The project focuses on the development and optimization of an innovative, non-conventional specimen geometry for mechanical testing of engineering ductile materials. The new specimen is then used to investigate material strength, under different loading conditions. This is of major importance, being well known from literature, that material final failure is strongly dependent on the stress state. The argument is scientifically and practically of interest, provided that the information about the material ultimate resistance is crucial in virtually any kind of machine design related safety assessment. More in detail, in this study an effective way to load the samples with a combination of shear and tension is devised, designing a proper specimen geometry and related gripping system. The goal is to obtain stress states in test runs different as much as possible one with the other, with specimens easy to be machined, and using just a standard universal testing machine. This would make the biaxial tests available to a broad group of end users, even industrial. Beside the standard data acquisition during tests, numerical simulations of the experiments will be performed, to get detailed local information about the material behaviour. The experimental-numerical results will be used to evaluate the material ultimate strength under multiaxial loading conditions, and to verify the accuracy of numerical models for the prediction of ductile damage leading to failure. All results will be presented, the effectiveness of the new devised geometry checked, along with the capacity of the gripping system to properly transfer the load to the sample. The final outcome of the project is therefore a testing methodology which can be adopted by the industry to better characterize the materials used for structural applications and to improve the efficacy FEA software to predict material ultimate strength under complex loading conditions.
