Multi-mechanism modeling of amorphous polymers

• Multi-mechanism modeling of the mechanical behavior of amorphous glassy polymers.
• Extension to the case of three mechanisms of the multi-mechanism model.
• An individual strain variable is associated to each observed physical mechanism.
• FE simulation is performed to assess the model prediction capability.
• Good description of the behavior for different strain rates and range of temperatures.

The paper is devoted to a multi-mechanism (MM) model for the mechanical behavior of amorphous glassy polymers. A finite strain formulation through updated Lagrangian formalisms is used. In the proposed phenomenological model, three mechanisms are respectively associated to three physical regimes of plastic deformation. The model was successful in describing the stress–strain behavior of glassy polymers for different strain rates and range of temperatures. The description of the three regions observed in the monotonic stress–strain curves is obtained through a coupling matrix between the isotropic hardening variables. A modular strategy based on the determination of the material parameters in three steps is proposed.