Micromechanical criteria of damage and fracture

Intensive development of advanced engineering materials raises a need for appropriate procedures for establishing a relation between their microstructural properties and prediction of macroscopic behaviour of the structure under external loading. Quantitative description of damage evolution in the material requires a complex methodology -experimental, analytical and numerical methods. Numerous investigations have shown that usually used fracture mechanics parameters, defined by standards, and so-called global criteria of failure have a limited applicability. For a reliable estimation of the components and structures integrity under a broad spectrum of combined mechanical and coupled (thermo-mech.) loadings, often additionally endangered by an aggressive environment during the exploitation, adequate micromechanical criteria will be defined. Through research of physical sense and methods for determining these criteria, combined procedures (typically exp.-num., E-N) suitable for practical application will be developed. Verification of the defined criteria and developed procedures will include many examples of damage evolution analysis until the structures (especially joints) final failure, both in the lab conditions and from the engineering practice. The research results should contribute to a further development of novel materials with an improved resistance to various damage and fracture types, as well as to an optimization of the parameters of metal forming/joining processes.