Dynamical Models for Multidimensional Structures Using Bond Graphs

1980 ◽  
Vol 102 (3) ◽  
pp. 180-187 ◽  
Author(s):  
D. L. Margolis
Keyword(s):  
Finite Element ◽  
Dynamic System ◽  
Finite Element Methods ◽  
Bond Graph ◽  
Dynamical Models ◽  
Bond Graphs ◽  
Long Wavelength ◽  
Lawrence Livermore Laboratory

Bond graphs are used to construct finite mode, long wavelength models of multidimensional structures. These structures are, in some cases, either too large or constructed from so many physical pieces that complete modeling using finite element methods is prohibited. Bond graph development for this type of dynamic system is given. The technique is demonstrated for the Lawrence Livermore Laboratory Shiva-Nova laser spaceframe.

Dynamic System Synthesis With a Bond Graph Approach: Part I—Synthesis of One-Port Impedances

1993 ◽  
Vol 115 (3) ◽  
pp. 357-363 ◽  
Author(s):  
R. C. Redfield ◽  
S. Krishnan
Keyword(s):  
Dynamic System ◽  
Frequency Domain ◽  
Conceptual Design ◽  
Transfer Functions ◽  
Multiple Bond ◽  
Bond Graph ◽  
Bond Graphs ◽  
Active Systems ◽  
Graph Structures ◽  
Synthesis Approach

This is the first part of a two-part paper developing a procedure for impedance synthesis and dynamic system conceptual design using a bond graph approach. The first part examines impedance synthesis with bond graphs and develops some useful properties of impedance related to bond graph structure. The second part of the paper uses the impedance synthesis approach as a tool in conceptual design for generating dynamic system solutions meeting frequency domain input-output specifications. In Part I, impedance and transfer functions are directly formulated from bond graphs. An invertible procedure is developed in order to allow for synthesis. Frequency domain properties of bond graphs are developed that will aid in impedance synthesis and the synthesis of bond graph structures from impedance specifications is formulated with a view toward conceptual design. The synthesis is not unique, a given impedance can be synthesized into multiple bond graph structures depending on its complexity. The work presented focuses on the synthesis of passive impedances but may be generalized for active systems.

Lagrangian Bond Graphs for Solid Continuum Dynamics Modeling

1994 ◽  
Vol 116 (2) ◽  
pp. 178-192 ◽  
Author(s):  
E. P. Fahrenthold ◽  
J. D. Wargo
Keyword(s):  
Finite Element ◽  
Bond Graph ◽  
Dynamics Modeling ◽  
Bond Graphs ◽  
Element Discretization ◽  
Large Order ◽  
Wide Range ◽  
Bond Graph Modeling ◽  
Continuum Dynamics ◽  
Fixed Bond

The limitations of existing continuum bond graph modeling techniques have effectively precluded their use in large order problems, where nonrepetitive graph structures and causal patterns are normally present. As a result, despite extensive publication of bond graph models for continuous systems simulations, bond graph methods have not offered a viable alternative to finite element analysis for the vast majority of practical problems. However, a new modeling approach combining Lagrangian (mass fixed) bond graphs with a selected finite element discretization scheme allows for direct simulation of a wide range of large order solid continuum dynamics problems. With appropriate modifications, including the use of Eulerian (space fixed) bond graphs, the method may be extended to include fluid dynamics modeling.

Extended Bond Graph Representation of the Traction Problem in Linear Elastodynamics

1991 ◽  
Vol 113 (1) ◽  
pp. 118-121 ◽  
Author(s):  
M. E. Ingrim ◽  
G. Y. Masada
Keyword(s):  
Finite Element ◽  
Finite Element Methods ◽  
Solid Mechanics ◽  
A Priori ◽  
Bond Graph ◽  
Elasticity Tensor ◽  
Graph Representation ◽  
Approximation Techniques ◽  
Elastic Bodies ◽  
Linear Elastodynamics

To illustrate the use of the extended bond graph notation, a reticulation is developed for a conjugate variable approximation of the traction problem in linear elastodynamics. This reticulation is general in the sense that all vector and tensor quantities are expressed using direct notation; that is, no specific coordinate system is chosen a priori. In addition, the only limitation placed upon the elasticity tensor C(X) is that it be symmetric. This allows homogeneous and inhomogeneous isotropic, orthotropic, etc., linearly elastic bodies to be modeled using these results. The conjugate approximations used here are entirely compatible with Galerkin based finite element methods. Consequently, this extended bond graph reticulation allows well-developed approximation techniques in solid mechanics to be directly incorporated into bond graph based system models.

Equilibrium Profile of Modern Belted Radial Ply Tires: Its Determination and Performance Benefits

2013 ◽  
Vol 41 (2) ◽  
pp. 127-151
Author(s):  
Rudolf F. Bauer
Keyword(s):  
Finite Element ◽  
Aspect Ratio ◽  
Finite Element Methods ◽  
Mathematical Analysis ◽  
Internal Stresses ◽  
Stress Concentrations ◽  
Equilibrium Profiles ◽  
Equilibrium Profile ◽  
And Performance ◽  
Beneficial Property

ABSTRACT The benefits of a tire's equilibrium profile have been suggested by several authors in the published literature, and mathematical procedures were developed that represented well the behavior of bias ply tires. However, for modern belted radial ply tires, and particularly those with a lower aspect ratio, the tire constructions are much more complicated and pose new problems for a mathematical analysis. Solutions to these problems are presented in this paper, and for a modern radial touring tire the equilibrium profile was calculated together with the mold profile to produce such tires. Some construction modifications were then applied to these tires to render their profiles “nonequilibrium.” Finite element methods were used to analyze for stress concentrations and deformations within all tires that did or did not conform to equilibrium profiles. Finally, tires were built and tested to verify the predictions of these analyses. From the analysis of internal stresses and deformations on inflation and loading and from the actual tire tests, the superior durability of tires with an equilibrium profile was established, and hence it is concluded that an equilibrium profile is a beneficial property of modern belted radial ply tires.

Finite element methods for internal flow calculations

1983 ◽  
Author(s):  
W. HABASHI ◽  
M. HAFEZ ◽  
P. KOTIUGA
Keyword(s):  
Finite Element ◽  
Finite Element Methods ◽  
Internal Flow
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