The modeling of physical systems constitutes an aspect of great importance within all engineering fields because it allows us to understand the behavior of the system without having to experiment on it. It also allows the determination of certain characteristics of the system and can give important information on operating conditions with the use of relatively simple and inexpensive procedures. Bond graphs are a multidisciplinary and unified graphical modeling language, which provides, from this point of view, a convenient and useful tool for model builder conception. The bond graph is a modeling and simulation tool, providing many possibilities. It allows both a causal and a behavioral system analysis. From the behavioral point of view, bond graph tool allows to deal with the enormous amount of equations describing the dynamic behavior of different phenomena which occur in the system. It allows, independent of the physical nature of the studied system, precisely by its graphical nature, to display the exchange of power in a system, including storage and transformation and the instrumentation diagram (sensor location in the real process). Furthermore, the bond graph is subject to evolution, that is to say, the model can be refined by adding graphically more elements like thermal losses or inertia and storage effects, without having to start all over again. This property is very important and is on of the main advantages of this method. This work presents the application of bond graph method in modeling of dynamic systems. Pneumatic control valve actuator, hydraulic system (Level-flow rate control) and Hydro-Pneumatic suspension system have been modeled. Its applications in hydraulic system, thermofluid system, control system, computational fluid dynamic problem and fault detection in dynamic system have been described. Application of B.G. modeling in the aforementioned areas, which are different in disciplines, shows that the B.G. approach is very efficient tool for tackling multidisciplinary problems in our real world.
