Mechanics and Joining of Light-weight Materials

The present research topic focuses on deformation, damage and fracture mechanics of novel light-weight materials and structures, their manufacturing, using advanced joining technologies, and their in-service integrity. Particular emphasis is placed on structures made of multi-material components as they promise novel solutions to the problem of saving structural mass. The envisaged areas of application are represented by airframe, car body, ship and railway structures. The long-term vision is the creation of assessment tools for structual life cycle prediction, including multi-material components. This requires novel material models for deformation and damage, developed in cooperation with the Topic "Light-Weight Structural Materials", and will consist of process and design rules as well as methods for the simulation of fabrication processes and assessment of structural integrity. Here materials are treated in the context of components produced by specific production processes and operating under service conditions as given by mechanical and thermal loads and chemical environment.

During the next years, it shall be demonstrated that light-weight structures made of combinations of different materials, such as magnesium, aluminium and advanced high strength steel, can be fabricated using various novel joining procedures. It is also envisaged to cover metal/polymer components in cooperation with the Topic "Functionalised Materials". In this context, a sophisticated process modelling which combines experimental data with numerical simulations and artificial neural networks will be established. Furthermore, the understanding of the fundamentals of deformation, damage, and fracture of light-weight materials is essential to control and predict the mechanical properties of light-weight structures as the product of complex production and joining processes. Last but not least, reliable methods for assessing structural integrity have to be an integral ingredient of any design and operation of light-weight structures. This is of even higher importance in the case of multi-material structures, whose complexity may give rise to safety issues which are not known from homogeneous structures.

The expected outputs of the present topic will comprise

understanding the relevant deformation, damage, and failure mechanisms and providing the mechanical properties of light-weight materials and their hybrids on the nano-, micro and macro scale;
novel material models derived using hybrid numerical/experimental procedures and their application to the simulation of extrusion and joining processes as well as to structural assessment;
high quality welding procedures to obtain "low stress-low distortion" welds for similar and different materials, tailored to specific areas of application;
innovative instruments for assessing structural integrity of novel light-weight structures.