Numerical and Experimental Analysis Mechanical Systems

The physical and mechanical properties of materials have a main effect on strain behavior and deflection of structural components. Mechanical system subjected to dynamic loading response with strain, deformation and deflection, what can be used as input data for mechanical behavior characterization. Development of model for accurate description of stress-strain behavior of material with functional gradients of mechanical properties is essential for optimal use of up-today materials and structural components. Higher resistance to fracture and failure is possible to achieve by combining different mechanical properties of assembled materials. The understanding of damage evolution in small structures is important in many fields of modern technology, e.g. in thin films for micro electro-mechanical systems, magnetic storage media, thermal barriers in gas turbines, and in coatings for electronic, optical and tribological applications. The final results will be in form of parametric models for modelling and design of heterogeneous microstructure of material regarding to optimal behaviour of material with highest possible fracture resistance on static and fatigue cracking. This project is addressed to overarching goals that cannot be achieved within the frame of industrial projects.

Within the framework of the research programme we carried out fundamental research on the effect of heterogenous material structure on fracture behaviour with the purpose of achieving not just a higher resistance to fatigue crack growth but also stabilising the growth. For that purpose, we used existing and developed new algorithms for calculating and modelling the configuration forces to quantify the changes in the fracture parameters. This lead to our results becoming applicable to multilayer metal materials, composite structures and for organic biological structures for different loading regimes. In conjunction with fundamental we also carried out applicative investigations on the effect of residual stresses on the maximum dynamical loading capacity on torsional and bending overloaded components. To survey fatigue crack growth, we developed a system of »on-line health monitoring«, which tracks the change in the amplitude of the deformation behaviour during crack growth by forming a calibration curve. With the purpose of reducing the number of surveyed areas we successfully developed a new algorithm for optimising component topology, which along with reducing weight reduces stress concentrations as well. Based on the investigation we developed a sample for determining the toughness of thin-walled pipelines. The scientific impact of these results can be seen in their application in further research at institutes and universities abroad. The complete realisation of the set programme allowed advances in the understating of the behaviour of heterogenous materials, the effect of the material state on its fracture behaviour as well as the development of new techniques for surveying stress/strain states on the surfaces of materials. For the behaviour of heterogenous materials we developed models based on the concept of configurational forces of crack propagation, which proved successful for interpreting the fracture behaviour under static [COBISS 16995862,18284566,17860886,17174806, 15086358] and dynamic loading [Ref.19101206]. The scientific results form a basis for further development of systems for surveying the dynamical response of structural components in aerospace technologies.

The development of load-bearing components tracks the progress of modern industry, into which knowledge of component behaviour under static and dynamic multi-axial loading needs to be transferred. The development of engineering and numerical models, verified by experiment, is possible while knowing the behaviour and the state of the material as well as a system for the deformation behaviour. The transfer of the scientific discoveries through economy seminars and congress meeting in Slovenian contributes to the development of new methods and processes in machine manufacturing, the steel industry as well as the electronic economy. For surveying the deformation behaviour, we have successfully implement a new model for determining the stresses on components of electric energy systems. The scientific research was partially carried out in cooperation with institutes of the Austrian Academy of Sciences, the Russian Academy of Sciences as well as research universities abroad. The discoveries were publicised together with foreign research in prestigious international journals and conferences which directly contributes to the recognition and international reputation of the (research) group.