Multiport Models for the Kinematic and Dynamic Analysis of Gear Power Transmissions

1979 ◽  
Vol 101 (2) ◽  
pp. 258-267 ◽  
Author(s):  
R. R. Allen
Keyword(s):  
Large Scale ◽  
Dynamic Models ◽  
Power Transmission ◽  
Bond Graph ◽  
Angular Velocities ◽  
Machine Elements ◽  
Gear Trains ◽  
Machine Systems ◽  
Kinematic Mechanisms ◽  
Kinematic Transformation

The kinematics of a gear power transmission may be characterized by a power-conserving kinematic transformation between independent and dependent angular velocities. The conjugate of this transform provides a relation between input and output torques. A bond graph multiport representing these kinematic relations provides a power-conserving core to which dissipative, inertial, and compliance effects may be added. This dynamic model of a power transmission may be connected with other machine elements (such as other kinematic mechanisms, motors, driveshafts, and loads) to form large-scale, computable dynamic models. Bond graph techniques are shown to facilitate the process of developing and assembling computable dynamic models for the study of gear trains as elements of machine systems. A numerical example is presented.

The Bond Graph as a Unified Data Base for Engineering System Design

1975 ◽  
Vol 97 (4) ◽  
pp. 1333-1337 ◽  
Author(s):  
R. C. Rosenberg
Keyword(s):  
Data Base ◽  
Large Scale ◽  
Dynamic Models ◽  
Systems Design ◽  
Bond Graph ◽  
Graph Representation ◽  
Model Description ◽  
Engineering System ◽  
State Equations ◽  
Engineering System Design

In developing a unified data base for support of engineering systems design there are several important factors to consider, such as efficiency of model description, ease of modifying models, and characteristics of assembling device models into systems. The multipart model and its associated bond graph representation can serve very effectively as a unified data base, especially when devices and systems involve several energy domains simultaneously (e.g., electromechanical or hydromechanical transduction). In addition to providing a succinct, flexible data base for linear and nonlinear, static and dynamic models, bond graphs can be processed causally to reveal important information about alternative input-output choices and device-level coupling factors when submodels are assembled into systems. Particularly for large-scale nonlinear systems this is an important feature in aiding the formulation of state equations. Illustrations of the bond graph data base approach are given.

scholarly journals Network isolators inhibit failure spreading in complex networks

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Franz Kaiser ◽  
Vito Latora ◽  
Dirk Witthaut
Keyword(s):  
Complex Networks ◽  
Large Scale ◽  
Power Transmission ◽  
Power Grids ◽  
Cascading Failure ◽  
Critical Infrastructures ◽  
Daily Lives ◽  
Supply Networks ◽  
Water Transmission ◽  
Complete Collapse

AbstractIn our daily lives, we rely on the proper functioning of supply networks, from power grids to water transmission systems. A single failure in these critical infrastructures can lead to a complete collapse through a cascading failure mechanism. Counteracting strategies are thus heavily sought after. In this article, we introduce a general framework to analyse the spreading of failures in complex networks and demostrate that not only decreasing but also increasing the connectivity of the network can be an effective method to contain damages. We rigorously prove the existence of certain subgraphs, called network isolators, that can completely inhibit any failure spreading, and we show how to create such isolators in synthetic and real-world networks. The addition of selected links can thus prevent large scale outages as demonstrated for power transmission grids.

scholarly journals Synthesis of the Sparse Uniform-Amplitude Concentric Ring Transmitting Array for Optimal Microwave Power Transmission

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Hua-Wei Zhou ◽  
Xue-Xia Yang ◽  
Sajjad Rahim
Keyword(s):  
Microwave Power ◽  
Large Scale ◽  
Power Transmission ◽  
Synthesis Method ◽  
Pso Algorithm ◽  
Practical Significance ◽  
Concentric Ring ◽  
Swarm Optimization ◽  
Key Factor ◽  
Feed Network

