At the end of the 1980's, a number of research projects were begun at the Institute involving the non-linear analysis of structures and industrial processes. This has provided affirmation of the Institute's work in several new areas. As well as performing fundamental research into non-linear numerical procedures and the development of computer programs, the Institute also participates in the solving of complex practical engineering problems. Various non-linear numerical models have been developed, together with software for the non-linear analysis of reinforced-concrete structures, for the analysis of the dynamic interaction between structures and liquids, and for the non-linear, transient analysis of heat transfer and of thermo-mechanical problems (ranging from tools for the heat treatment of industrial products, to industrial semi-conductors). Apart from various non-linear models for the description of the mechanical behaviour of materials (e.g. the elasto-plastic model, the elasto-visco-plastic model, the realistic model for concrete, which takes into account cracks in tension and failure in compression), a model for rubberlike materials and elastomers has also been developed. A model for the description of the movement of landslides has been developed on the viscous flow formulation. A special thermo-mechanical model for the simulation of processes for the treatment of glass and plastics has also been derived. The availability of all these non-linear numerical models have made it possible to analyse a wide spectrum of tasks which either could not be solved by using standard linear methods or whose solutions would be insufficiently accurate.
At present a new model for the static and dynamic analysis of thin shells is being developed, which will, in comparison with presently known formulations, make possible more accurate analysis of thin shell structures with large displacements and rotations, and will also be applicable to the analysis of large plastic-laminate containers. Improvements are being made to the model for the realistic non-linear behaviour of reinforced-concrete, which will make this model suitable for the analysis of complex structures such as cooling towers, chimneys, large industrial buildings, bridges, etc. A start has been made to the development of a modern program for the computerized design of tunnels and deep excavations.
In this field, the Institute is involved in a number of international projects financed by the European Union within the framework of the TEMPUS, COPERNICUS and CEEPUS programs.