||Objects resonate and cause structural damage when the frequencies of forced vibrations are similar to the natural frequency of the object. Therefore, the purpose of this study was to identify the natural frequency of micro-proton-exchange membrane fuel cells (micro PEMFCs) to establish an acceptable vibration source frequency in fuel cells. In this study, ANSYS Workbench software was used for simulating micro PEMFCs, using the 3D finite-element method, to examine vibrations in fuel cells. A spectrum analyzer and impulse hammer were used to verify the reliability of the natural frequency measurements in the finite-element simulations.|
This paper presents three discussions. First, three boundary conditions of natural frequencies and the modal effects of fuel cells were evaluated. The results showed that the first and the second frequencies of the three boundary conditions were reduced by 60% and 67%, respectively, compared with the free boundary condition. Second, the Young modulus and density effects of various components of the fuel cell were considered. The simulation results showed that the Young modulus and density of the outer end plate was ±15%, causing the natural frequencies to be ±5%–7% and ∓4%–6% of the variation, and the remaining component’s Young modulus and density variations effects were extremely small. Finally, a 3D model of the fuel cell stack showed that for two or more fuel cell stacks, the natural frequency decreases when the number of layers increases at the free boundary.