A novel test system for mixed mode-I/II/III fracture tests - Part 1: Modeling and numerical analyses

In this paper, a new test system is proposed to be used for three-dimensional mixed mode-I/II/III fracture tests. Considering different types of configurations under high mode mixity combinations, three-dimensional stress analyses are performed by focusing on stress levels at critical locations, which improved the design. Having finalized dimensions of the loading device, detailed stress and fracture analyses are performed under different mixed mode-I/II/III loading conditions. The specimen material used in numerical and experimental analyses is Al 7075-T651 aluminum alloy (L-T rolling direction). The results show that the proposed fracture test system can be used for mixed mode-I/II/III fracture tests. In Part 2 of the article, details of fracture experiments and development of new improved mixed mode-I/II/III fracture criterion are presented.