Efficient Analysis of a Deep-Seabed Integrated Mining System Using a Subsystem Synthesis Method

2015 ◽  
Author(s):  
Sung-Soo Kim ◽  
Hong-seon Yun ◽  
Chang-Ho Lee ◽  
Hyung-Woo Kim ◽  
Sup Hong
Keyword(s):  
Dynamic Analysis ◽  
Equations Of Motion ◽  
Synthesis Method ◽  
Computational Time ◽  
Manganese Nodules ◽  
Flexible Pipe ◽  
Mining System ◽  
Pipe System ◽  
Multibody Model ◽  
Pipe Model

A deep-seabed integrated mining system for collecting manganese nodules consists of a mining vessel, a vertical lifting pipe, a lifting pump, an intermediate buffer station, a flexible pipe, and a self-propelled mining robot. Manganese nodules collected by the mining robot are transferred to the buffer and then lifted up to the vessel. Dynamic analysis of such a system is a challenging task, since large displacements due to deformation must be considered in the very long lifting pipe and the flexible pipe system. Because non-linear effects must be considered in the modeling of the lifting pipe and the flexible pipe model, nodal coordinates must be used in the flexible multibody model. This requires a large amount of computational time for the dynamic analysis. Moreover, the concept of multiple mining robots was introduced recently, increasing the complexity. An efficient method for the dynamic analysis of the integrated mining system is necessary. In this study, to improve the efficiency of analysis, a subsystem synthesis method was developed for the deep-seabed integrated mining system which can also be extended to efficiently analyze multiple mining robots. Subsystem equations of motion were separately generated for the vessel-lifting pipe subsystem and the flexible pipe-mining robot subsystem. The efficiency of the subsystem synthesis method was verified theoretically by comparing arithmetic operational counts of the developed subsystem synthesis method with those of the conventional method.

Frictional Flexible Pipe Model Using Macroelements

2020 ◽  
Author(s):  
Rodrigo Provasi ◽  
Fernando Geremias Toni ◽  
Clovis de Arruda Martins
Keyword(s):  
Structural Behavior ◽  
Computational Time ◽  
Memory Usage ◽  
Relative Movement ◽  
Flexible Pipe ◽  
Finite Element Software ◽  
Geometrical Characteristics ◽  
Pipe Model ◽  
Contact Formulation ◽  
Flexible Pipes

Abstract Flexible pipes are structures composed by many layers varying in composition and shapes, in which the structural behavior is defined by the role it must play. Flexible pipes construction is such that layers are unbounded, allowing relative movement between them and modifying its behavior. Many approaches are used to model such cables, both analytical and numerical, such as the macroelements model. This sort of model consists in finite elements where geometrical characteristics are taken into account by the formulation and is under development by the authors. Previous works have shown in detail the modeled cylindrical and helical elements, as well node-to-node connection elements (bounded, frictionless and frictional), which have allowed simplified flexible pipe with bonded elements simulations. This article will focus on modeling a simplified cable consisting in an external sheath, two armor layers and a polymeric core, since recent advances in the contact formulation opens the possibility to incorporate friction between the layers. Taking into consideration accuracy, computational time and memory usage, results from macroelements are compared to commercial finite element software.

A Vector Oriented Implementation Method for Efficient Dynamic Simulation of Multibody Vehicle Models

1999 ◽  
Author(s):  
D. S. Bae ◽  
H. W. Kim ◽  
H. Yae
Keyword(s):  
Dynamic Analysis ◽  
Low Cost ◽  
Equations Of Motion ◽  
Governing Equations ◽  
Multibody Model ◽  
Numerical Integration Methods ◽  
Implementation Method ◽  
Chord Method ◽  
Dynamics Models ◽  
Efficient Dynamic Simulation

Abstract The most time taking processes in a dynamic analysis of multibody vehicle models are generation and LU-decomposition of various matrices. This research proposes a vector oriented implementation algorithm for explicit numerical integration methods so that relatively low cost computers can be used for the realtime simulation of the multibody vehicle dynamics models consisting of many bodies and joints, a powertrain model, antiroll bars, and tires. Newton chord method is employed to solve the equations of motion and constraints. The equations of motion and constraints are formulated such that the Jacobian matrix for Newton chord method is needed to be generated and LU-decomposed only once for a dynamic analysis. As a result, only computations which need to be carried out in runtime are residual vectors of the governing equations. Convergence analysis of Newton chord method with the proposed Jacobian generation method is carried out. The proposed algorithm yielded close solutions to exact solutions for a prototype vehicle multibody model in realtime on a 400 Mhz PC compatible.

