Bond Graph Junction Structures

1975 ◽  
Vol 97 (2) ◽  
pp. 189-195 ◽  
Author(s):  
A. S. Perelson
Keyword(s):  
Constitutive Equations ◽  
Internal Bond ◽  
Bond Graph ◽  
Graph Theoretic ◽  
Junction Structure ◽  
The Relationship

The relationship between the port constitutive equations of a bond graph junction structure and the constitutive equations of its individual junctions is investigated. By combining network, bond graph, and graph theoretic techniques, the roles of bond orientation and causal assignments in determining when internal bond variables may be eliminated are examined. Graphical criteria are proven for establishing when a junction structure is an n-port.

The Properties of Bond Graph Junction Structure Matrices

1973 ◽  
Vol 95 (4) ◽  
pp. 362-367 ◽  
Author(s):  
J. R. Ort ◽  
H. R. Martens
Keyword(s):  
Sufficient Conditions ◽  
Bond Graph ◽  
Bond Graphs ◽  
Flow Equations ◽  
Correct Number ◽  
Constraint Equations ◽  
Necessary And Sufficient ◽  
Fundamental Theorems ◽  
Junction Structure ◽  
The Relationship

Some fundamental theorems concerning the relationship between the junction structure of bond graphs and the effort and flow equations, are presented. Necessary and sufficient conditions are stipulated to guarantee the correct number of constraint equations. The structure and rank of the coefficient matrices of the effort and flow equations are examined. An orthogonality relationship between effort and flow equations is established. The development yields the result that the number of effort and flow equations corresponding to a causal assignment are sufficient and their coefficient matrices are of maximum rank.

Representation of Mechanical Behavior in the Presence of Changing Internal Structure

1988 ◽  
Vol 55 (1) ◽  
pp. 1-10 ◽  
Author(s):  
E. T. Onat ◽  
F. A. Leckie
Keyword(s):  
Mechanical Behavior ◽  
Internal Structure ◽  
Applied Stress ◽  
Constitutive Equations ◽  
Creep Damage ◽  
Main Ideas ◽  
The Relationship ◽  
Small Deformations

The paper is concerned with the representation of the relationship that exists, for a given material and temperature and for small deformations, between histories of applied stress and the observed strain and the accompanying changes in internal structure of the material. Emphasis is given to creep damage in metals as a vehicle for illustration of the main ideas introduced in the paper. In particular, the role played by irreducible even rank tensors in the representation of internal structure is discussed and clarified. The restrictions placed by thermodynamics on constitutive equations are considered and the use of potentials in these equations is examined and criticized.

A representation for planar point contact joints in the multibody mechanical bond graph library

1998 ◽  
Vol 212 (4) ◽  
pp. 305-313 ◽  
Author(s):  
W Favre ◽  
S Scavarda
Keyword(s):  
Point Contact ◽  
Bond Graph ◽  
The Body ◽  
Graph Representation ◽  
Kinematic Constraints ◽  
Contact Joint ◽  
Cam Follower ◽  
Mechanical Bond ◽  
Junction Structure ◽  
Two Bodies

In this paper a bond graph representation of the point contact joint between two bodies with any outline curves and in planar motion is proposed. The body geometry and frames are described, the kinematic constraints attached to the point contact joint are identified and the bond graph junction structure is deduced. The example of an elliptic cam-follower is used to illustrate the bond graph representation. In particular this shows the need for the simulation to add strong damping and very stiff elements to the system.

Fault indicators and unique mode-dependent state equations from a fixed-causality diagnostic bond graph of linear models with ideal switches

2018 ◽  
Vol 232 (6) ◽  
pp. 695-708 ◽  
Author(s):  
Wolfgang Borutzky
Keyword(s):  
Linear Time ◽  
Bond Graph ◽  
Differential Algebraic Equations ◽  
Fault Detection And Isolation ◽  
Mode Switching ◽  
State Transitions ◽  
Algebraic Equations ◽  
State Equations ◽  
Analytical Redundancy ◽  
Junction Structure

Analytical redundancy relations are fundamental in model-based fault detection and isolation. Their numerical evaluation yields a residual that may serve as a fault indicator. Considering switching linear time-invariant system models that use ideal switches, it is shown that analytical redundancy relations can be systematically deduced from a diagnostic bond graph with fixed causalities that hold for all modes of operation. Moreover, as to a faultless system, the presented bond graph–based approach enables to deduce a unique implicit state equation with coefficients that are functions of the discrete switch states. Devices or phenomena with fast state transitions, for example, electronic diodes and transistors, clutches, or hard mechanical stops are often represented by ideal switches which give rise to variable causalities. However, in the presented approach, fixed causalities are assigned only once to a diagnostic bond graph. That is, causal strokes at switch ports in the diagnostic bond graph reflect only the switch-state configuration in a specific system mode. The actual discrete switch states are implicitly taken into account by the discrete values of the switch moduli. The presented approach starts from a diagnostic bond graph with fixed causalities and from a partitioning of the bond graph junction structure and systematically deduces a set of equations that determines the wanted residuals. Elimination steps result in analytical redundancy relations in which the states of the storage elements and the outputs of the ideal switches are unknowns. For the later two unknowns, the approach produces an implicit differential algebraic equations system. For illustration of the general matrix-based approach, an electromechanical system and two small electronic circuits are considered. Their equations are directly derived from a diagnostic bond graph by following causal paths and are reformulated so that they conform with the matrix equations obtained by the formal approach based on a partitioning of the bond graph junction structure. For one of the three mode-switching examples, a fault scenario has been simulated.

