Anagrafe della ricerca

The present research project focuses on two specific issues that limit the exploitable tensile and compressive strengths for annealed glass, thus limiting its use in load-carrying structural components: the stress corrosion and the stress concentration. The stress corrosion is the phenomenon of decrease of the tensile strength over time, and is related to the sub-critical growth of cracks during aging in the given environment, under load. The stress concentration herein considered, is that taking place in the bulk when contact pressures are applied along the edges of a glass plate. Such concentrations are a direct consequence of the roughness of the edges and, combined with the Poisson effect and the high brittleness of glass determine the appearance of splitting cracks for compressive stresses below the nominal strength. A technological solution is sought by means of the development of functional polymeric coatings. Highly hydrophobic coatings, optimized to guarantee also good adhesion with the glass substrate, appear as an effective solution to the stress corrosion. On the other hand, thick coatings having tailored mechanical properties, may reduce the stress concentration by accommodating the roughness of the edges and redistributing the stresses. The development of such new materials is supported by experimental tests to evidence the aspects involved in the problems, numerical simulations to identify the theoretical optimal solutions, and testing of the performance, both on small-scale specimens and on real structural components. The proposed research is highly interdisciplinary, since it requires competences from material science, numerical modelling and structural design. The degree of innovation of the project is expected to be significantly high, from both the scientific standpoint and the applied one. The developed coatings can have a direct application in the glass industry since they contribute to improve the reliability of glass structural members.