchmarked with that of conventional linear inerter-based VEHs. The results show that the IPVEH has larger bandwidth and harvested power and the improvement is correlated with the strength of its inertia nonlinearity.","PeriodicalId":398186,"journal":{"name":"Volume 7: 32nd Conference on Mechanical Vibration and Noise (VIB)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121202245","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 nonlinear dynamics and energy harvesting performance of a novel bi-stable piezoelectric energy harvester inspired by the rapid shape transition of the Venus flytrap leaves. The harvester is composed of a piezoelectric MFC transducer, a tip mass, and two sub-beams. The two sub-beams are akin to the bidirectionally curved Venus flytrap leaves that could rapidly snap-through from the open state to the closed state. To realize the bistability of the Venus flytrap leaves induced by the stored potential energy, an in-plane pre-displacement constraint is applied to the free ends of the sub-beams. The pre-displacement constraint leads to bending and twisting deformations and creates the potential energy in the harvester. The bio-inspired design is introduced in detail and a prototype is fabricated to validate the conceptual design. The nonlinear dynamics of the bio-inspired bi-stable piezoelectric energy harvester is investigated under base acceleration excitations. Results show that the sub-beams of the harvester experience more complicated local vibrations containing broadband high-frequency components as the snap-through motion happens. The energy harvesting performance of the harvester is evaluated at different excitation levels. The broadband energy harvesting is achieved at higher excitation levels and an average power output of 0.193 mW is attained under the excitation of 10 Hz and 4.0 g.
{"title":"A Novel Bi-Stable Piezoelectric Energy Harvester Inspired by the Venus Flytrap","authors":"Feng Qian, L. Zuo","doi":"10.1115/detc2020-22349","DOIUrl":"https://doi.org/10.1115/detc2020-22349","url":null,"abstract":"\u0000 This paper studies the nonlinear dynamics and energy harvesting performance of a novel bi-stable piezoelectric energy harvester inspired by the rapid shape transition of the Venus flytrap leaves. The harvester is composed of a piezoelectric MFC transducer, a tip mass, and two sub-beams. The two sub-beams are akin to the bidirectionally curved Venus flytrap leaves that could rapidly snap-through from the open state to the closed state. To realize the bistability of the Venus flytrap leaves induced by the stored potential energy, an in-plane pre-displacement constraint is applied to the free ends of the sub-beams. The pre-displacement constraint leads to bending and twisting deformations and creates the potential energy in the harvester. The bio-inspired design is introduced in detail and a prototype is fabricated to validate the conceptual design. The nonlinear dynamics of the bio-inspired bi-stable piezoelectric energy harvester is investigated under base acceleration excitations. Results show that the sub-beams of the harvester experience more complicated local vibrations containing broadband high-frequency components as the snap-through motion happens. The energy harvesting performance of the harvester is evaluated at different excitation levels. The broadband energy harvesting is achieved at higher excitation levels and an average power output of 0.193 mW is attained under the excitation of 10 Hz and 4.0 g.","PeriodicalId":398186,"journal":{"name":"Volume 7: 32nd Conference on Mechanical Vibration and Noise (VIB)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122505906","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 study aims to design two types of vibration isolators, with different spring mechanisms, using a foldable structure that is based on a cylinder torsional buckling pattern, and evaluate the vibration isolation performance of each design. Vibration isolation is achieved through nonlinear spring characteristics of the isolators, which have zero spring stiffness, achieved by attaching a linear spring to the foldable isolator structure. The two vibration isolators differ in the mechanical elements that constitute the foldable structure, which undergo tensile forces as the structure folds. For the first isolator, the mechanical elements are represented only by tension springs, which appropriately undergo tension. For the second isolator, the mechanical elements are designed so that embedded compression springs within the elements compress under tension, thus enabling the elements to work as tension springs. The excitation experiment results revealed that the different spring mechanisms produced equivalent resonance frequencies but different damping effects at the resonance and higher frequencies. When oscillations with multiple amplitudes were input, larger input amplitudes were found to correspond to lower resonance frequencies for both isolators. This trend contradicts that described in the nonlinear vibration theory modeled by the Duffing equation, and was determined to be caused by hysteresis of the spring phenomena in the vibration isolators.
