A pseudo-elastic damage-based model for compressive stress in expanded polystyrene foams

• A pseudo-elastic model is developed to describe the uniaxial compressive stressstrain behavior of expanded polystyrene (EPS) foams. • The model combines an Ogden-based hyperfoam formulation for loading with a damage-based approach for unloading. • Three damage-related parameters ( m , r , n ) are introduced to capture the degradation of the material’s response under uniaxial compression. • Experimental validation shows excellent agreement between model predictions and experimental data, with R 2 values close to unity. • The proposed model provides an effective tool for analyzing the compressive mechanical response of EPS foams. This work presents the application of a pseudo-elastic model to address the uniaxial compressive stress-strain behavior of expanded polystyrene foams. The model combines an Ogden-based hyperfoam formulation for the loading path of experimental testing with a damage-dependent approach for the unloading. The loading during compression is described using a simplified hyperfoam strain-energy function that effectively captures the nonlinear response of compressible polymer foams. For the unloading path, the model incorporates a scalar damage parameter controlled by three key variables: maximum damage, a damage evolution rate, and a transition parameter. Experimental validation confirms the model’s accuracy in predicting the mechanical response of polystyrene foams, including inelastic phenomena. This precision is supported by coefficient of determination R 2 values close to unity when comparing the model’s predictions with experimental data. Thus, the proposed model provides a practical tool for analyzing the compressive stress response in polystyrene foams.