Beam capture efficiency (BCE) is one key factor of the overall efficiency for a microwave power transmission (MPT) system, while sparsification of a large-scale transmitting array has a practical significance. If all elements of the transmitting array are excited uniformly, the fabrication, maintenance, and feed network design would be greatly simplified. This paper describes the synthesis method of the sparse uniform-amplitude transmitting array with concentric ring layout using particle swarm optimization (PSO) algorithm while keeping a higher BCE. Based on this method, uniform exciting strategy, reduced number of elements, and a higher BCE are achieved simultaneously for optimal MPT. The numerical results of the sparse uniform-amplitude concentric ring arrays (SUACRAs) optimized by the proposed method are compared with those of the random-located uniform-amplitude array (RLUAA) and the stepped-amplitude array (SAA), both being reported in the literatures for the maximum BCE. Compared to the RLUAA, the SUACRA saves 32% elements with a 1.1% higher BCE. While compared to the SAA, the SUACRA saves 29.1% elements with a bit higher BCE. The proposed SUACRAs have higher BCEs, simple array arrangement and feed network, and could be used as the transmitting array for a large-scale MPT system.

scholarly journals Modular Dynamic Biomolecular Modelling: The Unification of Stoichiometry, Thermodynamics, Kinetics and Data

2021 ◽  
Author(s):  
Peter J. Gawthrop ◽  
Michael Pan ◽  
Edmund J. Crampin
Keyword(s):  
Dynamic Models ◽  
System Development ◽  
Kinetic Modelling ◽  
Simulation Models ◽  
Bond Graph ◽  
Model Parameters ◽  
Biomolecular Systems ◽  
Genome Wide ◽  
Estimation Of Model Parameters ◽  
Genome Scale

AbstractRenewed interest in dynamic simulation models of biomolecular systems has arisen from advances in genome-wide measurement and applications of such models in biotechnology and synthetic biology. In particular, genome-scale models of cellular metabolism beyond the steady state are required in order to represent transient and dynamic regulatory properties of the system. Development of such whole-cell models requires new modelling approaches. Here we propose the energy-based bond graph methodology, which integrates stoichiometric models with thermo-dynamic principles and kinetic modelling. We demonstrate how the bond graph approach intrinsically enforces thermodynamic constraints, provides a modular approach to modelling, and gives a basis for estimation of model parameters leading to dynamic models of biomolecular systems. The approach is illustrated using a well-established stoichiometric model of E. coli and published experimental data.

Nomographs for Enumeration of Clutching Sequences Associated With Epicyclic-Type Automatic Transmission Mechanisms

2008 ◽  
Author(s):  
Essam L. Esmail
Keyword(s):  
Automatic Transmission ◽  
Root Cause ◽  
Transmission Mechanisms ◽  
Epicyclic Gear ◽  
Angular Velocities ◽  
Gear Mechanism ◽  
Gear Trains ◽  
Exact Size ◽  
Algorithmic Techniques ◽  
Transmission Gear

A new methodology for the enumeration of feasible clutching sequences for a given epicyclic gear mechanism (EGM) is presented using the kinematic nomographs of epicyclic-type transmission mechanisms. From such nomographs, the kinematic characteristics of an epicyclic gear mechanism can be expressed in terms of the gear ratios of its gear pairs. From a single nomograph, the angular velocities for all of the coaxial links can be estimated and compared directly without specifying the exact size of each gear. In addition, the angular velocities can be arranged in a descending sequence without using complicated artificial intelligence or algorithmic techniques. Then, a procedure for the enumeration of feasible clutching sequences associated with a transmission mechanism composed of two or more fundamental gear entities (FGEs) is developed. The reliability of the methodology is established by applying it to two transmission gear trains for which solutions are either fully or partially available in the literature. In the process, an incomplete in the results reported in previous literature is brought to light. And the root cause of this incompleteness is explored. The present methodology is judged to be more efficient for enumeration of all feasible clutching sequences of an EGM.