{"title":"Design and Amplitude Dependence of Resonance Frequency of Origami-Inspired Vibration Isolators With Quasi-Zero-Stiffness Characteristic","authors":"Kouya Yamaguchi, Sachiko Ishida","doi":"10.1115/detc2020-22171","DOIUrl":"https://doi.org/10.1115/detc2020-22171","url":null,"abstract":"This study aims to design two types of vibration isolators, with different spring mechanisms, using a foldable structure that is based on a cylinder torsional buckling pattern, and evaluate the vibration isolation performance of each design. Vibration isolation is achieved through nonlinear spring characteristics of the isolators, which have zero spring stiffness, achieved by attaching a linear spring to the foldable isolator structure. The two vibration isolators differ in the mechanical elements that constitute the foldable structure, which undergo tensile forces as the structure folds. For the first isolator, the mechanical elements are represented only by tension springs, which appropriately undergo tension. For the second isolator, the mechanical elements are designed so that embedded compression springs within the elements compress under tension, thus enabling the elements to work as tension springs. The excitation experiment results revealed that the different spring mechanisms produced equivalent resonance frequencies but different damping effects at the resonance and higher frequencies. When oscillations with multiple amplitudes were input, larger input amplitudes were found to correspond to lower resonance frequencies for both isolators. This trend contradicts that described in the nonlinear vibration theory modeled by the Duffing equation, and was determined to be caused by hysteresis of the spring phenomena in the vibration isolators.","PeriodicalId":398186,"journal":{"name":"Volume 7: 32nd Conference on Mechanical Vibration and Noise (VIB)","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115581440","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}
Ren Yamashita, K. Mukaiyama, Hiroki Sakuda, S. Matsui, T. Hirogaki, E. Aoyama
Nowadays, the improvement in Noise Vibration Harshness (NVH) is one of the most important issues for meeting the needs of the user in the automobile industry. It is well-known that the tooth surface accuracy significantly influences the vibration in gear meshing. The hypoid gear used in the automobile differential has a complex shape, and estimation of the contact conditions is difficult. Therefore, we attempt to develop a novel method to analyze the tooth contact conditions by using highly sensitive infrared thermography with a high response; this method acts as a noncontact analysis that is based on monitoring the temperature distribution during meshing between the pinion and the gear surface. In this report, we designed three types of hypoid gears with different offsets to observe changes in the meshing phenomenon, which occurred due to the differences in the offset. Moreover, by employing accelerometers during a driving test, the dynamic behavior was also examined. Simultaneously, a tooth contact analysis was carried out using thermography. Consequently, the relationship between the rise in temperature at the tooth contact area and the tendency of the rotational vibration was elucidated.
