An Analytical Investigation of the Impact of Design Parameters on the Performance of Centrifugal Pendulum Vibration Absorbers

2019 ◽  
Author(s):  
Bahadir Sarikaya ◽  
Murat Inalpolat ◽  
Hyun Ku Lee ◽  
Moo Suk Kim
Keyword(s):  
Dynamic Model ◽  
Translational Motion ◽  
Vibration Reduction ◽  
Analytical Investigation ◽  
Design Parameters ◽  
Vibration Absorbers ◽  
Modeling Framework ◽  
Centrifugal Pendulum Vibration Absorbers ◽  
Fast Prediction ◽  
The Impact

Abstract A generalized nonlinear time-varying, planar dynamic model of bifilar centrifugal pendulum vibration absorbers (CPVA) is proposed. This dynamic model enables fast prediction of vibration reduction performance of any CPVA design considering the impact of absorber rollers, gravity, end stops and translational motion of the system. The modeling framework provides comparative, simultaneous simulation results for numerous different design possibilities, and thus can be used to optimize CPVA designs. The dynamic model is generic and can handle N individually designed absorbers on a rotor with numerous path options ranging from circular to cycloid. Absorbers can be designed to be equally or unequally spaced. In this study, first the dynamic model of the bifilar CPVAs is derived. Then, case studies are provided to showcase the capabilities of the modeling framework. Initially, maximum applicable dynamic torque to a CPVA and vibration reduction performance are investigated by considering the effect of tuning order and different absorber path options for different operating speeds. Then, impact of different modelling features on system frequency response and limit dynamic torque is investigated. Interactions between the important design parameters are highlighted. Finally, the influence of end stop positioning on the CPVA dynamic response is illustrated.

Dynamic Analysis of Helical Planetary Gear Train

2013 ◽  
Vol 404 ◽  
pp. 312-317 ◽  
Author(s):  
Xian Zeng Liu ◽  
Jun Zhang
Keyword(s):  
Steady State ◽  
Free Vibration ◽  
Dynamic Model ◽  
Planetary Gear ◽  
Gear Train ◽  
Dynamic Responses ◽  
Design Parameters ◽  
Planetary Gear Train ◽  
State Dynamic ◽  
The Impact

A dynamic model for helical planetary gear train (HPGT) is proposed. Based on the model, the free vibration characteristics, steady-state dynamic responses and effects of design parameters on system dynamics are investigated through numerical simulations. The free vibration of the HGPT is classified into 3 categories. The classified vibration modes are demonstrated as axial translational and torsional mode (AT mode), radial translational and rotational mode (RR mode) and planet mode (P mode) followed by the characteristics of each category. The simulation results agree well with those of previous discrete model when neglecting the component flexibilities, which validates the correctness of the present dynamic model. The steady-state dynamic responses indicate that the dynamic meshing forces fluctuate about the average static values and the time-varying meshing stiffness is one of the major excitations of the system. The parametric sensitivity analysis shows that the impact of the central component bearing stiffness on the dynamic characteristic of the HPGT system is significant.

scholarly journals Mobile Access Hub Deployment for Urban Parcel Logistics

2020 ◽  
Vol 12 (17) ◽  
pp. 7213 ◽  
Author(s):  
Louis Faugère ◽  
Chelsea White ◽  
Benoit Montreuil
Keyword(s):  
Urban Space ◽  
Environmental Sustainability ◽  
Urban Areas ◽  
Integer Program ◽  
Design Parameters ◽  
Illustrative Case ◽  
City Logistics ◽  
Modeling Framework ◽  
Mobile Access ◽  
The Impact

Last-mile logistics is an essential yet highly expensive component of city logistics responsible for many nuisances in urban areas. Mobile access hubs are flexible consolidation and transshipment points aiming at creating more sustainable city logistics systems by dynamically using urban space as logistics facilities. In this paper, we examine the potential of mobile access hub deployments for urban parcel logistics by identifying the impact of design parameters on economic and environmental performance. We propose a mathematical modeling framework and an integer program to assess the performance of mobile access hub deployments, and study the impact of a set of design parameters through synthetic cases and an illustrative case inspired from a large parcel express carrier’s operations. Results indicate design flexibility relative to the location of hubs and pronounced advantages in highly variable environments. The illustrative case shows significant savings potential in terms of cost and time efficiency as well as environmental sustainability. It emphasizes a trade-off between operational efficiency and environmental sustainability that can be balanced to achieve global sustainability goals while being economically sound.

Vibration Analysis and Methods of Dry Friction Damping of Tubed Vortex Reducer

2020 ◽  
Author(s):  
Siyuan Chen ◽  
Yanrong Wang ◽  
Dasheng Wei ◽  
Yanbin Luo ◽  
Shimin Gao
Keyword(s):  
Dry Friction ◽  
Vibration Analysis ◽  
Damping Ratio ◽  
Vibration Reduction ◽  
Vibration Characteristics ◽  
Design Parameters ◽  
Vibration Test ◽  
Friction Damping ◽  
The Impact ◽  
Dry Friction Damping

Abstract The tubed vortex reducer is a new structure of aero-engine, which is widely used in advanced large bypass ratio high performance turbofan engines. It is usually installed between the rear two-stage discs of the high-pressure compressor, and reduces the generation of free vortex by restricting the flow path of the cooling airflow, thereby reducing the pressure loss of the cooling airflow and improving the engine efficiency. In this paper, vibration analysis of tubed vortex reducer is carried out by experiments and numerical simulations. Using the finite element method, the natural vibration characteristics of the vortex reducer are calculated with ANSYS. The sensitivity analysis of the impact of design parameters on the vibration characteristics is carried out. In addition, the vibration test bench of the vortex reducer is set up, and the vibration test of the vortex reducer is conducted by means of frequency sweeping and hammer hitting respectively. The experimental results satisfactorily reproduce the simulation results. Then the theoretical model of dry friction damping of vortex reducer is established. Based on the dynamic model of the complex contact system composed of vortex reducer and damping sleeve, the relationship between energy dissipation in different directions is derived. And a method evaluating the performance of vibration reduction is presented for calculating its equivalent damping ratio. Finally, the influence of the key design parameters and different installation methods on the damping ratio is analyzed. Overall, this work can provide reference for vibration reduction design and optimization of vortex reducer.

