Assessment of Fracture Mechanics of Metallic Materials for Aerospace Field

In aerospace applications, products must comply with the highest standards and quality or performance under extreme conditions. The modern aerospace industry demands the most innovative and high quality metals able to maintain the integrity of the structure and to be resistant to corrosion or high temperature oxidation. Because of the high costs of tests, it is essential to limit their number preferring sophisticated numerical models necessary to predict the behavior of the real structure. In this research work, experimental tests and numerical models on High strength steel grades have been performed to increase the reliability of virtual testing used for the development of new industrial solutions. High strength steels increase the cost-effectiveness of the designed solutions providing more competitiveness when compared to other materials. In fact, High strength steels have tight controlled mechanical properties that enable better energy absorption in the event of a crash and guarantee high performance of the product, with a significant reduction of structure weight. A campaign of experimental tests on specimens with different shapes has been carried out, focused on the determination of the needed parameters to define the triaxiality stress factor. A numerical calibration and regularization process has been required in order to provide a more precise hardening curve after necking, investigating an engineering method to eliminate mesh size effect in solid elements.