{"title":"Tooth Meshing Estimation Based on Monitoring Rotational Vibration and Infrared Thermography Image of Hypoid Gear","authors":"Ren Yamashita, K. Mukaiyama, Hiroki Sakuda, S. Matsui, T. Hirogaki, E. Aoyama","doi":"10.1115/detc2020-22140","DOIUrl":"https://doi.org/10.1115/detc2020-22140","url":null,"abstract":"\u0000 Nowadays, the improvement in Noise Vibration Harshness (NVH) is one of the most important issues for meeting the needs of the user in the automobile industry. It is well-known that the tooth surface accuracy significantly influences the vibration in gear meshing. The hypoid gear used in the automobile differential has a complex shape, and estimation of the contact conditions is difficult. Therefore, we attempt to develop a novel method to analyze the tooth contact conditions by using highly sensitive infrared thermography with a high response; this method acts as a noncontact analysis that is based on monitoring the temperature distribution during meshing between the pinion and the gear surface. In this report, we designed three types of hypoid gears with different offsets to observe changes in the meshing phenomenon, which occurred due to the differences in the offset. Moreover, by employing accelerometers during a driving test, the dynamic behavior was also examined. Simultaneously, a tooth contact analysis was carried out using thermography. Consequently, the relationship between the rise in temperature at the tooth contact area and the tendency of the rotational vibration was elucidated.","PeriodicalId":398186,"journal":{"name":"Volume 7: 32nd Conference on Mechanical Vibration and Noise (VIB)","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131293560","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}
Experimental modal testing is a technique through which the dynamic response of a system can be found. Parameters such as the natural frequencies and mode shapes of a system can be extracted through experimentation, and these results can be used to confirm computational models and guide structural improvements. This paper provides an overview of experimental modal analysis performed on two aircraft fuselage half scale subassemblies, with the use of shaker excitation. The experimental methodology including the construction of each structure, data acquisition parameters, and validity checks, is presented in detail. Linearity and repeatability checks were used to validate the testing methodology and increase the level of confidence in the experimental results. The experimental natural frequencies were correlated with the computational results, and recommendations were made. The experimental results presented in this work provide a basis for computational model updating work to be considered in future work.
{"title":"Experimental Modal Analysis of Business Jet Fuselage Tail Section Sub-Assemblies","authors":"Ian Donaldson, C. Mechefske","doi":"10.1115/detc2020-22314","DOIUrl":"https://doi.org/10.1115/detc2020-22314","url":null,"abstract":"\u0000 Experimental modal testing is a technique through which the dynamic response of a system can be found. Parameters such as the natural frequencies and mode shapes of a system can be extracted through experimentation, and these results can be used to confirm computational models and guide structural improvements. This paper provides an overview of experimental modal analysis performed on two aircraft fuselage half scale subassemblies, with the use of shaker excitation. The experimental methodology including the construction of each structure, data acquisition parameters, and validity checks, is presented in detail. Linearity and repeatability checks were used to validate the testing methodology and increase the level of confidence in the experimental results. The experimental natural frequencies were correlated with the computational results, and recommendations were made. The experimental results presented in this work provide a basis for computational model updating work to be considered in future work.","PeriodicalId":398186,"journal":{"name":"Volume 7: 32nd Conference on Mechanical Vibration and Noise (VIB)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130087779","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}
J. Tempelman, Audun D. Myers, J. Scruggs, Firas A. Khasawneh
The ability to characterize the state of dynamic systems has been a pertinent task in the time series analysis community. Traditional measures such as Lyapunov exponents are often times difficult to recover from noisy data, especially if the dimensionality of the system is not known. More recent binary and network based testing methods have delivered promising results for unknown deterministic systems, however noise injected into a periodic signal leads to false positives. Recently, we showed the advantage of using persistent homology as a tool for achieving dynamic state detection for systems with no known model and showed its robustness to white Gaussian noise. In this work, we explore the robustness of the persistence based methods to the influence of colored noise and show that colored noise processes of the form 1/ f α lead to false positive diagnostic at lower signal to noise ratios for α < 0.
