Structural Stability Analysis of a High Power PEMFC Stack

An automobile fuel cell stack mounted horizontally will be subjected to a large impact in the direction parallel with the cells. This may cause interfacial slippage between cells, showing a downward bowing phenomenon, which may cause decay in the performance, and even stack leakage. Therefore, ensuring structural and mechanical integrity is very important in stack assembly design, especially for high power stacks with hundreds of unicells. In this paper, the authors presented numeric analysis for a 300 kW stack with 550 unicells, and analyzed the local vibration from the stack global modes based on finite element analysis (FEA), further evaluated the vibration responses, such as deformed shape and directions, then modified the stack structurally by applying the reinforcement bars, and finally confirmed the robustness of the reinforced stack. It is demonstrated that with proper design, a single stack with hundreds of unicells can be produced for vehicle applications.