Influence of temperature and cooling liquid immersion on the mechanical behavior of a PPS composite: experimental study and constitutive equations

Abstract

This paper presents an experimental and theoretical study conducted on a PolyPhenylene Sulfide with 40 wt.% of short glass fibers (PPS GF40) and its matrix. Widely used for under-the-hood applications in the automotive industry, this material is subjected to high temperatures and to the ageing effects of the cooling liquids. Therefore, the consideration of those conditions is essential to design mechanical parts. Thus, an experimental campaign in the tensile mode was carried out at different temperatures and for various glycol proportions in the cooling liquid, under monotonic and cyclic loadings on neat and reinforced PPS. The results of these tests enabled us to highlight some of the main physical phenomena occurring during these experiments under tough hydrothermal conditions. Following this analysis, a visco-elasto-pseudo-viscoplastic model is proposed. Moreover, this model enables the consideration of the effects of the cooling liquid and its constituents using a temperature/humidity equivalence. This model also takes into account the consequences of the glass transition on the mechanical behavior of the material. Its accuracy was confronted to that of an artificial-intelligence-based model, so as to know what the physically possible maximum accuracy is. Finally, the evolution of the model parameters was studied with the adjunction of short glass fibers and for various orientation distributions of those fibers.