Biaxial test on composite and polymeric materials

The development of the aircraft with the use of composite materials involves the mechanical characterization of these materials that have the suitable properties to be used in the design phases. The characterization of these materials is made in the mono axial field. However, research activities in recent years are focusing the attention on the study of biaxial tests to get more information to use during the design for the best use of materials. My thesis has been mainly focused on the development of a new biaxial equipment about composite and polymeric materials. It will try to show that the equipment is able to correctly load the specimens in two perpendicular directions. Then the selected test setup was applied experimentally for biaxial tests on a general aviation carbon resin. The thesis is divided into four sections. In the first one, the machines and equipment for biaxial tests present in the literature are only presented. Then the forms of biaxial test specimens most used by researchers in the last years for both metallic, composite and polymeric materials have been described. In the second section, the agreement that led to the creation of a new test rig, with which the tests have been described, are in the fourth section. The third part deals with the choice and optimization of a specimen shape through the use of finite element analysis. In the fourth section, the new equipment and the shape of the specimen chosen in the previous section have been used to carry out tests on a composite material in carbon resin. Here, the materials and the methods used to perform the experimental exercise are described. The used material is provided within the Tabasco project promoted by the Campania DAC. This project concerns the technologies and the production processes of low-cost components for general aviation. Conclusive remarks, where the main results are summarized, close this work