Modeling and analysis of linearly coupled dynamical systems with theGreen's element method (GEM)

1990 ◽  
Author(s):  
JAMES WOOLLEY ◽  
DAVID RUSSELL
Keyword(s):  
Dynamical Systems ◽  
Modeling And Analysis ◽  
Element Method

Dynamics of 3D Micropolar Gyroelastic Beams

2014 ◽  
Author(s):  
Soroosh Hassanpour ◽  
G. R. Heppler
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Dynamic Modeling ◽  
Dynamic Equations ◽  
Hamilton’S Principle ◽  
The Finite Element Method ◽  
Hamilton's Principle ◽  
Modeling And Analysis ◽  
Element Method

This paper is devoted to the dynamic modeling of micropolar gyroelastic beams and explores some of the modeling and analysis issues related to them. The simplified micropolar beam torsion and bending theories are used to derive the governing dynamic equations of micropolar gyroelastic beams from Hamilton’s principle. Then these equations are solved numerically by utilizing the finite element method and are used to study the spectral and modal behaviour of micropolar gyroelastic beams.

Geomechanical Controls on Frac-Hits

2022 ◽  
Author(s):  
Dharmendra Kumar ◽  
Ahmad Ghassemi
Keyword(s):  
Pore Pressure ◽  
Fracture Propagation ◽  
Horizontal Wells ◽  
Operational Parameters ◽  
Modeling And Analysis ◽  
Matrix Deformation ◽  
In Situ Conditions ◽  
Fracture Fluid ◽  
Poroelastic Model ◽  
Element Method

Abstract The communication among the horizontal wells or "frac-hits" issue have been reported in several field observations. These observations show that the "infill" well fractures could have a tendency to propagate towards the "parent" well depending on reservoir in-situ conditions and operational parameters. Drilling the horizontal wells in a "staggered" layout with both horizontal and vertical offset could be a mitigation strategy to prevent the "frac-hits" issue. In this study, we present a detailed geomechanical modeling and analysis of the proposed solution. For numerical modeling, we used our state-of-the-art fully coupled poroelastic model "GeoFrac-3D" which is based on the boundary element method for the rock matrix deformation/fracture propagation and the finite element method for the fracture fluid flow. The "GeoFrac-3D" simulator fully couples pore pressure to stresses and allows for dynamic modeling of production/injection and fracture propagation. The simulation results demonstrate that production from a "parent’ well causes a non-uniform reduction of the reservoir pore pressure around the production fractures, resulting in an anisotropic decrease of the reservoir total stresses, which could affect fracture propagation from the "infill" wells. We examine the optimal orientation and position of the "infill" well based on the numerical analysis to reduce the "frac-hits" issue in the horizontal well refracturing. The posibility of "frac-hits" can be reduced by optimizing the direction and locations of the "infill" wells, as well as re-pressurizing the "parent" well. The results suggest that arranging the horizontal wells in a "staggered" or "wine rack" arrangement decreases direct well interference and could increase the drainage volume.

scholarly journals Discrete element method approach to modelling VPP dampers

2018 ◽  
Vol 157 ◽  
pp. 02014
Author(s):  
Pawel Chodkiewicz ◽  
Jakub Lengiewicz ◽  
Robert Zalewski
Keyword(s):  
Discrete Element Method ◽  
Granular Medium ◽  
Discrete Element ◽  
Modeling And Analysis ◽  
Novel Approach ◽  
Particle Dampers ◽  
Pressure Boundary Conditions ◽  
Dem Model ◽  
Method Approach ◽  
Element Method

In this paper, we present a novel approach to modeling and analysis of Vacuum Packed Particle dampers (VPP dampers) with the use of Discrete Element Method (DEM). VPP dampers are composed of loose granular medium encapsulated in a hermetic envelope, with controlled pressure inside the envelope. By changing the level of underpressure inside the envelope, one can control mechanical properties of the system. The main novelty of the DEM model proposed in this paper is the method to treat special (pressure) boundary conditions at the envelope. The model has been implemented within the open-source Yade DEM software. Preliminary results are presented and discussed in the paper. The qualitative agreement with experimental results has been achieved.

