Issue 53

Y. Saadallah, Frattura ed Integrità Strutturale, 53(2020) 417-425; DOI: 10.3221/IGF-ESIS.53.32 424 (c) Figure 7: Nonlinear behavior of cork in compression at different densities in g.cm - 3 : a) 0.2340 ; b) 0.2477 ; c) 0.2534). Figure 8: Evolution of the loading derivative. . C ONCLUSION he present work aimed to establish two models for the representation of the behavior of cork in compression. Compression tests were conducted on cubic samples of cork in the non-radial direction. The shape of the curves with three domains made it possible to propose first a trilinear model of which each domain is represented by a slope. Then, another non-linear model with four parameters was put in place. The parameters of the trilinear model are determined by direct linear regression from the stress-strain curves while those of the nonlinear model required a third order polynomial regression. The comparison of test-model results reveals that the nonlinear model is more refined and has fewer parameters than the trilinear model. It was concluded that the trilinear model, being relatively crude, is suggested to fulfill educational functions. However, the nonlinear model, because of its relevance, can serve as a tool of choice to exploit in the field of behavior modeling of materials. R EFERENCES [1] Pereira, H. (2011). Cork: biology, production and uses, Elsevier. T