表征动态系统状态的能力一直是时间序列分析界的一个相关任务。传统的测量方法，如李雅普诺夫指数，往往很难从噪声数据中恢复，特别是如果系统的维度是未知的。最近基于二进制和网络的测试方法已经为未知的确定性系统提供了有希望的结果，但是注入周期信号的噪声会导致误报。最近，我们展示了使用持久同调作为工具来实现未知模型系统的动态状态检测的优势，并展示了其对高斯白噪声的鲁棒性。在这项工作中，我们探讨了基于持久性的方法对彩色噪声影响的鲁棒性，并表明形式为1/ f α的彩色噪声过程在较低的信噪比下导致假阳性诊断。
{"title":"Effects of Correlated Noise on the Performance of Persistence Based Dynamic State Detection Methods","authors":"J. Tempelman, Audun D. Myers, J. Scruggs, Firas A. Khasawneh","doi":"10.1115/detc2020-22592","DOIUrl":"https://doi.org/10.1115/detc2020-22592","url":null,"abstract":"\u0000 The ability to characterize the state of dynamic systems has been a pertinent task in the time series analysis community. Traditional measures such as Lyapunov exponents are often times difficult to recover from noisy data, especially if the dimensionality of the system is not known. More recent binary and network based testing methods have delivered promising results for unknown deterministic systems, however noise injected into a periodic signal leads to false positives. Recently, we showed the advantage of using persistent homology as a tool for achieving dynamic state detection for systems with no known model and showed its robustness to white Gaussian noise. In this work, we explore the robustness of the persistence based methods to the influence of colored noise and show that colored noise processes of the form 1/ f α lead to false positive diagnostic at lower signal to noise ratios for α < 0.","PeriodicalId":398186,"journal":{"name":"Volume 7: 32nd Conference on Mechanical Vibration and Noise (VIB)","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122665547","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 multi-stage design space refinement (MSDSR) technique increases the likelihood of convergence of topology optimization (TO) with large volume fraction constraints. This work considers MSDSR TO of an aircraft engine support frame with a natural frequency-based objective function. The problem statement maximized the first natural frequency, effectively maximizing the stiffness to mass ratio of the frame. The problem statement considered natural frequency constraints, which eliminated all natural frequencies within 5% of the engine excitation frequency times a safety factor of two. The design space did not consider the initial geometry; therefore, allowing for the determination of the optimal stiffener location on the initial geometry. The results of this work increased the first natural frequency of the engine support frame by 25.9%, eliminated all natural frequencies within 11.3% of the engine excitation frequency, and added only 0.253 kg of mass to the frame. The results of this work further demonstrate the advantages of MSDSR TO and the impact that it can have on the aerospace industry. Specifically, the design space considered in this work allows for the structural reinforcement of a pre-existing design, which is easier to implement and easier to regulate than similar results from the literature.
{"title":"Natural Frequency Based Topology Optimization of an Aircraft Engine Support Frame","authors":"Braden T Warwick, C. Mechefske, I. Kim","doi":"10.1115/detc2020-22286","DOIUrl":"https://doi.org/10.1115/detc2020-22286","url":null,"abstract":"\u0000 The multi-stage design space refinement (MSDSR) technique increases the likelihood of convergence of topology optimization (TO) with large volume fraction constraints. This work considers MSDSR TO of an aircraft engine support frame with a natural frequency-based objective function. The problem statement maximized the first natural frequency, effectively maximizing the stiffness to mass ratio of the frame. The problem statement considered natural frequency constraints, which eliminated all natural frequencies within 5% of the engine excitation frequency times a safety factor of two. The design space did not consider the initial geometry; therefore, allowing for the determination of the optimal stiffener location on the initial geometry. The results of this work increased the first natural frequency of the engine support frame by 25.9%, eliminated all natural frequencies within 11.3% of the engine excitation frequency, and added only 0.253 kg of mass to the frame. The results of this work further demonstrate the advantages of MSDSR TO and the impact that it can have on the aerospace industry. Specifically, the design space considered in this work allows for the structural reinforcement of a pre-existing design, which is easier to implement and easier to regulate than similar results from the literature.","PeriodicalId":398186,"journal":{"name":"Volume 7: 32nd Conference on Mechanical Vibration and Noise (VIB)","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127312290","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}
One of the most frustrating features of joint mechanics is that all the important processes take place precisely where they cannot be seen or measured directly — the interface between contacting bodies. In order to achieve some insight into the mechanisms that give rise to the nonlinearities of joints one naturally turns to analytic or numerical models of interface mechanics. With such models, one can explore the significance of different assumptions of kinematics or surface mechanics and compare those with laboratory experiments on the integrated joints. Among the limitations of such modeling strategies are the twin problems of 1) employing suitable models for friction and 2) solving the resulting equations. There is evidence that the commonly used Coulomb friction model is inconsistent with the experimentally observed behavior of lap joints; it is necessary to explore the use of more complex models. Additionally, even when computing contact and sliding with the relatively simple Coulomb friction model, capturing the evolution of traction fields from one load set to the next in a physically plausible manner has been a continuing challenge. Obtaining fidelity to such path dependence for more complex models would be consequently more difficult. This issue has motivated the research reported here on the source of the difficulty in modeling path-dependent contact and possible solutions. A two-parameter Coulomb friction model is used to test a conventional contact algorithm and a newer one devised specifically to capture path dependence correctly. The evolution of lateral traction during cyclic loading is used to illustrate how the shear traction distribution at each load step evolves from that of the previous.