Generic Dynamic Models for Modeling Wind Power Plants and Other Renewable Technologies in Large-Scale Power System Studies

2017 ◽  
Vol 32 (3) ◽  
pp. 1108-1116 ◽  
Author(s):  
Pouyan Pourbeik ◽  
Juan J. Sanchez-Gasca ◽  
Jayapalan Senthil ◽  
James D. Weber ◽  
Pouya Sajjad Zadehkhost ◽  
...  
Keyword(s):  
Power System ◽  
Wind Power ◽  
Power Plants ◽  
Large Scale ◽  
Dynamic Models ◽  
Wind Power Plants

3D linked megathrust, dynamic rupture and  tsunami propagation and inundation modeling:  Dynamic effects of supershear and tsunami earthquakes 

2021 ◽  
Author(s):  
Sara Aniko Wirp ◽  
Alice-Agnes Gabriel ◽  
Elizabeth H. Madden ◽  
Maximilian Schmeller ◽  
Iris van Zelst ◽  
...  
Keyword(s):  
Subduction Zones ◽  
Large Scale ◽  
Dynamic Models ◽  
Initial Conditions ◽  
Poisson Ratio ◽  
Fault Slip ◽  
Moment Magnitude ◽  
Dynamic Rupture ◽  
S Wave ◽  
Tsunami Propagation

<p>Earthquake rupture dynamic models capture the variability of slip in space and time while accounting for the structural complexity which is characteristic for subduction zones. The use of a geodynamic subduction and seismic cycling (SC) model to initialize dynamic rupture (DR) ensures that initial conditions are self-consistent and reflect long-term behavior. We extend the 2D geodynamical subduction and SC model of van Zelst et al. (2019) and use it as input for realistic 3-dimensional DR megathrust earthquake models. We follow the subduction to tsunami run-up linking approach described in Madden et al. (2020), including a complex subduction setup along with their resulting tsunamis. The distinct variation of shear traction and friction coefficients with depth lead to realistic average rupture speeds and dynamic stress drop as well as efficient tsunami generation. </p><p>We here analyze a total of 14 subduction-initialized 3D dynamic rupture-tsunami scenarios. By varying the hypocentral location along arc and depth, we generate 12 distinct unilateral and bilateral earthquakes with depth-variable slip distribution and directivity, bimaterial, and geometrical effects in the dynamic slip evolutions. While depth variations of the hypocenters barely influence the tsunami behavior, lateral varying nucleation locations lead to a shift in the on-fault slip which causes time delays of the wave arrival at the coast. The fault geometry of our DR model that arises during the SC model is non-planar and includes large-scale roughness. These features (topographic highs) trigger supershear rupture propagation in up-dip or down-dip direction, depending on the hypocentral depth.</p><p>In two additional scenarios, we analyze variations in the energy budget of the DR scenarios. In the SC model, an incompressible medium is assumed (ν=0.5) which is valid only for small changes in pressure and temperature. Unlike in the DR model where the material is compressible and a different Poisson’s ratio (ν=0.25) has to be assigned. Poisson’s ratios between 0.1 and 0.4 stand for various compressible materials. To achieve a lower shear strength of all material on and off the megathrust fault and to facilitate slip, we increase the Poisson ratio in the DR model to ν=0.3 which is consistent with basaltic rocks. As a result, larger fault slip is concentrated at shallower depths and generates higher vertical seafloor displacement and earthquake moment magnitude respectively. Even though the tsunami amplitudes are much higher, the same dynamic behavior as in the twelve hypocenter-variable models can be observed. Lastly, we increase fracture energy by changing the critical slip distance in the linear slip-weakening frictional parameterization. This generates a tsunami earthquake (Kanamori, 1972) characterized by low rupture velocity (on average half the amount of s-wave speed) and low peak slip rate, but at the same time large shallow fault slip and moment magnitude. The shallow fault slip of this event causes the highest vertical seafloor uplift compared to all other simulations. This leads to the highest tsunami amplitude and inundation area while the wavefront hits the coast delayed compared to the other scenarios.</p>

