Mechanical analyses of flat sheet water treatment membranes

In this work, we address the mechanical response of the flat sheet polymeric water treatment membranes under the assumed operational loading conditions. Firstly, we perform quasi-static analyses of the membranes under normal pressure loads, which is the condition that resembles the actual loading for flat sheet membranes in the submerged membrane bioreactors. Then, the long-term deformation of the membranes is studied under the assumed filtration durations for the same loading conditions by utilizing the viscoelastic material models. The quasi-static and viscoelastic membrane simulations are performed by a commercial finite element code ANSYS. Finally, the mechanical fatigue life predictions are carried out based on the stress distributions from the quasi-static analyses and the long-term effects from the viscoelastic analyses.