Bondgraph method is a unified approach to represent a system combined with mechanical, hydraulic and electrical sub-systems. Recently, this method has been used to design hydraulic systems as well as to analyze their dynamic characteristics. Pipes are indispensable for hydraulic systems as an element transporting hydraulic power between components. Pipes often play an important role on pressure fluctuations. Considering a total hydraulic system, it is important and convenient to use a unified approach to analyze the dynamic characteristics in the other components as well as pipes. A basic Bondgraph model of a pipe has already been established as a lumped parameter system. With reliability of the lump model of a pipe, Bondgraph method would be more useful and more convenient for designing hydraulic circuits.
The reliability of Bondgraph lump model of a pipe on pressure fluctuations was investigated by using a straight and connected pipe through comparing the results by Bondgraphs with the results by the characteristic method and the experiments. This study proved that a Bondgraph lump model was the same precise as the other results with suitable number of pipe element lump model.