Modeling the Mechanical Performance of Bendable Display under Cyclic Loading

Bendable displays used in foldable phones have a stack-up of multiple substrate layers bonded by a soft adhesive. The material property of the adhesive layer has a significant impact on the bending and shear deformation behaviour. In this paper we evaluate the impact of adhesive material on the cyclic fold-unfold behaviour of a simplified display assembly using finite element simulations. We use a viscoelastic material model for the adhesive to represent its time dependent behaviour and assess the residual stress over repeated load cycles. A comparison of the system's response to two material models is done to evaluate the factor that drives the residual stresses in the display.