scholarly journals On some method of the heredity kernel parameters determination of nonlinear viscoelastic materials under the complex stress state

2019 ◽  
pp. 178-181
Author(s):  
V. S. Reznik
Keyword(s):  
Stress State ◽  
Constitutive Equations ◽  
Strain Tensor ◽  
Complex Stress ◽  
Complex Stress State ◽  
Nonlinear Viscoelastic ◽  
Nonlinear Viscoelastic Materials ◽  
The Relationship ◽  
Kernel Parameters

The deformation of viscoelastic medium given by means of constitutive equations of the hereditary type. These equations establish the relationship between the components of strain tensor, the components of stress tensor and the integral time operator, and contain the set of function and coefficients that are determined from the basic experiments. А method of the heredity kernel parameters determination of nonlinear viscoelastic materials is developed. As the visco-elastic model, the constitutive equations of the hereditary type are chosen in which the relationship between the components of the strain tensor and the stress tensor is given based on the hypothesis of the deviators proportionality. The nonlinearity of the viscoelastic properties is given by the equations of Ratotnov’s type. The method is based on the relations between the creep kernels under complex stress state and the creep kernels under one-dimensional stress state. The method verified experimentally for the problems of determination of creep deformations under combined loading applied to the thin-walled tubular elements made of polyethylene of high density.

Molecular analysis of the tight junction

1989 ◽  
Vol 47 ◽  
pp. 810-811
Author(s):  
Bruce R. Stevenson ◽  
Matthew B. Heintzelman ◽  
James Melvin Anderson ◽  
Sandra Citi ◽  
I. Deborah Braun ◽  
...  
Keyword(s):  
Tight Junction ◽  
Plasma Membranes ◽  
Cell Structure ◽  
Ultrastructural Localization ◽  
Physical Analysis ◽  
Biochemical Level ◽  
Membrane Contact ◽  
Relationship Of ◽  
Junction Structure ◽  
The Relationship

The tight junction (zonula occludens) constitutes a selectively permeable barrier in the paracellular pathway of most epithelia. It is also thought to play a role in the maintenance of the cell surface compositional asymmetry characteristic of epithelial cells. The identification of ZO-1 and cingulin, the first two proteins found to be exclusively associated with the tight junction, permits novel investigations of this important epithelial cell structure at the biochemical level.ZO-1 is a high molecular weight polypeptide (>200 kD) found at the tight junctions of a variety of epithelia as well as endothelia, and ultrastructural localization studies on isolated liver plasma membranes indicate that this molecule is clustered at the points of membrane contact on the cytoplasmic surface of the junction. Physical analysis demonstrates ZO-1 to be an elongated, monomeric, phosphorylated protein, peripherally associated with the junctional membrane. Cingulin was originally isolated from chicken intestine, and, like ZO-1, is a peripheral membrane component of the junction which exhibits an elongated shape. Antibodies directed against this molecule show two primary bands at 140 kD and 108 kD on immunoblots of several epithelial tissues, although the relationship between these two elements remains undefined. Little information currently exists regarding the relationship of ZO-1 and cingulin to each other or to tight junction structure or function. We report here a comparison of the immunocytochemical properties of these junctional components as well as an examination of the phosphorylation state of ZO-1.

A Vector Bond Graph Method of Kineto-Static Analysis for Complex Planar Linkage

2012 ◽  
Vol 482-484 ◽  
pp. 1062-1067
Author(s):  
Zhong Shuang Wang ◽  
Jian Guo Cao ◽  
Ji Chen
Keyword(s):  
Static Analysis ◽  
Graph Model ◽  
Bond Graph ◽  
Constraint Forces ◽  
Constraint Force ◽  
Graph Method ◽  
Algebraic Problem ◽  
Complete Form ◽  
Junction Structure ◽  
Force Vectors

For the kineto-static analysis of complex planar linkage, the procedure based on vector bond graph is proposed. The constraint force vectors at joints can be considered as unknown effort source vectors and added to the corresponding 0-junctions of the system vector bond graph model, most of the differential causalities in system vector bond graph model can be eliminated . In the case of mixed causality, the unified formulae of driving moment and constraint forces at joints are derived based on vector bond graph, which are easily derived on a computer in a complete form. As a result, the very difficult algebraic problem caused by differential causality and nonlinear junction structure can be overcome, and the automatic kineto-static analysis of complex planar linkage on a computer is realized. By a practical example, the validity of this procedure is illustrated.

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