Dynamic Analysis of Cage Stress in Tapered Roller Bearings Using Component-Mode-Synthesis Method

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Tomoya Sakaguchi ◽  
Kazuyoshi Harada
Keyword(s):  
Rigid Body ◽  
Dynamic Analysis ◽  
Boundary Point ◽  
Axial Load ◽  
Synthesis Method ◽  
Load Condition ◽  
Component Mode Synthesis ◽  
Analysis Model ◽  
Tapered Roller ◽  
Tapered Roller Bearings

In order to investigate cage stress in tapered roller bearings, a dynamic analysis tool considering both the six degrees of freedom of motion of the rollers and cage and the elastic deformation of the cage was developed. Cage elastic deformation is equipped using a component-mode-synthesis (CMS) method. Contact forces on the elastically deforming surfaces of the cage pocket are calculated at all node points of finite-elements on it. The location and pattern of the boundary points required for the component-mode-synthesis method were examined by comparing cage stresses in a static condition of pocket forces and constraints calculated by using the finite-element and the CMS methods. These results indicated that one boundary point lying at the center on each bar is appropriate for the effective dynamic analysis model focusing on the cage stress, especially at the pocket corners of the cages, which are actually broken. A behavior measurement of a polyamide cage in a tapered roller bearing was conducted for validating the analysis model. It was confirmed in both the experiment and analysis that the cage whirled under a large axial load condition and the cage center oscillated in a small amplitude under a small axial load condition. In the analysis, the authors discussed the four models including elastic bodies having a normal eigenmode of 0, 8 or 22, and rigid-body. There were small differences among the cage center loci of the four models. These two cages having normal eigenmodes of 0 and rigid-body whirled with imperceptible fluctuations. At least approximately 8 normal eigenmodes of cages should be introduced to conduct a more accurate dynamic analysis although the effect of the number of normal eigenmodes on the stresses at the pocket corners was insignificant. From the above, it was concluded to be appropriate to introduce one boundary point lying at the center on each pocket bar of cages and approximately 8 normal eigenmodes to effectively introduce the cage elastic deformations into a dynamic analysis model.

A New Approach to the Rigid Finite Element Method in Modeling Spatial Slender Systems

2018 ◽  
Vol 18 (02) ◽  
pp. 1850017 ◽  
Author(s):  
Iwona Adamiec-Wójcik ◽  
Łukasz Drąg ◽  
Stanisław Wojciech
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Dynamic Analysis ◽  
Equations Of Motion ◽  
Nonlinear Dynamic Analysis ◽  
New Approach ◽  
Static And Dynamic Analysis ◽  
Rigid Finite Element Method ◽  
Longitudinal Flexibility ◽  
Element Method

The static and dynamic analysis of slender systems, which in this paper comprise lines and flexible links of manipulators, requires large deformations to be taken into consideration. This paper presents a modification of the rigid finite element method which enables modeling of such systems to include bending, torsional and longitudinal flexibility. In the formulation used, the elements into which the link is divided have seven DOFs. These describe the position of a chosen point, the extension of the element, and its orientation by means of the Euler angles Z[Formula: see text]Y[Formula: see text]X[Formula: see text]. Elements are connected by means of geometrical constraint equations. A compact algorithm for formulating and integrating the equations of motion is given. Models and programs are verified by comparing the results to those obtained by analytical solution and those from the finite element method. Finally, they are used to solve a benchmark problem encountered in nonlinear dynamic analysis of multibody systems.

Dynamic Analysis of Elastic Link Mechanisms by Reduction of Coordinates

1972 ◽  
Vol 94 (2) ◽  
pp. 577-581 ◽  
Author(s):  
R. C. Winfrey
Keyword(s):  
Dynamic Analysis ◽  
Complete Solution ◽  
Practical Interest ◽  
Elastic Behavior ◽  
Computational Time ◽  
Linear Matrix ◽  
Considerable Saving ◽  
Matrix Differential Equations ◽  
Elastic Link ◽  
Matrix Differential

Techniques for the solution of linear matrix differential equations have previously been applied to the dynamic analysis of a mechanism. However, because the mechanism changes geometry as it rotates, a large number of solutions are necessary to predict the mechanism’s elastic behavior for even a few revolutions. Also, a designer is frequently concerned with the elastic behavior of only one point on the mechanism and has no practical interest in a complete solution. For these reasons, a method is given here for reducing the total number of coordinates to one coordinate at the point of design interest. A considerable saving in computational time is obtained since the dynamic solution involves one degree of freedom instead of many. Further, since any solution will make use of some limiting assumptions, results here indicate that, for design purposes, reducing the coordinates does not significantly affect comparable accuracy.

Modeling and Dynamic Analysis of a Slider-Crank Mechanism With Flexible Coupler and Joint

1991 ◽  
Author(s):  
Junghsen Lieh ◽  
Imtiaz Haque
Keyword(s):  
Dynamic Analysis ◽  
Virtual Work ◽  
Equations Of Motion ◽  
Joint Stiffness ◽  
Mechanism Model ◽  
Double Frequency ◽  
Varying Coefficients ◽  
Matrix Expansion ◽  
Time Varying Coefficients ◽  
Crank Mechanism

Abstract Modeling and dynamic analysis of a slider-crank mechanism with flexible joint and coupler is presented. The equations of motion of the mechanism model are formulated using a virtual work multibody formalism and cast in terms of a minimum set of generalized coordinates through a Jacobian matrix expansion. Numerical results show the influence of time-varying coefficients on the mechanism dynamic behavior due to a repeated task. The results illustrate that the joint motion and coupler deformation are highly coupled. The joint response is dominated by double frequency of input, however, the coupler deformation is influenced by the same frequency as that of excitation. Increase in joint stiffness tends to decrease the variations in coupler deformation.