Demonstrating the Generation of Bond Graphs From 3D Assemblies

2020 ◽  
Author(s):  
Corey J. Alicchio ◽  
Justin S. Vitiello ◽  
Pradeep Radhakrishnan
Keyword(s):  
Bond Graph ◽  
Dynamic Responses ◽  
Bond Graphs ◽  
Mechatronic Systems ◽  
3D Cad ◽  
Related Information ◽  
Grammar Rules ◽  
Gear Trains ◽  
System Graph ◽  
Future Work

Abstract The bond graph method provides a generic and simple way to compute differential equations and dynamic responses for complex mechatronic systems. This paper will illustrate the process of automatically generating bond graphs from 3D CAD assemblies of gear-trains. Using appropriate CAD application programming interfaces (APIs), information on parts and mates within an existing assembly is extracted. The extracted information is stored as an identity graph, which also stores all geometry and mass related information of every part. Grammar rules are then used to transform the identity graph to a system graph, which is then converted to bond graph using an existing bond graph generation program. The paper will discuss the process, challenges and planned future work.

Using Large-Scale Programs to Help Develop Technological Capabilities

2021 ◽  
pp. 413-435
Author(s):  
Xudong Gao
Keyword(s):  
Technological Innovation ◽  
High Speed ◽  
Large Scale ◽  
Power Transmission ◽  
Technological Capability ◽  
Capability Development ◽  
High Speed Rail ◽  
Equipment Industry ◽  
The World ◽  
Power Generation Equipment

China is a developing country but has made impressive progress in technological capability development. One strategy proved to be effective is the use of large-scale programs to help technological capability development. Examples include the subway equipment industry, the high-speed rail industry, the power generation equipment industry, the power transmission industry, the telecom equipment industry, etc. In all these sectors, China was lagging behind the technological innovation frontier before the related large-scale programs but is now among the world leaders. In this chapter we will try to understand the process of initiating and managing these large-scale programs.

scholarly journals Fault Detection in Power Equipment via an Unmanned Aerial System Using Multi Modal Data

Sensors ◽  
2019 ◽  
Vol 19 (13) ◽  
pp. 3014 ◽  
Author(s):  
Bushra Jalil ◽  
Giuseppe Riccardo Leone ◽  
Massimo Martinelli ◽  
Davide Moroni ◽  
Maria Antonietta Pascali ◽  
...  
Keyword(s):  
Transmission Lines ◽  
Power Plants ◽  
Large Scale ◽  
Infrared Imaging ◽  
Power Transmission ◽  
Video Stream ◽  
Power Lines ◽  
Power Transmission Lines ◽  
Ground Station ◽  
Illumination Changes

The power transmission lines are the link between power plants and the points of consumption, through substations. Most importantly, the assessment of damaged aerial power lines and rusted conductors is of extreme importance for public safety; hence, power lines and associated components must be periodically inspected to ensure a continuous supply and to identify any fault and defect. To achieve these objectives, recently, Unmanned Aerial Vehicles (UAVs) have been widely used; in fact, they provide a safe way to bring sensors close to the power transmission lines and their associated components without halting the equipment during the inspection, and reducing operational cost and risk. In this work, a drone, equipped with multi-modal sensors, captures images in the visible and infrared domain and transmits them to the ground station. We used state-of-the-art computer vision methods to highlight expected faults (i.e., hot spots) or damaged components of the electrical infrastructure (i.e., damaged insulators). Infrared imaging, which is invariant to large scale and illumination changes in the real operating environment, supported the identification of faults in power transmission lines; while a neural network is adapted and trained to detect and classify insulators from an optical video stream. We demonstrate our approach on data captured by a drone in Parma, Italy.

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