Use of Finite Element Method in Optimization of Quay Crane's Grab

2013 ◽  
Vol 837 ◽  
pp. 346-350
Author(s):  
Cristina Dragomir
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Permanent Deformation ◽  
Metal Structure ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Modeling And Analysis ◽  
Quay Cranes ◽  
Tie Rods ◽  
Element Method

This Finite element method is one of the most advanced calculating methods for approximation of accurate solutions to engineering problems. Optimization of grabs quay cranes is necessary because most port operators use this type of equipment for loading and unloading bulk cargo. Initial research methods applied in this study are based on observations and surveys conducted on Bocşa 16 t - 32 m mobile quay cranes of MinMetal S.A. Constanta port operator. Modeling and analysis for grabs structure optimization was made with FEMAP and NX NASTRAN - version 10.3.1 applications, which use the finite element method and finite element analysis. After calculations and analysis, the following optimizations resulted:-to increase the grabs closing force (in order to minimize the loss of cargo between jaws and to increase digging force) the lower beam weight must be reduced.-to reduce the amount of cargo drained from the grabs jaws at loading, rubber jaws barriers can be fixed or bars can be welded at grabs jaws.- if cargo has high granulation, in order to reduce grabs weight the plate of the jaw can be cropped.-cups supporting tie rods could be replaced by hydraulic cylinders.The greatest tension is located in the cups supportive arms and in the area where cups are attached to arms. Shafts tensions are larger than the grabs metal structure and are located in shafts-arms contact areas, ie support bearings. In these areas, an optimization can be made by installing ball bearings to reduce friction. The largest deformations occur in the middle area of the arms. To increase safety in operation it is necessary to change the material of the four arms supporting cups, given that deformation of 89.7 mm (~ 9 cm) combined with external factors and / or shock loads can lead to permanent deformation or even material breaks. After changing the material, the model showed that the deformations in the middle area of the arms are substantially reduced, at only 4 mm. In the contact area of the upper arms with the two bars of the upper beam, hazardous tensions may be minimized if there are inserted bearings.

scholarly journals Modeling and Analysis of IC Engine Rubber Mount Using Finite Element Method and RSM

2012 ◽  
Vol 38 ◽  
pp. 1683-1692 ◽  
Author(s):  
T. Ramachandran ◽  
K.P. Padmanaban ◽  
P. Nesamani
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Ic Engine ◽  
Modeling And Analysis ◽  
Element Method

scholarly journals Implications of Noise on Neural Correlates of Consciousness: A Computational Analysis of Stochastic Systems of Mutually Connected Processes

Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 583
Author(s):  
Pavel Kraikivski
Keyword(s):  
Dynamical Systems ◽  
Stochastic Systems ◽  
System Size ◽  
Neural Correlates ◽  
Spectral Entropy ◽  
Modeling And Analysis ◽  
Neural Correlates Of Consciousness ◽  
Power Spectral ◽  
Neuronal Processes ◽  
Random Fluctuations

Random fluctuations in neuronal processes may contribute to variability in perception and increase the information capacity of neuronal networks. Various sources of random processes have been characterized in the nervous system on different levels. However, in the context of neural correlates of consciousness, the robustness of mechanisms of conscious perception against inherent noise in neural dynamical systems is poorly understood. In this paper, a stochastic model is developed to study the implications of noise on dynamical systems that mimic neural correlates of consciousness. We computed power spectral densities and spectral entropy values for dynamical systems that contain a number of mutually connected processes. Interestingly, we found that spectral entropy decreases linearly as the number of processes within the system doubles. Further, power spectral density frequencies shift to higher values as system size increases, revealing an increasing impact of negative feedback loops and regulations on the dynamics of larger systems. Overall, our stochastic modeling and analysis results reveal that large dynamical systems of mutually connected and negatively regulated processes are more robust against inherent noise than small systems.

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