The originality of this paper is in the presentation of the experimental results on tension splices in steel S690 with three or four bolts, positioned in the direction of loading. The tests were also numerically simulated to evaluate the stress and deformation state in the steel plates due to localized pressure of the bolts. It was shown that the distribution of forces between bolts may be nonuniform and as such it is not included in any of the Eurocode rules. The results were compared to the Eurocode bearing resistance formula and it was proven that the bearing resistance is not properly defined and it also does not properly limit the bolthole deformation. It was demonstrated that the unfavourable initial position of the bolts due to fabrication tolerances did not significantly affect the force distribution or the resistance. The new bearing resistance formula is also proposed in the paper. The new formula defines the bearing resistance in a more consistent way and can differ between failure modes. In comparison to tests it gives better results than Eurocode bearing resistance formula.
COBISS.SI-ID: 5173345
The paper presents modified automatic differentiation approach that leads to the new notation of the classical mechanical problems and automation of derivation of transient coupled problems.
COBISS.SI-ID: 4708193
Problem of high energy use for heating in Slovenian buildings is analysed with exergy and energy analysis. Results are compared and discussed, and the most effective solutions are defined. Three cases of exterior building walls are located in 3 climatic zones in winter conditions. If the comparison is made only on the energy and exergy supply, the results are the same. Exergy calculations enable us to analyze how much exergy is consumed in which part, from boiler to building envelope. The most effective solution is holistic approach.
COBISS.SI-ID: 4969825
Thermal degradation of the TSSS PU B and TISS PU A coatings, both deposited on aluminium substrates, was studied by following, as close as possible, the methodology worked out within TASK 10 of the IEA's Solar and Heating Programme. Thermal load tests were performed in the temperature range from 170 to 200 °C at various time intervals (1, 6, 10, 15, 21 days). Degradation of the coatings was assessed using a variety of degradation indicators: changes of solar absorptance and thermal emittance determined from the hemispherical IR and VIS/NIR spectra, intensity changes of selected vibrational modes attributed to the polymeric backbone and ester and urethane linkages and combined with peeloff tests used as adhesion and cohesion indicators. The results revealed that the degradation of the polyurethane resin binder was attributable to the reaking of the urethane linkages, also shown from the AFM and XPS spectra measurements. For the TISS PU A coating, the life expectancy was estimated to be 22.77 years (activation energy (Ea)=163.2 kJ/mol, Teff=113.4 °C), while for the TSSS PU B coatings it was at least 25.96 years (activation energy (Ea)=96 kJ/mol, Teff=102 ° C).
COBISS.SI-ID: 5509729
This paper deals with buckling interaction of longitudinally stiffened steel panels subjected to large bending moments and shear forces. The results of four full scale tests are presented and discussed as well as compared against results obtained from numerical simulations. The results from numerical simulations are comparable to the results of tests, which confirm the adequacy of the numerical model. The test resistance is compared to the resistance determined according to European standard EN 199315 which covers the design of plated structural elements. For all test cases it has been shown that EN 199315 gives 3% to 30% smaller capacity.
COBISS.SI-ID: 6247009