A Variable-Inertia Flywheel Model for Regenerative Braking on a Bicycle

2014 ◽  
Author(s):  
Matthew P. Figliotti ◽  
Mario W. Gomes
Keyword(s):  
Cost Functions ◽  
Spring Model ◽  
Generator System ◽  
Physical Size ◽  
Vehicle Simulation ◽  
Efficiency Losses ◽  
Non Linear ◽  
Linear Spring ◽  
Actuator System ◽  
Device Size

Kinetic energy storage systems for powering vehicles currently exist but are not prevalent. Often the coupling between the flywheel and the vehicle is done using a separate actuator/generator system. This separate actuator system necessarily results in efficiency losses. In this paper we present a design for a spring-coupled variable inertia flywheel which directly couples the flywheel and vehicle. Simulation results for the non-linear dynamic behavior of the system are given and show that it can be used to store more than 99% of the energy of the vehicle when braking, but that there is a tradeoff between device size, deceleration rate, and energy stored. We found that a parameter exploration using three cost functions related to braking time, energy stored, and flywheel radius, shows that one can optimize at most two of the three cost functions. Analytic results are also given for a driven mass-flywheel model, which mitigates some of the problems of the linear spring model. However, this model, if it uses equivalent non-linear springs, is able to store at most 75% of the system energy. The driven-mass/non-linear spring model allows for a lower deceleration and smaller physical size than the linear spring model.

Non-linear spring model for backfill grout-consolidation behind shield tunnel lining

2021 ◽  
Vol 136 ◽  
pp. 104235
Author(s):  
Xiao-Xue Liu ◽  
Shui-Long Shen ◽  
Ye-Shuang Xu ◽  
Annan Zhou
Keyword(s):  
Tunnel Lining ◽  
Shield Tunnel ◽  
Spring Model ◽  
Non Linear ◽  
Linear Spring

A Non-Linear Spring Model for Predicting Modal Behavior of Oscillators Built from Double Walled Carbon Nanotubes

2019 ◽  
Vol 60 ◽  
pp. 21-32
Author(s):  
Yan Wen Lin ◽  
Wu Gui Jiang ◽  
Li Ang Chen ◽  
Wen Guang Liu ◽  
Hang Zou
Keyword(s):  
Carbon Nanotubes ◽  
Natural Frequencies ◽  
Geometric Parameters ◽  
Spring Model ◽  
Nonlinear Spring ◽  
Non Linear ◽  
Linear Spring ◽  
Double Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Vdw Interaction

A nonlinear spring model is proposed to investigate the oscillation behavior of oscillators based on double-walled carbon nanotubes (DWCNTs) with open end by using the finite element (FE) method, where non-linear spring elements are used to represent the van der Waals (vdW) interaction between tubes. Compared to the linear spring FE model, the proposed non-linear springs can more accurately describe the interaction between nanotubes because the vdW interaction is a kind of strongly non-linear force. The influence of boundary conditions, geometric parameters of the DWCNTs, and the layer spacing of tubes on the natural frequencies is especially studied. Various oscillation modes and the corresponding natural frequencies are obtained. Compared to the results obtained by using the linear spring model, the natural frequencies of oscillators based on DWCNTs are in qualitatively better agreement with those obtained from the analytical method and the molecular dynamics (MD) method. From the FE results, it also can be seen that, DWCNTs is expected to be a nanoscale oscillatory device, and its oscillation mode and natural frequency can be adjusted by changing the geometric parameters and boundary condition of the tubes. The proposed nonlinear spring model is helpful for the design of the nano-oscillators under various conditions.

Bemessung von zugbeanspruchten Befestigungen in Beton mit einem nicht-linearen Federmodell- Hintergrund und Softwarelösung für die Versagensart Betonausbruch/A non-linear spring model for design of tension loaded anchorages in concrete- Background and software solution for concrete cone failure

Bauingenieur ◽  
2019 ◽  
Vol 94 (09) ◽  
pp. 326-335
Author(s):  
Boglárka Bokor ◽  
Thilo Pregartner ◽  
Akanshu Sharma ◽  
Jan Hofmann
Keyword(s):  
Spring Model ◽  
Finite Elemente ◽  
Non Linear ◽  
Linear Spring

