A general problem of parameter sensitivity of non-linear transient thermal systems is considered. The non-linear sensitivity path is followed by a weighted residual method employing the continuum description. The resulting finite element equations are derived. Both the direct differentiation and adjoint system methods are employed to evaluate sensitivity functional increments during the integration time step. Numerical results illustrate the method proposed.

The complexity of the physical engineering objects requires new technologies in software development able to simulate real-life cases. The huge number of such cases can be covered by object-oriented paradigm. This general idea and some advantages of using object-oriented language (Smalltalk) are exemplified by a presentation of a system for earth dam control. The system is an expert type program equipped with advanced monitoring and visualisation functions for existing dams. The software development process starting from the requirement description is presented. The structure of the dam model and of the inference engine as well as of the class hierarchy is shown as the examples. The re-usability of the system is proved by its implementation for different earth dams.

A tying algorithm for the linking of two originally geometrically incompatible finite element meshes with different degrees of refinement is proposed. It is characterized by the enforcement of geometric continuity between the two meshes at their common boundary and by specification of displacement constraints for the nodes located on this boundary. The two-dimensional as well as the three-dimensional case is considered. The proposed tying algorithm is applied to finite element analysis of the model of an automobile tire with a simplified tread profile. Consideration of this tread profile is restricted to the anticipated region of contact of the tire with the road surface and to its vicinity. For the remaining part of the analysis model a coarser finite element mesh is used. The tying algorithm is also applied to the generation of a finite element mesh with a realistic tread geometry in the aforementioned region.

Numerical solutions by means of the space-time finite element method to initial-boundary value problems for a hyperbolic model of heat conduction, are obtained. The heat conduction description is based on a concept a rigid conductor with a scalar internal state variable, that leads to a modified Fourier law. The obtained results are compared with existing experimental data know for semi-conductor crystals at low temperature.

The paper discusses the discrete optimization problem in structural space truss design. The optimal structure should satisfy limit state capacity and serviceability conditions. If the serviceability conditions are violated, the structure is not eliminated from considerations but it is modified by increasing structural stiffness. Many different ways to increase the stiffness of the structure are considered. The cross-sectional areas of truss bars A_k picked from a catalogue of circular hollow sections T and a number of elements in the catalogue t are taken as discrete design variables. The stress, local stability, displacement (design) constraints as well as technological and computational constraints are taken into account. The mass of truss bars including that of joints as well as exploitation and maintenance costs are chosen as optimization criteria. A labour consumption corresponding with a number of elements in the catalogue t is minimized, i.e., it is also regarded as an optimization criterion. Sets of non-dominated (efficient) and compromise (Pareto optimal) solutions, and the preferable solution for space truss are found. The results are presented in the form of diagrams and tables.