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The natural plant fibers and biopolymers are a very important alternative to replace the inorganic fibers most used in the mechanical reinforcement of composite materials (carbon, glass, ...) and synthetic polymers (Epoxy, PEEK, ...), and at the same time they have a very low environmental impact and a very reasonable price. In this article, we have studied, by a numerical simulation based on genetic approach, the fiber-matrix interface damage of composite materials made up from the PHA (polyhydroxyalkanoates) matrix and the carbon, glass, jute, and hemp reinforcements with the same volume fraction equal to 30% for each fiber chosen. Our results showed that the damage at the fiber-matrix interface of the biocomposite hemp/PHA is the lowest compared with the other biocomposite materials glass/PHA, jute/PHA, and carbon/PHA. This finding is similar to that found by Antoine Le Duigou et al. and Bodros et al., where they have shown experimentally that the natural reinforcements greatly improve the properties of composite materials and also they have a very low environmental impact. To our knowledge, no published research reports on the study of fiber-matrix interface damage of biocomposite materials based on PHAs and carbon, glass, jute, and hemp fibers for potential textile applications, packaging, and other interesting areas. [ABSTRACT FROM AUTHOR]

In this article, a comparative study was carried out on two types of thermosetting and thermoplastic matrices to study the effect of the fiber-matrix interface damage on the behavior of thermosetting and thermoplastic composites reinforced by the same natural alfa and wood fibers. The genetic modeling was based on the probabilistic formalism of Weibull. The results have been compared with those obtained by the nonlinear acoustic technique, the two results found to coincide perfectly. The numerical simulation also shows a good concordance with the real behavior of the materials studied, and shows that thermosetting composites are the most resistant to applied thermal stress by 21% compared to thermoplastic composites. Statistical analysis demonstrates that the correlation coefficient values found are very close to 1 (0.964 and 0.973), these values are very satisfactory, and confirm that the results obtained by the genetic model and the nonlinear acoustic technique are in very good agreement with the statistical analysis data. The experimental work presented by Antoine Le Duigou et al. and the work of Bodros et al. have shown that the use of natural fibers greatly improves the mechanical properties of composite materials. [ABSTRACT FROM AUTHOR]

In this paper, we have studied the effect of thermal stress on the damage of fiber-matrix interface of a hybrid biocomposite composed of two natural fibers, Hemp, Sisal, and Starch matrix. Our genetic modeling used the nonlinear acoustic technique based on Cox’s analytical model,Weibull’s probabilistic model, and Lebrun’s model describing the thermal stress by the two coefficients of expansion. The stress applied to our representative elementary volume is a uni-axial tensile stress. The numerical simulation shows that the Hemp- Sisal/Starch hybrid biocomposite is most resistant to thermal stresses as compared withHemp/Starch biocomposite. It also shows that hybrid biocomposite materials have a high resistance to applied stresses (mechanical and thermal) compared to traditional materials and biocomposite materials. The results obtained in our study coincide perfectly with the results of Antoine et al., which showed through experimental tests that natural fibers perfectly improve the mechanical properties of biocomposite materials. [ABSTRACT FROM AUTHOR]