Zusammenfassung Die Bemessung von zugbeanspruchten Befestigungen in Beton nach den aktuellsten Normen und Richtlinien weist viele grundlegende Einschränkungen zur Anwendung der Konzepte auf. Sie beschränkt sich beispielsweise auf rechteckige Dübelanordnungen und setzt die Verwendung einer ausreichend steifen Ankerplatte voraus. Definitionen und Regelungen zur Bestimmung einer ausreichend steifen Ankerplatte sind in den derzeitig gültigen Vorschriften nicht enthalten. Aufgrund von technischen, funktionellen oder baulichen Anforderungen werden jedoch auch solche Befestigungen in der Baupraxis ausgeführt, für die die Bemessung durch die aktuellen Vorschriften nicht abgedeckt ist. Dieser Beitrag stellt ein neuartiges Bemessungskonzept vor, das einen federmodellbasierten Ansatz mit einem 3D-Finite-Elemente-Solver kombiniert. Dadurch steht eine Softwarelösung für die Bemessung und Bewertung von zugbeanspruchten Gruppenbefestigungen in Beton zur Verfügung, die die wesentlichen Einschränkungen der aktuellen Bemessungsnormen behebt. Das Konzept des nicht-linearen Federmodells, das in einer benutzerfreundlichen Dübelbemessungssoftware implementiert ist, basiert auf der Annahme, dass innerhalb einer Gruppenbefestigung die Zugkräfte von den Befestigungsmitteln aufgenommen werden, während die Druckkräfte direkt durch das Anbauteil in den Beton eingeleitet werden. Zur Modellierung des Dübelverhaltens werden nicht-lineare Federn verwendet. Um den Einfluss des Bauteilrandes und der benachbarten Befestigungen zu berücksichtigen, wird ein Ansatz für die Flächenaufteilung angewendet, der auf der Grundlage einer Vielzahl von experimentellen Untersuchungen der Autoren entwickelt wurde, Bokor et al. [25]. Die Ankerplatte wird mit finiten Solid-Elementen modelliert, um die Steifigkeit der Ankerplatte und Lastumlagerungen zwischen den Befestigungen einschließlich möglicher Versteifungen der Ankerplatte realistisch zu betrachten.

Lot-Size Planning with Non-Linear Cost Functions Supporting Environmental Sustainability

2010 ◽  
Vol 1 (1) ◽  
pp. 34-39 ◽  
Author(s):  
Markus Heck ◽  
Guenter Schmidt
Keyword(s):  
Environmental Impact ◽  
Cost Function ◽  
Environmental Sustainability ◽  
Production Costs ◽  
Cost Functions ◽  
Size Optimization ◽  
Lot Size ◽  
Non Linear ◽  
Linear Cost

In this paper, the authors propose a non-linear cost function based on ecological considerations for lot-size planning. The classical approaches of lot-size optimization, the Wagner-Whitin algorithm and the Part-Period Balancing heuristic, are enhanced with so-called eco-factors. These eco-enhanced approaches combined with eco-balancing help to reduce overall production costs. Simultaneously, the environmental impact is also reduced.

Optimal Two-commodity Flows with Non-linear Cost Functions

1995 ◽  
Vol 46 (10) ◽  
pp. 1192-1107 ◽  
Author(s):  
N. L. Boland ◽  
A. T. Ernst ◽  
C. J. Goh ◽  
A. I. Mees
Keyword(s):  
Cost Functions ◽  
Commodity Flows ◽  
Non Linear ◽  
Linear Cost

Non-Stationary Response of Non-Linear SDOF Systems by Perturbation of Wavelet Coefficients

2001 ◽  
Author(s):  
Pranesh Chatterjee ◽  
Biswajit Basu
Keyword(s):  
Wavelet Domain ◽  
Wavelet Coefficients ◽  
Algebraic Equations ◽  
Single Degree Of Freedom ◽  
Displacement Response ◽  
Spring Force ◽  
Non Linear ◽  
Linear Spring ◽  
Random Vibration Theory ◽  
Statistical Functionals

Abstract A wavelet based random vibration theory has been developed for the non-stationary seismic response of single degree of freedom (SDOF) systems with cubic type non-linearity in the spring force. The ground motion process has been characterized by statistical functionals of wavelet coefficients. The wavelet transformed coefficient of the displacement response of the oscillator has been perturbed to obtain a series of wavelet domain algebraic equations. The stochastic response of the system has been obtained by using these sets of wavelet domain equations. The root mean square (r.m.s.) displacement response has been obtained in terms of the functionals of the input wavelet coefficients. Parametric variations are carried out to observe the effects of variation of the magnitudes of non-linear spring stiffness on the temporal variation of instantaneous r.m.s. values of oscillator displacements.

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