Some advance in the study of the deformation of the piston-cylinder unit of a pressure balance using FE models

Abstract

Previous works carried out by us were concerned by the development of axisymmetric Finite Elements (FE) in order to model metrological pressure balance. In this paper, a given pressure balance is studied. The very question is to verify if the analytical formulae, commonly used to deduce the pressure, are accurate. In particular, in the analytical approach, the piston-cylinder deformation is taking into account by the use of a global distortion coefficient obtained by tests. This approach is compared to FE calculations where local deformations are naturally considered. For the pressure balance under study, and for the model used, the relative error obtained when comparing the FE effective area and the analytical effective area is of 0.1 per cent.