Mechanics of Materials and microstructure

Initiation of a secondary crack and further growth of this crack under in-phase biaxial loading

Investigation of damage tolerance properties of metallic light alloys is one of the major tasks within the field of Metallic Materials and Structures. More efficient methods to characterise damage tolerance behaviour are developed. These more fundamental studies result in technical expertise to assess fatigue, crack growth and residual strength of metallic structures analytically.

Numerical modelling of crack growth behaviour is advanced on the basis of profound analytical knowledge. Fatigue life of metallic structures is simulated by integration of resulting crack growth laws. A large-scale biaxial test rig allows verifying crack growth predictions for in-plane biaxial loading of structural components up to one square metre.

Friction Stir Welding is optimised with respect to light metals and structures made from light metals. It is illustrated that the welding parameters chosen are directly connected to the joint’s microstructure, strength and corrosive behaviour. Furthermore, various friction stir welded joint geometries are inspected non-destructively by high-frequency ultrasonics.