Effect of Material and Manufacturing Variations on Membrane Electrode Assembly Pressure Distribution

A design is robust when it is not sensitive to variations in noise parameters such as manufacturing tolerances, material properties, environmental temperature, humidity, etc. In recent years several robust design concepts have been introduced in an effort to obtain optimum designs and minimize the variation in the product characteristics. Increasing the pressure on a PEM (Proton Exchange Membrane) fuel cell’s MEA (Membrane Electrode Assembly) leads to increasing the electric conductivity and reducing the permeability of the assembly. In this study, a probabilistic FEA analysis was performed on a simplified fuel cell stack in order to identify the effect of material and manufacturing variations on the MEA’s pressure distribution. The bi-polar flow plate thickness, the modulus of elasticity and the end plate bolt loading were considered as randomly varying parameters with given mean and standard deviation. The normal stress uniformity of the MEA was determined in terms of the probabilistic input variables. The methodology for implementing robust design used in this research effort is summarized in a reusable workflow diagram.