{"title":"Some Exploration of the Path-Dependence in the Contact Analysis","authors":"Gaurav Chauda, D. Segalman","doi":"10.1115/detc2020-22439","DOIUrl":"https://doi.org/10.1115/detc2020-22439","url":null,"abstract":"\u0000 One of the most frustrating features of joint mechanics is that all the important processes take place precisely where they cannot be seen or measured directly — the interface between contacting bodies. In order to achieve some insight into the mechanisms that give rise to the nonlinearities of joints one naturally turns to analytic or numerical models of interface mechanics. With such models, one can explore the significance of different assumptions of kinematics or surface mechanics and compare those with laboratory experiments on the integrated joints.\u0000 Among the limitations of such modeling strategies are the twin problems of 1) employing suitable models for friction and 2) solving the resulting equations. There is evidence that the commonly used Coulomb friction model is inconsistent with the experimentally observed behavior of lap joints; it is necessary to explore the use of more complex models. Additionally, even when computing contact and sliding with the relatively simple Coulomb friction model, capturing the evolution of traction fields from one load set to the next in a physically plausible manner has been a continuing challenge. Obtaining fidelity to such path dependence for more complex models would be consequently more difficult. This issue has motivated the research reported here on the source of the difficulty in modeling path-dependent contact and possible solutions.\u0000 A two-parameter Coulomb friction model is used to test a conventional contact algorithm and a newer one devised specifically to capture path dependence correctly. The evolution of lateral traction during cyclic loading is used to illustrate how the shear traction distribution at each load step evolves from that of the previous.","PeriodicalId":398186,"journal":{"name":"Volume 7: 32nd Conference on Mechanical Vibration and Noise (VIB)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116813595","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 uses the Reduced Order Model (ROM) as well as the Method of Multiple Scales (MMS) in order to investigate behavior of electrostatically actuated micro-electro-mechanical systems (MEMS) circular plates under superharmonic resonance of third order. ROM is solved using two methods, the first is a continuation and bifurcation approach by using software package called AUTO 07p in order to obtain the voltage response, and the second approach is a numerical integration using the Matlab built in function ode15s for obtaining time responses of the system. Overall MMS and ROM provide similar results, especially in the lower amplitudes. These methods seem to differ at higher amplitudes. The ROM shows a second unstable branch that MMS does not have. The time responses agree with the ROM voltage response. Furthermore, the influences of different parameters such as that of the detuning parameter, and damping are investigated.