Multirate Integration for Multibody Dynamic Analysis With Decomposed Subsystems

1999 ◽  
Author(s):  
Sung-Soo Kim ◽  
Jeffrey S. Freeman
Keyword(s):  
Dynamic Analysis ◽  
Multibody System ◽  
Equations Of Motion ◽  
Low Frequency ◽  
Inertia Force ◽  
Integration Scheme ◽  
Integration Algorithm ◽  
Multibody Dynamic ◽  
Higher Order Derivative ◽  
Derivative Information

Abstract This paper details a constant stepsize, multirate integration scheme which has been proposed for multibody dynamic analysis. An Adams-Bashforth Moulton integration algorithm has been implemented, using the Nordsieck form to store internal integrator information, for multirate integration. A multibody system has been decomposed into several subsystems, treating inertia coupling effects of subsystem equations of motion as the inertia forces. To each subsystem, different rate Nordsieck form of Adams integrator has been applied to solve subsystem equations of motion. Higher order derivative information from the integrator provides approximation of inertia force computation in the decomposed subsystem equations of motion. To show the effectiveness of the scheme, simulations of a vehicle multibody system that consists of high frequency suspension motion and low frequency chassis motion have been carried out with different tire excitation forces. Efficiency of the proposed scheme has been also investigated.

Optimization of Flexible Pipes Dynamic Analysis Using Artificial Neural Networks

2016 ◽  
Author(s):  
Victor Chaves ◽  
Luis V. S. Sagrilo ◽  
Vinícius Ribeiro Machado da Silva
Keyword(s):  
Dynamic Analysis ◽  
Fem Simulation ◽  
Training Data ◽  
Local Analysis ◽  
Flexible Pipe ◽  
Nonlinear Fem ◽  
Irregular Wave ◽  
Flexible Pipes ◽  
Artificial Neural ◽  
Hybrid Methodology

Irregular wave dynamic analysis is an extremely computational expensive process on flexible pipes design. One emerging method that aims to reduce these computational costs is the hybrid methodology that combines Finite Element Analyses (FEA) and Artificial Neural Network (ANN). The proposed hybrid methodology aims to predict flexible pipe tension and curvatures in the bend stiffener region. Firstly using short FEA simulations to train the ANN, and then using only the ANN and the prescribed floater motions to get the rest of the response histories. Two approaches are developed with respect to the training data. One uses an ANN for each sea state in the wave scatter diagram and the other develops an ANN for each wave incidence direction. In order to evaluate the accuracy of the proposed approaches, a local analysis is applied, based on the predicted tension and curvatures, to calculate stresses in tension armour wires and the corresponding flexible pipe fatigue lifes. The results are compared to those from full nonlinear FEM simulation.

scholarly journals Novel analysis methods of dynamic properties for vehicle pantographs

2018 ◽  
Vol 180 ◽  
pp. 01005 ◽  
Author(s):  
Andrzej Wilk
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Simulation ◽  
High Speed ◽  
Dynamic Properties ◽  
Equations Of Motion ◽  
Computer Software ◽  
Fem Analysis ◽  
Electrical Energy ◽  
Modern Approach ◽  
Static And Dynamic Analysis

Transmission of electrical energy from a catenary system to traction units must be safe and reliable especially for high speed trains. Modern pantographs have to meet these requirements. Pantographs are subjected to several forces acting on their structural elements. These forces come from pantograph drive, inertia forces, aerodynamic effects, vibration of traction units etc. Modern approach to static and dynamic analysis should take into account: mass distribution of particular parts, physical properties of used materials, kinematic joints character at mechanical nodes, nonlinear parameters of kinematic joints, defining different parametric waveforms of forces and torques, and numerical dynamic simulation coupled with FEM calculations. In this work methods for the formulation of the governing equations of motion are presented. Some of these methods are more suitable for automated computer implementation. The novel computer methods recommended for static and dynamic analysis of pantographs are presented. Possibilities of dynamic analysis using CAD and CAE computer software are described. Original results are also presented. Conclusions related to dynamic properties of pantographs are included. Chapter 2 presents the methods used for formulation of the equation of pantograph motion. Chapter 3 is devoted to modelling of forces in multibody systems. In chapter 4 the selected computer tools for dynamic analysis are described. Chapter 5 shows the possibility of FEM analysis coupled with dynamic simulation. In chapter 6 the summary of this work is presented.

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