The contact pressure between bipolar plate(BP) and gas diffusion layer(GDL) directly affects the mass transfer of the gas diffusion layer

thus to affect the performance of proton exchange membrane fuel cell(PEMFC). Against this problem

a three-dimensional finite element model was built for the PEMFC

to investigate change rules of the contact pressure with assembly bolt torques under conditions with different flow fields and materials. The results show that

the graphite BP had smaller contact pressure and better uniformity than the 316 L stainless steel

the parallel flow field had the largest contact pressure while the serpentine flow field had the smallest

the parallel flow field had the best uniformity while the tree bionic flow field had the worst. It is found that the contact pressure distribution for the parallel flow field had the best uniformity when the bolt torques at interzone(1.5 N·m

2 N·m)

the serpentine flow filed and the tree flow field both at interzone(2 N·m

2.5 N·m).To improve the performance of PEMFC from view of optimizing the contact pressure and distribution uniformity

the material with small elastic modulus should be selected

the passageway with small direct contact area between the bipolar plate and the gas diffusion layer and large channel number as well as uniformity should be adopted

and the PEMFC should be packed with the most suitable bolt torque.