{"title":"Superharmonic Resonance of Third Order of Electrostatically Actuated MEMS Circular Plates: Effect of AC Frequency on Voltage Response","authors":"Julio Beatriz, D. Caruntu","doi":"10.1115/detc2020-22130","DOIUrl":"https://doi.org/10.1115/detc2020-22130","url":null,"abstract":"\u0000 This paper uses the Reduced Order Model (ROM) as well as the Method of Multiple Scales (MMS) in order to investigate behavior of electrostatically actuated micro-electro-mechanical systems (MEMS) circular plates under superharmonic resonance of third order. ROM is solved using two methods, the first is a continuation and bifurcation approach by using software package called AUTO 07p in order to obtain the voltage response, and the second approach is a numerical integration using the Matlab built in function ode15s for obtaining time responses of the system. Overall MMS and ROM provide similar results, especially in the lower amplitudes. These methods seem to differ at higher amplitudes. The ROM shows a second unstable branch that MMS does not have. The time responses agree with the ROM voltage response. Furthermore, the influences of different parameters such as that of the detuning parameter, and damping are investigated.","PeriodicalId":398186,"journal":{"name":"Volume 7: 32nd Conference on Mechanical Vibration and Noise (VIB)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116717665","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 effect of rotor blade aerodynamics and rotor grouping on the accuracy of open-loop simulations with respect to generated trajectories and energy consumption for multi-rotor drones. To examine these effects an 18-rotor high performance drone carrying a 30 kg payload is used. The effect of the rotor blade aerodynamic model on simulation results is examined by comparing roll, pitch, yaw, and vertical motion trajectories produced when using blade element theory model with trajectories produced when using a lumped blade model. The results show a 20% difference between the maximum roll and pitch angle achieved, a 58% difference in maximum altitude achieved, and a 91% percent difference in the maximum yaw angle achieved. These results indicate that the choice of aerodynamic model for the rotor blades has a significant effect on the simulated trajectories and in the calculated energy consumption of those trajectories. The effect of rotor groupings on energy consumption is examined by comparing two different rotor groupings for the 18-rotor drone. Roll, pitch, and yaw motions are simulated for both groupings and the resulting energy calculation shows a 4–5% difference in energy with a motor efficiency curve and a 8–9% difference with a motor efficiency curve included in the power calculation. These results indicate that rotor grouping is important in over-actuated drones for reducing the overall energy consumption of the drone, and thus increase its endurance. This energy reduction may become especially important when closing the loop with a control system or in extreme flight conditions such as stall or strong gusts.
{"title":"Analysis of High Fidelity Modeling of Drone Dynamics and Aerodynamics for Reduced Energy Consumption","authors":"S. Hoang, L. Marsh, A. Aliseda, I. Shen","doi":"10.1115/detc2020-22481","DOIUrl":"https://doi.org/10.1115/detc2020-22481","url":null,"abstract":"\u0000 This paper studies the effect of rotor blade aerodynamics and rotor grouping on the accuracy of open-loop simulations with respect to generated trajectories and energy consumption for multi-rotor drones. To examine these effects an 18-rotor high performance drone carrying a 30 kg payload is used. The effect of the rotor blade aerodynamic model on simulation results is examined by comparing roll, pitch, yaw, and vertical motion trajectories produced when using blade element theory model with trajectories produced when using a lumped blade model. The results show a 20% difference between the maximum roll and pitch angle achieved, a 58% difference in maximum altitude achieved, and a 91% percent difference in the maximum yaw angle achieved. These results indicate that the choice of aerodynamic model for the rotor blades has a significant effect on the simulated trajectories and in the calculated energy consumption of those trajectories. The effect of rotor groupings on energy consumption is examined by comparing two different rotor groupings for the 18-rotor drone. Roll, pitch, and yaw motions are simulated for both groupings and the resulting energy calculation shows a 4–5% difference in energy with a motor efficiency curve and a 8–9% difference with a motor efficiency curve included in the power calculation. These results indicate that rotor grouping is important in over-actuated drones for reducing the overall energy consumption of the drone, and thus increase its endurance. This energy reduction may become especially important when closing the loop with a control system or in extreme flight conditions such as stall or strong gusts.","PeriodicalId":398186,"journal":{"name":"Volume 7: 32nd Conference on Mechanical Vibration and Noise (VIB)","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121960399","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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