332-OR: Determining the Impact of Additional Macronutrients on the Glycemic-Insulin Dynamic Model

Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 332-OR
Author(s):  
BOYI JIANG ◽  
YUXIANG ZHONG ◽  
PRATIK AGRAWAL ◽  
TONI L. CORDERO ◽  
ROBERT VIGERSKY
Keyword(s):  
Dynamic Model ◽  
The Impact

Dynamic model for high-speed rotors based on their experimental characterization

2017 ◽  
Vol 2 (4) ◽  
pp. 25
Author(s):  
L. A. Montoya ◽  
E. E. Rodríguez ◽  
H. J. Zúñiga ◽  
I. Mejía
Keyword(s):  
Dynamic Model ◽  
High Speed ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Experimental Characterization ◽  
Rotating Systems ◽  
Computing Performance ◽  
The Impact ◽  
Stiffness Distribution ◽  
Good Agreement

Rotating systems components such as rotors, have dynamic characteristics that are of great importance to understand because they may cause failure of turbomachinery. Therefore, it is required to study a dynamic model to predict some vibration characteristics, in this case, the natural frequencies and mode shapes (both of free vibration) of a centrifugal compressor shaft. The peculiarity of the dynamic model proposed is that using frequency and displacements values obtained experimentally, it is possible to calculate the mass and stiffness distribution of the shaft, and then use these values to estimate the theoretical modal parameters. The natural frequencies and mode shapes of the shaft were obtained with experimental modal analysis by using the impact test. The results predicted by the model are in good agreement with the experimental test. The model is also flexible with other geometries and has a great time and computing performance, which can be evaluated with respect to other commercial software in the future.

Design of a Robust Memristive Spiking Neuromorphic System with Unsupervised Learning in Hardware

2021 ◽  
Vol 17 (4) ◽  
pp. 1-26
Author(s):  
Md Musabbir Adnan ◽  
Sagarvarma Sayyaparaju ◽  
Samuel D. Brown ◽  
Mst Shamim Ara Shawkat ◽  
Catherine D. Schuman ◽  
...  
Keyword(s):  
Unsupervised Learning ◽  
Recognition Task ◽  
Single Layer ◽  
Process Variations ◽  
Spike Timing ◽  
System Level ◽  
Design Parameters ◽  
Digital Pulse ◽  
Neuromorphic System ◽  
The Impact

Spiking neural networks (SNN) offer a power efficient, biologically plausible learning paradigm by encoding information into spikes. The discovery of the memristor has accelerated the progress of spiking neuromorphic systems, as the intrinsic plasticity of the device makes it an ideal candidate to mimic a biological synapse. Despite providing a nanoscale form factor, non-volatility, and low-power operation, memristors suffer from device-level non-idealities, which impact system-level performance. To address these issues, this article presents a memristive crossbar-based neuromorphic system using unsupervised learning with twin-memristor synapses, fully digital pulse width modulated spike-timing-dependent plasticity, and homeostasis neurons. The implemented single-layer SNN was applied to a pattern-recognition task of classifying handwritten-digits. The performance of the system was analyzed by varying design parameters such as number of training epochs, neurons, and capacitors. Furthermore, the impact of memristor device non-idealities, such as device-switching mismatch, aging, failure, and process variations, were investigated and the resilience of the proposed system was demonstrated.

Making Up 3D Bodies

2021 ◽  
Vol 4 (2) ◽  
pp. 1-9
Author(s):  
Kiona Hagen Niehaus ◽  
Rebecca Fiebrink
Keyword(s):  
Software Tool ◽  
The Body ◽  
Design Parameters ◽  
Artistic Practice ◽  
Human Form ◽  
Modeling Systems ◽  
Exploratory Approach ◽  
Disability Status ◽  
High Level ◽  
The Impact

This paper describes the process of developing a software tool for digital artistic exploration of 3D human figures. Previously available software for modeling mesh-based 3D human figures restricts user output based on normative assumptions about the form that a body might take, particularly in terms of gender, race, and disability status, which are reinforced by ubiquitous use of range-limited sliders mapped to singular high-level design parameters. CreatorCustom, the software prototype created during this research, is designed to foreground an exploratory approach to modeling 3D human bodies, treating the digital body as a sculptural landscape rather than a presupposed form for rote technical representation. Building on prior research into serendipity in Human-Computer Interaction and 3D modeling systems for users at various levels of proficiency, among other areas, this research comprises two qualitative studies and investigation of the impact on the first author's artistic practice. Study 1 uses interviews and practice sessions to explore the practices of six queer artists working with the body and the language, materials, and actions they use in their practice; these then informed the design of the software tool. Study 2 investigates the usability, creativity support, and bodily implications of the software when used by thirteen artists in a workshop. These studies reveal the importance of exploration and unexpectedness in artistic practice, and a desire for experimental digital approaches to the human form.

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