Search

In this paper, we studied the container-content interaction between a high-density polyethylene-based packaging (HDPE) and amyl acetate solution considered as diffusing agent. We were specifically interested in the impact of sorption and diffusion phenomena on the mechanical properties of HDPE bottles under static conditions at different stages of physical aging. Several uniaxial tests were realized on samples cut from bottles and structural tests were performed on bottles. The analysis of such various experimental results highlighted the Fickian nature of the diffusion phenomenon and the decrease of the compression strength of the bottles with the preconditioning time. We have also focused on the modelling of the mechanical behavior of HDPE taking into account the mass transfer induced by the diffusion phenomenon. Elastic-viscoplastic model was proposed and implemented in the finite element code ABAQUS. The parameters of this model were identified from tensile tests by solving an optimization problem. The identified models have been validated by numerical simulation of top-load compression of HDPE bottles. The obtained numerical results are in a good agreement with experimental measurements. [ABSTRACT FROM AUTHOR]

This work aims to present a method to predict the acoustic properties of flexible polyurethane foams from the numerical results of a macroscopic simulation of the foaming process. The foaming process simulation is carried out using a meshless method and a set of models taking into account the main chemical reactions, the exothermic effect as well as the thermo-rheo-kinetic coupling. To predict the acoustic properties of the foam, a semi-phenomenological model is used to avoid the experimental characterization of the foam microstructure. The distribution of the non-acoustical parameters involved in the Johnson-Champoux-Allard model were determined using the proposed method for a square panel mold. These results are used to calculate the normal-incidence sound absorption coefficient, which is compared to experimental and numerical results presented in the literature. The predicted acoustic behavior of the polyurethane foam is in good agreement with results in previous works. [ABSTRACT FROM AUTHOR]

This article presents an efficient pseudo-inverse approach for the damage prediction in cold forging process simulation. Pseudo-inverse approach combines the advantages of the fast inverse approach and accurate incremental approaches. Some intermediate configurations are created geometrically and corrected mechanically to well describe the deformation path. The formulation of an axi-symmetrical element based on pseudo-inverse approach is presented. A strain-based damage model is introduced in the flow theory of plasticity. A direct scalar integration algorithm of plasticity-damage is developed, leading to a fast and robust algorithm for large strain increments. The cold forging processes of two axi-symmetrical parts are simulated to validate pseudo-inverse approach by the incremental approach ABAQUS/Explicit. Pseudo-inverse approach gives very good results, but uses much less CPU time. [ABSTRACT FROM PUBLISHER]