A theoretical and numerical FSI approach is used to predict the mass flow in a Coriolis flow meter. By comparing with the experimental results according to the relationship between mass flow and the time phase difference at the inlet and outlet of the tubes, the authors could determine the reliability of the present results from a theoretical and numerical approach in this paper. The mass flow has a linear relationship with the time phase difference, which is a unique parameter to measure true mass flow; therefore, for more precise measurement, it should be long enough to detect the signal within the given time resolution afforded by the detecting system and control system. Compact size and manufacturability, which are the important factors that decide the product competitiveness, should also be considered. In this paper, inversed triangle shaped and conventional U shaped Coriolis flow meters are designed, their time phase difference performances are predicted, and the results from experiments are well matched with the predicted results from the above-mentioned analysis.

In general, it is noted that the time domain technique becomes difficult to predict with the use of the accurate fatigue life, due to the lack of dynamic information of the structure. When the multi-axial stress is generated by the random vibration excitation in the mechanical structure, the fatigue analysis should have performed in the frequency domain as based on the multi-axial PSDs due to the problems presented above. Notably, Premont proposed a method to calculate the equivalent stress using PSDs in the frequency domain. In calculating the equivalent stress PSD, the phase difference between the multi-axial stress components was not considered at that time. This study propose a frequency domain fatigue analysis technique which can calculate the equivalent stress from the multi-axial PSD, as it works considering the phase difference that can appear in the real vibration excited structure. To verify this method, the conventional time-domain method as similar to a multi-axial rainflow method, is compared with the proposed frequency domain method in a simple simulation model. The multi-axial PSD and finally the von Mises stress model is reviewed, according to whether the phase difference between the multi-axial stress components is considered or not is analyzed.